Given the desirability of power tube distortion in guitar amplifiers and the somewhat unpleasant volume levels that it may be associated with in domestic settings, load boxes and similar things are attractive. Given that they most often do not match the impedance (reactive load) of a real spear, results can be mixed. Some amps come with their own power-soak features and oftentimes these seem to be like a built-in load-box (some amount of the output gets shed to ground through a resistor).
There are also modifications that go deeper and into the amp and reduce the actual output power of the power section but I wasn't able to find much information on how these work in general. (See https://londonpower.com/about-power-scaling-kits/)
How would one modify a standard PP power section to either implement a switch that reduces the output power by a high degree (say -40 dB). Or even better: make the reduction adjustable with a potentiometer - sort of like a master-volume that controls the output of the power section instead of one that attenuates the input that goes to the power section. Does it just come down to adjusting plate-voltate and bias to produce less output swing?
Cheers,
Lars
There are also modifications that go deeper and into the amp and reduce the actual output power of the power section but I wasn't able to find much information on how these work in general. (See https://londonpower.com/about-power-scaling-kits/)
How would one modify a standard PP power section to either implement a switch that reduces the output power by a high degree (say -40 dB). Or even better: make the reduction adjustable with a potentiometer - sort of like a master-volume that controls the output of the power section instead of one that attenuates the input that goes to the power section. Does it just come down to adjusting plate-voltate and bias to produce less output swing?
Cheers,
Lars
I never actually tried the London Power, and I'd like to hear from those who did.
I have a Pignose GR60, and here're the stuff I've done:
I have a Pignose GR60, and here're the stuff I've done:
- Power Attenuator, for the tone.
I use a Monacor/Song Huei AT-60H power attenuator, designed for ceiling speakers. It's rated for 50W, which is too low, so I added a pre-attenuator with a 2.2R in series and a 22R in //, for -3dB before the device - Triode/pentode switch, for both the tone and the loudness
- Input choke for the power supply
The Pignose is known to blow its tiny power transformer. Changing to choke input (LC) reduces the HV to about 320V from 450V, and the power to 30W or so. This requires a bias change. A small buck transformer is also a viable alternative.
Yes. Basically it comes down to that. This is at least what goes on under London Power's "Power Scaling" trademark.
Another typical alternative in similar vein is adjusting screen voltage. The screens draw much less current so the regulator will dissipate less power. This type of circuitry is employed at least by modern Marshall and Blackstar amps (and many more I don't remember from top of my head).
Then there are schemes where phase inverter stage's headroom is limited instead of power tubes. These are generally applied in three different methods; first being adjustable supply voltage of the PI stage, second being adjustable bias point of the PI stage, and third being some kind of "post PI" master volume control.
Fairly popular method was also to wire the output pentode tubes to triode operation. The triode mode is less efficient so it results to output power decrease but the triodes also have higher damping factor, lower gain and different distortion characteristics than pentode tubes so the tone changes quite radically in the process. High and low power operation modes become inconsistent in regards to overall tone.
The major problem of all of these is that they quench natural current draw of the power amp and therefore prevent or diminish dynamic effects that would result from power supply sag under load. The attenuated amp responses stiffer and lacks some of the "feel" associated to tube power sections.
Transferring distortion to PI stage will also quench dynamic effects of bias shifts of power tube grids and compression by screen voltage modulation. It will practically neuter the entire power amp, IMHO.
PPIMV will also alter open loop gain and in amps that have negative feedback loop this once again results to distinct inconsistency of tone between high and low power operation.
Incredibly few "power scaling" schemes try to counteract these drawbacks and therefore I personally believe that quite many modelling amps (that actually model those dynamic effects regardless of output power setting) can introduce more realistic "tubeness" and "feel" than genuine tube amps neutered with "power scaling" and alike attenuation methods. It's naturally a sort of a taboo as an opinion.
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I have heard of using a variac to bring the line voltage down to maybe 90 volts to get a specific sound from an amp. Just try to choose a variac that does not let you torn the dial above 120 volts. Or maybe get a switched bucking transformer that can get you 6 volt increments of line drop.
Like said, tube amp makers scarcely put any effort to this. Maven Peal used to make amplifiers that emulated the dynamic sag on current draw (the feature was also user adjustable) but that was 20 years ago (IIRC) and more recently Fryette has had a similar effect integrated to maybe a handful of their (pre)amps at max.
Just two examples of genuine tube amps is a sorry state of things given that these kinds of emulations are commonplace in solid-state units.
The usual analog circuit topology to "fake sag" is following and stages a lot of resemblance to techniques to generate a control signal for e.g. compressor circuits :
- make an "envelope follower" that tracks the audio signal, basically full wave rectify the signal
- filter the envelope follower signal: IOW apply suitable filtering to achieve wanted attack and decay characteristics of the supposed "sag"
- subtrack the resulting signal from a suitable DC voltage reference; you now get a "DC" signal that drops and recovers in correspondance to average signal amplitude, basically behaving very much like supply voltage under dynamic current draw
- Use the result signal to drive a linear regulator of the power supply.
(Solid-state circuits can just skip this part and use the signal as reference voltage for clipping diodes etc).
Thank you @teemuk these are great insights. Especially around tone consistency regarding current-draw/sag characteristic of the system as a whole. OT saturation is probably another factor that isn't addressed when reducing power-stage output.
I think the take-away is that, if tone-consistency is the goal, soaking power post OT is the most effective way to go, as long as the load is sufficiently consistent with impedance response of the actual speaker cabinet and not a pure resistive load. What remains unsolved in any case is the contributions of the speaker/cab that depend on the power at which it is driven (speaker-dive/cone-cry...). I don't think anyone has figured out how to make a speaker that sounds like a Greenback that gets hit with 25W at 5W or less...
I think the take-away is that, if tone-consistency is the goal, soaking power post OT is the most effective way to go, as long as the load is sufficiently consistent with impedance response of the actual speaker cabinet and not a pure resistive load. What remains unsolved in any case is the contributions of the speaker/cab that depend on the power at which it is driven (speaker-dive/cone-cry...). I don't think anyone has figured out how to make a speaker that sounds like a Greenback that gets hit with 25W at 5W or less...
That’s interesting, do speakers sound different? I mean are the electrical properties changing in an audible way as the power increases? I know there is a whole load of psychoacoustics going on at different volume levels, so something other than that.
It would be good to hear normalised sound clips of the 5W vs 25W case you mentioned - I don’t know if anyone has done that before?
That would indeed be interesting. Theoretically, there should be non-linear effects as the speaker gets into saturation. Getting actual measurements of that or comparisons would be cool.
I might be able to experiment with speaker-drive on a Celestion. Cone-cry would be difficult as I don’t have a tube amp with enough power. I think with a solid-state amp the damping won’t be right to get the interaction…
https://www.klippel.de/fileadmin/kl...rature/Papers/Klippel_Nonlinearity_Poster.pdf
Has some info
That would lower all the filament voltages as well, so it would not work very well.
Unless the filaments were on a separate transformer not lowered by the Variac.
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according to
Ian White from Celestion… "The effect of signal level is not huge,” says Ian White, "and certainly not as big as it is on the amplifier. These cone break-up mechanisms happen at a few microvolts input. You don't need to drive 20 Volts into the thing to make them happen. There are some level-related effects that come into play, but they're not the ones we've been talking about up to now. As the level goes up, the voice coil does heat up naturally. That will cause some compression and it could cause some other things to change slightly as well, so the sound will change a little bit as the speaker is driven harder. But the sound character of the speaker is just as much there at low levels as it is at high levels.”
https://www.soundonsound.com/techniques/understanding-recording-guitar-speakers
So, non-linear effects in loudspeakers caused by high volumes don’t play a huge role… the dominating characteristics are present at low levels as well.
There is of course psychoacoustics. “Loud is more good!” ;-)
Ian White from Celestion… "The effect of signal level is not huge,” says Ian White, "and certainly not as big as it is on the amplifier. These cone break-up mechanisms happen at a few microvolts input. You don't need to drive 20 Volts into the thing to make them happen. There are some level-related effects that come into play, but they're not the ones we've been talking about up to now. As the level goes up, the voice coil does heat up naturally. That will cause some compression and it could cause some other things to change slightly as well, so the sound will change a little bit as the speaker is driven harder. But the sound character of the speaker is just as much there at low levels as it is at high levels.”
https://www.soundonsound.com/techniques/understanding-recording-guitar-speakers
So, non-linear effects in loudspeakers caused by high volumes don’t play a huge role… the dominating characteristics are present at low levels as well.
There is of course psychoacoustics. “Loud is more good!” ;-)
Actually, back in the days Music Man amps had such a simple power reduction feature and decreased filament voltage was even a key ingredient in it: The tubes operate less efficiently with low filament voltage so it kinda makes sense to hinder filament operation when the goal is overall power reduction.
But, AFAIK, reliability of the tube is not guaranteed with continuous low filament voltage, and naturally the tube stops working alltogether when the voltage decreases enough. So yes, there is indeed an aspect of it not working very well too.
Music Man amps had like 70 - 50 percent power reduction - on a switch, not these modern continuos adjustments going down to 90 or 99 percent of power reduction.
Greetings. I am making my first post on this part of the forum. Please pardon as is will be a long one. I have posted a couple of times in the tubes part of the forum, but I am still trying to get the forum thing figured out. I am an "old timer" who is now retired and doing what I have done since 1982, working on guitar amps.
Now I am trying to better understand the theory behind it all and am pursuing my hobby a little more seriously. On the tube side of the forum and was helped a lot there with some vintage Hi-Fi, PA, and organ amplifier circuit questions, as I purchase these things on the cheap and attempt to modify them for guitar and bass amplification purposes.
The audiophiles there suggested that I come here for some further study material and help with further questions that I may have. I found this post about power scaling and that is something that interests me. I am studying the Ultimate Tone book by Kevin O'Connor which I think well worth the cash although expensive. I purchased a Power Scaling "kit" from his company London Power and installed it in a small tube amp. It is a cathode biased version and he recommended also using a voltage clamp "kit" as well.
The only modification made to the small two tube amp was rewiring the power cord to provide a three pronged, properly grounded one and re-tubing it. While the "tone" is not what I want yet and here is a little more hum to be dealt with, I believe that the results were better than any of the previous attenuation type products that I have tried. I really love the "overdriven" blues type tone that I grew up listening too.
However, my situation at home is such that I can't crank it up anymore and cant afford anymore hearing loss as well. I admit that my previous uses of attenuation were limited in number, and I have not been satisfied with the resulting tone that I got either. I installed the London Power circuits using O'Connor's instructions and with some personal correspondence from him. I was impressed with that level of customer service. His "stuff" Ain't cheap, but he seems genuine in his concern for one's satisfaction.
I did this with only my assembly experience(avionics) to get the job done otherwise, as I am just now reading his book that concerns power scaling. That one is volume 4. The other books have helped me considerably with my general knowledge, but I still have a long way to go to be able to do what I want to do WELL.
I am NOT trying to advertise for London Power and have no other connection to them besides being a customer. Now, the reason I post here is to get ANY other experiences or opinions about power scaling and any other attenuation methods that the guitar/bass amp community here have had and might share with me. I still am learning electronics theory in general, have a basic understanding of Ohm's Law, the power equation, and how components work.
I have studied how vacuum tubes work and why they fail and that's about it. Perhaps my biggest problem is with higher math. I began amp work and got "hooked" by getting lucky fixing a $50, '65 Fender Princeton w. reverb in 1982 that had a bad chassis ground and have always maintained my own equipment through the years and now being retired, with time on my hands(hopefully, I'm 66) I am spending that time and some money doing what I enjoy and trying to figure out why I get the results I do and sometimes don't! Thanks in advance for any replies, and I hope this post is ok, and doesn't infringe on any rules. I am still learning.
Now I am trying to better understand the theory behind it all and am pursuing my hobby a little more seriously. On the tube side of the forum and was helped a lot there with some vintage Hi-Fi, PA, and organ amplifier circuit questions, as I purchase these things on the cheap and attempt to modify them for guitar and bass amplification purposes.
The audiophiles there suggested that I come here for some further study material and help with further questions that I may have. I found this post about power scaling and that is something that interests me. I am studying the Ultimate Tone book by Kevin O'Connor which I think well worth the cash although expensive. I purchased a Power Scaling "kit" from his company London Power and installed it in a small tube amp. It is a cathode biased version and he recommended also using a voltage clamp "kit" as well.
The only modification made to the small two tube amp was rewiring the power cord to provide a three pronged, properly grounded one and re-tubing it. While the "tone" is not what I want yet and here is a little more hum to be dealt with, I believe that the results were better than any of the previous attenuation type products that I have tried. I really love the "overdriven" blues type tone that I grew up listening too.
However, my situation at home is such that I can't crank it up anymore and cant afford anymore hearing loss as well. I admit that my previous uses of attenuation were limited in number, and I have not been satisfied with the resulting tone that I got either. I installed the London Power circuits using O'Connor's instructions and with some personal correspondence from him. I was impressed with that level of customer service. His "stuff" Ain't cheap, but he seems genuine in his concern for one's satisfaction.
I did this with only my assembly experience(avionics) to get the job done otherwise, as I am just now reading his book that concerns power scaling. That one is volume 4. The other books have helped me considerably with my general knowledge, but I still have a long way to go to be able to do what I want to do WELL.
I am NOT trying to advertise for London Power and have no other connection to them besides being a customer. Now, the reason I post here is to get ANY other experiences or opinions about power scaling and any other attenuation methods that the guitar/bass amp community here have had and might share with me. I still am learning electronics theory in general, have a basic understanding of Ohm's Law, the power equation, and how components work.
I have studied how vacuum tubes work and why they fail and that's about it. Perhaps my biggest problem is with higher math. I began amp work and got "hooked" by getting lucky fixing a $50, '65 Fender Princeton w. reverb in 1982 that had a bad chassis ground and have always maintained my own equipment through the years and now being retired, with time on my hands(hopefully, I'm 66) I am spending that time and some money doing what I enjoy and trying to figure out why I get the results I do and sometimes don't! Thanks in advance for any replies, and I hope this post is ok, and doesn't infringe on any rules. I am still learning.
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FWIW my approach is not yet tried out but a small project I have on the go is a practice amp in the VOX vintage camp and my plan was to scale the power by adjusting the screen grid voltage on the power tube (as has been mentioned above) with the idea that this is the best way to keep the curves more or less the same 'shape' in an attempt to retain the same 'sound'. A high voltage MOSFET source follower allows me to keep dc current out of a control potentiometer.
Hi Bigun. What model of Vox amp do you have? My only experience working on one has been an early AC30 that I did some wiring on years ago, burned from overheating, and maintaining and modifying my son's Ac50cp2. I Have worked on other amps of similar design that used EL84 output tubes.
I see that you are from Canada where the London Power company is, but it sounds that you are doing the scaling yourself. I have to admit that I am not up to snuff on Mosfets as you must be. Can you tell me more about the D.C. current getting to a potentiometer?
As I stated, I really did my experiment before even doing much research on power scaling, not expecting the good results that I got. Until this installation I had found my best results with a Weber *** attenuator. I do not like the Hot Plate types and have not found an amp that comes with attenuation "built in" that I liked either.
I don't look for a large amount of attenuation for the tone I have always striven for, but it is hard to even talk about something in an intelligent way about something so subjective in the first place. This is especially true when I love both the "sweet" overdriven sound tone that Otis Rush got on So Many Roads and Eric Clapton's Bluesbreaker days and with Cream. The difference in equipment used there is significant and perhaps impossible to replicate with one "rig" to say the least.
However, I have nothing that I enjoy better than trying. I would like to hear about the Mosfet prevention of D.C. thing, as well as any opinion you might have about Mr. O'Connor/London Power circuits if and when you find the time. Mr. O'Connor is quite opinionated and he has evidently has some "issues" with others use of public domain work and trying to patent it?! I am just trying to get a handle on the whole thing. Thanks.
I see that you are from Canada where the London Power company is, but it sounds that you are doing the scaling yourself. I have to admit that I am not up to snuff on Mosfets as you must be. Can you tell me more about the D.C. current getting to a potentiometer?
As I stated, I really did my experiment before even doing much research on power scaling, not expecting the good results that I got. Until this installation I had found my best results with a Weber *** attenuator. I do not like the Hot Plate types and have not found an amp that comes with attenuation "built in" that I liked either.
I don't look for a large amount of attenuation for the tone I have always striven for, but it is hard to even talk about something in an intelligent way about something so subjective in the first place. This is especially true when I love both the "sweet" overdriven sound tone that Otis Rush got on So Many Roads and Eric Clapton's Bluesbreaker days and with Cream. The difference in equipment used there is significant and perhaps impossible to replicate with one "rig" to say the least.
However, I have nothing that I enjoy better than trying. I would like to hear about the Mosfet prevention of D.C. thing, as well as any opinion you might have about Mr. O'Connor/London Power circuits if and when you find the time. Mr. O'Connor is quite opinionated and he has evidently has some "issues" with others use of public domain work and trying to patent it?! I am just trying to get a handle on the whole thing. Thanks.
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Hi Guys
Power Scaling works exactly how you want it to and hope for it to work. It's the real deal. I modified my Marshall using London Power's kits and needed a little help from KOC and got working. It truly does what he says it will. If you have questions about it, talk to the guy who invented it!! Why guess?
He has written about changing just the screen voltage in a Vox. It works fine and is close enough for people afraid to control everything and deal with the heat. Stephenson Amps uses Power Scaling in the Stage Hog and a bunch of other amps they made over the years. he also does repairs and said that the Marshall slash amp sounded much better without their screen control. He said it didn't sound like a marshall with it working. I asked Kevin about it and he said that Marshall s mistake had to do with how they controlled the tiny mosfet they used. It did not have to change the tone, they were just being too clever and too cheap.
Kevin has opinions like everyone esle, but he is very generous with his time and information. He helped me improve the sound of my amp more than I thought was possible. He encouraged me to try a lot of things in my amp and I can do everything i want with just one amp now. For me his opinion on tech matters is beyond questioning. From what I learned from him, I believe none of the options listed in the second post get you output tube distortion. Only Power Scaling does. It doesn't mess with the amp driving the speaker like an attenuator does, so the sound stays the same. Maybe you gotta hear it to believe it???
He told me once about guys who listen about the symmetric stage stage setup - ya ya sure sure - and then later come back with Wow that really works! I tried it too and have never set up the stage differently since then. The bass player liked it better to. Power scaling is a bigger deal - more peole have their doubts or think they know better -- so maybe you gotta hear it for yourself.
Power Scaling works exactly how you want it to and hope for it to work. It's the real deal. I modified my Marshall using London Power's kits and needed a little help from KOC and got working. It truly does what he says it will. If you have questions about it, talk to the guy who invented it!! Why guess?
He has written about changing just the screen voltage in a Vox. It works fine and is close enough for people afraid to control everything and deal with the heat. Stephenson Amps uses Power Scaling in the Stage Hog and a bunch of other amps they made over the years. he also does repairs and said that the Marshall slash amp sounded much better without their screen control. He said it didn't sound like a marshall with it working. I asked Kevin about it and he said that Marshall s mistake had to do with how they controlled the tiny mosfet they used. It did not have to change the tone, they were just being too clever and too cheap.
Kevin has opinions like everyone esle, but he is very generous with his time and information. He helped me improve the sound of my amp more than I thought was possible. He encouraged me to try a lot of things in my amp and I can do everything i want with just one amp now. For me his opinion on tech matters is beyond questioning. From what I learned from him, I believe none of the options listed in the second post get you output tube distortion. Only Power Scaling does. It doesn't mess with the amp driving the speaker like an attenuator does, so the sound stays the same. Maybe you gotta hear it to believe it???
He told me once about guys who listen about the symmetric stage stage setup - ya ya sure sure - and then later come back with Wow that really works! I tried it too and have never set up the stage differently since then. The bass player liked it better to. Power scaling is a bigger deal - more peole have their doubts or think they know better -- so maybe you gotta hear it for yourself.
nauta. I must agree with you about Mr. O'Connor's expertise. I will say that I have heard a lot of attenuated amps that guys were excited about and for them, I think that's fine, but they all fizzed and sizzled too much for my needs and at least the London Power cathode biased, voltage clamped circuits worked out better than anything else I have heard, OR used myself. They are not cheap but as you mentioned Mr. O'Connor helped Me out a lot with many correspondences by email that got me over some rough spots and up and running. I am a good assembler and can hand solder avionics components all day without error, but theory is another thing. Especially at this level.
I just contacted him about a fixed bias project I just purchased today and I would be surprised if he doesn't email me tomorrow. I have only made the one purchase from him but he spent a lot of time just to type out the amount of advise he gave me. I am reading his entire series of books now and volume 4 is the one on power scaling itself, but the others that I have already read have taught me a lot, and I don't soak things up in one reading like I used to. Thanks to you and all who have contributed to my knowledge base here so far, I appreciate it.
I just contacted him about a fixed bias project I just purchased today and I would be surprised if he doesn't email me tomorrow. I have only made the one purchase from him but he spent a lot of time just to type out the amount of advise he gave me. I am reading his entire series of books now and volume 4 is the one on power scaling itself, but the others that I have already read have taught me a lot, and I don't soak things up in one reading like I used to. Thanks to you and all who have contributed to my knowledge base here so far, I appreciate it.
Also Google (Bing, etc) "VVR tube" and see what shows up! A DIY version of this started at ampgarage.com awhile back.
While I appreciate the talent and what is called his Brown Sound, the style of music and tonal quality of it are too far away from what I am after so I don't know what to think about the effect on the video. The use of a Variac is covered in one of the TUT books and all that I remember without referring back to it was that he did say that of course it reduces Voltage to the entire amplifier, and that he had some reasons not to do it. I will have to look that up and will also check out the VVR Tube thing as well. Not yet being Any kind of an authority on power scaling, I cannot make much of an argument either way.
I here enough of the Cream sound in this that I definitely know it is a Marshall type tone, but my old ears are not good enough anymore to notice the subtle differences that younger ears must hear. Here, I actually like the Park sound which I was not familiar with until now, better. I would like to hear it done with a lower powered amp and perhaps a Fender type, trying for a little less distortion. Van Halen was an amazing guitarist and I have respect, or at least try to for his music and those who enjoy it. I just never got into it myself. I guess that I am too old and stuck in blues that I have a narrow mind when it not only comes to music, but to tone or timbre as well, which ever is proper.
Although I have read that Clapton played a Gibson through a Marshall( and I could be wrong) on say, Crossroads, I sure don't hear tone like that hear, but I would suppose that he was pushing it very hard too. I haven't even tried to get That with the power scaled amp that I have yet. I probable don't play well enough to even try though. I am convinced that anybody of his or Van Halen's signature sound is about 90% in their talented fingers. Even Otis Rush was an amazing player in my opinion although no Clapton or Van Halen. However, he played an upside down strung guitar and a Guild, through who know's what on So Many Roads, but it sends chills up my back and I would love to recreate it. I am pretty sure that whatever he Did played it was "jumping all around" as he said in an interview that I read. A lot of those old timers didn't even own their own amps and cannot remember what they played or when. It is said that Chuck Berry just showed up with guitar in hand and played through whatever the supporting band provided. Also, I am sure that some of what I really liked was played directly through a recording board which I suppose was tube powered as well, at least in Otis's day.
I will definitely check into this further and get back when I have am a little more educated so as to have an opinion about all of it. iI Is a great thing to learn about the other methods in the attempt to get a "cranked" sound at a much lower SPL. Thanks for the continuing education gentlemen. I look forward to more opinions and information about it. I have to wonder about what I would suppose would be a decrease in the amount of gain ,albeit compensation for it, and if it affects the tone. I am not exactly up to snuff as to the relationship between incoming signal, lower operating V., and gain. Maybe it just ain't no big deal? That's is a question, not a statement.
I here enough of the Cream sound in this that I definitely know it is a Marshall type tone, but my old ears are not good enough anymore to notice the subtle differences that younger ears must hear. Here, I actually like the Park sound which I was not familiar with until now, better. I would like to hear it done with a lower powered amp and perhaps a Fender type, trying for a little less distortion. Van Halen was an amazing guitarist and I have respect, or at least try to for his music and those who enjoy it. I just never got into it myself. I guess that I am too old and stuck in blues that I have a narrow mind when it not only comes to music, but to tone or timbre as well, which ever is proper.
Although I have read that Clapton played a Gibson through a Marshall( and I could be wrong) on say, Crossroads, I sure don't hear tone like that hear, but I would suppose that he was pushing it very hard too. I haven't even tried to get That with the power scaled amp that I have yet. I probable don't play well enough to even try though. I am convinced that anybody of his or Van Halen's signature sound is about 90% in their talented fingers. Even Otis Rush was an amazing player in my opinion although no Clapton or Van Halen. However, he played an upside down strung guitar and a Guild, through who know's what on So Many Roads, but it sends chills up my back and I would love to recreate it. I am pretty sure that whatever he Did played it was "jumping all around" as he said in an interview that I read. A lot of those old timers didn't even own their own amps and cannot remember what they played or when. It is said that Chuck Berry just showed up with guitar in hand and played through whatever the supporting band provided. Also, I am sure that some of what I really liked was played directly through a recording board which I suppose was tube powered as well, at least in Otis's day.
I will definitely check into this further and get back when I have am a little more educated so as to have an opinion about all of it. iI Is a great thing to learn about the other methods in the attempt to get a "cranked" sound at a much lower SPL. Thanks for the continuing education gentlemen. I look forward to more opinions and information about it. I have to wonder about what I would suppose would be a decrease in the amount of gain ,albeit compensation for it, and if it affects the tone. I am not exactly up to snuff as to the relationship between incoming signal, lower operating V., and gain. Maybe it just ain't no big deal? That's is a question, not a statement.