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#1
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Recently completed project
Andre asks what all the tubeheads are doing.
You can see what this tubehead is doing at: http://www.kolumbus.fi/iain.churches/Preamp/203A.html It's a joint effort together with my pal Markus. He is a very skilled metal worker and made the casework, and also laser-cut the stainless steel top grille. We decided to do as much possible ourselves. Any comments would be of interest. Regards to all Iain |
#2
Posted to rec.audio.tubes
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Iain Churches wrote: Andre asks what all the tubeheads are doing. You can see what this tubehead is doing at: http://www.kolumbus.fi/iain.churches/Preamp/203A.html Ooh, nice. It's a joint effort together with my pal Markus. How much for your metalworker, Iain? He is a very skilled metal worker and made the casework, and also laser-cut the stainless steel top grille. We decided to do as much possible ourselves. Any comments would be of interest. Regards to all Iain Andre Jute Visit Jute on Amps at http://members.lycos.co.uk/fiultra/ "wonderfully well written and reasoned information for the tube audio constructor" John Broskie TubeCAD & GlassWare "an unbelievably comprehensive web site containing vital gems of wisdom" Stuart Perry Hi-Fi News & Record Review |
#3
Posted to rec.audio.tubes
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Recently completed project
In article ,
"Iain Churches" wrote: Andre asks what all the tubeheads are doing. You can see what this tubehead is doing at: http://www.kolumbus.fi/iain.churches/Preamp/203A.html It's a joint effort together with my pal Markus. He is a very skilled metal worker and made the casework, and also laser-cut the stainless steel top grille. We decided to do as much possible ourselves. Any comments would be of interest. It would be interesting to hear how you implemented the "balanced-line XLR" inputs and outputs on the "balanced line version" of the Type 203 Pre-amplifier? Regards, John Byrns -- Surf my web pages at, http://fmamradios.com/ |
#4
Posted to rec.audio.tubes
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"Iain ****wit Churches" Andre asks what all the tubeheads are doing. You can see what this tubehead is doing at: http://www.kolumbus.fi/iain.churches/Preamp/203A.html It's a joint effort together with my pal Markus. He is a very skilled metal worker and made the casework, and also laser-cut the stainless steel top grille. We decided to do as much possible ourselves. Any comments would be of interest. ** What a pile of masturbation fantasy CRAP !!!! Bags of non linear distortion added to buckets full of noise. 120 uV at line level is just APPALLING !!! OK for well used, 78 rpm shellacs !!!!!!! ......... Phil |
#5
Posted to rec.audio.tubes
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Iain Churches wrote: Andre asks what all the tubeheads are doing. You can see what this tubehead is doing at: http://www.kolumbus.fi/iain.churches/Preamp/203A.html It's a joint effort together with my pal Markus. He is a very skilled metal worker and made the casework, and also laser-cut the stainless steel top grille. We decided to do as much possible ourselves. Any comments would be of interest. Regards to all Iain Blimey, fancy welcoming comments of interest so soon. People are already questioning noise levels and implementation of balanced/unbalanced. So where is the schematic? Patrick Turner. |
#6
Posted to rec.audio.tubes
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"Phil Allison" wrote in message
"Iain ****wit Churches" Andre asks what all the tubeheads are doing. You can see what this tubehead is doing at: http://www.kolumbus.fi/iain.churches/Preamp/203A.html It's a joint effort together with my pal Markus. He is a very skilled metal worker and made the casework, and also laser-cut the stainless steel top grille. We decided to do as much possible ourselves. Any comments would be of interest. ** What a pile of masturbation fantasy CRAP !!!! Phil, regrettably, it all seems real enough - no fantasy. It may be crap, but it is gilt-edged crap. ;-) Bags of non linear distortion added to buckets full of noise. Note the use of the outdated and obfuscatory THD measurement. 120 uV at line level is just APPALLING !!! Agreed. Gives that nice *sheen* to your vinyl. ;-) OK for well used, 78 rpm shellacs !!!!!!! |
#7
Posted to rec.audio.tubes
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"John Byrns" wrote in message ... It would be interesting to hear how you implemented the "balanced-line XLR" inputs and outputs on the "balanced line version" of the Type 203 Pre-amplifier? Hi John Broadcast grade line transformers type 3575e and 5069e from Sowter UK. Iain |
#8
Posted to rec.audio.tubes
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"Phil Allison" wrote in message ... ** What a pile of masturbation fantasy CRAP !!!! Thanks Phil. I just *knew* you would be enthusiastic:-))) Bags of non linear distortion added to buckets full of noise. THD is 0.02% 120 uV at line level is just APPALLING !!! Ref 2V it equates to -84dB that's 90 dB A weighted. With gain at max driving the Radford STA 100 and also my own EL34 PPP 50Wamp, there is no noise audible from the listening position. It sounds very well indeed. Just as a 6SN7 tube amp should. Iain |
#9
Posted to rec.audio.tubes
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"Patrick Turner" wrote in message ... Iain Churches wrote: Andre asks what all the tubeheads are doing. You can see what this tubehead is doing at: http://www.kolumbus.fi/iain.churches/Preamp/203A.html It's a joint effort together with my pal Markus. He is a very skilled metal worker and made the casework, and also laser-cut the stainless steel top grille. We decided to do as much possible ourselves. Any comments would be of interest. Regards to all Iain Blimey, fancy welcoming comments of interest so soon. This preamp has been auditioned by a lot of people all of whom have liked it very much, so I was interested to hear the comments from people here on RAT. I just knew that Phil and Arny would be the first to take the hook. I learned long ago not to take either of them too seriously - neither of them seem to have built anything. But I am glad they have teamed up, they deserve each other:-))) People are already questioning noise levels and implementation of balanced/unbalanced. John's question about the symmetrical input/output is a valid one. Sowter make excellent broadcast grade transformers for this purpose, which are used in many studios that have tube equipment. The amp itself does not need to have a differential in/out. So where is the schematic? Its the generic ALCF (Tremaine etc etc) Regards Iain |
#10
Posted to rec.audio.tubes
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"Andre Jute" wrote in message ups.com... Iain Churches wrote: Andre asks what all the tubeheads are doing. You can see what this tubehead is doing at: http://www.kolumbus.fi/iain.churches/Preamp/203A.html Ooh, nice. It's a joint effort together with my pal Markus. How much for your metalworker, Iain? Hi Andre, Building this preamp has been an interesting exercise. We started off by asking a panel of about twenty people what they would like to see and hear from a tube amp. It became clear quite early on that "perceived quality" is important these days. We had a huge list of questions, and made up several chassis and front panels in different formats. Comments were interesting. Most people were averse to the ubiquitous silver anodised equipment that seems to adorn every hi fi shop. Most preferred filament indicator lamps to LEDs (when someone bothered to show them the difference) Most preferred engraved panels to silk screen. All preferred our laser etched dials to either of the other two possibilities. There were three versions built, a) a mu follower, b) a cascode c) this active load cathode follower. In listening tests, people chose C. Where CD is the principal source one does not need a shirtload of gain, so this topology seems ideal. Best regards Iain |
#11
Posted to rec.audio.tubes
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On Apr 10, 3:51 am, "Iain Churches" wrote:
Andre asks what all the tubeheads are doing. You can see what this tubehead is doing at: http://www.kolumbus.fi/iain.churches/Preamp/203A.html It's a joint effort together with my pal Markus. He is a very skilled metal worker and made the casework, and also laser-cut the stainless steel top grille. We decided to do as much possible ourselves. Any comments would be of interest. Regards to all Iain Well, it is gorgeous. And it appears to offer all sorts of flexibility with standard RCA and XLR options. I am sure you would not let anything escape into the world if it did not also sound well too. My only question offered tongue-in-cheek would be as to whether you auditioned the circuits to your *listeners* (as compared to your *viewers*) prior to making the units? The build-quality (electrically/ mechanically) looks as good as the cabinets. I also noted the engraved lettering (same laser, I guess?). A very nice touch. I will look at the kluge I have presently sitting to one side of the bench and dream about putting it in better surroundings. It "works", so far, but has a long way to go before it is fit for polite society. I have no capacity to bend gauge-metal in-house but I can punch and drill accurately. So a lot of thought will have to go into the chassis before I send out to have it bent. This also precludes laser work as I cannot justify the cost, but silk-screen work or even photo-etching is possible and within my skill-set. We shall see... July/August at best for a product worthy of pictures. Thanks for the inspiration. Peter Wieck Wyncote, PA |
#12
Posted to rec.audio.tubes
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"Peter Wieck" wrote in message ps.com... On Apr 10, 3:51 am, "Iain Churches" wrote: Andre asks what all the tubeheads are doing. You can see what this tubehead is doing at: http://www.kolumbus.fi/iain.churches/Preamp/203A.html Well, it is gorgeous. And it appears to offer all sorts of flexibility with standard RCA and XLR options. I am sure you would not let anything escape into the world if it did not also sound well too. My only question offered tongue-in-cheek would be as to whether you auditioned the circuits to your *listeners* (as compared to your *viewers*) prior to making the units? The build-quality (electrically/ mechanically) looks as good as the cabinets. Yes indeed. They got to listen to all three topologies. Both the mu follower and the cascode have considerable gain so we had to make sure that all units played at the same level. The viewers were also the listeners. It's fun to start with a blank sheet of paper as it were, and to ask people what they would like to see. Many don't want to commit themselves. It is quite a different matter when faced with a fait-accomplis for them to be able to ask "why did you do it like that?" :-)) I will look at the kluge I have presently sitting to one side of the bench and dream about putting it in better surroundings. It "works", so far, but has a long way to go before it is fit for polite society. For me that has always been the major problem with home made amps - to make them look like hand-made amps. My first attempt at a power amp was distinctly "agricultural" even though it performed as well as a commercially produced unit, and still does. This amp is nearly forty years old. It was originally housed in a gold hammer finish chassis. http://www.kolumbus.fi/iain.churches...ier/252.02.jpg I have no capacity to bend gauge-metal in-house but I can punch and drill accurately. So a lot of thought will have to go into the chassis before I send out to have it bent. This also precludes laser work as I cannot justify the cost, but silk-screen work or even photo-etching is possible and within my skill-set. We shall see... July/August at best for a product worthy of pictures. Please keep us up to date. You have a lot more technical knowledge than I have. Your thread will be of great interest. RAT needs a massive injection of vitamin T Best regards Iain |
#13
Posted to rec.audio.tubes
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Recently completed project
Iain Churches wrote:
c) this active load cathode follower. In listening tests, people chose C. Shh! Allen Wright will come demand a royalty. That's the big secrets his guru passed on to him, to use cathode followers and to tie the wright (sic -- heh-heh!) currents down tight. I'm not surprised that that quality of casework gives people a perceived sense of high added value and that this carries over into their perception of the sound. Nor am I at all surprised that they chose the active load cathode follower topology. There is a lot going on below the official limit of audibility that remains to be investigated because it definitely affects people's reactions. Andre Jute Visit Jute on Amps at http://members.lycos.co.uk/fiultra/ "wonderfully well written and reasoned information for the tube audio constructor" John Broskie TubeCAD & GlassWare "an unbelievably comprehensive web site containing vital gems of wisdom" Stuart Perry Hi-Fi News & Record Review |
#14
Posted to rec.audio.tubes
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"Iain Churches" "Phil Allison" ** What a pile of masturbation fantasy CRAP !!!! Thanks Phil. I just *knew* you would be enthusiastic:-))) Bags of non linear distortion added to buckets full of noise. THD is 0.02% 120 uV at line level is just APPALLING !!! Ref 2V it equates to -84dB ** Shame how that is way below normal hi-fi standards. No way the noise level sound be THAT high in a unity gain tube stage. What the hell did you do wrong ? ........ Phil |
#15
Posted to rec.audio.tubes
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"Iain Churches" wrote in message .fi... "Peter Wieck" wrote in message ps.com... On Apr 10, 3:51 am, "Iain Churches" wrote: Andre asks what all the tubeheads are doing. You can see what this tubehead is doing at: http://www.kolumbus.fi/iain.churches/Preamp/203A.html Well, it is gorgeous. And it appears to offer all sorts of flexibility with standard RCA and XLR options. I am sure you would not let anything escape into the world if it did not also sound well too. My only question offered tongue-in-cheek would be as to whether you auditioned the circuits to your *listeners* (as compared to your *viewers*) prior to making the units? The build-quality (electrically/ mechanically) looks as good as the cabinets. Yes indeed. They got to listen to all three topologies. Both the mu follower and the cascode have considerable gain so we had to make sure that all units played at the same level. The viewers were also the listeners. It's fun to start with a blank sheet of paper as it were, and to ask people what they would like to see. Many don't want to commit themselves. It is quite a different matter when faced with a fait-accomplis for them to be able to ask "why did you do it like that?" :-)) I will look at the kluge I have presently sitting to one side of the bench and dream about putting it in better surroundings. It "works", so far, but has a long way to go before it is fit for polite society. For me that has always been the major problem with home made amps - to make them look like hand-made amps. My first attempt at a power amp was distinctly "agricultural" even though it performed as well as a commercially produced unit, and still does. This amp is nearly forty years old. It was originally housed in a gold hammer finish chassis. http://www.kolumbus.fi/iain.churches...ier/252.02.jpg I have no capacity to bend gauge-metal in-house but I can punch and drill accurately. So a lot of thought will have to go into the chassis before I send out to have it bent. This also precludes laser work as I cannot justify the cost, but silk-screen work or even photo-etching is possible and within my skill-set. We shall see... July/August at best for a product worthy of pictures. Please keep us up to date. You have a lot more technical knowledge than I have. Your thread will be of great interest. RAT needs a massive injection of vitamin T Best regards Iain Simply gorgeous Iain. What type of RCA connectors are you using? The way they are seated looks smart, but this is the first time I seen that configuration type. Also, are those Jensen Oil Caps used for the coupling? You only needed 1 per stage? Maybe there's another turret in there. Anyway, I think you set the bar real high for us, at least as looks go. west |
#16
Posted to rec.audio.tubes
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Recently completed project
In article ,
"Phil Allison" wrote: "Iain Churches" "Phil Allison" ** What a pile of masturbation fantasy CRAP !!!! Thanks Phil. I just *knew* you would be enthusiastic:-))) Bags of non linear distortion added to buckets full of noise. THD is 0.02% 120 uV at line level is just APPALLING !!! Ref 2V it equates to -84dB ** Shame how that is way below normal hi-fi standards. No way the noise level sound be THAT high in a unity gain tube stage. What the hell did you do wrong ? For the first time in a long time I have to agree with Phil, something just doesn't add up here. By the way, where did these specs. come from, did I miss a link on Ian's page? Regards, John Byrns -- Surf my web pages at, http://fmamradios.com/ |
#17
Posted to rec.audio.tubes
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"John Byrns "Phil Allison" "Iain Churches" ** What a pile of masturbation fantasy CRAP !!!! Thanks Phil. I just *knew* you would be enthusiastic:-))) Bags of non linear distortion added to buckets full of noise. THD is 0.02% 120 uV at line level is just APPALLING !!! Ref 2V it equates to -84dB ** Shame how that is way below normal hi-fi standards. No way the noise level sound be THAT high in a unity gain tube stage. What the hell did you do wrong ? For the first time in a long time I have to agree with Phil, something just doesn't add up here. By the way, where did these specs. come from, did I miss a link on Ian's page? ** The specs are at the bottom of the page. 120uV of input noise is equivalent to that of a 50 Mohm resistor !! The figure ought to be more like 5 or 10 uV. ......... Phil |
#18
Posted to rec.audio.tubes
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Andre Jute wrote: Iain Churches wrote: c) this active load cathode follower. In listening tests, people chose C. Shh! Allen Wright will come demand a royalty. That's the big secrets his guru passed on to him, to use cathode followers and to tie the wright (sic -- heh-heh!) currents down tight. I think perhaps you could be guessing about what is in Iain's preamp. He has avoided giving us a schematic. He started off saying it was generic 6SN7 used as a gain stage followed by cathode follower, as Tremaine may have desribed in 1963, but then talks about listening tests using vastly fifferent topolgies, and just what is in the box is a complete mystery. Perhaps he don't want to give away copyable secrets. This is not very nice. At r.a.t we are supposed to be a free tube-craft information outlet for the WWW. I have 18mB at a website and page after page of schematics which anyone is free to use. But Allan Wright's special super cathode follower is only just that, and whether it dramatically increases sonic heaven's enthralling qualities is a moot point. Patrick Turner. I'm not surprised that that quality of casework gives people a perceived sense of high added value and that this carries over into their perception of the sound. Nor am I at all surprised that they chose the active load cathode follower topology. There is a lot going on below the official limit of audibility that remains to be investigated because it definitely affects people's reactions. Andre Jute Visit Jute on Amps at http://members.lycos.co.uk/fiultra/ "wonderfully well written and reasoned information for the tube audio constructor" John Broskie TubeCAD & GlassWare "an unbelievably comprehensive web site containing vital gems of wisdom" Stuart Perry Hi-Fi News & Record Review |
#19
Posted to rec.audio.tubes
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John Byrns wrote: In article , "Phil Allison" wrote: "Iain Churches" "Phil Allison" ** What a pile of masturbation fantasy CRAP !!!! Thanks Phil. I just *knew* you would be enthusiastic:-))) Bags of non linear distortion added to buckets full of noise. THD is 0.02% 120 uV at line level is just APPALLING !!! Ref 2V it equates to -84dB ** Shame how that is way below normal hi-fi standards. No way the noise level sound be THAT high in a unity gain tube stage. What the hell did you do wrong ? For the first time in a long time I have to agree with Phil, something just doesn't add up here. By the way, where did these specs. come from, did I miss a link on Ian's page? Regards, John Byrns It should be possible to select a 6SN7 which has no more than 4uV of input noise, with input grounded via a shorting plug in an RCA input socket. If the gain is a typical 16, noise should then become 64uV at the output. If we only want 64mV of signal to give healthy levels in a power amp, the SNR would then be -60dB, unweighted. In Leak amp whose sensitivity is 100mV for 20 watts, 64mV is too much, but in a modern amp needing 1V for 100W, 64mV could be about right to make a very loud 2.8V at the speaker. So perhaps only 16mV is needed for ordinary listening, so the SNR would then be only -48dB, unweighted. But we have no schematic of what Iain has done inside the fancy-shmancy box. I've found that 6CG7 generally have less noise than 6SN7, with the same gain & Ra, and some samples measure only 1uV of input noise. If there is no gain, and the input signal from the CD player is just attentated with a pot from 1V to 16mV, ( -36dB, or about 9am pot position ), then fed to a CF then tube noise isn't amplified, and a good SNR is maintained. Patrick Turner. -- Surf my web pages at, http://fmamradios.com/ |
#20
Posted to rec.audio.tubes
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Phil Allison wrote: "John Byrns "Phil Allison" "Iain Churches" ** What a pile of masturbation fantasy CRAP !!!! Thanks Phil. I just *knew* you would be enthusiastic:-))) Bags of non linear distortion added to buckets full of noise. THD is 0.02% 120 uV at line level is just APPALLING !!! Ref 2V it equates to -84dB ** Shame how that is way below normal hi-fi standards. No way the noise level sound be THAT high in a unity gain tube stage. What the hell did you do wrong ? For the first time in a long time I have to agree with Phil, something just doesn't add up here. By the way, where did these specs. come from, did I miss a link on Ian's page? ** The specs are at the bottom of the page. 120uV of input noise is equivalent to that of a 50 Mohm resistor !! The figure ought to be more like 5 or 10 uV. If the gain is 16, typical for a 6SN7, getting 10uV of output noise even with a grounded input seems unlikely/impossible. The only way to achieve it would be to throw out the tube and use fet input such as a 2SK369/2SK170/2SK147 etc, or perhaps a high gm triode, 6C45pi, 417A etc. But all these devices have far too much gain necessitating lots of NFB. Perhaps he did not test with a grounded input. And perhaps he used a noisy 6SN7. We do not really know anything much about Iain's amp without seeing the schematic. There is no accompanying Draft Report of several pages about his amp. Patrick Turner. ........ Phil |
#21
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"Patrick Turner" If the gain is 16, typical for a 6SN7, ** The stage is a cathode follower. Has unity gain. The first line on Iain's page says so. ......... Phil |
#22
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"Patrick Turner" It should be possible to select a 6SN7 which has no more than 4uV of input noise, with input grounded via a shorting plug in an RCA input socket. If the gain is a typical 16, noise should then become 64uV at the output. ** The stage is a cathode follower. Has unity gain. The first line on Iain's page says so. ......... Phil |
#23
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"west" wrote in message news:9tWSh.1407$ok6.1308@trnddc07... http://www.kolumbus.fi/iain.churches/Preamp/203A.html Simply gorgeous Iain. What type of RCA connectors are you using? The way they are seated looks smart, but this is the first time I seen that configuration type. Hi West. They are the size D Neutrik pattern NF-2D-B-W They are standard issue in studio and broadcast facilities. You can see them at: http://www.audiogear.com/Neutrik-RCA-Plugs.html They are isolated from the chassis, so that you can make a separate star ground back to a single point. Also they use the same hole as the XLR connector, making it possible to "mix and match" inputs and outputs using the same panel. Also, are those Jensen Oil Caps used for the coupling? Those are the output caps. They are copper foil paper in oil type. There is a silver version, several times the price. I am not sure if this can be justified. You only needed 1 per stage? Maybe there's another turret in there. Anyway, I think you set the bar real high for us, at least as looks go. It sounds well too. West. Posting anything to RAT is inviting a hail of ridicule and derision from a few people who do not actually build anything themselves. You know who they a-) Don't be discouraged by this. A great many people avoid Usenet to keep away from these belligerents. That's a great loss to the subscribers here on RAT. I have received as many replies and comments re this preamp, by e.mail direct as I have on the NG, and people off-list are usually much more helpful and constructive. Best regards Iain |
#24
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"Andre Jute" wrote in message ups.com... Iain Churches wrote: c) this active load cathode follower. In listening tests, people chose C. Shh! Allen Wright will come demand a royalty. That's the big secrets his guru passed on to him, to use cathode followers and to tie the wright (sic -- heh-heh!) currents down tight. This is not the Wright Schematic, but the generic active load cathode follower which can be found in many textbooks. I'm not surprised that that quality of casework gives people a perceived sense of high added value and that this carries over into their perception of the sound. Nor am I at all surprised that they chose the active load cathode follower topology. There is a lot going on below the official limit of audibility that remains to be investigated because it definitely affects people's reactions. I got the idea for this unit while recently working at a CD mastering facility that had an all tube listenening room, set up for clients to approve their CDs at the pre production stage. Their system had a mu-follower which sounded very good indeed, but had too much gain. When we did the original aural evaluation of the three possible formats, we had a completed psu, with three bare chassis, each with its own board. Most people listened with their eyes closed:-) The pics are perhaps not good enough to show them but there are some very nice design touches. For example the stainless steel graduation disc on each knob is 45mm in diameter by 2mm. These are set into a milled out circular recess in the front panel 45.5mm by 2.4mm so that the disc sits flush with the front panel. Removing the stainless steel grille to change the tubes reveals what appears like an empty compartment with just the tubes and the tube bases set horizontally into a 4mm bulkhead. There is a "false floor" under which the cable harness runs to the input selector and switched attenuators at the front. Regards Iain |
#25
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"John Byrns" wrote in message ... For the first time in a long time I have to agree with Phil, something just doesn't add up here. By the way, where did these specs. come from, did I miss a link on Ian's page? Morning John. Last night, I listened to Shostakovich 2nd Symphony (Op 14) the excellent interpretation by Gothenburg Symphony Orchestra conducted by Neeme Järvi. I turned up the level so that I could not stay in the room. Then, using the remote, I put the CD player onto pause, and returned to my listening chair. There was silence, so I think the performance of the preamp is as it should be. There are two possibilities here. a) The pair of tubes I have fitted (RCA cleartops) are noisy (possible but unlikely) b) My noise measurement methods are incorrect (much more likely) The preamp has been packed up now, and shipped off to the first of several people who want to hear it. So I shall not be able to investigate further for a while. What sort of a SNR (A weighted) should I expect from an active loaded cathode follower? Many thanks for your input Iain |
#26
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"Patrick Turner" wrote in message ... Andre Jute wrote: Iain Churches wrote: c) this active load cathode follower. In listening tests, people chose C. Shh! Allen Wright will come demand a royalty. That's the big secrets his guru passed on to him, to use cathode followers and to tie the wright (sic -- heh-heh!) currents down tight. I think perhaps you could be guessing about what is in Iain's preamp. He has avoided giving us a schematic. He started off saying it was generic 6SN7 used as a gain stage followed by cathode follower, as Tremaine may have described in 1963, but then talks about listening tests using vastly fifferent topolgies, and just what is in the box is a complete mystery. Tremaine 4th edition dates from 1975. No mystery Patrick. I stated clearly that it is an active load cathode follower, which was chosen after comparison with a mu-follower and a cascode. I have no schematic drawn. It can be found in any one of a dozen books Perhaps he don't want to give away copyable secrets. Copyable secrets? LOL. People have been using this topology for 50 years:-)) It was used in line and distribution amps in studios and broadcast everywhere. I can remember seeing racks and racks of 'em. But Allan Wright's special super cathode follower is only just that, and whether it dramatically increases sonic heaven's enthralling qualities is a moot point. I thought the Allen Wright super deluxe sounded rather good. Iain |
#27
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Phil Allison wrote: "Patrick Turner" If the gain is 16, typical for a 6SN7, ** The stage is a cathode follower. Has unity gain. The first line on Iain's page says so. You are right. My Netscape 4.8 browser didn't open the page up very well at all, but its much clearer in OE, and sure, 2.1V in, 2.0V out, and 120uV of noise is, well, quite attrocious as you say. I did Iain's post where I had asked... So where is the schematic? and he answers..... Its the generic ALCF (Tremaine etc etc) Am I supposed to be able to read minds or something? Eventually, we will coax a schematic from the man, and why the noise is so high. Patrick Turner. ........ Phil |
#28
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Iain Churches wrote: "west" wrote in message news:9tWSh.1407$ok6.1308@trnddc07... http://www.kolumbus.fi/iain.churches/Preamp/203A.html Simply gorgeous Iain. What type of RCA connectors are you using? The way they are seated looks smart, but this is the first time I seen that configuration type. Hi West. They are the size D Neutrik pattern NF-2D-B-W They are standard issue in studio and broadcast facilities. You can see them at: http://www.audiogear.com/Neutrik-RCA-Plugs.html They are isolated from the chassis, so that you can make a separate star ground back to a single point. Also they use the same hole as the XLR connector, making it possible to "mix and match" inputs and outputs using the same panel. Also, are those Jensen Oil Caps used for the coupling? Those are the output caps. They are copper foil paper in oil type. There is a silver version, several times the price. I am not sure if this can be justified. You only needed 1 per stage? Maybe there's another turret in there. Anyway, I think you set the bar real high for us, at least as looks go. It sounds well too. West. Posting anything to RAT is inviting a hail of ridicule and derision from a few people who do not actually build anything themselves. You know who they a-) Don't be discouraged by this. A great many people avoid Usenet to keep away from these belligerents. That's a great loss to the subscribers here on RAT. I have invited a hail of criticism at times but made sure I was well covered with facts and answers. I am continually making piles of stuff, and am repairing/re-engineering gear all through my days, and the results of the thought behind the dull boring donkey work of arrangeing bits of metal to fit together are all carefully displayed and explained at my website. So when anyone else presents their gear with what seems to be a noise problem, and no schematic, and only some rather hard to see dark photos, indicating the obvious craftwork on the metal and fittings, I wonder just how good it is, because metalwork has almost zero effect on the sound and electronic functions. Its your grasp of electronic understanding that we wish to witness. If all you have in the box is a cathode follower, fine, it should definately sound fine, and have low THD, and low noise. But is there not a gain stage? what are all the bits I see on the turret board? Patrick Turner. I have received as many replies and comments re this preamp, by e.mail direct as I have on the NG, and people off-list are usually much more helpful and constructive. Best regards Iain |
#29
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Iain Churches wrote: "Andre Jute" wrote in message ups.com... Iain Churches wrote: c) this active load cathode follower. In listening tests, people chose C. Shh! Allen Wright will come demand a royalty. That's the big secrets his guru passed on to him, to use cathode followers and to tie the wright (sic -- heh-heh!) currents down tight. Allan Wright's super CF or whatever he calls it has the anode supply to the actual signal handling CF bootstrapped of the signal CF by a seconf CF. And I recall there is an active cathode load. This is not the Wright Schematic, but the generic active load cathode follower which can be found in many textbooks. But there are more ways than one to do active loading and such details are rare in texbooks. So where is the schematic? Patrick Turner. I'm not surprised that that quality of casework gives people a perceived sense of high added value and that this carries over into their perception of the sound. Nor am I at all surprised that they chose the active load cathode follower topology. There is a lot going on below the official limit of audibility that remains to be investigated because it definitely affects people's reactions. I got the idea for this unit while recently working at a CD mastering facility that had an all tube listenening room, set up for clients to approve their CDs at the pre production stage. Their system had a mu-follower which sounded very good indeed, but had too much gain. When we did the original aural evaluation of the three possible formats, we had a completed psu, with three bare chassis, each with its own board. Most people listened with their eyes closed:-) The pics are perhaps not good enough to show them but there are some very nice design touches. For example the stainless steel graduation disc on each knob is 45mm in diameter by 2mm. These are set into a milled out circular recess in the front panel 45.5mm by 2.4mm so that the disc sits flush with the front panel. Removing the stainless steel grille to change the tubes reveals what appears like an empty compartment with just the tubes and the tube bases set horizontally into a 4mm bulkhead. There is a "false floor" under which the cable harness runs to the input selector and switched attenuators at the front. Regards Iain |
#30
Posted to rec.audio.tubes
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Iain Churches wrote: "Patrick Turner" wrote in message ... Andre Jute wrote: Iain Churches wrote: c) this active load cathode follower. In listening tests, people chose C. Shh! Allen Wright will come demand a royalty. That's the big secrets his guru passed on to him, to use cathode followers and to tie the wright (sic -- heh-heh!) currents down tight. I think perhaps you could be guessing about what is in Iain's preamp. He has avoided giving us a schematic. He started off saying it was generic 6SN7 used as a gain stage followed by cathode follower, as Tremaine may have described in 1963, but then talks about listening tests using vastly fifferent topolgies, and just what is in the box is a complete mystery. Tremaine 4th edition dates from 1975. No mystery Patrick. I stated clearly that it is an active load cathode follower, which was chosen after comparison with a mu-follower and a cascode. I have no schematic drawn. It can be found in any one of a dozen books Hardly any of us have a copy of Tremaine's 4th Edition, Audio Encyclopedia. There IS a MYSTERY. How can we talk about your amp details without a schematic???????? It will be just bull****ting into the wind without one. You may indeed have a nice device, but here you have to proove it. Here is where when someone says something, it better be right, and reasons given, or its deemed to be wrong. When you show something, its prudent to offer the full story with a schematic. Perhaps he don't want to give away copyable secrets. Copyable secrets? LOL. People have been using this topology for 50 years:-)) Gee, I wish I knew what they were copying. It was used in line and distribution amps in studios and broadcast everywhere. I can remember seeing racks and racks of 'em. But we have no schematic. Studios used a huge range of gear But Allan Wright's special super cathode follower is only just that, and whether it dramatically increases sonic heaven's enthralling qualities is a moot point. I thought the Allen Wright super deluxe sounded rather good. But it's extremely difficult to make a bad sounding triode catholic follower. Patrick Turner. Iain |
#31
Posted to rec.audio.tubes
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Iain Churches wrote: "Andre Jute" wrote in message ups.com... Iain Churches wrote: c) this active load cathode follower. In listening tests, people chose C. Shh! Allen Wright will come demand a royalty. That's the big secrets his guru passed on to him, to use cathode followers and to tie the wright (sic -- heh-heh!) currents down tight. This is not the Wright Schematic, but the generic active load cathode follower which can be found in many textbooks. I know, Iain. I was making a joke about the way Allen in his book makes it sound as if his guru received the cathode follower and the constant current source from the finger of God himself. Anyway, you're not ready to be an audio guru yet. You're too young and you have too much hair. Allen Wright and Holger Stein and Dieter Ennemoser and I decided long ago that the only people who are qualified to build good audio equipment are over fifty and going light on top -- like us. I'm not surprised that that quality of casework gives people a perceived sense of high added value and that this carries over into their perception of the sound. Nor am I at all surprised that they chose the active load cathode follower topology. There is a lot going on below the official limit of audibility that remains to be investigated because it definitely affects people's reactions. I got the idea for this unit while recently working at a CD mastering facility that had an all tube listenening room, set up for clients to approve their CDs at the pre production stage. Their system had a mu-follower which sounded very good indeed, but had too much gain. When we did the original aural evaluation of the three possible formats, we had a completed psu, with three bare chassis, each with its own board. Most people listened with their eyes closed:-) The pics are perhaps not good enough to show them but there are some very nice design touches. For example the stainless steel graduation disc on each knob is 45mm in diameter by 2mm. These are set into a milled out circular recess in the front panel 45.5mm by 2.4mm so that the disc sits flush with the front panel. Music is an artistic experience. It should be accompanied by tactile pleasure and pleasing design of the equipment. Black on black just shows a lack of thought. Removing the stainless steel grille to change the tubes reveals what appears like an empty compartment with just the tubes and the tube bases set horizontally into a 4mm bulkhead. There is a "false floor" under which the cable harness runs to the input selector and switched attenuators at the front. The Quad 22 pre was built that way, with turrets screwed into the metal to attach the components on the underside of the chassis holding the tubes on top, and thus very easy to work on. Regards Iain Slainte! Andre Jute Visit Jute on Amps at http://members.lycos.co.uk/fiultra/ "wonderfully well written and reasoned information for the tube audio constructor" John Broskie TubeCAD & GlassWare "an unbelievably comprehensive web site containing vital gems of wisdom" Stuart Perry Hi-Fi News & Record Review |
#32
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On Apr 10, 4:20 pm, "Iain Churches" wrote:
"Peter Wieck" wrote in message ps.com... On Apr 10, 3:51 am, "Iain Churches" wrote: http://www.kolumbus.fi/iain.churches...ier/252.02.jpg Wowsers... looks vaguely like: http://www.radfordaudio.co.uk/ mid-page right. Is yours the chicken or the egg? Peter Wieck Wyncote, PA |
#33
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In article . com,
"Peter Wieck" wrote: On Apr 10, 4:20 pm, "Iain Churches" wrote: "Peter Wieck" wrote in message ps.com... On Apr 10, 3:51 am, "Iain Churches" wrote: http://www.kolumbus.fi/iain.churches...ier/252.02.jpg Wowsers... looks vaguely like: http://www.radfordaudio.co.uk/ mid-page right. Is yours the chicken or the egg? How do you tell, which came first, the chicken or the egg? My wild guess would be that Ian's amp was the "egg". Regards, John Byrns -- Surf my web pages at, http://fmamradios.com/ |
#34
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"Andre Jute" I know, Iain. I was making a joke about the way Allen in his book makes it sound as if his guru received the cathode follower and the constant current source from the finger of God himself. ** Well, as a life long Scientologist - he would imply that, wouldn't he. Only the "God" in question was his implanted, operating Thetan. Anyway, you're not ready to be an audio guru yet. You're too young and you have too much hair. Allen Wright and Holger Stein and Dieter Ennemoser and I decided long ago that the only people who are qualified to build good audio equipment are over fifty and going light on top -- like us. ** Whaaaaattt ??? Kiwi ex pat Scientologist " Alien " Wright was going very thin on top way back in 1980. Looked a like some demented woman's idea of Yul Brynner. I know, cos I briefly worked for the shonky idiot and met his various " ladyfriends ". LOL !! ........ Phil |
#35
Posted to rec.audio.tubes
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In article ,
"Iain Churches" wrote: No mystery Patrick. I stated clearly that it is an active load cathode follower, which was chosen after comparison with a mu-follower and a cascode. I have no schematic drawn. It can be found in any one of a dozen books The cathode follower part sounds straight forward enough, but the "active load" part could be anyone of a number of things. Is the circuit what I think is called a "White" cathode follower? Regards, John Byrns -- Surf my web pages at, http://fmamradios.com/ |
#36
Posted to rec.audio.tubes
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Recently completed project
In article ,
"Iain Churches" wrote: Removing the stainless steel grille to change the tubes reveals what appears like an empty compartment with just the tubes and the tube bases set horizontally into a 4mm bulkhead. There is a "false floor" under which the cable harness runs to the input selector and switched attenuators at the front. Wouldn't it be better to eliminate the false floor and provide a steel grille on the bottom to provide improved air circulation for better cooling? Maybe I shouldn't even suggest that as the steel grille on top is the one design element that doesn't look quite right to my eye, although I am not sure why. Regards, John Byrns -- Surf my web pages at, http://fmamradios.com/ |
#37
Posted to rec.audio.tubes
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Patrick Turner wrote: Andre Jute wrote: Iain Churches wrote: c) this active load cathode follower. In listening tests, people chose C. Shh! Allen Wright will come demand a royalty. That's the big secrets his guru passed on to him, to use cathode followers and to tie the wright (sic -- heh-heh!) currents down tight. I think perhaps you could be guessing about what is in Iain's preamp. He has avoided giving us a schematic. He started off saying it was generic 6SN7 used as a gain stage followed by cathode follower, as Tremaine may have desribed in 1963, but then talks about listening tests using vastly fifferent topolgies, and just what is in the box is a complete mystery. Perhaps he don't want to give away copyable secrets. This is not very nice. At r.a.t we are supposed to be a free tube-craft information outlet for the WWW. I have 18mB at a website and page after page of schematics which anyone is free to use. But Allan Wright's special super cathode follower is only just that, and whether it dramatically increases sonic heaven's enthralling qualities is a moot point. Patrick Turner RAT is a voluntary association. Everyone publishes what he likes in whatever form he likes, and whatever he chooses to share with us is a favour. We have no right to demand any more. Your demand in another post that anyone who wants to post an amp on RAT should document it fully, *and be prepared to defend it*, encourages exactly the sort of adversarial procedure that has made RAT the sewer it is. Andre Jute |
#38
Posted to rec.audio.tubes
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Phil Allison wrote: "Andre Jute" I know, Iain. I was making a joke about the way Allen in his book makes it sound as if his guru received the cathode follower and the constant current source from the finger of God himself. ** Well, as a life long Scientologist - he would imply that, wouldn't he. Only the "God" in question was his implanted, operating Thetan. Anyway, you're not ready to be an audio guru yet. You're too young and you have too much hair. Allen Wright and Holger Stein and Dieter Ennemoser and I decided long ago that the only people who are qualified to build good audio equipment are over fifty and going light on top -- like us. ** Whaaaaattt ??? Kiwi ex pat Scientologist " Alien " Wright was going very thin on top way back in 1980. Naw, he didn't see the light about the best designers being over fifty until he was himself over fifty... The minute he explained it to me, I saw it too, probably because I'd just turned fifty. Looked a like some demented woman's idea of Yul Brynner. I know, cos I briefly worked for the shonky idiot and met his various " ladyfriends ". LOL !! Allen's a guy of sudden enthusiasms, which is a kind way of saying eccentric. I wonder how he goes down in Germany. ....... Phil Thanks for the giggle, Phil. Andre Jute Visit Jute on Amps at http://members.lycos.co.uk/fiultra/ "wonderfully well written and reasoned information for the tube audio constructor" John Broskie TubeCAD & GlassWare "an unbelievably comprehensive web site containing vital gems of wisdom" Stuart Perry Hi-Fi News & Record Review |
#39
Posted to rec.audio.tubes
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Recently completed project
"Iain Churches" wrote in message .fi... "west" wrote in message news:9tWSh.1407$ok6.1308@trnddc07... http://www.kolumbus.fi/iain.churches/Preamp/203A.html Simply gorgeous Iain. What type of RCA connectors are you using? The way they are seated looks smart, but this is the first time I seen that configuration type. Hi West. They are the size D Neutrik pattern NF-2D-B-W They are standard issue in studio and broadcast facilities. You can see them at: http://www.audiogear.com/Neutrik-RCA-Plugs.html They are isolated from the chassis, so that you can make a separate star ground back to a single point. Also they use the same hole as the XLR connector, making it possible to "mix and match" inputs and outputs using the same panel. Also, are those Jensen Oil Caps used for the coupling? Those are the output caps. They are copper foil paper in oil type. There is a silver version, several times the price. I am not sure if this can be justified. You only needed 1 per stage? Maybe there's another turret in there. Anyway, I think you set the bar real high for us, at least as looks go. It sounds well too. West. Posting anything to RAT is inviting a hail of ridicule and derision from a few people who do not actually build anything themselves. You know who they a-) Don't be discouraged by this. A great many people avoid Usenet to keep away from these belligerents. That's a great loss to the subscribers here on RAT. I have received as many replies and comments re this preamp, by e.mail direct as I have on the NG, and people off-list are usually much more helpful and constructive. Best regards Iain Thanks for the kind words, Iain. When you throw a rock at a pack of jackals, the closest one screams. Look at the follow-up thread. Need I say more? Cordially, west |
#40
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Iain:
http://www.kolumbus.fi/iain.churches/Preamp/203A.html It's a joint effort together with my pal Markus. He is a very skilled metal worker and made the casework, and also laser-cut the stainless steel top grille. We decided to do as much possible ourselves. Any comments would be of interest. Nice power plugs. Screws holding the grill spoil the plot IMHO, more than your accustomed eyes might suggest. Difficult to know what to think of it otherwise without knowing what the circuit is, exactly. Depends on context. Things I build for myself, I try to style like weird science, rather than engineering from the days of Edison, and your use of a double skin chassis is well OTT. As something styled for market, it would be interesting to know which. These days, reliability and precision are hardly associated with weightiness. People have learned the opposite. All that metal should look like art, because it is obviously not engineering. Look at Border Patrol, or Audio Note. Chunky is out, svelte is in, for the longer view. But where is the circuit diagram. What did you hope we might discuss? cheers, Ian |
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