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#1
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Vellman tube kits
Hello,
I'm interested in Velleman tube amp kits. Does anyone know if Velleman has quality products? Thanks, Eddie |
#2
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Vellman tube kits
On Oct 21, 3:36*am, "Edward Morris" wrote:
Hello, * * I'm interested in Velleman tube amp kits. *Does anyone know if Velleman has quality products? Thanks, Eddie Have you searched the Web with Google using say "Velleman tube amp kits" or Velleman tube amp reviews"? Whatever may have ever been said in Web forums may come up. Patrick Turner. |
#3
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Vellman tube kits
On Oct 21, 3:36*am, "Edward Morris" wrote:
Hello, * * I'm interested in Velleman tube amp kits. *Does anyone know if Velleman has quality products? Thanks, Eddie And I had a look at the Velleman schematics which can be found in the online kit manuals. There is an amp with 4 x EL34 in each channel, Kit K404. It has separate fixed bias adjust pots for all 8 output tubes - good. The setting of the bias involves adjusting pots until a red LED just begins to turn on while fiddling with little tiny switches. There is an LM3914 chip which works the LED but better would be to have 2 x 4 way opamps working differentially to work a yellow and red LED so that bias is too low when te yellow comes on and too high when red turns on, and when both are not on the bias current is correct at +/- 2mA from a wanted 40mA. Alternatively a red-green bi-colour LED could work the same way, and LEDS placed adjacent to each tube so the bias condition can be checked at a glance any time the amp is on. Its a small additional step to get such a circuit board to also include active protection and turn off the amp if Iadc in one or more EL34 goes to say 60mA for longer than 4 seconds. The K404 has a single 12AX7 set up with 1/2 for a concertina phase inverter and the other 1/2 as an SET input triode which has to make slightly more grid drive voltage than is applied to either side of the EL34 PP grid circuit, ie, about 20Vrms max. There is considerablr global NFB used but I don't know why 12AX7 was used as the input & driver tube when much better would have been a 6CG7 LTP plus another 1/2 6CG7 SE input tube. The remaining 1/2 6CG7 could have been for a stand alone preamp if wanted.. There is a preamp with 12AU7 and no GNFB and there is a switchable choice of whether you include an input pot or not. methinks without the gain pot the power amp plus preamp would be much too sensitive. For CD players, it might be best to omit the 12AU7 altogether and just have the CD player feeding the gain pot which then feeds the power amp input. I cannot view any specs for the OPT or PT but they are all toroidal. I have seen many really horrible toroidal OPTs which have been designed and wound by morons who have not used sufficiently thick insulation betwen P and S windings which results in far too much transformer shunt capacitance. Judging by the advertised LOW prices methinks its probable the whole range of amp kits or the main parts are all made in China. Unfortunately, the Chinese have some way to go before I can endorse most of their audio frequency transformer integrity. I'm sure knowledgeable ppl might find more to criticise but with minor modding one could probably greatly improve the product. One would have to say the K404 might give you far better performance than a Dynaco ST70 kit, and in real dollar terms allowing for the passage of 40+years the Velleman are cheaper, probably we need again send thanks to the Chinese slave labourers which continue to be ruthlessly exploited by anyone buying anything made in China. Patrick Turner. |
#4
Posted to rec.audio.tubes
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Vellman tube kits
On 10/21/10 02:09, Patrick Turner so witilly quipped:
On Oct 21, 3:36 am, "Edward wrote: Hello, I'm interested in Velleman tube amp kits. Does anyone know if Velleman has quality products? Thanks, Eddie And I had a look at the Velleman schematics which can be found in the online kit manuals. snip I cannot view any specs for the OPT or PT but they are all toroidal. I have seen many really horrible toroidal OPTs which have been designed and wound by morons who have not used sufficiently thick insulation betwen P and S windings which results in far too much transformer shunt capacitance. Judging by the advertised LOW prices methinks its probable the whole range of amp kits or the main parts are all made in China. Unfortunately, the Chinese have some way to go before I can endorse most of their audio frequency transformer integrity. I'm sure knowledgeable ppl might find more to criticise but with minor modding one could probably greatly improve the product. was that K404 or K4040? I found this: http://www.vellemanusa.com/us/enu/pr...iew/?id=350535 If it would be necessary to modify such a kit for better performance, it sort of makes the case to just publish an easy-to-build reliable schematic, chassis layout, and parts list and then convince a single distributor to offer it as a "kit". The chassis seems to be the biggest limiting factor here (somewhat expensive per-unit to do a limited run, lots of uncertainty on stocking completed chassis, etc.). Convincing Velleman to offer an upgraded version of their kit might actually be cheaper. (I have a nice big roll of 0.1" 63:37 PbSn WRAP and I'm not afraid to use it) |
#5
Posted to rec.audio.tubes
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Vellman tube kits
On Oct 20, 5:36*pm, "Edward Morris" wrote:
Hello, * * I'm interested in Velleman tube amp kits. *Does anyone know if Velleman has quality products? Thanks, Eddie Pay no attention to the wailing willies on RAT; they're talking through the backs of their necks; I fell about laughing when I read that crap in this thread about the transformers in this amp: Velleman uses very desirable transformers built to the highest standard by Amplimo, a European company whose factory I've actually visited; Amplimo was chosen by Menno van der Veen, the world's leading audio transformer designes, to build the monster toroidal outputs for my custom kilowatt SV511-3 amp (80W SE -- this is heavy duty gear). Any Velleman kit is the good stuff, and the Velleman EL34 PP amp is a particularly good one. I've built one and operated it for years, and still have it. It is good for thumping performance to about 18W in Class A (yes, that's not a misprint, this is a monster of an amp) and in Class B it stretches to well over 100W. At earsaving volumes the distortion is basically nil. You can't get the beautiful stainless steel casework made for what you pay for the entire amp. If you go wrong in the build, Velleman guarantees to fix it for you, and the entire thing is upgradeable (careful, most of those parts work very well together -- in the end my permanent changes amounted to dumping one ceramic cap...). The Velleman EL34 kits is one of abiding bargains in tube amp kits, very likely the greatest of them all; I know of only one better EL34 kit, made by Audio Innovations, and that cost about twice as much as the Velleman kit, was limited to a total output of around what the Velleman would do in Class A alone, and hasn't been made in almost twenty years. See my review of the Velleman in Glass Audio for more information and opinion. Andre Jute Visit Jute on Amps at http://www.audio-talk.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 |
#6
Posted to rec.audio.tubes
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Vellman tube kits
On Oct 21, 8:57*pm, Big Bad Bob BigBadBob-at-mrp3-
wrote: On 10/21/10 02:09, Patrick Turner so witilly quipped: On Oct 21, 3:36 am, "Edward *wrote: Hello, * * *I'm interested in Velleman tube amp kits. *Does anyone know if Velleman has quality products? Thanks, Eddie And I had a look at the Velleman schematics which can be found in the online kit manuals. snip I cannot view any specs for the OPT or PT but they are all toroidal. I have seen many really horrible toroidal OPTs which have been designed and wound by morons who have not used sufficiently thick insulation betwen P and S windings which results in far too much transformer shunt capacitance. Judging by the advertised LOW prices methinks its probable the whole range of amp kits or the main parts are all made in China. Unfortunately, the Chinese have some way to go before I can endorse most of their audio frequency transformer integrity. I'm sure knowledgeable ppl might find more to criticise but with minor modding one could probably greatly improve the product. was that K404 or K4040? *I found this:http://www.vellemanusa.com/us/enu/pr...iew/?id=350535 The K4040 at the link you just quoted did not have the schematics, just kit details in 4 languages. The K4040 looks like the K404. Or did I leave a nought out? If it would be necessary to modify such a kit for better performance, it sort of makes the case to just publish an easy-to-build reliable schematic, chassis layout, and parts list and then convince a single distributor to offer it as a "kit". *The chassis seems to be the biggest limiting factor here (somewhat expensive per-unit to do a limited run, lots of uncertainty on stocking completed chassis, etc.). *Convincing Velleman to offer an upgraded version of their kit might actually be cheaper. (I have a nice big roll of 0.1" 63:37 PbSn WRAP and I'm not afraid to use it) Without seeing the Velleman on my bench and examining it, I don't know what I might think about the build quality. But in a manual I did find elsewhere the schematic was given and I thought some changes would make considerable improvement. What Andre says in favour of Velleman may be 100% correct and certainly the price is good. With a quad of EL34 in PP one can indeed get superlative performance without ever moving above the class A to AB threshold. At listening levels which will never cause a divorce the THD is below 0.03%, providing you have at least average speaker sensitivity of say 90dB/W/M. One wonders how a kit can be prepared for the price and still generate a profit, hence my concerns that parts are sourced from China. Not everything from China is crook though. So let's not assume anything. Its just that I have had a number of Chinese made amps land on my bench for drastic surgery to remove the inbuilt fire crackers so blithely included by our Chinese friends.... Patrick Turner. |
#7
Posted to rec.audio.tubes
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Vellman tube kits
On 10/23/10 04:09, Patrick Turner so witilly quipped:
One wonders how a kit can be prepared for the price and still generate a profit, hence my concerns that parts are sourced from China. Not everything from China is crook though. So let's not assume anything. Its just that I have had a number of Chinese made amps land on my bench for drastic surgery to remove the inbuilt fire crackers so blithely included by our Chinese friends.... I ran the numbers and guessed that (minus chassis) the parts would individually cost around $1000 or so (excluding any taxes and shipping). A tube amp kit for a guitar (different source) runs around $500 (single channel) for a bit less power, but is close to my estimate of $1000 for 90W/channel stereo. And those are retail prices, not dealer prices on the parts. So I'd guess they're making money (which is good, for a number of reasons). I'm guessing the added value would be the instructions, support, and that really shiny chassis with the chrome thingies around the tube sockets, and not having to extrapolate all of the discrete component values from the tube specs. |
#8
Posted to rec.audio.tubes
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Vellman tube kits
On Oct 23, 12:09*pm, Patrick Turner wrote:
On Oct 21, 8:57*pm, Big Bad Bob BigBadBob-at-mrp3- wrote: On 10/21/10 02:09, Patrick Turner so witilly quipped: On Oct 21, 3:36 am, "Edward *wrote: Hello, * * *I'm interested in Velleman tube amp kits. *Does anyone know if Velleman has quality products? Thanks, Eddie And I had a look at the Velleman schematics which can be found in the online kit manuals. snip I cannot view any specs for the OPT or PT but they are all toroidal. I have seen many really horrible toroidal OPTs which have been designed and wound by morons who have not used sufficiently thick insulation betwen P and S windings which results in far too much transformer shunt capacitance. Judging by the advertised LOW prices methinks its probable the whole range of amp kits or the main parts are all made in China. Unfortunately, the Chinese have some way to go before I can endorse most of their audio frequency transformer integrity. I'm sure knowledgeable ppl might find more to criticise but with minor modding one could probably greatly improve the product. was that K404 or K4040? *I found this:http://www.vellemanusa.com/us/enu/pr...iew/?id=350535 The K4040 at the link you just quoted did not have the schematics, just kit details in 4 languages. The K4040 looks like the K404. Or did I leave a nought out? If it would be necessary to modify such a kit for better performance, it sort of makes the case to just publish an easy-to-build reliable schematic, chassis layout, and parts list and then convince a single distributor to offer it as a "kit". *The chassis seems to be the biggest limiting factor here (somewhat expensive per-unit to do a limited run, lots of uncertainty on stocking completed chassis, etc.). *Convincing Velleman to offer an upgraded version of their kit might actually be cheaper. (I have a nice big roll of 0.1" 63:37 PbSn WRAP and I'm not afraid to use it) Without seeing the Velleman on my bench and examining it, I don't know what I might think about the build quality. But in a manual I did find elsewhere the schematic was given and I thought some changes would make considerable improvement. What Andre says in favour of Velleman may be 100% correct and certainly the price is good. With a quad of EL34 in PP one can indeed get superlative performance without ever moving above the class A to AB threshold. At listening levels which will never cause a divorce the THD is below 0.03%, providing you have at least average speaker sensitivity of say 90dB/W/M. One wonders how a kit can be prepared for the price and still generate a profit, hence my concerns that parts are sourced from China. Not everything from China is crook though. So let's not assume anything. Its just that I have had a number of Chinese made amps land on my bench for drastic surgery to remove the inbuilt fire crackers so blithely included by our Chinese friends.... Patrick Turner. The trick of making a profit is to sell basically the same kit for many years; Velleman has been selling that big EL34 kit for decades, so I imagine they've long, long since recovered the design and development costs, and of course profit is not just the margin but related to the number of units sold, and that kit is a bestseller, for the good reasons I already outlined. It's a whole different paradigm from the manufacture of custom amps one at a time. On the other hand, I imagine Velleman loses money on every kit they sell on which they have to meet their guarantee to fix it if the builder gets it wrong. For a review I was writing, I deliberately built another, smaller, Velleman kit wrong, just to see what the service was like, and it was excellent: they found the error (an ear on a variable resistor bent in under the body of the thing), repaired it and had it back to me in working condition less than a fortnight later. To my mind, for the the amateur builder, *that* is the "added value" Bob talks about. You expect proven design and stunning casework for the premium price (there are many cheaper kits), but if you're evaluating the "something else" you get, surely a guarantee to "get you going" must top the list. Andre Jute Visit Jute on Amps at http://www.audio-talk.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 |
#9
Posted to rec.audio.tubes
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Vellman tube kits
On Oct 23, 12:31*pm, Big Bad Bob BigBadBob-at-mrp3-
wrote: On 10/23/10 04:09, Patrick Turner so witilly quipped: One wonders how a kit can be prepared for the price and still generate a profit, hence my concerns that parts are sourced from China. Not everything from China is crook though. So let's not assume anything. Its just that I have had a number of Chinese made amps land on my bench for drastic surgery to remove the inbuilt fire crackers so blithely included by our Chinese friends.... I ran the numbers and guessed that (minus chassis) the parts would individually cost around $1000 or so (excluding any taxes and shipping). * A tube amp kit for a guitar (different source) runs around $500 (single channel) for a bit less power, but is close to my estimate of $1000 for 90W/channel stereo. *And those are retail prices, not dealer prices on the parts. Ha! Maybe I'm out of touch, but when I blow a grand on parts, they'd better be the parts to build a 300B... You've put your finger on the point about kit amps. The amateur gets a proven (or at least, in most cases, a professional) design, and parts discounted by volume purchase -- and he pays carriage only once. A custom amp can easily eat a fifth of the total budget just for the many minimum postage and courier charges for the parts. So I'd guess they're making money (which is good, for a number of reasons). *I'm guessing the added value would be the instructions, support, and that really shiny chassis with the chrome thingies around the tube sockets, and not having to extrapolate all of the discrete component values from the tube specs. And the hassle. I had one amp of my own design on which it took two years and then some for all the custom parts eventually to arrive. After that I decided to build only with off-the shelf parts. Andre Jute "The brain of an engineer is a delicate instrument which must be protected against the unevenness of the ground." -- Wifredo-Pelayo Ricart Medina |
#10
Posted to rec.audio.tubes
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Vellman tube kits
On Oct 24, 9:28*am, Andre Jute wrote:
On Oct 23, 12:09*pm, Patrick Turner wrote: On Oct 21, 8:57*pm, Big Bad Bob BigBadBob-at-mrp3- wrote: On 10/21/10 02:09, Patrick Turner so witilly quipped: On Oct 21, 3:36 am, "Edward *wrote: Hello, * * *I'm interested in Velleman tube amp kits. *Does anyone know if Velleman has quality products? Thanks, Eddie And I had a look at the Velleman schematics which can be found in the online kit manuals. snip I cannot view any specs for the OPT or PT but they are all toroidal.. I have seen many really horrible toroidal OPTs which have been designed and wound by morons who have not used sufficiently thick insulation betwen P and S windings which results in far too much transformer shunt capacitance. Judging by the advertised LOW prices methinks its probable the whole range of amp kits or the main parts are all made in China. Unfortunately, the Chinese have some way to go before I can endorse most of their audio frequency transformer integrity. I'm sure knowledgeable ppl might find more to criticise but with minor modding one could probably greatly improve the product. was that K404 or K4040? *I found this:http://www.vellemanusa.com/us/enu/pr...iew/?id=350535 The K4040 at the link you just quoted did not have the schematics, just kit details in 4 languages. The K4040 looks like the K404. Or did I leave a nought out? If it would be necessary to modify such a kit for better performance, it sort of makes the case to just publish an easy-to-build reliable schematic, chassis layout, and parts list and then convince a single distributor to offer it as a "kit". *The chassis seems to be the biggest limiting factor here (somewhat expensive per-unit to do a limited run, lots of uncertainty on stocking completed chassis, etc.). *Convincing Velleman to offer an upgraded version of their kit might actually be cheaper. (I have a nice big roll of 0.1" 63:37 PbSn WRAP and I'm not afraid to use it) Without seeing the Velleman on my bench and examining it, I don't know what I might think about the build quality. But in a manual I did find elsewhere the schematic was given and I thought some changes would make considerable improvement. What Andre says in favour of Velleman may be 100% correct and certainly the price is good. With a quad of EL34 in PP one can indeed get superlative performance without ever moving above the class A to AB threshold. At listening levels which will never cause a divorce the THD is below 0.03%, providing you have at least average speaker sensitivity of say 90dB/W/M. One wonders how a kit can be prepared for the price and still generate a profit, hence my concerns that parts are sourced from China. Not everything from China is crook though. So let's not assume anything. Its just that I have had a number of Chinese made amps land on my bench for drastic surgery to remove the inbuilt fire crackers so blithely included by our Chinese friends.... Patrick Turner. The trick of making a profit is to sell basically the same kit for many years; Velleman has been selling that big EL34 kit for decades, so I imagine they've long, long since recovered the design and development costs, and of course profit is not just the margin but related to the number of units sold, and that kit is a bestseller, for the good reasons I already outlined. It's a whole different paradigm from the manufacture of custom amps one at a time. On the other hand, I imagine Velleman loses money on every kit they sell on which they have to meet their guarantee to fix it if the builder gets it wrong. For a review I was writing, I deliberately built another, smaller, Velleman kit wrong, just to see what the service was like, and it was excellent: they found the error (an ear on a variable resistor bent in under the body of the thing), repaired it and had it back to me in working condition less than a fortnight later. To my mind, for the the amateur builder, *that* is the "added value" Bob talks about. You expect proven design and stunning casework for the premium price (there are many cheaper kits), but if you're evaluating the "something else" you get, surely a guarantee to "get you going" must top the list. Sure, volume sales helps to make a profit. If one works backwards from say the price of a typical Hammond OPT and assigns the freight, profit and costs of everything used one finds that it is exceedingly difficult to compete with Hammond on price alone. But Hammond surely do have to pay costs which always rise over time at about the rate of inflation, or "consumer price index" and perhaps by a higher margin if the demand for the item reduces and sales numbers shrink. So to keep making the same profit one must raise prices each year. In 1994 there was a local guy here called Bill, and he tried to make 40W per channel integrated stereo tube amps for about $3,000 which was not too bad a price considering the Chinese had almost nothing to offer anyone, and that if you wanted a decent tube amp you bought from ARC, CJ, Manely Labs, or you got a kit which almost nobody thought of doing, or wanted to do, because it seems like it is too technical, and with damned dangerous voltages. So 3 grand was a good price but Bill may have only made 3 amps in 2 years and that didn't pay many expenses. He tried making 10 SS amps at a time and that didn't work out either. I watched Bill and though that because I don't pay rent or a mortgage, I could make something and sell it. Well, it is now 17 years later and sure, maybe I make 1 pair of amps each year, and for SE class A and 60W per channel in 2 monoblocs, price is $10,000. But there are other companies making more hi-falooting hi-end class A amps than I do and many produce 1/2 the PO at twice the price. The Chinese usually charge peanuts for their amps, and you get what you pay for. I have a fair idea about costs. And part of the cost is labour for assembly time. The dollar value of this usually a small % of the total price, and with many kits of anything when the maker offers to supply the item fully assembled and working, the price increase is not great. So when a kit price seems low, and you assume say 20% of that for labour costs, then there isn't much left over for profits. In China, I suspect Quad 40 amps are made in a factory for about $200. But in the hi-fi shop they are many thousands of bucks. The western middle man makes the biggest rip off. So if Velleman can avoid the middle men and sell direct, they don't have to share profits. But I have never seen a Velleman here in Oz, maybe the freight cost is too high. I raise my hat to good products at a low price. I don't have to raise it very often. But I also raise my hat to mediocre products at high prices, For then I stand a chance to be able to compete..... Patrick Turner. Andre Jute Visit Jute on Amps at *http://www.audio-talk.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- Hide quoted text - - Show quoted text - |
#11
Posted to rec.audio.tubes
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Vellman tube kits
Hello and thanks to everyone who has chimed in on my question. Do I stand a
good chance of getting a decent amp kit from Velleman? I'm not looking for "high-end" stuff but I also don't want a fire bottle. Thanks, Eddie " |
#12
Posted to rec.audio.tubes
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Vellman tube kits
"Edward Morris" wrote in message ... Hello and thanks to everyone who has chimed in on my question. Do I stand a good chance of getting a decent amp kit from Velleman? I'm not looking for "high-end" stuff but I also don't want a fire bottle. Thanks, Eddie " There are a few other kits. K8010, 4x KT88 monobloc including case. K8011, 4x EL34 monobloc without case. K8020, Preamp Did'nt have a close look but the K8011 seems to be 1/2 a K4040 or maybe just the innards (modified for EL34)of the K8010. Manual/schematics downloads at: (just type in the kit number) http://www.velleman.eu/distributor/s...try=be&lang=en Some kits come as built versions too, just replace Kxxxx with Mxxxx. Rgds, Gio |
#13
Posted to rec.audio.tubes
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Vellman tube kits
On 25.10.2010 03:41, Edward Morris wrote:
Hello and thanks to everyone who has chimed in on my question. Do I stand a good chance of getting a decent amp kit from Velleman? I'm not looking for "high-end" stuff but I also don't want a fire bottle. Hi, a friend of mine built the k4040 some years ago. The kit has a few drawbacks and shortcomings like an almost inacessible mains fuse that blows quite often when you skip the standby position on the mains switch. The Bias adjustment circuit is questionable, but the potentiometers used are very reliable. Still, should they ever fail for whatever reason the el34 and output transformer might be damaged. You may want to modify the phase spliter to reduce distortion. On the other hand the stock kit sounds just fine and i think it is worth buying. Alexander Dyszewski |
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