Hi, I have the Goldenear Triton Ones along with a Marantz 8802a preamp. My current amp quit working

[Irvrobinson]

Right.

"Like to see" is not the same as "critical measurement parameter".

The type of music that you listen to is completely irrelevant to your argument. We are discussiing inherent amplifier parameters.

The fact is that the amp building experts educate us on the fact that the SNR is not a critical parameter for an AMP. On the other hand, SNR is THE critial parameter for a PRE-AMP.

When I get a chance, I will find the citation in the literature and post it here.

I do completely agree with you on your 80db SNR, that is likely the minimum number that I "would consider for my amp" too.

How many amps have you built and measured?

You're going to get snippy with me? How quaint.

In my youth I was fascinated by headphone amps, and designed and built a few, but I quickly came to the conclusion that really good low-noise electronics needed circuit boards, not point-to-point wiring, and I lost interest.

I happen to think that low noise is a general measure of circuit design and layout quality, so I pay a lot of attention to it. As for the type of music being irrelevant, I disagree. For quiet portions of classical music (which are often played by strings), with moderately efficient speakers the amplifier output may be only a tenth of a watt or so. If you're playing rap, somewhat more. Noise in circuits is mostly a constant voltage, so noise relative to output is a factor, IMO. I don't really care what some book says.

 

[Irvrobinson]

Well, it is tough to argue against that!

I'll have to brush up on it, perhaps I was thinking the "weighted" SNR should be 80dB or better?

Maybe, but Andy is making my point for me. There's essentially no difference in measured values between 78db and 80db. I've noticed over the years that Atkinson's measured SNRs tend to be lower than other testers get.

 

[Irvrobinson]

I don't know....

According to Stereophile, most amps have a WIDE-BAND Unweighted SNR of less than 80dB!

$99,000/pair Boulder monoblock - "The 2150 was extremely quiet—its unweighted, wideband signal/noise ratio with the input shorted to ground measured 78.5dB ref. 2.83V into 8 ohms."

Read more at https://www.stereophile.com/content/boulder-amplifiers-2150-monoblock-power-amplifier-measurements#wOqHqK6YqRuPTi3V.99

$55,000/pair Dan D'Agostino monoblock - "The unweighted, wideband signal/noise ratio, ref. 2.83V into 8 ohms and taken with the input shorted, was a good 77.2dB."

https://www.stereophile.com/content/dan-dagostino-momentum-monoblock-power-amplifier-measurements

$50,000 Mark Levinson monoblock - "The No.53's unweighted, wideband signal/noise ratio, ref. 1W into 8 ohms with the input shorted, was therefore still lower than usual, at just 52.1dB."

Read more at https://www.stereophile.com/content/mark-levinson-no53-reference-monoblock-power-amplifier-measurements#7c2wKuYjVc5ogkov.99

$30,000/pair Mark Levinson - "With the input shorted to ground, the Mark Levinson No.536 amplifier offered a wideband, unweighted signal/noise ratio of 71dB, ref. 1W into 8 ohms."

Read more at https://www.stereophile.com/content/mark-levinson-no536-monoblock-power-amplifier-measurements#k756T9cJJ6iexOcq.99

$30,000/pair AVM Ovation monoblock - "The wideband signal/noise ratio ref. 1W into 8 ohms, taken with the input shorted to ground, was okay, at 74.6dB".

Read more at https://www.stereophile.com/content/avm-ovation-ma82-monoblock-power-amplifier-measurements#SS1YtmDzy1iRCiiQ.99

$22,500/pair Krell 575 monoblock - "Measured with the balanced input shorted to ground, the unweighted, wideband signal/noise ratio was very good, at 78.2dB ref. 2.83V into 8 ohms."

Read more at https://www.stereophile.com/content/krell-solo-575-monoblock-power-amplifier-measurements#MvyPo05ozJ3q5SkR.99

$14,000/pair Classe monoblocks - "The Classé CT-M600 is among the quietest amplifiers I have measured. Its wideband, unweighted signal/noise ratio (with the input shorted and ref. 1W into 8 ohms) was a superb 79.6dB."

Read more at https://www.stereophile.com/content/measurements#KhP0sIrfqVXVE6zE.99


$12,000/pair Theta Digital Prometheus monoblock - "the unweighted, wideband signal/noise ratio, ref. 2.83V into 8 ohms, was 76.3dB"

Read more at https://www.stereophile.com/content/theta-digital-prometheus-monoblock-power-amplifier-measurements#YvA30QF7EtsI8W1u.99

$12,000/pair Bryston monoblock - "The 7B SST2 is a quiet amplifier. Its unweighted signal/noise ratio (ref. 1W into 8 ohms) measured 75.6dB"

Read more at https://www.stereophile.com/content/bryston-7b-sstsup2sup-monoblock-power-amplifier-measurements#W2ckQg26tWeiXDml.99

$11,000/pair Pass Labs XA60.5 monoblock - "The unweighted, wideband signal/noise ratio, ref. 1W into 8 ohms and taken with the input shorted to ground, was a good 79dB."

Read more at https://www.stereophile.com/content/pass-labs-xa605-monoblock-power-amplifier-measurements#3GzBW1uS0hLJdEfZ.99

$7,000/pair Anthem M1 monoblock- "Without the AP filter, the Anthem's wideband, unweighted signal/noise ratio, ref. 2.83V into 8 ohms with the input shorted, was miserable: 10.4dB".

Read more at https://www.stereophile.com/content/anthem-statement-m1-monoblock-power-amplifier-measurements#hsHUhtIETyDHs1kV.99

Andy, your posts, with all of their emotion, capitals, colors, and exclamation points have become obnoxious, but thanks for making my point for me that 80db SNRs are about SOTA.

 

[PENG]

Well, it is tough to argue against that!

I'll have to brush up on it, perhaps I was thinking the "weighted" SNR should be 80dB or better?

Even then there is still the issue of testing at 1W vs rated output, wide band vs audio band etc. S&V seems to measured it in the audio band, with A weighting but I only recall seeing the reference to @1W into an 8 ohm load once, may be twice.

 

[PENG]

Andy, your posts, with all of their emotion, capitals, colors, and exclamation points have become obnoxious, but thanks for making my point for me that 80db SNRs are about SOTA.

He measured SNRs in wide band but also provided much higher numbers for the audio band, using 22 to 22KHz. If you read the full review you will see that those numbers increased a lot when tested in the audio band.

 

[Irvrobinson]

He measured SNRs is wide band but also provided much higher numbers for the audio band, using 22 to 22KHz. If you read the full review you will see that those numbers increased a lot when tested in the audio band.

I usually read JA's measurement sections. (The subjective portions of the reviews don't impress me much.) I think they're the most consistent source of measurements available. It's a little unfortunate that he only measures high-end equipment, but I understand that's his business model.

 

[slipperybidness]

You're going to get snippy with me? How quaint.

In my youth I was fascinated by headphone amps, and designed and built a few, but I quickly came to the conclusion that really good low-noise electronics needed circuit boards, not point-to-point wiring, and I lost interest.

I happen to think that low noise is a general measure of circuit design and layout quality, so I pay a lot of attention to it. As for the type of music being irrelevant, I disagree. For quiet portions of classical music (which are often played by strings), with moderately efficient speakers the amplifier output may be only a tenth of a watt or so. If you're playing rap, somewhat more. Noise in circuits is mostly a constant voltage, so noise relative to output is a factor, IMO. I don't really care what some book says.

Oh yes, PCBs are by far the better way to go vs. pt to pt wiring. Furthermore, ICs have better specs than ptp as well, no argument there. There is no reason that you cannot design and etch you own PCBs! Or send an Eagle file out to a vendor to get a few PCBs produced, it is pretty dang cheap nowadays (out of China, of course).

Yeah, circuit layout and proper grounding/grounding planes are absolutely critical to obtaining a low-noise, world-class amp! Again, we agree there.

The disagreement comes back to the SNR. SNR is not a critical parameter for amp performance. The critical parameter for amp performance for noise is tied up in the THD+N spec.

FWIW, I have 2 different rigs where I can feed it no input signal, turn all my gains to the maximum levels, put my ear right on the tweet, and hear.....absolute silence! That is ALWAYS my goal when noise or SNR is concerned. That is the metric that I go by. I can't always achieve that, it is a lofty goal for sure, but I have achieved it several times.

EDIT: I will add, before I read up on the topic, I would have been on your side of the argument, and I would have argued until I was blue in the face that the SNR is a critical parameter for an AMP. Well, I read up on the info from respected experts in the field, and therefore changed my viewpoint due to the info that the experts provided.

"Being right" isn't always the best approach, no?

 

[AcuDefTechGuy]

He measured SNRs in wide band but also provided much higher numbers for the audio band, using 22 to 22KHz. If you read the full review you will see that those numbers increased a lot when tested in the audio band.

Bottom line, do you think any of these SNR (weighted or unweighted, audio-band or wide-band) are audible from our listening distance of at 8-17FT away?

It it nice to have really great measurements. The $2.5K Bel Canto has an unweighted wide-band 1w SNR of 110dB, which I believe is the best SNR I have ever seen. But it's really just academic, isn't it?

https://www.stereophile.com/content/bel-canto-eone-ref600m-power-amplifier-measurements

https://www.amazon.com/Bel-Canto-Monoblock-Amplifier-Faceplate/dp/B01N2TXL1R/ref=sr_1_1?ie=UTF8&qid=1505845607&sr=8-1&keywords=Bel+Canto+600

 

[AcuDefTechGuy]

S&V seems to measured it in the audio band...

Monoprice amp - The signal-to-noise ratio with an 8-ohm load from 10 Hz to 24 kHz with “A” weighting was –119.10 dBrA.—MJP

Read more at https://www.soundandvision.com/content/monoprice-monolith-7-amplifier-review-test-bench#LmPBI5QqidLMMmAA.99

ATI amp - The signal-to-noise ratio with an 8-ohm load from 10 Hz to 24 kHz with “A” weighting was –122.05 dBrA using the RCA input and –122.51 dBrA using the XLR input.—MJP

Read more at https://www.soundandvision.com/content/ati-at6005-amplifier-test-bench#TIJ15Reg4jSVTFvC.99

Krell amp - The signal-to-noise ratio with an 8-ohm load from 10 Hz to 24 kHz with “A” weighting was –106.12 dBrA using the RCA input and –106.21 using the XLR input.—MJP

Read more at https://www.soundandvision.com/content/krell-chorus-7200-amplifier-test-bench#ETjKyZdMD9zipc47.99

Bryston amp - The signal-to-noise ratio with an 8-ohm load from 10 Hz to 24 kHz with “A” weighting was –105.13 dBrA using the RCA input and –111.10 using the XLR input.—MJP

Read more at https://www.soundandvision.com/content/bryston-sp3-surround-processor-and-9b-sstsup2-amplifier-ht-labs-measures#rRkJHqFOf3CphYPe.99

Parasound Halo amp - The signal-to-noise ratio with an 8-ohm load from 10 Hz to 24 kHz with “A” weighting was –99.03 dBrA using the RCA input and –99.30 using the XLR input. —MJP

Read more at https://www.soundandvision.com/content/parasound-halo-p-7-multichannel-preamplifier-51-multichannel-amplifier-amp-jc-1-single-chan-2#p0iqBAGhhImFL5dr.99

McIntosh amp - The signal-to-noise ratio with an 8-ohm load from 10 hertz to 24 kHz with “A” weighting was –106.90 dBrA. —MJP

Read more at https://www.soundandvision.com/content/dreaming-not-impossible-dream-ht-labs-measures#hDmFxuBR1eHavljK.99

Isn't 10Hz-24kHz wide-band?

 

[Irvrobinson]

Isn't 10Hz-24kHz wide-band?

No. Some amps have some significant noise above 20KHz, which is why a low-pass is applied, in an attempt to produce a higher figure of merit.

 

[Irvrobinson]

Oh yes, PCBs are by far the better way to go vs. pt to pt wiring. Furthermore, ICs have better specs than ptp as well, no argument there. There is no reason that you cannot design and etch you own PCBs! Or send an Eagle file out to a vendor to get a few PCBs produced, it is pretty dang cheap nowadays (out of China, of course).

I know, but when I was doing most of the headphone amp design work in the late 1970s, Eagle hadn't been invented yet. You could still get custom PCBs made, but they weren't cheap or quick.

 

[slipperybidness]

I know, but when I was doing most of the headphone amp design work in the late 1970s, Eagle hadn't been invented yet. You could still get custom PCBs made, but they weren't cheap or quick.

Ok, I had a chance to flip through my books a little and I will paraphrase from "Designing Audio Power Amplifiers" by Bob Cordell. For what it's worth, we used a few chapters out of this book for my Solid State class at the local CC.

He says that SNR for amps is "less critical" than SNR for pre-amps. But it is "still important" because amps don't have associated volume knobs to lower the noise from the input stage (that may be debateable depending on amp). Furthermore, amp SNR becomes more important if you have high-efficiency speakers!

So, the ultimate effects of SNR to what we hear is tied more to the speakers, not the source material.

I think that is all reasonable and we can agree on this, right? I may have exaggerated a little on my original post about amp SNR since I was going by memory.

Another interesting point, both Cordell and Slone say "-80dB was considered good 10 to 20 years ago, but today we can achieve -90dB to -110dB"! Unweighted SNR here.

Of course we are talking in the DIY realm where u can make fewer compromises.

For reference, Cordell says that -90dB is quieter than your own breathing noise.

 

[Irvrobinson]

Ok, I had a chance to flip through my books a little and I will paraphrase from "Designing Audio Power Amplifiers" by Bob Cordell. For what it's worth, we used a few chapters out of this book for my Solid State class at the local CC.

He says that SNR for amps is "less critical" than SNR for pre-amps. But it is "still important" because amps don't have associated volume knobs to lower the noise from the input stage (that may be debateable depending on amp). Furthermore, amp SNR becomes more important if you have high-efficiency speakers!

So, the ultimate effects of SNR to what we hear is tied more to the speakers, not the source material.

No, both speakers and the source material are factors in my opinion, though I agree that very high sensitivity speakers can be a greater factor, but arguably a more rare one. The large majority of people do not use very sensitive speakers.

I think that is all reasonable and we can agree on this, right? I may have exaggerated a little on my original post about amp SNR since I was going by memory.

Another interesting point, both Cordell and Slone say "-80dB was considered good 10 to 20 years ago, but today we can achieve -90dB to -110dB"! Unweighted SNR here.

I suspect Cordell and Sloan are referring to SNR measured at rated power, not one watt.

course we are talking in the DIY realm where u can make fewer compromises.

I'm not so sure about that. Production designs can often eliminate flying wires altogether.

reference, Cordell says that -90dB is quieter than your own breathing noise.

Yes, and noise that's 80db down is probably inaudible too. -60db? I'm not so sure. The objective is to make sure noise is inaudible, with headroom for error.

 

[AcuDefTechGuy]

Unfortunately as we all know, there is not a single standard or definition for SNR.

Looking at some of the same SNR I linked earlier, as PENG stated, if we look at the "Audio Band" 22Hz-22kHz, then it seems the unweighted SNR goes from the 70's to the 90's. If this is the "standard" that we are all referring to, then I think we can agree that 80dB SNR Unweighted is a good minimum.

This means the $7,000/pair Anthem M1 is one pathetic amp because the 22Hz-22kHz Unweighted SNR is only 75dB.

 

[PENG]

Unfortunately as we all know, there is not a single standard or definition for SNR.

Looking at some of the same SNR I linked earlier, as PENG stated, if we look at the "Audio Band" 22Hz-22kHz, then it seems the unweighted SNR goes from the 70's to the 90's. If this is the "standard" that we are all referring to, then I think we can agree that 80dB SNR Unweighted is a good minimum.

This means the $7,000/pair Anthem M1 is one pathetic amp because the 22Hz-22kHz Unweighted SNR is only 75dB.

The audio band is commonly considered as 20Hz-20kHz. I assume JA extended it to 22kHz to allow the filters to take full effect, to make sure he was getting full output at 20kHz. As for his "wide-band" measurement, you would have to ask him for the exact bandwidth. What it was, it must have been >>22kHz, may be as high as 50kHz, the practical limit of SACD's frequency response.

Edit: Just read the M1 review you linked, and indication was that he used up to 500kHz for his measurements, and that picked up the relatively (he referenced the Mark Levinson) high switching noise of the M1, so that may not be an issue for real world use.

 

[PENG]

Unfortunately as we all know, there is not a single standard or definition for SNR.

Looking at some of the same SNR I linked earlier, as PENG stated, if we look at the "Audio Band" 22Hz-22kHz, then it seems the unweighted SNR goes from the 70's to the 90's. If this is the "standard" that we are all referring to, then I think we can agree that 80dB SNR Unweighted is a good minimum.

This means the $7,000/pair Anthem M1 is one pathetic amp because the 22Hz-22kHz Unweighted SNR is only 75dB.

75dB unweighted and 82.1dB A weighting at 1W is as good as some mid range AVR. I wouldn't call it pathetic because of it's high output capability, but for $7,000, if one can live with half the output then there are no shortages of amps that offer better specs.

By the way, thank you for the multiple links, I always enjoy reading JA's measurements especially when the DUT are within my reach, in terms of affordability.

 

[AcuDefTechGuy]

Perhaps "pathetic" is too harsh.

But for $7K/pr, the Anthem has the lowest wideband SNR I've seen at only 10dB.

The ($8K Mark Levinson) No.532H (looks like an ATI AT3002 amp) is also superbly quiet; its wideband, unweighted signal/noise ratio, ref. 2.83V output with the input short-circuited, measured 93dB in both channels.

Read more at https://www.stereophile.com/content/mark-levinson-no532h-power-amplifier-measurements#MQ3Pt6wZC8RAV5Py.99

The $5K/pr Bel Canto is probably the best one as far as SNR.

https://www.stereophile.com/content/bel-canto-eone-ref600m-power-amplifier-measurements

 

[Irvrobinson]

The audio band is commonly considered as 20Hz-20kHz. I assume JA extended it to 22kHz to allow the filters to take full effect, to make sure he was getting full output at 20kHz. As for his "wide-band" measurement, you would have to ask him for the exact bandwidth. What it was, it must have been >>22kHz, may be as high as 50kHz, the practical limit of SACD's frequency response.

Edit: Just read the M1 review you linked, and indication was that he used up to 500kHz for his measurements, and that picked up the relatively (he referenced the Mark Levinson) high switching noise of the M1, so that may not be an issue for real world use.

I'm pretty sure low-pass filters came into vogue for SNR measurements when Class D amps appeared (to eliminate the measurement component from switching noise), and the testers apply the same filter to conventional amps to produce comparable numbers from all amps.

 

[<eargiant]

The Benchmark AHB2 is the real deal.

https://www.stereophile.com/content/benchmark-media-systems-ahb2-power-amplifier-measurements

The AHB2 meets the new Audio Precision APx555 (see last page)

http://www.audioxpress.com/files/attachment/2584

Don't miss Bob Cordell in the picture with John Siau.

 

[PENG]

I'm pretty sure low-pass filters came into vogue for SNR measurements when Class D amps appeared (to eliminate the measurement component from switching noise), and the testers apply the same filter to conventional amps to produce comparable numbers from all amps.

That's just one example of something that is not audible but measurable and found not insignificant as shown in JA's measurements. It is funny that many audiophiles worry about things that they claim are audible to them, but not measured, or measurable by audio test benches (so they claim).