Tube Rolling: Does it Make a Difference?

[mhardy6647]

The question is, if someone could perform a definitive study that would discredit the whole guitarist’s holy grail tube industry, would we be able to convince Joe Walsh or Brian May or Eric Clapton?

Well... I mean... at least Dr. May is a scientist!

Legendary Queen guitarist Brian May is also an astrophysicist with a PhD

Talk about a side hustle: After three decades as a legendary musician, Brian May put everything on hold for a year' to finish his PhD.

www.cnbc.com

I do think that tubes can make a difference in an instrument amplifier, but such amplifiers are designed to do things to the input signal (on purpose, and not by accident, as would be the case in a "hifi" amplifier)!

 

[srkbear]

Well... I mean... at least Dr. May is a scientist!

Legendary Queen guitarist Brian May is also an astrophysicist with a PhD

Talk about a side hustle: After three decades as a legendary musician, Brian May put everything on hold for a year' to finish his PhD.

www.cnbc.com

I do think that tubes can make a difference in an instrument amplifier, but such amplifiers are designed to do things to the input signal (on purpose, and not by accident, as would be the case in a "hifi" amplifier)!

If I only had a fraction of the wattage Brian May has above his neck, I’d likely be preoccupied with matters far more consequential to scientific inquiry than worrying about whether the tube industry is a sham.

How one man manages in his teens to construct a completely novel and coveted guitar out of a fireplace mantel, subsequently innovates an entirely unique and instantly recognizable guitar tone and playing style by his mid-twenties, then goes on to conquer the world with some of the most iconic and complex songs, solos and tours of the rock era—all the while obtaining a PhD in Astrophysics at a university as esteemed as Imperial College in his spare time—is beyond my comprehension of mortal beings.

 

[Bob from Florida]

The question is, if someone could perform a definitive study that would discredit the whole guitarist’s holy grail tube industry, would we be able to convince Joe Walsh or Brian May or Eric Clapton?

Brian May's signature tone was not from a tube amp. It was from a 1.5 watt Germanium transistor amp that was retrieved from a dumpster. Read about its origins here https://guitar.com/features/gallery/the-story-of-brian-mays-deacy-amp/
Clapton reportedly used a 5 watt Fender Champ - 6V6 output tube - for Layla.
Weber Speakers made a tube amp kit called "smokin Joe" in honor of Joe Walsh IIRC. 15 watt EL84 push-pull amp - https://www.tedweber.com/sjii-c-kt/

Generalizations are rarely accurate.

 

[MarkS]

Wish there was a way to do this sort of scientific testing with tube rolling on guitar amps. I really want to know if these insanely pricey Mullard and Amperex tubes should command the premiums they do.

Easy! Just listen blind!

Have a friend swap a tube (or not, according the result of a coin flip) in your amp. Then play/listen for a day (without, of course, being able to see the tube), and write down which tube you think is in there. Repeat for as many days as you can. Your friend keeps track of which tube was used on which days. Eventually, compare notes, and see how you did at identifying which tube you were using.

 

[Jim Shaw]

I see no parallel between guitar amps and hifi amps except they draw power and often make noise.

A guitar amp is intended to alter sound coming from a pickup (which also alters sound) to a speaker. The two become a musical instrument, making artistry and virtuosity into various kinds of music (or noise). Screwing around with tubes in guitar amp sockets will alter the 'thing' that the guitar amp does. Kinda like adding a guitar fuzz pedal or such.

A hifi amp is intended to make small signals from its input into large and powerful signals that are closely representative of the input. No artistry is intended in that amp, and the virtuosity is left to the source (and too often the speakers).

Messing around with the tubes in a hifi amp messes around with all sorts of parameters that likely were never intended. Screwing with tubes will not make your Harry Phibeetz into Jimi Hendricks. It will make Harry into a possible train wreck that appeals to you. If your hifi tube amp is any good at all, its designer took pains to place each tube into its optimum operating circumstance for accurate reproduction. Changing tube types and manufacturers simply rolls the dice on operating points. Is it a worthwhile goal to make Jimi's guitar sound more like a banjo? A harpsichord?

Are you inclined to buy a solid state amp, learn soldering, and change transistors to tickle forth your wet dreams? It'll happen, but it requires some repair bench skills.

If you think a tube is bad, replace it with the same type and reset the bias if you're able. Tube rolling won't make you a composer. Or a musician. Or even a producer. It will make you kind of cranky.

 

[beefkabob]

To be honest, this whole topic is causing me a bit of a cognitive crisis—because although I‘ve spoken of these concepts from a guitar amp perspective as accepted dogma for so long, the more I talk about them from a skeptical audiophile standpoint the more it sounds like nonsense to me!

Slow clap.

You have figured out my evil plan.

Distortion does make guitars sound nice. Settings and equipment can definitely lead to a certain sound. However, those certain sounds are likely easier and cheaper to create with software and a bit of knowhow, as opposed to being a gear junky chasing the next magical tube.

 

[beefkabob]

I see no parallel between guitar amps and hifi amps except they draw power and often make noise.

A guitar amp is intended to alter sound coming from a pickup (which also alters sound) to a speaker. The two become a musical instrument, making artistry and virtuosity into various kinds of music (or noise). Screwing around with tubes in guitar amp sockets will alter the 'thing' that the guitar amp does. Kinda like adding a guitar fuzz pedal or such.

A hifi amp is intended to make small signals from its input into large and powerful signals that are closely representative of the input. No artistry is intended in that amp, and the virtuosity is left to the source (and too often the speakers).

I think 99% of hifi marketers, salesmen, and similar scammers would disagree with you. Hence the need for this site.

 

[MattHooper]

If you think a tube is bad, replace it with the same type and reset the bias if you're able. Tube rolling won't make you a composer. Or a musician. Or even a producer. It will make you kind of cranky.

I agree you've made some good points. But your points I think generally derive from the assumption of desiring neutrality/accuracy, hence "the job of an amp and other components is not to alter the signal."

But as we know plenty of audiophiles don't approach the hobby like that. They aren't looking at their sound system as some neutral conduit, but as having a sonic presentation in of itself, and they want the system to "sound how they like." And also that the sound of a system can be nudged in the direction they want. This naturally invites the idea of personalizing your sound, of you having your own level of creative input to achieve a distinct result. A lot of people find this type of interaction gratifying. It's why, for instance, people may build their own speakers or amps, even though they could just buy off the shelf gear. Nature of the hobbyist.

And obviously tube rolling fits in to this idea perfectly - insofar as you buy in to the idea different tubes can change the sound, the hobbyist gets to play around and have fun. It's clear to me that many tube amp owners enjoy doing this.

Personally, even though I've owned different tube amps, and my current tube amps for 20 years or so, I was never in to tube rolling. Just couldn't be bothered. When I had to replace my power tubes, I'd just replace them with the same type of tube. Done. Never noticed a difference in the sound.

Last year, though, my amps started distorting. I traced the problem to the small input tubes. I realized I don't think I'd changed them since I bought the amp! Never needed to. To remedy the issue I grabbed some of the same type of tubes, though a different brand/era. Distortion was gone. But...the amps didn't sound the same! They sounded "ultra tubey" - lush to the point of mushy. None of the high frequency sparkle, none of the snap and punch to drums, bass a bit mushy. It sounded, for lack of better description, like an underpowered amp! I was totally bummed that I didn't have the sound I was used to.

So instead I looked at the original driver tubes I'd taken out, which were now out of production, and tracked down those exact same GE tubes (NOS).
Fingers crossed I replaced the new tubes with the those GE tubes and..voila! The whole sound snapped right back to how it had always been. Vivid, punchy as hell, etc. Total relief!

So your point is well taken that you can really just screw up the sound by random tube replacements.

But on the other hand...since then I actually ended up trying other different tubes in my amps - e.g. KT120 tubes in place of the usual 6550s - and have been pretty blown away at the results. Playing with different power and input tubes has been a blast, as I seem to have pushed the sound around in ways I really enjoy. Some combos seem to produce really tight, punchy sound with a tighter smaller soundstage/imaging, other combos seem to produce bigger, more lush sound, some combos tighter bass, some looser, etc.

I have no objective data to supply, so it's up to the reader how plausible he finds the idea of changing tubes might alter the sound of an amp, so ignore all that as you please. But if one accepts for sake of argument that tube rolling can alter the sound at all, and then ask "why would anyone bother playing with that?"...I can understand why.

 

[majingotan]

I agree you've made some good points. But your points I think generally derive from the assumption of desiring neutrality/accuracy, hence "the job of an amp and other components is not to alter the signal."

But as we know plenty of audiophiles don't approach the hobby like that. They aren't looking at their sound system as some neutral conduit, but as having a sonic presentation in of itself, and they want the system to "sound how they like." And also that the sound of a system can be nudged in the direction they want. This naturally invites the idea of personalizing your sound, of you having your own level of creative input to achieve a distinct result. A lot of people find this type of interaction gratifying. It's why, for instance, people may build their own speakers or amps, even though they could just buy off the shelf gear. Nature of the hobbyist.

And obviously tube rolling fits in to this idea perfectly - insofar as you buy in to the idea different tubes can change the sound, the hobbyist gets to play around and have fun. It's clear to me that many tube amp owners enjoy doing this.

Personally, even though I've owned different tube amps, and my current tube amps for 20 years or so, I was never in to tube rolling. Just couldn't be bothered. When I had to replace my power tubes, I'd just replace them with the same type of tube. Done. Never noticed a difference in the sound.

Last year, though, my amps started distorting. I traced the problem to the small input tubes. I realized I don't think I'd changed them since I bought the amp! Never needed to. To remedy the issue I grabbed some of the same type of tubes, though a different brand/era. Distortion was gone. But...the amps didn't sound the same! They sounded "ultra tubey" - lush to the point of mushy. None of the high frequency sparkle, none of the snap and punch to drums, bass a bit mushy. It sounded, for lack of better description, like an underpowered amp! I was totally bummed that I didn't have the sound I was used to.

So instead I looked at the original driver tubes I'd taken out, which were now out of production, and tracked down those exact same GE tubes (NOS).
Fingers crossed I replaced the new tubes with the those GE tubes and..voila! The whole sound snapped right back to how it had always been. Vivid, punchy as hell, etc. Total relief!

So your point is well taken that you can really just screw up the sound by random tube replacements.

But on the other hand...since then I actually ended up trying other different tubes in my amps - e.g. KT120 tubes in place of the usual 6550s - and have been pretty blown away at the results. Playing with different power and input tubes has been a blast, as I seem to have pushed the sound around in ways I really enjoy. Some combos seem to produce really tight, punchy sound with a tighter smaller soundstage/imaging, other combos seem to produce bigger, more lush sound, some combos tighter bass, some looser, etc.

I have no objective data to supply, so it's up to the reader how plausible he finds the idea of changing tubes might alter the sound of an amp, so ignore all that as you please. But if one accepts for sake of argument that tube rolling can alter the sound at all, and then ask "why would anyone bother playing with that?"...I can understand why.

IMO the tube roll depends on the type of tube amp topology of the amps. I find that SET OPT amps are much more susceptible to tube roll than the OTL WCF or Push-Pull balanced amps. Try the KT88 tubes as well. I find that tube kind good sounding on most amps as well IMO. My amp isn't compatible the KT120 unfortunately

 

[MattHooper]

IMO the tube roll depends on the type of tube amp topology of the amps. I find that SET OPT amps are much more susceptible to tube roll than the OTL WCF or Push-Pull balanced amps. Try the KT88 tubes as well. I find that tube kind good sounding on most amps as well IMO. My amp isn't compatible the KT120 unfortunately

I'm fortunate that my CJ premier 12 amps are compatible with everything between 6550s to KT120s.

As I believe I mentioned earlier in this thread: I didn't actually intend to tube roll. Once I fixed the distortion issue with the NOS input tubes, I was done.
However I happened upon a great deal on some updated Premier 12s, in better condition than mine cosmetically, and more newly updated and gone over by CJ. Since mine were getting old in the tooth I grabbed that pair since I could sell my own at very little loss. I expected they would use 6550s but to my surprise the owner shipped them with a set of KT120s. So for quite a while I had two sets of the same Premier 12s, my originals and the "new" ones, at the same time to compare.

When I switched in the newer premier 12s I was taken aback: I'd never heard such seemingly deep, controlled bass from my speakers, and the highs seemed more prominent, sparkly and "airy." It was like the sound "opened up" at both ends. The soundstage and imaging seemed to expand. It was wild. So I was puzzled as to why I might be hearing any difference - same amps after all. The most obvious difference between the amps was the power tubes - 6550s in my original, KT120s in the new ones. So to check, I switched the KT120 tubes in to my original Premier 12 amps and...zoinks!...there it was! The same thing, the deeper more controlled sounding bass, more open high end, bigger sound overall. Total shock to my system!

After, I started to research the KT120 tubes and was intrigued to see over and over the same reports for people who'd switched 6550s or KT88s for the KT120s. "deeper, more controlled bass, more open high end, bigger sound stage." My skeptical mind remains questioning. It seems at least plausible to me that a tube for which my amp wasn't originally designed could alter the sound of my amps. It seems more odd to me, though, that a specific tube type would have something of a characteristics "sound" across other amps (which were perhaps designed for 6550s or other tubes). But the fact I perceived exactly those sonic traits with the KT120s and only afterward discovered many people report the same results is kinda intriguing to me.

In any case, whatever the explanation (see my tag line!) the KT120s have become my preferred power tube in my amps.

 

[Jim Shaw]

I agree you've made some good points. But your points I think generally derive from the assumption of desiring neutrality/accuracy, hence "the job of an amp and other components is not to alter the signal."

But as we know plenty of audiophiles don't approach the hobby like that. They aren't looking at their sound system as some neutral conduit, but as having a sonic presentation in of itself, and they want the system to "sound how they like." And also that the sound of a system can be nudged in the direction they want. This naturally invites the idea of personalizing your sound, of you having your own level of creative input to achieve a distinct result. A lot of people find this type of interaction gratifying. It's why, for instance, people may build their own speakers or amps, even though they could just buy off the shelf gear. Nature of the hobbyist.

And obviously tube rolling fits in to this idea perfectly - insofar as you buy in to the idea different tubes can change the sound, the hobbyist gets to play around and have fun. It's clear to me that many tube amp owners enjoy doing this.

Personally, even though I've owned different tube amps, and my current tube amps for 20 years or so, I was never in to tube rolling. Just couldn't be bothered. When I had to replace my power tubes, I'd just replace them with the same type of tube. Done. Never noticed a difference in the sound.

Last year, though, my amps started distorting. I traced the problem to the small input tubes. I realized I don't think I'd changed them since I bought the amp! Never needed to. To remedy the issue I grabbed some of the same type of tubes, though a different brand/era. Distortion was gone. But...the amps didn't sound the same! They sounded "ultra tubey" - lush to the point of mushy. None of the high frequency sparkle, none of the snap and punch to drums, bass a bit mushy. It sounded, for lack of better description, like an underpowered amp! I was totally bummed that I didn't have the sound I was used to.

So instead I looked at the original driver tubes I'd taken out, which were now out of production, and tracked down those exact same GE tubes (NOS).
Fingers crossed I replaced the new tubes with the those GE tubes and..voila! The whole sound snapped right back to how it had always been. Vivid, punchy as hell, etc. Total relief!

So your point is well taken that you can really just screw up the sound by random tube replacements.

But on the other hand...since then I actually ended up trying other different tubes in my amps - e.g. KT120 tubes in place of the usual 6550s - and have been pretty blown away at the results. Playing with different power and input tubes has been a blast, as I seem to have pushed the sound around in ways I really enjoy. Some combos seem to produce really tight, punchy sound with a tighter smaller soundstage/imaging, other combos seem to produce bigger, more lush sound, some combos tighter bass, some looser, etc.

I have no objective data to supply, so it's up to the reader how plausible he finds the idea of changing tubes might alter the sound of an amp, so ignore all that as you please. But if one accepts for sake of argument that tube rolling can alter the sound at all, and then ask "why would anyone bother playing with that?"...I can understand why.

I anxiously await adoption of tube rolling as an Olympic Sport.

 

[beefkabob]

1. Do not trust your ears.
2. Measurements or it didn't happen.
3. The psychoacoustic effect is real.
4. Send your amps and your tubes to Amir if you think you can really hear a difference. I'd love to see it.

 

[MattHooper]

1. Do not trust your ears.
2. Measurements or it didn't happen.

"I have no objective data to supply, so it's up to the reader how plausible he finds the idea of changing tubes might alter the sound of an amp, so ignore all that as you please."

3. The psychoacoustic effect is real.

I know:

That's why I'm one of the few here who has actually supplied details about my blind tests, e.g.:

Blind Test Results: Benchmark LA4 vs Conrad Johnson Tube Preamp

Hey folks, I thought I'd post about a little blind test I did between my two current preamplifiers: Benchmark LA4 vs. Conrad Johnson Premier 16LS2 tube preamplifier. People are familiar with the Benchmark LA4 I'm sure: https://benchmarkmedia.com/products/benchmark-la4-line-amplifier A...

www.audiosciencereview.com

4. Send your amps and your tubes to Amir if you think you can really hear a difference. I'd love to see it.

LOL. Not a chance.

These things are 51 lb each, I haven't the original boxes, and I'd never chance it.

Plus they've already been measured by stereophile:

Conrad-Johnson Premier Twelve monoblock amplifier Measurements

Sidebar 3: Measurements Following its preconditioning test, the Conrad-Johnson Premier Twelve was hot—typical for a tube amplifier. The bias was found to be slightly off during the distortion measurements, was recalibrated, and the prior measurements were rechecked to ensure that the results had...

www.stereophile.com

(I can sympathize with your wanting to see them measured by Amir. If I could snap my fingers and magically transport my speakers and other gear to Amir to be measured I probably would. I do appreciate that other folks have taken the chance and effort to send Amir their gear. I'm curious, but not curious enough to risk my precious gear being shipped).

 

[mhardy6647]

I anxiously await adoption of tube rolling as an Olympic Sport.

I've heard of doping semiconductors -- so I hope they won't have any problems with tube doping.

 

[beefkabob]

Blind tests for sounds that are minutes apart don't work. Hours? Days? Nah.
Stereophile didn't roll the tubes. Amir did and look what he found.

 

[MarkS]

Blind tests for sounds that are minutes apart don't work. Hours? Days? Nah.

Of course they work. They reveal that, even if differences can be heard in a rapid-switching test, they are too small to matter under actual listening conditions.

 

[MattHooper]

Blind tests for sounds that are minutes apart don't work.

Yes they can work.

But are you referring to my blind test? If so, the switching wasn't minutes apart. It was seconds (about 3 seconds or so).

In any case: I think you might be mixing up ideas perhaps. Quick switching is always ideal. The subtler the sonic difference, the more you need instant or very quick switching. The problem is, if for the subtlety of the sound you aren't switching fast enough, the test may not be reliable for ruling OUT sonic differences. So if it was a very subtle sonic difference that would only be reliably distinguished with quick switching, if you aren't quick switching and you get random results, you can't rule out sonic differences. So quick switching is mostly for what you can say about negative/random results.

That doesn't mean however that any results would be invalid using longer times between switching sources.

POSITIVE results for identifying differences well beyond chance are positive results...whether you were switching within seconds, minutes, hours or whatever. So long as you didn't know which device you were listening to, if you identify between the devices 16 times correctly in a row, that clearly suggests it wasn't chance.

(I presume you think you could reliably identify the voices of two people you know very well, under blind conditions, minutes apart).

 

[MattHooper]

Of course they work. They reveal that, even if differences can be heard in a rapid-switching test, they are too small to matter under actual listening conditions.

You don't really believe that do you?

(Hard to tell without a smiley).

 

[MarkS]

Of course I believe it.

If I go buy a new amp because I think it sounds better, I should be able to tell whether my new or old amp is in my system after a decently-long listening session. If I can't tell, there is functionally no difference for me. Why would I spend money on something that I can't hear in normal listening?

 

[MattHooper]

Of course I believe it.

If I go buy a new amp because I think it sounds better, I should be able to tell whether my new or old amp is in my system after a decently-long listening session. If I can't tell, there is functionally no difference for me. Why would I spend money on something that I can't hear in normal listening?

That's just it.

Why are you presuming that sonic differences that can be identified under blind tests are not heard during normal listening?

(For instance, I hear the differences between my tube and SS preamp during normal listening - the same characteristics I heard under blind listening).