Why people still use tube amps when there are plenty of tubes already used in the making of music

[krabapple]

People don't need controls to understand what they like.

LOL. Science, how does it work?

 

[krabapple]

Unfortunately measurement is very unreliable at predicting what people actually like. I cook Paella some people love it because of the 'burnt' bottom, others hate it for the same reason. It's not better or worse its what you like.

Unfortunately , but not at all surprisingly, you offer no real evidence for your claim.

Real evidence as in research studies, like the ones that showed, for speakers, that measurements *are* pretty good predictors of what people will like...in terms of sound.

(And much of that has to do with how they do bass.)

 

[krabapple]

Guys, why are you engaging a rather stupid and unimaginative troll? Don’t feed, the supply of banality just multiplies.

And yet, Henry is a member here since May of 2023.

Another lost soul.

 

[krabapple]

Indeed. However I think that there are quite a few people, here and elsewhere, who happen to like to listen to both SS and valves. And why not...
It's just a hobby.

My god, this must be the answer!

How could we not ever have seen it before?

 

[mhardy6647]

I have done a well controlled ABX between a engineered tube amp (Dynaco ST-70) and a high performance SS amp (Neurochrome Mod 86) and could not tell them apart even though I could measure differences.

When you say engineered... what do you mean exactly?

The ST-70 as "produced" (most, of course, were sold as kits) by Dynaco (David Hafler) has excellent output iron but a somewhat dodgy driver section, netting mediocre overall performance. A surprisingly large cottage industry of upgrades, updates, and modifications to the ST-70 (and even "manufactured" modern variants thereof, in some cases just cobbled up from upgrade boards) was spawned by the unrealized potential of the ST-70 and still exists to this day.

If the ST-70 in your test was "stock" in configuration and was indistinguishable from a Neurochrome Mod 86, I don't think that speaks too well of the latter.

If it was engineered as in improved, that could be a different matter -- what modifications/upgrades were performed on it?

 

[Chr1]

krabapple, off your meds mate?
...ranting just a tad.

 

[levimax]

When you say engineered... what do you mean exactly?

The ST-70 as "produced" (most, of course, were sold as kits) by Dynaco (David Hafler) has excellent output iron but a somewhat dodgy driver section, netting mediocre overall performance. A surprisingly large cottage industry of upgrades, updates, and modifications to the ST-70 (and even "manufactured" modern variants thereof, in some cases just cobbled up from upgrade boards) was spawned by the unrealized potential of the ST-70 and still exists to this day.

If the ST-70 in your test was "stock" in configuration and was indistinguishable from a Neurochrome Mod 86, I don't think that speaks too well of the latter.

If it was engineered as in improved, that could be a different matter -- what modifications/upgrades were performed on it?

The ST-70 was stock. When I say "engineered" I mean David Hafler used science and measurements and engineering to design the St-70 to perform as accurately as possible at the time for it's budget. This is in contrast to many modern tube amps that are designed using "pop/fad science" to be "special" and use poor ideas like no feedback in their design and measure and perform poorly. Amir tested my ST-70 and you can read the results. SINAD of ~60 distortion ~0.1% flat and extended frequency response. You can read the Neochrome specs here https://neurochrome.com/products/modulus-86 pretty much SOTA.

People give way too much credit too their own hearing. Of course maybe I am deaf but if you think you can tell the difference between a well designed 60 SINAD amp and a 110 SINAD amp I would like to see you prove it with a valid ABX test.

 

[DMill]

People give way too much credit too their own hearing. Of course maybe I am deaf but if you think you can tell the difference between a well designed 60 SINAD amp and a 110 SINAD amp I would like to see you prove it with a valid ABX test.

I also would like to see this test. I have no doubt that pushing an amp to clipping would reveal it for many. It’s very difficult for my ears at 56 to detect much difference between my office system (tubes) vs SS (reference) at even loud-ish listening levels (around 85-90 dB) it’s a tough call. But I’m sure I can’t hear as much I as used to.

 

[BDWoody]

I also would like to see this test. I have no doubt that pushing an amp to clipping would reveal it for many. It’s very difficult for my ears at 56 to detect much difference between my office system (tubes) vs SS (reference) at even loud-ish listening levels (around 85-90 dB) it’s a tough call. But I’m sure I can’t hear as much I as used to.

First post details his setup, second post gives the results.

If "Tube Sound" Is a Myth, Why Tubes?

Okay, is the variable resistor connected to a series resistor or is that a variable output 20 k ohm pot? I can't tell from the picture. If it is a variable output pot it should be fine. Max output impedance would be 5 k ohm at -6 db. And you'll be using it at a lower setting with an even...

audiosciencereview.com

Post in thread 'If "Tube Sound" Is a Myth, Why Tubes?' https://audiosciencereview.com/foru...be-sound-is-a-myth-why-tubes.8656/post-550116

 

[SIY]

a somewhat dodgy driver section

I made some money over the years replacing them, and occasionally improved the measurements a bit. But it was actually a pretty decent design- the cathodyne insured essentially perfect balance and low source impedance, and the required swing wasn't too excessive for the 7199 pentode section. I doubt that any of my mods had significant audible consequences.

The weak parts of the design were in the power supply section. Moving to solid state rectification and putting in regulation had a bigger effect at powers past a few watts.

 

[majingotan]

My god, this must be the answer!

How could we not ever have seen it before?

I'll play the devil's advocate here but if I ask a subjectivist, here's their answer for why people still use tubes for sound reproduction:

(borrowing post from @solderdude here: https://www.audiosciencereview.com/...n-susvara-headphone-review.50705/post-2075545)

Zooplankton or Phytoplankton​

Phytoplankton obviously has 'air' where Zooplankton may sound 'meaty' ? (yes, almost every tube amp users will mention these two bolded words together as tube amp "traits")

The phytoplankton below may sound a little sharp here and there.

As much as owning a zero feedback tube amp and listening to it everyday, I still couldn't hear any plankton like the one above

 

[wadude]

Tube amps can sound good, they are historically relevant to our hobby and they cast a romantic glow. Try them some time on a date, they’re chick magnets.

 

[kemmler3D]

Try them some time on a date, they’re chick magnets.

We don't take kindly to snake oil around here, sir.

 

[MattHooper]

I made some money over the years replacing them, and occasionally improved the measurements a bit. But it was actually a pretty decent design- the cathodyne insured essentially perfect balance and low source impedance, and the required swing wasn't too excessive for the 7199 pentode section. I doubt that any of my mods had significant audible consequences.

The weak parts of the design were in the power supply section. Moving to solid state rectification and putting in regulation had a bigger effect at powers past a few watts.

A question for your expertise. And I’m asking in the context that I’m pretty sure I know what you think about tube rolling.

As I’ve mentioned, I have the Conrad Johnson premiere 12 monoblocks. I’ve had them since somewhere around the late 90s..
And all that time I had never changed the driver tubes until they started cacking out a few years ago. I was replacing the two GE NOS 6FQ7 Driver tubes that originally came with the amplifiers.

I started looking up replacements and, admittedly, I got sucked into some good reviews for some NOS Mazda 6CG7 / 6FQ7.

Once those were installed in my amps the sound first struck me as more lush, but then it seemed more like “mush.” It just sounded too laid back and lacked punch, didn’t sound like the amps I “knew” but more like slightly underpowered amps for the speakers. I was quite bummed out by having lost the sound I liked, not to mention the money that felt wasted.

So I panicked and tracked down some NOS GE NOS 6FQ7 to hopefully replicate the original tube compliment. And once those were plugged in… bam… there it was. The amps sounded like themselves again. it was back to punchy powerful sound.

So my question is, sighted bias is an obvious plausible explanation, but if that wasn’t the case, might there be another technical explanation for the type of “ under driven mushy” performance with the MAZDA tubes?

I would imagine you can get some crappy results by putting the wrong tubes in an amp that it was not built around?

Is it possible that those were the wrong tubes?

Or since they were old tubes (claimed NOS) could they have been defective?

 

[MattHooper]

I have done a well controlled ABX between a engineered tube amp (Dynaco ST-70) and a high performance SS amp (Neurochrome Mod 86) and could not tell them apart even though I could measure differences. The subtle differences being discussed here seem unlikely to be audible with music playing (the add distortion tests on the internet show most people need very high distortion added to music, like >5%, for it to be audible) even though there are measurable differences. I don't know how to "objectively" test this but my assertion is that 90%+ of perceived "tube sound" is sighted bias.

This is I was interesting and it goes along with how I’ve noticed personal experience Typically informs our views. Even engineers it seems to me can form somewhat differing views based on their personal experience, perhaps having worked with different designs.

I’m no engineer so I stay out of that stuff.

But you and I have had different experiences blind testing tube equipment. Your test for amplifiers failed to find a difference, and so I can see that as a strong personal experience shaping how you view the subject.

In my case I had positive results for identifying differences in my home blind test of my tube preamp versus my solid-state preamp. And no way do I take that as “ therefore most tube amplification sounds different.” I’m still with you that some very significant proportion of tube amp “ sound” could be due to bias. I’m not sure what percentage I put it at, but perhaps my intuition from my own experience would estimate as a little less than you do.

Reminds me of in the 90s when I was on an audio news group populated by a number of “ASR” type engineers or objectivists. Their view was essentially that CD players and DACs would distinguishable in blind tests (or should). I thought their view made sense, but on the other hand I owned a meridian CD player, a Sony CD player, and a Musatex DAC and they sure seemed to sound different to me. So I did two sets of blind tests, with the advice of those engineers, level match checked with a voltmeter, randomized switching. I very easily distinguished each CD player and DAC in the blinded conditions.

So what were the other folks on that Audio group to think? Well some applauded the effort and results, while at least some remained sceptical. Which I completely understand. To them I’m just some no-name on the Internet. Since I was there and experienced it, it informed my own views somewhat. I think digital and DACs are largely solved problems, I don’t fuss about that stuff, and if somebody really wanted to demonstrate differences, I want to see blind test results. But I wouldn’t rule absolutely out of hand that some CD players or DACs could sound different than others.

 

[SIY]

A question for your expertise. And I’m asking in the context that I’m pretty sure I know what you think about tube rolling.

As I’ve mentioned, I have the Conrad Johnson premiere 12 monoblocks. I’ve had them since somewhere around the late 90s..
And all that time I had never changed the driver tubes until they started cacking out a few years ago. I was replacing the two GE NOS 6FQ7 Driver tubes that originally came with the amplifiers.

I started looking up replacements and, admittedly, I got sucked into some good reviews for some NOS Mazda 6CG7 / 6FQ7.

Once those were installed in my amps the sound first struck me as more lush, but then it seemed more like “mush.” It just sounded too laid back and lacked punch, didn’t sound like the amps I “knew” but more like slightly underpowered amps for the speakers. I was quite bummed out by having lost the sound I liked, not to mention the money that felt wasted.

So I panicked and tracked down some NOS GE NOS 6FQ7 to hopefully replicate the original tube compliment. And once those were plugged in… bam… there it was. The amps sounded like themselves again. it was back to punchy powerful sound.

So my question is, sighted bias is an obvious plausible explanation, but if that wasn’t the case, might there be another technical explanation for the type of “ under driven mushy” performance with the MAZDA tubes?

I would imagine you can get some crappy results by putting the wrong tubes in an amp that it was not built around?

Is it possible that those were the wrong tubes?

Or since they were old tubes (claimed NOS) could they have been defective?

All possible. I’d put them in a jig and measure basic parameters and see how they line up. CCS plate load, a couple of LEDs in series to bias the cathodes. That will get you mu and distortion, put a series resistor in the grid lead and see if leakage is a problem.

 

[wadude]

I learned a lot listening through my Dyna MKIVs over a forty year period. My vested interest in them encouraged me to listen more deeply into the sound of the music and production of recordings. What more can you ask of a stereo?
The maintenance over that time led me to two techs, interesting and great people that have enriched the quality of my life intellectually far more than I enriched theirs financially.
In the beginning excellent tubes were readily available but that has changed over the years. Those 7199 driver tubes finally drove me out of my relationship with the amps. No regrets, only rewards.

 

[MattHooper]

All possible. I’d put them in a jig and measure basic parameters and see how they line up. CCS plate load, a couple of LEDs in series to bias the cathodes. That will get you mu and distortion, put a series resistor in the grid lead and see if leakage is a problem.

Thanks. I don’t have such equipment. But it is informative enough to know that its possible there was just something wrong with the tubes.

 

[MaxwellsEq]

Thanks. I don’t have such equipment. But it is informative enough to know that its possible there was just something wrong with the tubes.

https://www.reddit.com/r/TheWayWeWere/comments/5e3srg/tv_and_radio_tube_tester_1950s_and_60s_virtually

 

[mhardy6647]

I made some money over the years replacing them, and occasionally improved the measurements a bit. But it was actually a pretty decent design- the cathodyne insured essentially perfect balance and low source impedance, and the required swing wasn't too excessive for the 7199 pentode section. I doubt that any of my mods had significant audible consequences.

The weak parts of the design were in the power supply section. Moving to solid state rectification and putting in regulation had a bigger effect at powers past a few watts.

Busted. I played a little (too) fast and loose with my reply. Thanks for weighing in!
Upon reflection, I was probably thinking more about the "front end" of my own SCA-35 (Dynaco's little PP EL84 integrated), which is pretty rudimentary.