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

[DanielT]

Yes, the distortion is there but that what could be perceived as 'tube sound' (usually typical treble roll-off) might not be caused by the distortion components in the test files but the more obvious treble roll-off.
At least that's what seems to trigger most listeners, they mention the treble roll-off as indicator and not increased distortion.
So the increase in distortion effect might be 'masked' by the treble roll-off.

When there would be no roll-off and only the added harmonics and IM products (above all) there is a very big chance noone would be acing (the by danadam) level matched files, or at least not nearly as convincing and most people would state to hear no difference at all as the give-away (the treble roll-off) would not be there.

But a class D amplifier can also have non-pancake flat FR.PMA tends to get fired up by showing how small cheap class D amplifiers, depending on the load they are subjected to, can have fairly uneven FR.
Difference, and it can be big then, between tube amps and these small class D amps the word is cheap. Cheap is rarely something I associate with tube amps.

Pros to tube amp vs small class D amps are the looks.Ugly as beating these small cheap class D amps. That's a matter of taste, but still.

Speaking of treble roll-off and tube amps. A cheaper solution might then be a vintage transistor-based class AB amp with tone controls! For the treble tone control, they usually set it at 10 kH (if I remember correctly). You can probably read that in the technical manual, if you are lucky enough to have such information. Anyway, roll off and get a similar tube sound, or rather maybe mimic it a bit. When you get tired of coloring the sound, turn the tone control back to neutral.
Many vintage amps are also stylish, I think.If you don't need a lot of power, then a 30 WPC vintage amp (not a tube amp) doesn't cost a lot of money.

On the other hand, just as an example. A 25 WPC tube amp, price: $22,000

Produkter | Knispel Audio | Sverige

Erik Signature 70 - Integrated, transformer coupled, single ended amplifier with the russian GM70 directly heated triode. Built in Sweden by Knispel Audio.

www.knispelaudio.com

 

[solderdude]

When I have some time I will try to correct the tonal difference (increase treble acc to the measurements in this thread) and have a listen again to see if I can spot the differences as easily. That would make the tube vs original sound a lot more realistic (with the roll-off removed)
This thread is only about this particular load though.

 

[Sgt. Ear Ache]

has the actual identity of the various samples even been revealed yet?

 

[fpitas]

has the actual identity of the various samples even been revealed yet?

It almost doesn't matter. It's a fun test, but it will be heavily speaker dependent, this being a SET amp. So swap in another speaker and it's all different. That may suggest the old audiophile stuff about component matching being so important: sometimes it is.

 

[danadam]

has the actual identity of the various samples even been revealed yet?

The info on the poll says it will close on May the 4th (be with you). I guess it won't be before then.

 

[raindance]

By the way, to point out the (mostly) obvious, an SET-type amp will behave very differently into a more complex/difficult load, like a real speaker. This is possibly where the SET "magic" occurs

Exactly. The highish output impedance into a complex load coupled with minimal negative feedback gives the "300B EQ curve"...

 

[atmasphere]

Yes, the distortion is there but that what could be perceived as 'tube sound' (usually typical treble roll-off

Tube amps typically don't have an audible high frequency rolloff! If you put them on the bench and actually measure them you will see this is so. The typical weakness of a tube amplifier, in particular an SET, is bass response, not high frequencies.

There is a different reason that they don't seem to have as much high frequency energy. To understand this, its helpful to understand what Gain Bandwidth Product is, and how that's important when dealing with an amplifier using feedback.

SETs typically have no feedback. So when you graph distortion vs frequency, you get a flat line across the audio band. This is not the case with most amps using feedback, since they typically lack the GBP to support the feedback across the audio band. THD figures often sweep this problem under the carpet; when the distortion rises with frequency its doing so on a slope, which can mean that distortion is considerably higher at higher frequencies then the THD suggests.

A self oscillating class D amp, and a few AB designs available now, can get you that nice flat DvsF line across the audio band, since they have enough GBP to do the job.

So the increase in distortion effect might be 'masked' by the treble roll-off.

So this supposition is incorrect, unless the load in the highs for the SET is lower in impedance than it is in the midrange.

 

[krabapple]

Once the fine sound of a good 300B amplifier is put through the digital mill, it is ruined.

That is utterly unscientific nonsense.

 

[krabapple]

It’s both. It’s not a dichotomy.

Don't try to do both at once.

 

[krabapple]

um, I wonder if people realize the drum intro (and much of the rest of the drums, and all keyboards) on 'Owner of a Lonely Heart' are...samples? Digital samples? Quite early digital, at that?

 

[computer-audiophile]

That is utterly unscientific nonsense.

Haha, please don't be so unkind.
The way the test was set up here is also unscientific.

 

[krabapple]

Indeed. I'm not really seeing the point.

 

[Purité Audio]

Once the fine sound of a good 300B amplifier is put through the digital mill, it is ruined.

Once any fine sound is put through a 300B it is ruined.
Keith

 

[GXAlan]

The issue being does the publication of even small pieces of copyrighted works on a site like ASR for the purposes of testing, constitute education or entertainment? ASR is primarily a publication site for reviews and a large discussion forum.

US law is intentionally vague but at least in this context, it is clearly scholarly activity within the context of blind testing, data collection, discussion. The fact that it is enjoyable to post/comment/discuss on ASR doesn't change the fair use. That is, the enjoyment is in the discussion part -- not the musical content. The greatest "risk" is with the opening of "owner of a lonely heart" since it's such an iconic *part* of the track but no lawyer has complained to me yet.

has the actual identity of the various samples even been revealed yet?

I was going to do this on May 2 for this thread when the poll ends. I will PM you with the actual identity.

 

[fpitas]

Once any fine sound is put through a 300B it is ruined.
Keith

Please. It gets smoothed over and richened like the aroma of a vintage wine

 

[Purité Audio]

After hours at one Munich show, the ‘source’ contributor ( rooms are so expensive it makes sense to split the cost) set up his own prototype amp, it literally blew our socks after the dull turgid sound we had endured until then from the boutique/kitchen table manufacturer.
Looking back I guess it was just a properly designed amp that could really drive the speakers properly.
Keith

 

[RDoc]

I tried this test with a good pair of earphones and made my choices of which I liked best. However, then I started wondering if I actually could tell the difference or if it was just self deception so I loaded Lacinato's ABX tester (which is great!) and tried again.
What I found was that my original ranking remained, particularly if I just chose a short segment and kept running shootouts over the same segment. Using the same segment, I was quite consistent, about 85%. With different segments each time it was about 70%. Now I'm very curious to see if I actually like the tube sound.
However, I was quite surprised at how similar the two versions sounded considering the seemingly huge difference in SINAD rankings. It does make me wonder about the claims of being able to clearly hear the difference between an amp with a SINAD at -76 and one at -86.

 

[fpitas]

I tried this test with a good pair of earphones and made my choices of which I liked best. However, then I started wondering if I actually could tell the difference or if it was just self deception so I loaded Lacinato's ABX tester (which is great!) and tried again.
What I found was that my original ranking remained, particularly if I just chose a short segment and kept running shootouts over the same segment. Using the same segment, I was quite consistent, about 85%. With different segments each time it was about 70%. Now I'm very curious to see if I actually like the tube sound.
However, I was quite surprised at how similar the two versions sounded considering the seemingly huge difference in SINAD rankings. It does make me wonder about the claims of being able to clearly hear the difference between an amp with a SINAD at -76 and one at -86.

The vast majority of humans don't hear that well, so you should wonder.

 

[computer-audiophile]

After hours at one Munich show, the ‘source’ contributor ( rooms are so expensive it makes sense to split the cost) set up his own prototype amp, it literally blew our socks after the dull turgid sound we had endured until then from the boutique/kitchen table manufacturer.
Looking back I guess it was just a properly designed amp that could really drive the speakers properly.
Keith

Excuse me, but what does this nice story have to do with the thread here? I don't understand the context.

 

[Purité Audio]

Only that valve amps can sound really good, just like solid state in fact.
Keith