I have to agree being around since the time that Mesa started that the only complaint that I ever heard was they were to clean for rock and roll, more of a jazz amp at least in the beginning. For instrumentation there is no substitute for the sound of a tube amp unless you want to use emulation on a solid state amp and why would you do that?
This was the same problem I ran into years ago making speakers and horns for PA thinking I could get guys to use them for guitar, way to clean, none of the overtones that are what makes electric guitar and bass sound how we expect. Without the distortion and overtones it just doesn't have the musical sound we have learned to expect as normal.
I just feel sorry for whoever has to move that amp, I wouldn't want to be your roady that is for sure!
This was the same problem I ran into years ago making speakers and horns for PA thinking I could get guys to use them for guitar, way to clean, none of the overtones that are what makes electric guitar and bass sound how we expect. Without the distortion and overtones it just doesn't have the musical sound we have learned to expect as normal.
I just feel sorry for whoever has to move that amp, I wouldn't want to be your roady that is for sure!
I am a sound engineer and electronics engineer also over 60 so I agree, far too heavy for me. I get my roadies to move the gear and give the band the sound they request plus a few good ideas.
I have in the past however, placed the SM57 in front of the Boogie but not plugged it in. They don't waste energy with class A and heat, it all goes through the large magnet high SPL speaker!
I have in the past however, placed the SM57 in front of the Boogie but not plugged it in. They don't waste energy with class A and heat, it all goes through the large magnet high SPL speaker!
I encourage anyone who has the technical skill and the finances to build tube amps irrespective of the size and design.
It keeps the tube and transformer industry going and the field of research ongoing.
As for big amps - it's such that they are often built by the serious constructor who has the capability to both design and if need be wind their own transformers. These specialist amps often do not have off the shelf transformers, so one is left to wind their own.
An example of the type of thing I'm talking about is John Chambino's website where he builds big bass guitar amps with tubes. Here is a 1000 watt Amp using twenty 807 tubes with his own designed power and output transformers > http://www.chambonino.com/construct/const13.html
Today many take the lazy way out, by skimping on transformers, and design exercise by buying off the shelf - or building solid state or hybrid instead.
This is not wrong for some situations - but it does kill any sort of incentive to build something unique with tubes.
By designing a new tube amp, one may rediscover something that was missed by others !
It keeps the tube and transformer industry going and the field of research ongoing.
As for big amps - it's such that they are often built by the serious constructor who has the capability to both design and if need be wind their own transformers. These specialist amps often do not have off the shelf transformers, so one is left to wind their own.
An example of the type of thing I'm talking about is John Chambino's website where he builds big bass guitar amps with tubes. Here is a 1000 watt Amp using twenty 807 tubes with his own designed power and output transformers > http://www.chambonino.com/construct/const13.html
Today many take the lazy way out, by skimping on transformers, and design exercise by buying off the shelf - or building solid state or hybrid instead.
This is not wrong for some situations - but it does kill any sort of incentive to build something unique with tubes.
By designing a new tube amp, one may rediscover something that was missed by others !
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Totally depends on what 'sound' you're looking for in an amp. There's not a single right amount of THD (or frequency response, etc.) that will satisfy every player. I like mine a bit more clean
You like what kind of amplifier more clean? Are you talking about HiFi stereo, guitar amps or bass amps?
This is the musical instruments amp section of the forum. So frequency responce is kind of defined by the instrument. For example a standard tuned guitar only makes sound down to 80Hz and pretty much there is nothing above 8KHz, or 10K if you like fret noise
HiFi stereo is a completely different thing. THere you want a very clean amp with a wide bandwidth. Well, even there some people like the "tube sound" which of course is a kind of distortion
I like my bass amp relatively clean. Not to much dirt from e.g. overdriven tubes or various add-on filters. I'm more of a MarkBass than an Orange kind of guy so to speak. Although I do like them even harmonics to liven things up a bit.
Duh
Frequency response is DEFINITELY not just defined by the instrument. Otherwise every amp would sound the same(?). Besides the fact that instrument-amps have different low- and highpass responses, frequency response also entails the curvature of the response within this spectrum.
I think we all know what HiFi means
Have you measured THD in one of your clean amps? Just curious. I've seen some numbers for guitar amps that sound very clean, used by people playing "smooth jazz" and they measured THD is surprisingly high, 10% at the lowest. Just wondering what yours might be.
I don't have the exact numbers, but I do remember the first even harmonic being way lower than -20dB below the base signal. You keep mentioning guitar, but FWIW I do look at guitar- and bass amps as two different tonal approaches.
My DIY bass preamps measure at well under 0.1% for the solid state ones and 0.5-2% for the tube ones. I use PA grade power amps kept well under audible clipping at all times. Speakers are another story though, of course.
500w
Hi, The Hammond transformer I think its the 1650w Can be parrelled, you need two, Eight kt88,s will give you 500w, tetrode connected with 750v B+ and 420 volt on the screens, Svetlana and eh kt88,s are fine with this, I had my output Transformer wound for me, The Hammond transformers are conservatively rated and will do this easily.
Hi, The Hammond transformer I think its the 1650w Can be parrelled, you need two, Eight kt88,s will give you 500w, tetrode connected with 750v B+ and 420 volt on the screens, Svetlana and eh kt88,s are fine with this, I had my output Transformer wound for me, The Hammond transformers are conservatively rated and will do this easily.
Hi Guys
The Hammond 1650W can be used with three pairs of 6550 or KT-88 to provide 465Wrms at a loaded Va=770V and 390V on the screens. The usual supply in this type of amp is a voltage doubler.
Fender did exactly this in their PS-400 amp with 6550s. Their OT was the same Raa as the 1650W but without UL taps. Low impedance drive is needed for this type of amp.
The above performance is within tube safety rules for types specified.
At 280W or so, you'll have response to 30Hz. At 450W, the low end will be falling off around 50Hz.
The reason you see a sea of tubes for high power is many-fold: Low-z low-v requires high current, so many tubes in parallel unless you can find a type that provides very high current (sweep tubes can do this). Production amps must attain a certain reliability in multiple end-user's hands, so erring on the conservative side is best for the manufacturer. App-notes show conservative use, and these are the basis for most production designs.
Designers who do more than parrot the app-note realise a lot more power is available from a given tube type. A pair of EL-34s will put out 100W, as will a pair of 6L6GCs. A pair of 6550s will do 150W. A pair of real EL-509s will do almost 200W.
Most hobbyists have to begin with a stock OT, so that will set the design. Note that the operating ranges of the common power tubes overlap to a great extent, so most designs can be fitted with nearly any tube with the same pinout.
The 1650T can be used safely in 200W designs with a quad of tubes driving it. bass will be rolled off as above. A more conservative 160W design can use the 278CX PT and keeps the whole package to a manageable weight. When you are considering these kinds of power levels, it is really worthwhile to also consider biamping or triamping, to reduce the power per amplifier required.
Also, if you are ordering the Hammond OTs, get the ones with an "A" suffix for easy secondary wiring, so 1650TA, 1650WA, etc.
Have fun
The Hammond 1650W can be used with three pairs of 6550 or KT-88 to provide 465Wrms at a loaded Va=770V and 390V on the screens. The usual supply in this type of amp is a voltage doubler.
Fender did exactly this in their PS-400 amp with 6550s. Their OT was the same Raa as the 1650W but without UL taps. Low impedance drive is needed for this type of amp.
The above performance is within tube safety rules for types specified.
At 280W or so, you'll have response to 30Hz. At 450W, the low end will be falling off around 50Hz.
The reason you see a sea of tubes for high power is many-fold: Low-z low-v requires high current, so many tubes in parallel unless you can find a type that provides very high current (sweep tubes can do this). Production amps must attain a certain reliability in multiple end-user's hands, so erring on the conservative side is best for the manufacturer. App-notes show conservative use, and these are the basis for most production designs.
Designers who do more than parrot the app-note realise a lot more power is available from a given tube type. A pair of EL-34s will put out 100W, as will a pair of 6L6GCs. A pair of 6550s will do 150W. A pair of real EL-509s will do almost 200W.
Most hobbyists have to begin with a stock OT, so that will set the design. Note that the operating ranges of the common power tubes overlap to a great extent, so most designs can be fitted with nearly any tube with the same pinout.
The 1650T can be used safely in 200W designs with a quad of tubes driving it. bass will be rolled off as above. A more conservative 160W design can use the 278CX PT and keeps the whole package to a manageable weight. When you are considering these kinds of power levels, it is really worthwhile to also consider biamping or triamping, to reduce the power per amplifier required.
Also, if you are ordering the Hammond OTs, get the ones with an "A" suffix for easy secondary wiring, so 1650TA, 1650WA, etc.
Have fun
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