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#41
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Adam Stouffer wrote:
bulldog wrote: First of all I didn't sell amps. I repaired them. The owner already knew his amplifier. He knew what to do and not to do. He also knew what he should touch and what not to touch. Old 2 prong tube amps had their safety issues, but the owners accepted that, and continued using them because they liked them. Remember, the type of equipment in question was built long before everybody started seuing everybody else. How did people survive all those years with so many radios having a hot chassis? They seemed safe enough to be sold by the thousands to everyone. What really scares me are resistor cords... Most of those radio and TV sets had wooden chassis and plastic knobs, which kept anyone from directly touching the chassis. Some of them (most notably some notorious GE portable TV sets from the fifties) did not, and some folks occasionally got hurt on those. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#42
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chetatkinsdiet wrote: It's not knowing your **** that makes one hated. It's being a total dickhead, knowitall like you that has zero sense of humor that starts a conversation by trying to attack someone else for no reason. My advice to the guy to not worry so much about a vintage amp that he didn't even buy because he was worried about it shocking him wasn't really in the technical nature. So, **** you, **** off and always from now on, expect me to suggest someone else when looking for tubes. m Fine with me, sparky. And from now on, whenever you post ingnorant bull**** like you posted, I'll rub your nose in it. Fair enough? Lord Valve Expert |
#43
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"Geoff Wood" -nospam said:
Anyway, only pansy lberial commie socialist cry-babies would worry about a healthy dose of mains up the armpit, eh. Good strong christofascists like us can take it no problem. Then you assume Lord Valve is a pansy liberal commie socialist crybaby? BTW congrats on the creative use of language, LMAO! :-) -- Sander de Waal " SOA of a KT88? Sufficient. " |
#44
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Lord Valve wrote in message ...
*You* have no business handing out safety information. Go practice your scales (or, if you're a rock player, your scale) and leave the tech stuff to the people who know it. Maybe this is one way to help improve the gene pool. Anyway, a high-capacity & cheap islolation xfmr that one can make, maybe even in the ammo box mentioned by another, or at least in a similar safe enclosure, beats the bleep out of using filament xfmrs if real pwr is needed: Salvage the PT's from 2 junked microwave ovens (usually the magnetrons or electronics die leaving a good PT). Don't do this if you are a dumfuk or space cadet because their secondaries are very HV, death guaranteed (more gene pool refinement). Sometimes they are welded up & need to be ground open, but they are free. Connect the HV sec's back-to-back, and either weld their enclosures together, or do the ammo box trick with a chassis-mount 3-wire outlet and be smart about the layout. This will give you a ~ 1kw isolation xfmr for little or no cash. If you get bored with it, it might be used as a small boat mooring(gheavy). |
#45
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"Scott Dorsey" wrote in message
Most of those radio and TV sets had wooden chassis and plastic knobs, which kept anyone from directly touching the chassis. Some of them (most notably some notorious GE portable TV sets from the fifties) did not, and some folks occasionally got hurt on those. This reminds me of a story about some computer installation guys that were pushing some big cabinets around while they were still hooked to power. Two cabinets brushed in passing, there was a really big flash, and it took a crowbar to pry the welded sections apart. |
#46
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#47
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#48
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I'll build you a nice custom hand-wired, point-to-point tubed amp if you
want. I'll even use 50C5s, 35W4s and 12AV6s if that's what you want. Difference is, this one will be safe, using an input power transformer, full-wave rectifiers and push-pull outputs. Just send me the specs, features, and power requirements. Volume knobs only go up to 10, however. |
#49
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Geoff Wood wrote: Two-prong cords are not the same as 'hot chassis'. You can have a two-prong cord with the chassis still isolated by a mains transformer. This is the crucial point! There is "vintage" and there is "vintage". If your tube lineup is all 6XX and 12XXX, you are OK because these almost certainly have a power transformer isolating the amp from the line. If the tube lineup has things like 50C5, 35W4, numbers like that, the novice should be wary because it is probably a power-transformer-less design and could present a shock hazard in normal operation. -- Fred Gilham Comprehensive Computer Language Preference Survey Do you like Lisp? (Check one) [ ] Yes [ ] Sure [ ] You bet [ ] Yep [ ] Da |
#51
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That's what i meant. I was typing fast and was thinking hot chassis
and typing 2 prong cord. later, m |
#52
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"Geoff Wood" -nospam wrote in message ... "bulldog" wrote in message om... Sander deWaal wrote in message . .. (bulldog) said: Anyway, only pansy lberial commie socialist cry-babies would worry about a healthy dose of mains up the armpit, eh. Good strong christofascists like us can take it no problem. geoff What about we "Good strong christofascists" on the other side of the Atlantic in Europe. We have 230-240VAC. Do you think we can take it? :-)) Iain |
#53
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"Iain M Churches" in
: : : "Geoff Wood" -nospam wrote in message : ... : : "bulldog" wrote in message : om... : Sander deWaal wrote in message : . .. : (bulldog) said: : : Anyway, only pansy lberial commie socialist cry-babies would worry about a : healthy dose of mains up the armpit, eh. Good strong christofascists like : us can take it no problem. : : geoff Have to say I thought that was "Iberial" in Arial font ... (i.e. from Iberia;-) (still looks the same as I write:-) : What about we "Good strong christofascists" on the other side of the : Atlantic : in Europe. We have 230-240VAC. Do you think we can take it? :-)) : : Iain Sure. Just build one of these and test yourself, uh, out;-) http://www.emanator.demon.co.uk/bigclive/tickle.htm |
#54
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#56
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What a great word, "Christofascists"
Darwin who? Tom "Sander deWaal" wrote in message ... "Geoff Wood" -nospam said: Anyway, only pansy lberial commie socialist cry-babies would worry about a healthy dose of mains up the armpit, eh. Good strong christofascists like us can take it no problem. Then you assume Lord Valve is a pansy liberal commie socialist crybaby? BTW congrats on the creative use of language, LMAO! :-) -- Sander de Waal " SOA of a KT88? Sufficient. " |
#57
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#58
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"D. Lemon" wrote in message ...
A hand-wired, point-to-point, class A vintage tube amp for that "mojo' tone - that's the ticket! My ignorance was bliss. Here are my suggestions. First, forget about hot chassis amps -- there are enough designs out there to allow choosing one with an isolation transformer power supply. Second, take it to a tech and have them bring it up to modern safety standards. Third, don't bring it to a gig. Bring a POD instead. Thankfully, I play jazz, and it has been a long time since I've seen a tube amp on the bandstand. |
#59
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#60
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(Mike Rivers) wrote in message news:znr1101299358k@trad...
In article writes: Here are my suggestions. First, forget about hot chassis amps -- there are enough designs out there to allow choosing one with an isolation transformer power supply. Are there truly hot-chassis amplifiers that serious vintage tone lovers really want? Or are we talking about broken amplifiers with power transformers here? This discussion is getting a little silly-paranoid. If Some Famous Guitarist really uses a three-tube-no-power-transformer amplfier to get "that sound" I'm sure he has it well isolated so he will continue to be able to gig for many years. But I'll bet nobody really uses those things no matter how popular trash is in the guitar field. You'd be surprised at what people will dredge up out of the closet and plug a guitar into. I have never seen hot chassis gear, but plenty of other things. One time I got to the gig with easily five minutes to spare, and the guitarist had been there for an hour hooking up an amazing assemblage that included an old Marshall with a two-wire cord, some 240 Volt gadgets plugged into an autotransformer, and a relatively new "boutique" tube amp. All powered by a combination of those cheap two-prong extensions with the three little outlets on one end. The three-prong plugs were stuck into the outlets so the third prong was doing nothing. The Marshall was being used for vocals. And he told me he sometimes got a shock from it. From what I can tell, the famous guitarists are the ones using modern solid state gear. There may still be tube amps being used by some rock and blues players, but on jazz gigs, I see mostly small solid state amps. |
#61
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#62
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Georg Grosz wrote: From what I can tell, the famous guitarists are the ones using modern solid state gear. You should get out more. LV |
#63
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"play-on" wrote in message news On 24 Nov 2004 17:38:51 -0800, (Georg Grosz) wrote: From what I can tell, the famous guitarists are the ones using modern solid state gear. There may still be tube amps being used by some rock and blues players, but on jazz gigs, I see mostly small solid state amps. Maybe jazz players use them, but if you are going to talk about really "famous" guitar players (most jazz guitarist being totally unknown to the general public) the vast majority continue to use tube amps. Al I agree, Larry Carlton is a notable example and I don't know of a single blues guitarist who doesn't use tubes. Then again, I don't get out much either Blues |
#64
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Blues_Jam wrote: "play-on" wrote in message news On 24 Nov 2004 17:38:51 -0800, (Georg Grosz) wrote: From what I can tell, the famous guitarists are the ones using modern solid state gear. There may still be tube amps being used by some rock and blues players, but on jazz gigs, I see mostly small solid state amps. Maybe jazz players use them, but if you are going to talk about really "famous" guitar players (most jazz guitarist being totally unknown to the general public) the vast majority continue to use tube amps. Al I agree, Larry Carlton is a notable example and I don't know of a single blues guitarist who doesn't use tubes. Then again, I don't get out much either Blues BB king plays a Lab Series. LV |
#66
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Lord Valve wrote:
Blues_Jam wrote: "play-on" wrote: (Georg Grosz) wrote: From what I can tell, the famous guitarists are the ones using modern solid state gear. There may still be tube amps being used by some rock and blues players, but on jazz gigs, I see mostly small solid state amps. Maybe jazz players use them, but if you are going to talk about really "famous" guitar players (most jazz guitarist being totally unknown to the general public) the vast majority continue to use tube amps. I agree, Larry Carlton is a notable example and I don't know of a single blues guitarist who doesn't use tubes. Then again, I don't get out much either BB king plays a Lab Series. Albert King played a solid state amp. Harvey Gerst Indian Trail Recording Studio http://www.ITRstudio.com/ |
#67
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Harvey Gerst wrote: Lord Valve wrote: Blues_Jam wrote: "play-on" wrote: (Georg Grosz) wrote: From what I can tell, the famous guitarists are the ones using modern solid state gear. There may still be tube amps being used by some rock and blues players, but on jazz gigs, I see mostly small solid state amps. Maybe jazz players use them, but if you are going to talk about really "famous" guitar players (most jazz guitarist being totally unknown to the general public) the vast majority continue to use tube amps. I agree, Larry Carlton is a notable example and I don't know of a single blues guitarist who doesn't use tubes. Then again, I don't get out much either BB king plays a Lab Series. Albert King played a solid state amp. Yes, an Acoustic 270, as I recall. Heard it live. Sounded like ass. Admittedly, it was *LOUD* ass, but it was still ass. Betcha cash money he didn't record with one. LV |
#68
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Lord Valve wrote:
Harvey Gerst wrote: Lord Valve wrote: Blues_Jam wrote: "play-on" wrote: (Georg Grosz) wrote: From what I can tell, the famous guitarists are the ones using modern solid state gear. There may still be tube amps being used by some rock and blues players, but on jazz gigs, I see mostly small solid state amps. Maybe jazz players use them, but if you are going to talk about really "famous" guitar players (most jazz guitarist being totally unknown to the general public) the vast majority continue to use tube amps. I agree, Larry Carlton is a notable example and I don't know of a single blues guitarist who doesn't use tubes. Then again, I don't get out much either BB king plays a Lab Series. Albert King played a solid state amp. Yes, an Acoustic 270, as I recall. Heard it live. Sounded like ass. Admittedly, it was *LOUD* ass, but it was still ass. Betcha cash money he didn't record with one. LV, I think it was an Acoustic 261 and yes, he did record with it. Harvey Gerst Indian Trail Recording Studio http://www.ITRstudio.com/ |
#69
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Harvey Gerst wrote: Lord Valve wrote: Harvey Gerst wrote: Lord Valve wrote: Blues_Jam wrote: "play-on" wrote: (Georg Grosz) wrote: From what I can tell, the famous guitarists are the ones using modern solid state gear. There may still be tube amps being used by some rock and blues players, but on jazz gigs, I see mostly small solid state amps. Maybe jazz players use them, but if you are going to talk about really "famous" guitar players (most jazz guitarist being totally unknown to the general public) the vast majority continue to use tube amps. I agree, Larry Carlton is a notable example and I don't know of a single blues guitarist who doesn't use tubes. Then again, I don't get out much either BB king plays a Lab Series. Albert King played a solid state amp. Yes, an Acoustic 270, as I recall. Heard it live. Sounded like ass. Admittedly, it was *LOUD* ass, but it was still ass. Betcha cash money he didn't record with one. LV, I think it was an Acoustic 261 and yes, he did record with it. Still sounded like ass live. LV |
#70
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Lord Valve wrote:
Harvey Gerst wrote: Lord Valve wrote: Harvey Gerst wrote: Lord Valve wrote: Blues_Jam wrote: "play-on" wrote: (Georg Grosz) wrote: From what I can tell, the famous guitarists are the ones using modern solid state gear. There may still be tube amps being used by some rock and blues players, but on jazz gigs, I see mostly small solid state amps. Maybe jazz players use them, but if you are going to talk about really "famous" guitar players (most jazz guitarist being totally unknown to the general public) the vast majority continue to use tube amps. I agree, Larry Carlton is a notable example and I don't know of a single blues guitarist who doesn't use tubes. Then again, I don't get out much either BB king plays a Lab Series. Albert King played a solid state amp. Yes, an Acoustic 270, as I recall. Heard it live. Sounded like ass. Admittedly, it was *LOUD* ass, but it was still ass. Betcha cash money he didn't record with one. I think it was an Acoustic 261 and yes, he did record with it. Still sounded like ass live. Well, Albert seemed to like it. Harvey Gerst Indian Trail Recording Studio http://www.ITRstudio.com/ |
#71
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"Harvey Gerst" wrote in message ... Lord Valve wrote: Harvey Gerst wrote: Lord Valve wrote: Harvey Gerst wrote: Lord Valve wrote: Blues_Jam wrote: "play-on" wrote: (Georg Grosz) wrote: From what I can tell, the famous guitarists are the ones using modern solid state gear. There may still be tube amps being used by some rock and blues players, but on jazz gigs, I see mostly small solid state amps. Maybe jazz players use them, but if you are going to talk about really "famous" guitar players (most jazz guitarist being totally unknown to the general public) the vast majority continue to use tube amps. I agree, Larry Carlton is a notable example and I don't know of a single blues guitarist who doesn't use tubes. Then again, I don't get out much either BB king plays a Lab Series. Albert King played a solid state amp. Yes, an Acoustic 270, as I recall. Heard it live. Sounded like ass. Admittedly, it was *LOUD* ass, but it was still ass. Betcha cash money he didn't record with one. I think it was an Acoustic 261 and yes, he did record with it. Still sounded like ass live. Well, Albert seemed to like it. Harvey Gerst Indian Trail Recording Studio http://www.ITRstudio.com/ Finally...celebrity death match warm up, Harvey vs. Valve. |
#72
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On Fri, 26 Nov 2004 00:28:50 -0600, Harvey Gerst
wrote: Lord Valve wrote: Harvey Gerst wrote: Lord Valve wrote: Harvey Gerst wrote: Lord Valve wrote: Blues_Jam wrote: "play-on" wrote: (Georg Grosz) wrote: From what I can tell, the famous guitarists are the ones using modern solid state gear. There may still be tube amps being used by some rock and blues players, but on jazz gigs, I see mostly small solid state amps. Maybe jazz players use them, but if you are going to talk about really "famous" guitar players (most jazz guitarist being totally unknown to the general public) the vast majority continue to use tube amps. I agree, Larry Carlton is a notable example and I don't know of a single blues guitarist who doesn't use tubes. Then again, I don't get out much either BB king plays a Lab Series. Albert King played a solid state amp. Yes, an Acoustic 270, as I recall. Heard it live. Sounded like ass. Admittedly, it was *LOUD* ass, but it was still ass. Betcha cash money he didn't record with one. I think it was an Acoustic 261 and yes, he did record with it. Still sounded like ass live. Well, Albert seemed to like it. But Harvey, you must remember, LV knows everything. Al |
#73
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But Harvey, you must remember, LV knows everything.
Does he know *why* tube amps sound different than transistor amps? Does he know *how* a transistor amp might be designed to sound like a tube amp? Hint: It has to do with how these amps overload, iron in the signal path (or lack of it), and the amount, type and speed of feedback, etc. Hint: Tubes *and* FETs are both field-effect devices. Discuss. |
#74
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play-on wrote:
Harvey Gerst wrote: Lord Valve wrote: Albert King played a solid state amp. I think it was an Acoustic 261 and yes, he did record with it. Still sounded like ass live. Well, Albert seemed to like it. But Harvey, you must remember, LV knows everything. Al True, I just knew Albert. Harvey Gerst Indian Trail Recording Studio http://www.ITRstudio.com/ |
#75
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Karl Uppiano wrote:
But Harvey, you must remember, LV knows everything. Does he know *why* tube amps sound different than transistor amps? Does he know *how* a transistor amp might be designed to sound like a tube amp? Hell, I have been doing this since before freshman circuits lab involved building an AA5 radio, and I'm not really sure all the reasons why tube and solid state amps sound different. Hint: It has to do with how these amps overload, iron in the signal path (or lack of it), and the amount, type and speed of feedback, etc. Partially, but I can build you a zero-feedback tube amp and a zero-feedback solid state amp with the same output transformer and they'll sound different. Hint: Tubes *and* FETs are both field-effect devices. Sure, but the curves are different. Hell, for that matter, the curves on beam power tetrodes and straight pentodes are totally different. And the curves on different FET configurations are different. It's all different. It's a wonder anyone can agree on how things should sound at all. ---scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#76
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"Scott Dorsey" wrote in message ... Karl Uppiano wrote: But Harvey, you must remember, LV knows everything. Does he know *why* tube amps sound different than transistor amps? Does he know *how* a transistor amp might be designed to sound like a tube amp? Hell, I have been doing this since before freshman circuits lab involved building an AA5 radio, and I'm not really sure all the reasons why tube and solid state amps sound different. I wonder if anyone has done any controlled research on this. Musical instrument amplifiers tend to be overdriven a lot, or rely on non-linear characteristics. Tubes and transistors have obvious differences in their behavior in overload, partially due to the dramatically different design philosophies and parameters. Under strictly linear operating conditions, It's a lot harder to explain sonic differences, if any (especially if noise, frequency response and distortion are similar in the amplifiers being compared). Hint: It has to do with how these amps overload, iron in the signal path (or lack of it), and the amount, type and speed of feedback, etc. Partially, but I can build you a zero-feedback tube amp and a zero-feedback solid state amp with the same output transformer and they'll sound different. Are there any *measureable* differences between them? Are they running into overload at any time? Hint: Tubes *and* FETs are both field-effect devices. Sure, but the curves are different. Hell, for that matter, the curves on beam power tetrodes and straight pentodes are totally different. And the curves on different FET configurations are different. It's all different. It's a wonder anyone can agree on how things should sound at all. FET curves look a lot like tetrode curves to me, although the voltages and currents are much different. Some high-end tube enthusiasts only like to listen to triode amplifiers. Sometimes, only class-A amplifiers, despite the fact that the price per watt becomes enormous. My personal belief is that the quest for highest fidelity, from an engineering perspective (i.e., numerically, scientifically and objectively) is most easily accomplished using BJT designs. But if money (and reliability, repeatability and consistency) is no object, some interesting creations can be made by trial-and-error using other devices. This is a generalization, of course. I have designed with JFETs and MOSFETs or opamps because of some specific design requirement or another with very predictable results. So far, I have never been called upon by any employer to design any tube gear. For musical instrument amplifiers, and live recording (where the maximum level is not known in advance) tubes may have the advantage due to the way they overload. But according to articles I've read on the subject, this is partially due (as I said in my earlier post) to the amount of feedback, and the amount of iron in the audio path, as well as tube characteristics themselves. Of course, this is all speculation until someone actually publishes some scientific research, which may never happen. I doubt there's any money in it. I often wonder how audio history would have looked if FETs were the first transistors, instead of BJTs. The transition to solid state design would have been much smoother, I think. |
#77
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Harvey Gerst wrote: play-on wrote: Harvey Gerst wrote: Lord Valve wrote: Albert King played a solid state amp. I think it was an Acoustic 261 and yes, he did record with it. Still sounded like ass live. Well, Albert seemed to like it. But Harvey, you must remember, LV knows everything. Al True, I just knew Albert. Hey, one man's trash is another man's treasure. No-one said you can't like amps that sound like ass. I don't make the rules, I'm just an observer. If you're in love with three-legged fuses, no reason Albert can't be too. I know a few folks who aren't; turn your radio on and have a listen, won't you? It's all good. ;-) Lord Valve Tone Chaperone VISIT MY WEBSITE: http://www.nebsnow.com/LordValve I specialize in top quality HAND SELECTED NOS and current-production vacuum tubes for guitar and bass amps. Good prices, fast service. QSC amps, RNC compressors, lots of other good stuff! Partial Client List: * Derek Trucks/Allman Brothers Band * * Meatloaf * Catherine Wheel * Yo La Tengo * Let's Go Bowling * * Rob Hyckys (guitarist for Commander Cody) * Waky Amps * * Fleetwood Mac * Tyrin Benoit * Eugene Fodor * Dale Bruning * * Komet Amplification * Dr. Z * Maven Peal * Blockhead Amps * * Jim Kelley * Balls Amplification * Roccaforte Amplifiers * * Gerhart Amplification * Aiken Amplification * The Right Half of AGA * * Lots More * NBS Electronics, 230 South Broadway, Denver, CO 80209-1510 Phone orders/tech support after 1:30 PM Denver time at 303-778-1156 - Our 23rd Year - VISA - MASTERCARD - PAYPAL "It ain't braggin', if ya can do it." - Dizzy Dean |
#78
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Karl Uppiano wrote: But Harvey, you must remember, LV knows everything. Does he know *why* tube amps sound different than transistor amps? Probably. ;-) Does he know *how* a transistor amp might be designed to sound like a tube amp? Does he give a ****? Probably not. ;-) Hint: It has to do with how these amps overload, iron in the signal path (or lack of it), and the amount, type and speed of feedback, etc. Gosh, thanks. Hint: Tubes *and* FETs are both field-effect devices. Hint: trons need plenty of room to frolic. Now, if you wanna squish 'em all up into an itty-bitty piece of sand, you go right ahead. I prefer free-range organic trons which have plenty of room to do the bop, the shimmy, the shake, or whatever other gyrations their little homespun inspiration may lead them to try. Don't need no consarned foreign molecules in the way, or no dope, neither. Discuss. Go right ahead. Lord Valve Uberrohrenfuhrer, Thousand Year Glass Reich |
#79
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Karl Uppiano wrote:
I wonder if anyone has done any controlled research on this. Musical instrument amplifiers tend to be overdriven a lot, or rely on non-linear characteristics. Tubes and transistors have obvious differences in their behavior in overload, partially due to the dramatically different design philosophies and parameters. Under strictly linear operating conditions, It's a lot harder to explain sonic differences, if any (especially if noise, frequency response and distortion are similar in the amplifiers being compared). Lots and lots. There's that terrible 1972 JAES paper that keeps turning up, but there have also been some more careful studies like some of Marshall Leach's work. Doug Self's series on amplifier design in Wireless World talks a little bit about different distortion modes and their significance in different topologies. Remember, nothing is strictly linear, although some things are more linear than others. Hint: It has to do with how these amps overload, iron in the signal path (or lack of it), and the amount, type and speed of feedback, etc. Partially, but I can build you a zero-feedback tube amp and a zero-feedback solid state amp with the same output transformer and they'll sound different. Are there any *measureable* differences between them? Are they running into overload at any time? Of course! The curves are different, so the distortion spectrum is going to be measurably different. That's the real deal. And I can build you a transistor amp and you can swap the 2N3055 output transistors for MJ10004 (and rebias) and it'll sound different, again because the distortion spectrum is measurably different. (The same goes for a tube amp with swaps between tube types). Hint: Tubes *and* FETs are both field-effect devices. Sure, but the curves are different. Hell, for that matter, the curves on beam power tetrodes and straight pentodes are totally different. And the curves on different FET configurations are different. It's all different. It's a wonder anyone can agree on how things should sound at all. FET curves look a lot like tetrode curves to me, although the voltages and currents are much different. Some high-end tube enthusiasts only like to listen to triode amplifiers. Sometimes, only class-A amplifiers, despite the fact that the price per watt becomes enormous. I think in part that is a reaction to the obsession with amplifier power that we've been seeing since the seventies. FET curves are more like triode curves than they are like bipolar curves... but for that matter, the FET curves aren't all the same. Doesn't take much of a change to be audible, and kinks you can't see on the Tek curve tracer get quite easily measured when you are sweeping a mixture of high and low level signals through an amp. My personal belief is that the quest for highest fidelity, from an engineering perspective (i.e., numerically, scientifically and objectively) is most easily accomplished using BJT designs. But if money (and reliability, repeatability and consistency) is no object, some interesting creations can be made by trial-and-error using other devices. This is a generalization, of course. I have designed with JFETs and MOSFETs or opamps because of some specific design requirement or another with very predictable results. So far, I have never been called upon by any employer to design any tube gear. I have mostly designed tube amps, including a bunch of transformerless tube amps using very high transconductance regulator tubes, and it has been a hell of a lot of fun. I tend to prefer MOSFET designs over BJT stuff, if only because it's possible to build much simpler circuits with less to go wrong (no thermal compensation, etc.). But that's just me, and I don't know anything about guitar amps at all, just hi-fi stuff. For musical instrument amplifiers, and live recording (where the maximum level is not known in advance) tubes may have the advantage due to the way they overload. But according to articles I've read on the subject, this is partially due (as I said in my earlier post) to the amount of feedback, and the amount of iron in the audio path, as well as tube characteristics themselves. For the most part, yeah, but musical instrument amplifiers aren't really amplifiers. They are part of a more complex system in which an instrument, an amplifier, and a speaker, all interact. And they are specifically designed not to be accurate. The low level distortion spectra as well as the spectra at clipping are specifically designed for particular sounds, and often things are done in the amplifier that compensate for things in the speaker or the instrument so you can't easily separate the system into parts. This sounds like a lot of work to model effectively to me. Of course, this is all speculation until someone actually publishes some scientific research, which may never happen. I doubt there's any money in it. I often wonder how audio history would have looked if FETs were the first transistors, instead of BJTs. The transition to solid state design would have been much smoother, I think. FETs actually were the first transistors, having been discovered some time in the late 19th century. But they weren't practical (to the point of being able to carry useful current) until well after junction transistors had become popular. I'll think of the guy that discovered the things... Wentz I want to say? It's discussed in the MIT Press book on the history of electric power distribution. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
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