Could You Tell a Tube Integrated from a Solid State Receiver???

[toddalin]

Could You Tell a Tube Integrated from a Solid State Receiver (in a Video) If All Else Were Equal?
https://www.audiokarma.org/forums/index.php?threads/could-you-tell-a-tube-integrated-from-a-solid-state-receiver-in-a-video-if-all-else-were-equal.983586/#post-15316997 (https://www.audiokarma.org/forums/index.php?threads/could-you-tell-a-tube-integrated-from-a-solid-state-receiver-in-a-video-if-all-else-were-equal.983586/#post-15316997)

For those that doubt the efficacy of YouTube to demonstrate "subtle" differences, you are in for a real treat..., and you don't need uber-monitors to hear the differences.

This will also provide insite into the development of the Mermans and the pairing of not only the room, but the amplification to the speakers. It may also explain why Rob finds the Mermans to be bright, which may not be the speakers at all.

Enjoy!

[Riley Casey]

That Youtube 256k compression sounds nice.

[rusty jefferson]

Well, there's certainly a clearly audible difference listening through my earbuds which is nice if you're trying to demonstrate a difference. I think/assume the complaint about "auditioning" speakers via YouTube is it doesn't give you a realistic sense of what you're going to hear in your room.(?) I couldn't tell you which I might prefer in person, or whether I think the system as a whole sounds good or bad. I assume the tube amplifier is the top video and the SS amplifier is the bottom video. There's an easily audible difference regardless. :)

It's also necessary to voltage match 2 amplifiers when doing A/B/X tests not SPL match. We do it to +/- .003 volts with a 1khz test tone, though in this demonstration I assume the tonal shift is what you're demonstrating. When comparing similar amplifier types, even the tiniest difference in level will skew the results.

[toddalin]

Well, there's certainly a clearly audible difference listening through my earbuds which is nice if you're trying to demonstrate a difference. I think/assume the complaint about "auditioning" speakers via YouTube is it doesn't give you a realistic sense of what you're going to hear in your room.(?) I couldn't tell you which I might prefer in person, or whether I think the system as a whole sounds good or bad. I assume the tube amplifier is the top video and the SS amplifier is the bottom video. There's an easily audible difference regardless. :)

It's also necessary to voltage match 2 amplifiers when doing A/B/X tests not SPL match. We do it to +/- .003 volts with a 1khz test tone, though in this demonstration I assume the tonal shift is what you're demonstrating. When comparing similar amplifier types, even the tiniest difference in level will skew the results.


Thanks,

I don't subscribe to the 1kHz test tone, but rather prefer pink noise. The problem with using a 1 kHz tone is that if one speaker is "laid back" at 1kHz, and the other is "forward," you would turn up the laid back speaker and turn down the forward offering. This would then make the remainder of the band louder on the laid back speaker and quieter on the forward speaker and the laid back speaker would become louder overall making it sound preferable.

[Robh3606]

Thanks,

I don't subscribe to the 1kHz test tone, but rather prefer pink noise. The problem with using a 1 kHz tone is that if one speaker is "laid back" at 1kHz, and the other is "forward," you would turn up the laid back speaker and turn down the forward offering. This would then make the remainder of the band louder on the laid back speaker and quieter on the forward speaker and the laid back speaker would become louder overall making it sound preferable.

Hello toddalin

I think he means matching the output voltages measured on the amp terminals. Chances of the gain structures being the same is not good. I could hear the difference between the two easily so I would say the videos were useful for this comparison.

Rob:)

[rusty jefferson]

Hello toddalin

I think he means matching the output voltages measured on the amp terminals. Chances of the gain structures being the same is not good. I could hear the difference between the two easily so I would say the videos were useful for this comparison.

Rob:)
:yes:

[toddalin]

The shootout continues. This may be the most comprehensive test of this type on the 'net.

https://www.audiokarma.org/forums/index.php?threads/tube-vs-solid-state-shoot-out.984391/

[man00]

You sure won't hear that sound at Best Buy

[gasfan]

Imo the ss amp is noticeably louder notwithstanding the rolloff of the tube amp. Even though the ss amp is obviously more forward sounding, the entire mid range is clearly louder with the ss. Not sure it's a fair test here not because of what I just said but because ss and tube character could be much more closely matched in which case it would probably be a much different outcome.

[toddalin]

Imo the ss amp is noticeably louder notwithstanding the rolloff of the tube amp. Even though the ss amp is obviously more forward sounding, the entire mid range is clearly louder with the ss. Not sure it's a fair test here not because of what I just said but because ss and tube character could be much more closely matched in which case it would probably be a much different outcome.

But you are wrong. The Melton is ~0.1 dBA louder using the pink noise on the Stereophile disk and ~0.9A dB louder using the 1kHz tone on the same disk. I went to great lengths using professional equipment to match these volume-wise (and nothing was moved or changed between videos) giving the advantage (<0.1 dBA) to the Melton. All recorded measurements (19 sets of measurements with 133 parameters just in the set-up alone) were done in triplicate to ensure similarity and Leq levels never varied by more than 0.1 dBA, and were typically identical, in each set of triplicate readings.

[gasfan]

Okay, I stand corrected. I suppose the flatter response makes it seem louder?

[Mr. Widget]

All recorded measurements (19 sets of measurements with 133 parameters just in the set-up alone) were done in triplicate to ensure similarity and Leq levels never varied by more than 0.1 dBA, and were typically identical, in each set of triplicate readings.Can't say you aren't dedicated!

Did you take any high resolution FR measurements to see how the two systems diverge? Do you have impedance and phase response measurements? 1/3 octave RTA measurements don't tell you much.

Based on everyone's comments it would seem that one amp isn't operating properly or the load presented by the speakers under test are causing one or both of the amps to behave poorly. Unlike our old friend Julian Hirsch, I do agree with your premise that different amps have their own sound, but two properly operating amplifiers shouldn't sound grossly different.


Widget

[toddalin]

1/6th octave RTA, not 1/3rd. That's a separate band for every two notes in the diatonic scale. BTW, the RTA (Behringer DEQ2496) was not used in any of the testing.

The 1kHz and Pink Noise sources were taken from the Stereophile Test CD and monitoring was performed using a Quest Technologies Model 2900 Type 2 Integrating/logging Sound Level Meter. The unit meets the American National Standards Institute Standard S1.4-1983 for Type 2, International Electrotechnical Commission Standard 651-1979 for Type 2, and International Electro-technical Commission Standard 651-1979 for Type 2 sound level meters. I use this meter for the field measurements in my CEQA noise studies and have since I purchased it new ~25 years ago.

Everything is operating properly and you are welcome to come by and listen anytime.

I would urge you/people to do their own videos, even if you don't put it on the 'net, just to be able to instantaneously A/B two sounds. If you use good equipment in recording and playback, and make sure all other parameters are held the same, you may just be suprised how poor the ear's memory really is for changes in timbre over time.

[rusty jefferson]

I'm not sure what the debate is here. Transformer coupled tube amplifiers with high output impedance, and solid state amplifiers with low output impedance will almost always sound different in an A/B/X test for a variety of reasons. That's no surprise.


....Unlike our old friend Julian Hirsch, I do agree with your premise that different amps have their own sound, but two properly operating amplifiers shouldn't sound grossly different.


Widget
I believe his premise is that 2 amplifiers of similar type and that measure similarly (similar input impedance, similar output impedance) will generally speaking, sound the same if neither is driven into clipping during the test. I don't think Julian or anyone would expect a transformer coupled tube amp with 500k ohms of input impedance and 7 ohms of output impedance, and a solid state amp with 10k ohms of input impedance and 0.007 ohms of output impedance will sound the same on a typical speaker load. I have tried such A/B/X tests under controlled conditions. It surprised me just how easy/difficult it is to distinguish between 2 amplifiers based on these variables.

As far as matching 2 amplifiers in level, there's only 1 way to do it properly. That's using a high quality volt meter and matching the voltage on both amplifiers @ 1khz to a tight tolerance. We use +/- 0.003 volts. Measuring volume level is useless. Most inexpensive transformer coupled tube amplifiers lack in the low frequency and high frequency. Measuring sound levels with pink noise is apples and oranges.

[Mr. Widget]

1/6th octave RTA, not 1/3rd. That's a separate band for every two notes in the diatonic scale. BTW, the RTA (Behringer DEQ2496) was not used in any of the testing.I am not a fan of RTA measurements in general. They were the SOTA in 1982, but today we have better tools.


The 1kHz and Pink Noise sources were taken from the Stereophile Test CD and monitoring was performed using a Quest Technologies Model 2900 Type 2 Integrating/logging Sound Level Meter. The unit meets the American National Standards Institute Standard S1.4-1983 for Type 2, International Electrotechnical Commission Standard 651-1979 for Type 2, and International Electro-technical Commission Standard 651-1979 for Type 2 sound level meters. I use this meter for the field measurements in my CEQA noise studies and have since I purchased it new ~25 years ago.I assumed your noise measurements were using calibrated equipment from your work.


...you may just be surprised how poor the ear's memory really is for changes in timbre over time.No argument on the fallibility of our sonic memory and issues with perception in general. I am not sure recording the sounds helps over realtime comparisons though as a microphone doesn't "hear" in the same way as we do. A plot of a tight "cloud" of measurements is more representative than a single mic recording a test signal.


Widget

[Mr. Widget]

I'm not sure what the debate is here.I'm not sure there is a debate here. ;)


Transformer coupled tube amplifiers with high output impedance, and solid state amplifiers with low output impedance will almost always sound different in an A/B/X test for a variety of reasons. That's no surprise.Yes, but if the tube amp has top quality output transformers the impedance shouldn't be an issue. In my experience with high quality tube amps the differences between SS and tube are quite subtle. Vintage Macs and others tend to have rolled off tops and fat and lose bottom ends due to their design and possibly their transformers. OTL designs definitely sound "different".


I believe his premise [Julian Hirsch] is that 2 amplifiers of similar type and that measure similarly (similar input impedance, similar output impedance) will generally speaking, sound the same if neither is driven into clipping during the test. I don't think Julian or anyone would expect a transformer coupled tube amp with 500k ohms of input impedance and 7 ohms of output impedance, and a solid state amp with 10k ohms of input impedance and 0.007 ohms of output impedance will sound the same on a typical speaker load. I have tried such A/B/X tests under controlled conditions. It surprised me just how easy/difficult it is to distinguish between 2 amplifiers based on these variables. Perhaps, but since both were designed to work with low impedance loudspeakers, I believe Mr. Hirsch was of the belief that the operating principle of the amplifier was not relevant to the sound quality as long as both measured reasonably well. While he did measure 0.000000000000X IM, THD, TIM etc., he also said that these numbers were not really relevant past a certain point.


As far as matching 2 amplifiers in level, there's only 1 way to do it properly. That's using a high quality volt meter and matching the voltage on both amplifiers @ 1khz to a tight tolerance. We use +/- 0.003 volts. Measuring volume level is useless... Measuring sound levels with pink noise is apples and oranges."Useless" may be a bit strong, but I agree.


Most inexpensive transformer coupled tube amplifiers lack in the low frequency and high frequency.Cheap transformers will certainly have that effect. I am not familiar with the devices under test here, but if the tube amp is using economy or some vintage transformers that would certainly alter the sound in a manner described by the listeners. I had assumed the comparison was using top flight amps operating to a spec of +/- 0.25dB 20Hz to 20KHz or thereabouts.


Widget

[Robh3606]

Without looking at the speaker impedance curve you really don't have a complete picture. With a transformer coupled amp the more varied the impedance curve the more chance you have of FR deviations depending on the magnitude changes and where they are WRT frequencies effected.

Rob:)

[toddalin]

Cheap transformers will certainly have that effect. I am not familiar with the devices under test here, but if the tube amp is using economy or some vintage transformers that would certainly alter the sound in a manner described by the listeners. I had assumed the comparison was using top flight amps operating to a spec of +/- 0.25dB 20Hz to 20KHz or thereabouts.


Widget

Certainly the Yamaha far exceeds this but no idea on the Melton:
https://i.ebayimg.com/images/g/1XwAAOSwHcdfdElm/s-l1600.jpghttps://i.ebayimg.com/images/g/dTcAAOSw4VJfdEhP/s-l1600.jpg

http://meltonaudio.com/cart/amplifier/integrated-amplifier-mkt88p-80w/

https://i.ebayimg.com/images/g/2DwAAOSwbIRfgfMh/s-l1600.jpg

Even here through the JBLs, it seems that the top of the Melton is rolled off, though this recording leaves much to be desired.

https://youtu.be/aKiLEf7ltDY

[toddalin]

And here.

Sorry about two posts but the JBL format only allows one video per post.


https://youtu.be/yutv41IoC1Y

[toddalin]

Actually, rather than pink noise or a warbled 1kHz, maybe we should be using M-noise.

https://meyersound.com/news/m-noise-test-signal/

[Mr. Widget]

Hi Todd,

To get to the chase, what are you trying to demonstrate?


Widget

[rusty jefferson]

.... I had assumed the comparison was using top flight amps operating to a spec of +/- 0.25dB 20Hz to 20KHz or thereabouts.
Widget
So, we're saying the same thing. If he can hear an obvious difference in pink noise between these 2 amplifiers, one (at least) doesn't meet that standard. Only the very best and most expensive transformer coupled tube amplifiers will come close to (and not real close :)) those qualities and be hard to distinguish from SS in a double blind A/B/X test. I don't know anyone who has bothered to try it because it's generally not necessary if looking for differences. I've only done them with similar types of amplifiers to see if people can distinguish the difference between say a Crown and a Parasound, which have similar input/output impedance, frequency response, etc. but different topologies.


Without looking at the speaker impedance curve you really don't have a complete picture. With a transformer coupled amp the more varied the impedance curve the more chance you have of FR deviations depending on the magnitude changes and where they are WRT frequencies effected.

Rob:)
Absolutely.


Actually, rather than pink noise or a warbled 1kHz,.....
If you've been trying to do it with a warbled 1khz signal that's not going to work. You need a 1khz sine wave like from a signal generator.

[rusty jefferson]

And here.

Sorry about two posts but the JBL format only allows one video per post.


https://youtu.be/yutv41IoC1Y
Yikes, this Audiophile should lose his/her membership card for playing music in that room. YouTube is good enough to show how bad that room sounds. There is no way one could judge that equipment.

[toddalin]

If you've been trying to do it with a warbled 1khz signal that's not going to work. You need a 1khz sine wave like from a signal generator.

1kHz sine wave from the Stereophile test disk. But ultimately, I used the pink noise and not the sine wave to set the volumes the same

HAD TO BE THIS WAY! The Oppo feeds the Yamaha through the two HQ RCA outputs while the Melton comes from the two HQ XLR -> RCA outputs, so the Oppo player's different output levels (if they exist) had to be considered in the difference in volume levels. An external piece of equipment would not accomplish this.

[toddalin]

Hi Todd,

To get to the chase, what are you trying to demonstrate?


Widget

Many/most of the local members from AudioKarma who get together are into tube equipment and had been saying that I should try it so I bought the Melton. It's made overseas, but the distributor is local to me and I was able to pick it up and, if need be, have it serviced locally (2 year warrentee which is nice if you don't have to send something back to China to use it).

One of the AK members is on the fence and specifically asked that I play that Vanessa track on both pieces of equipment knowing that I had the ability to do it in a relatively fair manner.

I simply thought that others here may also be interested in the results as well as a demonstration as to the YouTube capability to distinguish sounds when everything else is held the same.

And, I thought it could generate some interest/hits and isn't that what hosting/having a website platform all about?

BTW, I calculate that the difference in voltage between the Yamaha and Melton was on the order of 0.02 volt and this equated to ~0.1 dBA differential. There is no way in Heil that one could set the Yamaha to a specific level and "twiddle" the analog Alps pot on the Melton to within 0.003 volt. Just the slightest touch of the Alps pot would be several tenths of a dB and it took me over an hour "just touching" the pot then checking the levels just to get them this close.

[rusty jefferson]

Many/most of the local members from AudioKarma who get together are into tube equipment and had been saying that I should try it so I bought the Melton....

....I simply thought that others here may also be interested in the results as well as a demonstration as to the YouTube capability to distinguish sounds when everything else is held the same....

I appreciate that and the demonstration. I just wasn't sure what you were demonstrating as there's so many variables.

As far as the capability of YouTube to distinguish differences in a demo like that, here's one I found interesting. Same source, amplification, speakers (2 pairs), cables, etc. but one pair of speakers have a high end footer added. Much like all the other YouTube videos, there's no way anyone could possibly tell if this system sounds good or not, but there's a clearly audible difference when they switch. Demonstration starts at the 1:00 mark.

https://youtu.be/wst_XwbwTqk

[Mr. Widget]

Many/most of the local members from AudioKarma who get together are into tube equipment and had been saying that I should try it so I bought the Melton. It's made overseas, but the distributor is local to me and I was able to pick it up and, if need be, have it serviced locally (2 year warrentee which is nice if you don't have to send something back to China to use it).

One of the AK members is on the fence and specifically asked that I play that Vanessa track on both pieces of equipment knowing that I had the ability to do it in a relatively fair manner.Thanks Todd for this detailed "backgrounder". Now I get it.

From my perspective I would put this amp in the same category as Lowther full range loudspeakers. There are many out there who get excited by certain sound qualities. Some want a pronounced midrange, others exaggerated bass, and others with rather unique choices. It would be interesting to audition this amp with a wide range ribbon speaker or any reasonably accurate design with very benign impedance/phase characteristics. Most home brew speakers can present a pretty difficult load and will generate unpredictable results with an amp like this. (This is what Rusty has been driving at and I hinted at in an earlier post.)

Based on this added info, I wouldn't want to deal with the unpredictable nature of this particular amp. FWIW: I find Yamahas to be a slightly on the hard side (not to be confused with the extreme frequency abborations demonstrated in your comparisons above) and their YPAO often sounds worse than no "correction". I have used CLIO and Studio Six Digital's LARSA to verify what YPAO is doing, and in many cases it wasn't beneficial. That said, we sell Yamahas every day. They are reliable well built units that will do the job as well or better than any other AVR.

In the case of this demo, I would agree with your choice of the Yamaha as your "laboratory standard" as it will provide a solid baseline for comparison purposes though it will digitize the signal, process it, and covert it back to analog... probably why I feel they sound hard.




And, I thought it could generate some interest/hits and isn't that what hosting/having a website platform all about?
Interesting notion. I think you are right for many.
Personally, if I can learn something new, or help someone avoid buying the "Emperors's new clothes", I think it is a good day.


Widget

[toddalin]

Thanks for the response.

Yes, there are many who consider the Yamahas to be bright and detailed as part of their "in-house signature."

But, in this case, the Oppo was fed to the "Pure Direct" input and all digital processing and lighting is turned off. The Oppo essentually goes from its analog outputs to the volume control, then the power amps. If the signal must be digitized to go through the volume control, I am not aware of it.

BTW, the YPAO does wonders for the L200/300s and I can't get nearly as good results by trying to use the onboard eq functions. It takes out the veil/depressions from the 2235 and crossover region and intelligability goes way up.

https://usa.yamaha.com/files/download/other_assets/9/319789/RXZ9_man.pdf

Would you like to hear the difference on a YouTube video? I can demonstate. ;)

[Mr. Widget]

Would you like to hear the difference on a YouTube video? I can demonstate. ;)Thanks for the generous offer... but I'll take a rain check.:D




But, in this case, the Oppo was fed to the "Pure Direct" input and all digital processing and lighting is turned off. The Oppo essentually goes from its analog outputs to the volume control, then the power amps. If the signal must be digitized to go through the volume control, I am not aware of it.
If you used a digital output from the Oppo, then you have eliminated one level of conversion, but if you go into the Yamaha on any of its analog inputs the AVR will convert it to digital (using Pure Direct bypasses the DSP and surround processing) before converting it back to analog.


Widget

[toddalin]

but if you go into the Yamaha on any of its analog inputs the AVR will convert it to digital (using Pure Direct bypasses the DSP and surround processing) before converting it back to analog.


Widget

In Pure Direct the analog input goes directly to the YAC520 chip volume control with 256 steps, then to the power amps. Everything else is turned off. The data sheets show the YAC520 takes analog input. Is there an internal digital conversion or is the digital portion just controlling the analog? From the descriptions, it would seem the latter.

https://datasheetspdf.com/pdf-file/623691/YAMAHACORPORATION/YAC520/1

https://cimg1.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/909x1098/80-screenhunter_391_jan_18_15_42_7b5a87e72aba2ee67358 16ae374001104b9b98f5.jpg

[Mr. Widget]

In Pure Direct the analog input goes directly to the YAC520 chip volume control with 256 steps, then to the power amps. Everything else is turned off. The data sheets show the YAC520 takes analog input. Is there an internal digital conversion or is the digital portion just controlling the analog? From the descriptions, it would seem the latter.
Talking to the Yamaha engineers, there is no way to avoid the A to D step. I have no idea why they chose to design their equipment this way… Maybe the volume controller only works in the digital domain? I don’t know. In any event, because of this we always use their digital inputs if at all possible.


Widget

[grumpy]

In the simplified block diagram for the receiver, it certainly appears that there's both a direct PCM mode (bypassing) DSP and necessarily using the PCM1792 DAC, and also a "Pure Direct" analog path through the volume control chip (digitally controlled, but appears to be analog in nature). Does seem like both paths go through the same volume control chip.

Whether the signal is typically less affected or 'sounds better' by bypassing a disc player's DAC and using the internal Yamaha DAC (Direct PCM mode), while it's within the confines of that Yamaha system is certainly up for debate, and I have no idea how 'simplified' the block diagram is. One would hope the Yamaha application engineers would have the best information available.

Might make for another interesting comparison/experiment. I would try both and just enjoy whatever sounded 'best' by whatever definition you choose, or if the same, whichever was more convenient. Enjoy! :)

[Ian Mackenzie]

Hi Todd,

Your having fun.

I think it’s reasonable to reason that differences can be detected on YouTube. Beyond that like everything in hifi, the subjectivity come down to the individual. It always has and always will.

Statistically a particular tube amp versus a receiver needs to be compared with a range of loudspeakers

Putting the tube amp aside, the receiver is not Lilly White. Under different load conditions what a multi channel receiver does as a 2 channel amplifier for hifi can vary just as a tube amplifier can. It all depends on the program material, the loudness and the particular loudspeaker load and efficiency presented to both amplifiers. It’s not rocket science. But what one Individual perceptions are compared with another will vary.

If l was going to do an objective test l would do a sine wave sweep over the full audio frequency range with different voltages and plot the voltage drive across the loudspeaker load. I would also measure and compare thd with REW of the audio output of the loudspeaker of the tests.

Without a doubt most tube amplifiers have a dominant 2nd order distortion content. Listeners perception vary but in general the 2nd order distortion will polarise the opinions of a group of listeners on perceived differences between SS and tube amplifiers. That is why there is a market for tube amplifiers. Not all tube amplifiers will exhibit a large 2nd order distortion but the majority do. Otherwise why manufacture a tube amplifier other thing the retro visual appearance which is very obvious on YouTube.

Depending on the amplifier the perceptions can range from perceived loudness to tonal differences across the audio frequency range.

This brings up another point. People listen with their eyes in an overwhelming bias towards how they make distinctions on sound differences. This is well founded statistically and is the reason for double blind tests. As YouTube is a visual media first and audible media you can draw all sorts of perceptions. No one is right or wrong ��. Amen.

I have personally used a Manley Stingray tube integrated amplifier and compared it with a pro solid state amplifier. On simple entertainment terms l preferred the Stingray. It had a boogie factor which is hard not to like.

Sometime later l used a Parasound hifi solid state power amplifier and my perceptions changed towards the Parasound by a clear margin.

How so? Like everything in audio and hifi not everything is created equal.
Would you detect the perceived differences on YouTube? As l said above that comes down to the individual. Enjoy.

[gasfan]

Hi Ian. I'm interested in your answer to your own question. "otherwise why manufacture a tube amplifier?" This comparison is clearly an apples and oranges one. On the one hand you've got an amp attempting to fool you into a real event and on the other bloom you can drift off to Timbuktu in. As you stated, not all tube amps have the "tubey" dominant 2nd order character. Some ss amps are manufactured to compete with that very 2nd order tube distortion. Whether it's tubes or ss, it's designed into the circuit. Why manufacture a tube amp that easily competes with a ss amp in transparency? Because it's easier and cheaper to do so. Some of those old console EL84/7189 amps are superb and as transparent as it gets. Even some old Fisher stand alones like the SA-100 for example. It would be interesting to see how the Fisher and the Yamaha compare in this test.