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

[slipperybidness]

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

I will double check, but I believe they were quoting "unweighted at 1W (or 2.83V into 8ohm).

For their designs published in the books, basically they say "we can't predict your SNR, but if you follow good construction techniques then you should expect at least -90dB".

 

[AcuDefTechGuy]

The Benchmark AHB2 is the real deal.

No. The Bel Canto is the real deal.

If we are just talking about pure academic SNR from the same source (Stereophile).

Benchmark amp - The wideband S/N ratio, measured in the high-gain, stereo condition with the input shorted to ground and ref. 1W into 8 ohms, was very high, at 89.3dB. Reducing the measurement bandwidth to 22Hz–22kHz increased the ratio to 106dB, while switching an A-weighting filter into circuit increased it further, to 108.5dB.

Read more at https://www.stereophile.com/content/benchmark-media-systems-ahb2-power-amplifier-measurements#cDEVz3z6XE1zLPFm.99

Bel Canto amp - the unweighted, wideband signal/noise ratio (ref. 2.83V into 8 ohms with the input shorted to ground) was an extraordinary 109.9dB, which improved to 113dB when A-weighted.

Read more at https://www.stereophile.com/content/bel-canto-eone-ref600m-power-amplifier-measurements#4liWzPFeB0VRaYc4.99

In terms of power, the Benchmark is only 100WPC into 8 ohms/ 190WPC into 4 ohms. You could bridge them, but that would increase cost, HEAT, distortion, and noise, which defeats the whole purpose.

The Bel Canto is 300WPC into 8 ohms/ 600WPC into 4 ohms.

So the Bel Canto has much more power and better SNR.

Of course, with a lot more power, the Bel Canto also costs more - $5,000/pair vs $3,000.

 

[PENG]

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

I think people would buy that Anthem for the sheer power and the Anthem name.

 

[slipperybidness]

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.

Hmmmmm......what I was reading, I believe they are saying that "filtering above 20kHz is weighting the results".....

 

[Irvrobinson]

No. The Bel Canto is the real deal.

If we are just talking about pure academic numbers from the same source (Stereophile).

Benchmark amp - The wideband S/N ratio, measured in the high-gain, stereo condition with the input shorted to ground and ref. 1W into 8 ohms, was very high, at 89.3dB. Reducing the measurement bandwidth to 22Hz–22kHz increased the ratio to 106dB, while switching an A-weighting filter into circuit increased it further, to 108.5dB.

Read more at https://www.stereophile.com/content/benchmark-media-systems-ahb2-power-amplifier-measurements#cDEVz3z6XE1zLPFm.99

Bel Canto amp - the unweighted, wideband signal/noise ratio (ref. 2.83V into 8 ohms with the input shorted to ground) was an extraordinary 109.9dB, which improved to 113dB when A-weighted.

Read more at https://www.stereophile.com/content/bel-canto-eone-ref600m-power-amplifier-measurements#4liWzPFeB0VRaYc4.99

In terms of power, the Benchmark is only 100WPC into 8 ohms/ 190WPC into 4 ohms. You could bridge them, but that would increase cost, HEAT, distortion, and noise, which defeats the whole purpose.

The Bel Canto is 300WPC into 8 ohms/ 600WPC into 4 ohms.

So the Bel Canto has much more power and better SNR.

Of course, with a lot more power, the Bel Canto also costs more - $5,000/pair vs $3,000.

Did you really read what those analyses say, or are you just blindly interpreting the measurements without context? (I think the latter.)

I admit that I don't understand the effects of sending 381mV of 442KHz noise for 1V of audio signal into my speakers. If these were the only two amps in the world, I'd choose the Benchmark product.

 

[slipperybidness]

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).

Well, noise at high frequencies may not be audible, but it may be important!

The output is fed back into the input as part of the negative feedback circuitry. Noise at freqs above the human hearing range will get fed back on the negative feedback loop.

I don't know "how important", or "what noise in the high freq is acceptable", etc, off the top of my head. But, I'm fairly certain that I have books that will educate me on the topic.

 

[AcuDefTechGuy]

I think people would buy that Anthem for the sheer power and the Anthem name.

You think there is an inverse relationship between Power and SNR/Distortion?

This kind of power (1,000W into 8 ohms, 2,000W into 4 ohms) reminds me of the pro amps like Crown, etc., which also have lower SNR.

The $2,000 Crown XTi-6002 is 1200W/8 ohms x 2Ch, 2100W/4 ohms x 2Ch, 3000W/2 ohms x 2Ch.

https://www.amazon.com/Crown-XTi-6002-2-channel-Amplifier/dp/B01ACVJ110/ref=sr_1_1_sspa?ie=UTF8&qid=1505925702&sr=8-1-spons&keywords=Crown+XTi+6002&psc=1

More powerful than the Anthem and costs a lot less ($2K vs $7K).

 

[PENG]

I think people would buy that Anthem for the sheer power and the Anthem name.

Well, noise at high frequencies may not be audible, but it may be important!

The output is fed back into the input as part of the negative feedback circuitry. Noise at freqs above the human hearing range will get fed back on the negative feedback loop.

I don't know "how important", or "what noise in the high freq is acceptable", etc, off the top of my head. But, I'm fairly certain that I have books that will educate me on the topic.

I don't think so, not for the very high ultrasonic noise. Any such unintentional feedback would be negligibly low or could be filtered in the loop. I'll think about it though.

 

[PENG]

You think there is an inverse relationship between Power and SNR/Distortion?

This kind of power (1,000W into 8 ohms, 2,000W into 4 ohms) reminds me of the pro amps like Crown, etc., which also have lower SNR.

If SNR is 80 at 1w, you can imagine how much higher it is at 100w right? Conversely if SNR is 80 at 100w, it will be much lower at 1w.

 

[PENG]

Did you really read what those analyses say, or are you just blindly interpreting the measurements without context? (I think the latter.)

I admit that I don't understand the effects of sending 381mV of 442KHz noise for 1V of audio signal into my speakers. If these were the only two amps in the world, I'd choose the Benchmark product.

At 442khz, the inductance of the tweeter alone will virtually block the signal and won't make a noise, I would think. Still, I don't want it there either, so I might take the Benchmark too unless I need the extra power.

 

[slipperybidness]

I don't think so, not for the very high ultrasonic noise. Any such unintentional feedback would be negligibly low or could be filtered in the loop. I'll think about it though.

True enough on the filters, and a cap in the feedback is common, but I'm not so sure that its primary purpose is for filtering.

Yeah, let me chew on this one a little, and likely go have another skim through the literature.

 

[slipperybidness]

You think there is an inverse relationship between Power and SNR/Distortion?

I think power and SNR may be somewhat correlated, but not really a direct relationship b/w them.

What are the sources of noise inside an amp chasis?

Well the dominate sources of noise are recombination noise in semiconductors (holes/electron movement) and Johnson noise in resistors (thermal noise).

Therefore, the power generated does not directly effect the noise, I would think.

 

[PENG]

True enough on the filters, and a cap in the feedback is common, but I'm not so sure that its primary purpose is for filtering.

Yeah, let me chew on this one a little, and likely go have another skim through the literature.

We can compare notes later.

 

[Irvrobinson]

At 442khz, the inductance of the tweeter alone will virtually block the signal and won't make a noise, I would think. Still, I don't want it there either, so I might take the Benchmark too unless I need the extra power.

I think the Benchmark will have similar issue but probably too low for JA to bother measuring.

Why do you think the Benchmark amp has similar HF noise? Because they talk about using a "switching power supply"? I admit that I can't tell what they're talking about, since they discuss Class H characteristics in their literature (to the point of that being responsible for the H in the product name), which implies output power rail voltage manipulation, and then they discuss a switching power supply (implying some sort of Class D-like operation). Of course, they are the same guys discussing "inter-sample overs" WRT to digital recording, so I do have some skepticism about Benchmark's literature.

 

[PENG]

I think power and SNR may be somewhat correlated, but not really a direct relationship b/w them.

What are the sources of noise inside an amp chasis?

Well the dominate sources of noise are recombination noise in semiconductors (holes/electron movement) and Johnson noise in resistors (thermal noise).

Therefore, the power generated does not directly effect the noise, I would think.

I would agree that it's not directly proportional but definitely a direct correlation such that the "number" increases/improves as output increases. You are still thinking the "N" gets amplified too I guess. I think you do need to check you notes/books.

 

[AcuDefTechGuy]

I think power and SNR may be somewhat correlated, but not really a direct relationship b/w them.

What are the sources of noise inside an amp chasis?

Well the dominate sources of noise are recombination noise in semiconductors (holes/electron movement) and Johnson noise in resistors (thermal noise).

Therefore, the power generated does not directly effect the noise, I would think.

Reason I said that is because of the SNR @ 1w of the Anthem 1,000WPC amp was so low compared to all the other amps that Stereophile tested.

But then I looked at the Bryston 1,000W amp - The unweighted, wideband signal/noise ratio (ref. 1W into 8 ohms) was an excellent 81.5dB...

Read more at https://www.stereophile.com/content/bryston-28b-sst-monoblock-power-amplifier-measurements#vucvcDWJoogM6XBH.99

So I guess not.

 

[AcuDefTechGuy]

We can compare notes later.

You guys talk like you're back in school comparing notes.

 

[slipperybidness]

I would agree that it's not directly proportional but definitely a direct correlation such that the "number" increases/improves as output increases. You are still thinking the "N" gets amplified too I guess. I think you do need to check you notes/books.

No, in general noise doesn't get amplified.

But, there is the specific case where noise on the INPUT does get amplified! That is precisely why a low noise input circuit is absolutely critical! And, now we are getting into the advantages of a balanced input stage. Same story for DC on the input, it would get amplified.

And, this ties back to exactly why SNR is critical for the Pre-Amp stage! Any noise on the Pre-Amp output will indeed get amplified by the amp stage.

Furthermore, we have a pretty good idea of how much input noise would be amplified, typical amp gain is in the +30 range.

 

[PENG]

No, in general noise doesn't get amplified.

But, there is the specific case where noise on the INPUT does get amplified! That is precisely why a low noise input circuit is absolutely critical! And, now we are getting into the advantages of a balanced input stage. Same story for DC on the input, it would get amplified.

And, this ties back to exactly why SNR is critical for the Pre-Amp stage! Any noise on the Pre-Amp output will indeed get amplified by the amp stage.

Furthermore, we have a pretty good idea of how much input noise would be amplified, typical amp gain is in the +30 range.

The way SNR is measured is by measuring the output with the input terminated with a resistor of predetermined value, or shorted (Stereophie seems to be doing that) to get the "noise" So if you measured SNR at 1W output and then at rated output of say 128W, mathematically speaking the SNR at 100W output would look 21dB higher/better. Assuming everything else being equal (such as both A weighting, 20-22,000Hz), if S&V and JA did the same test on the same 128W rated power amp and if Stereophile's JA measurement shows 80dB, S&V would likely show 101dB. That's the point I tried to make.

Yes, I agree with your point about preamps.

 

[PENG]

You guys talk like you're back in school comparing notes.

Yeah, that can be fun but it really depends on who you are talking to..