Take the blind challenge! 300B SET vs. Straight Wire with Gain

[Axo1989]

Total votes: 14.

How disappointing. Objectivists love to demand blind tests. So it seems, only if other people are performing it. And then nitpick other people's blind tests to death. When it comes to doing it yourself, you are too lazy to participate. What about getting off your behinds and participating? Are so many here really only armchair objectivists?

I don't think it's a revelation to consider that there are more than a few faux-objectivists enjoying the forum for the peer-group validation, rather than for the intellectual curiosity. That said, I appreciated the opportunity to experience a taste of the SET tube sound.

 

[Deleted member 48726]

I then switched out the speakers for a E1DA Cosmos ADC with a resistive load and recorded

Hmm. Is the resistive load replacing the speakers and we are supposed to assess the performance and amplifier differences on a load that isn't representative of a real load?

Might as well compare measurements between the two.

 

[GXAlan]

Hmm. Is the resistive load replacing the speakers and we are supposed to assess the performance and amplifier differences on a load that isn't representative of a real load?

Might as well compare measurements between the two.

Pretend I have a neodymium magnet based planar magnetic speaker that is efficient enough to listen to at 1W.

We certainly assess the performance of every other amplifier tested here based upon resistive loads.

The resistive load will put the tube amp in a better position than it probably achieves in real world. You can think of this like using a tube buffer if you need to.

 

[Deleted member 48726]

Pretend I have a neodymium magnet based planar magnetic speaker that is efficient enough to listen to at 1W.

We certainly assess the performance of every other amplifier tested here based upon resistive loads.

The resistive load will put the tube amp in a better position than it probably achieves in real world. You can think of this like using a tube buffer if you need to.

Because it's the standard method of measuring amplifiers doesn't make it correct and it will behave differently with real loads.

 

[GXAlan]

Because it's the standard method of measuring amplifiers doesn't make it correct and it will behave differently with real loads.

Preaching to the choir.

My amplifier review is coming. This is just the first part.

 

[Blumlein 88]

I am also surprised at how few people are trying these 10-15 second comparisons. I have no way to know how many times the files have been downloaded, but I suspect a good number of people don’t have confidence in their answers and so they don’t want to say that they are not confident.

To all, vote honestly and you can tell everyone else you were right when the results come out or pretend you didn’t vote at all. No one but you will know how you voted unless you volunteer that info.

I've put up things like this going back at least a decade. You never get large numbers of votes. Remove the labels and audiophiles suddenly become very timid when the wife does not tell them which is better from the kitchen.

So don't worry. And I do appreciate the trouble it is to do something like this. And don't worry too much about criticism as you always get that (and yeah i criticized a little bit). Sometimes you do learn how to do it better from the critiques.

At one time I've made things like this available and tracked them. Many get over 1000 downloads and I don't think many reached 20 votes.

Though not so much on this forum, in others you get very little response until you post the answers. Then sometimes lots of responses about what sounds different. You'd think they would realize how ridiculous that is. Especially as the argument about your files being no good or deceptive or made to create no difference gets tossed back and forth at least ten times as much as responses prior to revealing the answers. Over the years it has simply reinforced my opinion that most "ears only audiophiles" are about the eyes.

 

[dualazmak]

Even though I still not yet did my comparative listening, but please find other comparative views of MusicScope 2.1.0 as follows. ___I am very much interested in my subjective comparative listening using my DSP-based multichannel multi-SP-driver multi-amplifier audio setup (please refer to here #540, here #643, and here #688) to be done this weekend.

 

[GXAlan]

@Holdt @Axo1989 @pkane @computer-audiophile @amirm

Resistor vs. Speaker

Spoiler: For those who have already taken the test

Ignore the SPL numbers in the legend for all of these. You just want to look at the "shape of the curve".

I have recorded these using a resistor. Take a look at these REW sweeps at different dBFS. Except for the power supply noise getting into the 60/120Hz range, you don't worry too much. It looks similar.

Now look at the JBL XPL90 which has been measured here and look at the different results depending on the dBFS sweep. Again, ignore SPL -- I just ran the sweep and kept telling it to go -10 dBFS each time.

Note that the 300B does the opposite of a loudness curve. You get extra treble boost with higher energy, but at low volume, the treble increase is lower. This is all from a ton of distortion that's happening. There is even a bass boost at lower volumes. ALL distortion. But at least amongst 300B fans, the right "pattern/character/flavor" of distortion.

Now we're starting to see the effect of the SET and its role as an effects box. You cannot turn it on or off, but a simple Parametric EQ isn't going to let you replicate the "tube sound". You can pick one treble boost for the entire song, not a dynamic one that depends on the content.

We know the "showroom sound" can be fun for short periods of time, but the boost can be fatiguing. But you have to think about this in musical content. The showroom sound comes only on demand during transients! So imagine having an effects box where the effect is subdued in the normal parts and during transients, it jumps up even more.

This is also the challenge of recording the SET. You not only have to think about the actual speaker but all the volume it's running at.

Take a look at the slope of those REW sweeps. We start to see the rise at 3 kHz, right? Lets see what @amirm measured on the XPL90.

Do you see something at 3 kHz also? I don't know why we don't see as big of an effect in the bass, but remember that I'm not using a simulated speaker, I'm literally playing back through a speaker so maybe back EMF plays a role, since damping factor for SET is really low.

What's really neat is that if I take a few different 2-way speakers that I own, and eyeball-match to 1 kHz the SPL, we see that the relative to the resistor, you get a pretty consistent bass boost which is almost always snazzy while the treble gain differs between different speakers, but really does counteract the "rolled-off" highs that measurements can. I ran these off the 4 ohm tap, though they are all 6 ohm nominal.

 

[dualazmak]

Since my Adobe Audition 3.0.1 does not accept flac files, I converted them into aiff using dBpoweramp Music Converter 17.3 (64-bit), then analyzed their color spectrum.
As you can find, the x-axis time scale was synchronized using the yellow vertical marker line.

 

[Thomas_A]

My take: the tracks are certainly different in terms of audibility. I focused on the high frequencies and nailed all combinations there. For distortion, I would probably need other tracks or parts of the current track but I cannot be sure. The B track was harder than the other two but the C track was quite easy with respect to dynamics as well.

 

[Axo1989]

I've put up things like this going back at least a decade. You never get large numbers of votes. Remove the labels and audiophiles suddenly become very timid when the wife does not tell them which is better from the kitchen.

This one is hard for poseurs at both ends of the spectrum. The likely measurements of the SET amp are truly appalling for Sinad-inistas, so not differentiating successfully risks rendering oneself apostate. For the solipsists, similar failure undermines the very sensibility of the self. It's all a bit chickensh*t.

I tried again with a little added anolog-ality: wired headphones this time, and moar taps—Sony Z1R from Chord Mojo from iMac ...

Spoiler: no peeking

... again I heard obvious hum on track 3 but had previously expressed no preference between that pair. This time I reckon there's a bit of haze on the bass too, so I've revised my vote to include preference for track 1, which sounds clearer there. I've also warmed a bit to the content, which helps.

Comparing tracks 2 and 5, both sound nicer, it's harder to choose. I'm not noticing things I thought I heard via AirPods Max as easily. Turned them up a bit more to get the hum back on track 2. But both tracks sound 'more analog'. You lot that listen to acoustic instruments and unprocessed vocals just make life hard for yourselves.

Comparing tracks 4 and 6, same. Ok, the Sonys sound nicer again (listening to these brief snatches of relatively MoR sounds, fatigue doesn't set in) but 4 is still a bit flat/muffled (dynamically and tonally). I found the content even more irritating on this listening, had to back off the volume to keep things tolerable, which made comparative listening tougher.

So nothing new to change preferences for the second and third pair, but I may not have differentiated if I'd just used this reproduction chain.

 

[Sokel]

This one is hard for poseurs at both ends of the spectrum. The likely measurements of the SET amp are truly appalling for Sinad-inistas, so not differentiating successfully risks rendering oneself apostate. For the solipsists, similar failure undermines the very sensibility of the self. It's all a bit chickensh*t.

There should be a disclaimer that this will not go down to our permanent record
Come on people,it's a A-B,that should be next to the gospel in a forum like this,70 replies and 15 voters is embarrassing!

Folks should make that counter spin faster than the old cassette counters.
And it's fun,there's no right and wrong in preference!

 

[computer-audiophile]

SETs sound their best driving easy loads, not difficult loads! One thing to keep in mind is that the tech is so old that the voltage rules most people take for granted had not been adopted. They use 'power rules' instead. Back in the old days, speakers with weird phase angles didn't exist!

Good point.

A 300B amp, for example, can only show its performance well when you have the right speaker for it. These are not so easy to find on the market today. And you have to try it because interaction is so complex that the result cannot be predicted well. It has to be heard. I have also had some unfortunate combinations.

What about getting off your behinds and participating? Are so many here really only armchair objectivists?

I like to do listening comparisons, but not like this.

In the past, I have taken part in shoot-outs live where, for example, 300B SET amps with different circuits were A/B/C... examined, or test amps with different OPT were compared etc.. I find that better. Not least I have a rough idea of the quality of the Raphaelite 300B amplifier of the OP, because an acquaintance had exactly that - for a short time.

 

[Axo1989]

@Holdt @Axo1989 @pkane @computer-audiophile @amirm

Resistor vs. Speaker

Spoiler: For those who have already taken the test

Ignore the SPL numbers in the legend for all of these. You just want to look at the "shape of the curve".

I have recorded these using a resistor. Take a look at these REW sweeps at different dBFS. Except for the power supply noise getting into the 60/120Hz range, you don't worry too much. It looks similar.
View attachment 280586

Now look at the JBL XPL90 which has been measured here and look at the different results depending on the dBFS sweep. Again, ignore SPL -- I just ran the sweep and kept telling it to go -10 dBFS each time.

View attachment 280587

Note that the 300B does the opposite of a loudness curve. You get extra treble boost with higher energy, but at low volume, the treble increase is lower. This is all from a ton of distortion that's happening. There is even a bass boost at lower volumes. ALL distortion. But at least amongst 300B fans, the right "pattern/character/flavor" of distortion.

Now we're starting to see the effect of the SET and its role as an effects box. You cannot turn it on or off, but a simple Parametric EQ isn't going to let you replicate the "tube sound". You can pick one treble boost for the entire song, not a dynamic one that depends on the content.

We know the "showroom sound" can be fun for short periods of time, but the boost can be fatiguing. But you have to think about this in musical content. The showroom sound comes only on demand during transients! So imagine having an effects box where the effect is subdued in the normal parts and during transients, it jumps up even more.

This is also the challenge of recording the SET. You not only have to think about the actual speaker but all the volume it's running at.

Take a look at the slope of those REW sweeps. We start to see the rise at 3 kHz, right? Lets see what @amirm measured on the XPL90.

Do you see something at 3 kHz also? I don't know why we don't see as big of an effect in the bass, but remember that I'm not using a simulated speaker, I'm literally playing back through a speaker so maybe back EMF plays a role, since damping factor for SET is really low.

What's really neat is that if I take a few different 2-way speakers that I own, and eyeball-match to 1 kHz the SPL, we see that the relative to the resistor, you get a pretty consistent bass boost which is almost always snazzy while the treble gain differs between different speakers, but really does counteract the "rolled-off" highs that measurements can. I ran these off the 4 ohm tap, though they are all 6 ohm nominal.

View attachment 280588

I've always thought it at least potentially interesting to consider the dynamic behaviour of the amp-cable-speaker system (the amp-cable-speaker-rooom system, strictly speaking). This extra peaky treble peaks thing is fun to look at. I have no other experience with this type of gear though.

 

[Sgt. Ear Ache]

It’s both. It’s not a dichotomy.

In one of the music comparisons, the winning result is “I don’t hear a difference.” So you cannot presume that these are different sounding simply because I have stated that they are vastly different measuring.

Using you as an example. If you believe that these are different sounding and you believe that you do not prefer fixed sound effects, are you able to pick out the cleaner track each time? Grading the difference of the worse performer, would you grade the difference small, medium, or large? When the measurements come out, you can compare to your expectations.

Using me as an example, if the recordings are inadequately good to detect differences, or they have systematic bias (like one being louder), does everyone pick the louder track as their favorite?

These are all ways we can be better, scientific audiophiles. We can are learn from shared experiments and challenge our preconceived notions whether a subjective or objectivist.

If I can hear the differences and I prefer the tube sound, it doesn't matter to me, because I still don't want an amp that applies it's own special sauce to the equation - even if that special sauce might seem to improve the sound in some way. I don't "believe" that I do not prefer fixed sound effects...I just don't want a fixed sound effects box as an amp. Otoh, even If I can't hear any difference between one amp that measures transparent, and another one that measures "vastly differently," I still want the amp that measures transparent. That's the nice thing about measurements...they bring clarity even when our ears mislead or fail us.

I may go through the process and take the test just to play along but I don't see what the point of it is frankly.

 

[Sgt. Ear Ache]

This one is hard for poseurs at both ends of the spectrum. The likely measurements of the SET amp are truly appalling for Sinad-inistas, so not differentiating successfully risks rendering oneself apostate. For the solipsists, similar failure undermines the very sensibility of the self. It's all a bit chickensh*t.

Except that most of us objectivists don't worship at the SINAD alter like the subjectivists want to believe. We know we likely can't hear the difference between 90 and 110db SINAD. We just figure all things being equal we might as well get the 110db SINAD amp if we have the option.

 

[Sokel]

If I can hear the differences and I prefer the tube sound, it doesn't matter to me, because I still don't want an amp that applies it's own special sauce to the equation - even if that special sauce might seem to improve the sound in some way. I don't "believe" that I do not prefer fixed sound effects...I just don't want a fixed sound effects box as an amp. Otoh, even If I can't hear any difference between one amp that measures transparent, and another one that measures "vastly differently," I still want the amp that measures transparent. That's the nice thing about measurements...they bring clarity even when our ears mislead or fail us.

I may go through the process and take the test just to play along but I don't see what the point of it is frankly.

There is one point that could be made.
If two so vastly different amps makes such a small difference is pointless for example to spend $$$ if you already have an adequate amp just to know that is somehow more transparent.
Saves money and trouble!

 

[Sgt. Ear Ache]

There is one point that could be made.
If two so vastly different amps makes such a small difference is pointless for example to spend $$$ if you already have an adequate amp just to know that is somehow more transparent.
Saves money and trouble!

Absolutely. If you read around the forum here, in instances where people ask about improving the sound of their system...it's pretty rare that anyone says "you need to upgrade that amp." And if that is the recommendation it's either due to not enough raw power, or it's a subjective audiophile recommending some other amp on the basis that it sounds better. The common response from most of us is "you likely won't hear any difference with a different amp." In fact, that's kind of WHY we value measurements - because we realize our ears can't actually do what the subjectivie audiophiles think they can.

But, seeking an amp that is measurably transparent is to me a far more rational way to go about things than to subjectively listen to a bunch of different amps and just pick the one you think sounds the best.

 

[charleski]

which means that a very low SINAD and very high SINAD is not nearly as different as we think, if the low SINAD measurement is from a 300B.

Well there's been a fair amount of prominence given here to various distortion tests that are available (like Klippel), and they all end up showing that we're really pretty poor at hearing distortion. So the fact is that anyone who's been paying attention doesn't think there's much difference between high and low SINAD to begin with, and it doesn't matter what's causing it. I'd still prefer a cheap amp that does well on the test bench over an expensive amp that does poorly, even if I can't really hear the difference.
I couldn't hear any difference between these examples.

 

[Sgt. Ear Ache]

The SINAD strawman just keeps rearing it's silly head. Subjectivists can't seem to get past that number! lol...Guys, we aren't chasing SINAD because we think we have to have 121db of SINAD for our system to sound good. We "chase" SINAD bacause it's a measured sign of good engineering, it can be acquired extremely inexpensively, and it's at least something we can use to differenitate products that all sound the same!