Just checked and the amp tested is their 1et6525 amp, that's equivalent to our p482, not our p801. So the gain levels are definitely only 20.3dB/26.3dB.
If gain levels were the same as our P801 (23dB/29dB) their data would be several dB worse. Higher gain is required with the p801 9040 amps to allow them to reach full power output.
Alan Marchwrote:
Just checked and the amp tested is their 1et6525 amp, that's equivalent to our p482, not our p801. So the gain levels are definitely only 20.3dB/26.3dB.
If gain levels were the same as our P801 (23dB/29dB) their data would be several dB worse. Higher gain is required with the p801 9040 amps to allow them to reach full power output.
So, what would be your best guess for high/low gain THD+N numbers for your P482, compared to the A4216/E2?
And what is the difference between the P282 and P482 stereo amps, apart from power? They both have two 1et6525 modules each.
So from the Boxem measurements above, their 4216 on low gain is -110dB THD+N V our P482 which is -115dB THD+N.
If using the same buffer set to higher gain needed for the 9040 modules, their P801 equivalent would be maybe 108dB THD+N V our P801 which is 116dB THD+N.
BTW, the Boxem is the closest competitor to us terms of performance. The rest have worse performance again.
Alan Marchwrote:
So from the Boxem measurements above, their 4216 on low gain is -110dB THD+N V our P482 which is -115dB THD+N.
If using the same buffer set to higher gain needed for the 9040 modules, their P801 equivalent would be maybe 108dB THD+N V our P801 which is 116dB THD+N.
BTW, the Boxem is the closest competitor to us terms of performance. The rest have worse performance again.
Buckeye probably the worst.
Good to know and thanks for the test data ...now what module do these AP measurements belong to?
SmartOne_2000wrote:
Good to know and thanks for the test data ...now what module do these AP measurements belong to?
9040. Completely wrong gain settings for a 9040. The Buckeye won't get anywhete near to Max power with a 2 volt rca source. You would have to use the high 25dB gain with a 4 volt already source.
SmartOne_2000wrote:
Hey Alan, just curious ... how do your P282/P482 modules compare to the one below? 🙂
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@SmartOne_2000 Unfortunately you can't read too much into Boxem's results here, as Boxem mentioned the results are from the 1ET400A's input buffer, so it isn't a fair comparison, he should've followed up with his 1ET6525SA input buffer results but never did, not sure why on his reluctance there.
It appears I'm mistaken, Boxem has just recently posted the results of his Arthur 4216/E2 (1ET6525SA) based 2 Ch amp, could give competitors a run for their money, not sure how it compares to Alan's P482 but it appears to be pretty comparable performance.
Alan Marchwrote:
The reluctance is probably due to the composite buffer they use not providing much improvement in noise levels.
Hey Alan, sorry please see the results of my edited post above, it appears Boxem has provided such THD measurements after all, bragging about it too I might add. 😉
Thanks for the info. So we can ignore the unusable 12dB gain setting.
The plots for 21dB and 26.3dB show sinad of 109.1dB and 106.9dB.
Looking at the text above it seems he has used the snr ratio technique to eliminate the source noise issue as we have. Still about 1 or 2dB behind.
BTW my view is that Boxem is the only one of our competitors that has good understanding of electronics design. They also dont BS and inflate their specs (copy the Purifi datasheet).
A note, the 26.3dB gain is too low to get the 1et6525 to full power output with normal 2 volt rca source. It will reach about 428 watts. Whilst the 21dB medium gain would reach full power with a 4 volt source, the amp won't because of using a Hyoex PSU which has too low an output voltage.
Oh, I thought at 21dB Gain his SINAD is 114dB with a noise level of 6.5 uV(A) & at 26.3dB gain his SINAD is 112dB with a noise level of 8.7 uV(A).
Gain 12.3 dB: THD -131 dB, noise 7.5 uV(uw) => SINAD 115 dB Noise 5.2 uV(A)
Gain 21.0 dB: THD -130 dB, noise 8.9 uV(uw) => SINAD 114 dB Noise 6.5 uV(A)
Gain 26.3 dB: THD -128 dB, noise 11.7 uV(uw) => SINAD 112 dB Noise 8.7 uV(A)
Whilst Boxem may be suitably proficient with his designs, I still don't appreciate the use of Hypex PSUs, he feels it is the only safe & suitable to utilise at this point in time, as far as I'm concerned, you Alan are the only game in town for the true discerning individual, your technical prowess is unparalleled when it comes to your Purifi designs 🙂
Oniiz86wrote:
Oh, I thought at 21dB Gain his SINAD is 114dB with a noise level of 6.5 uV(A) & at 26.3dB gain his SINAD is 112dB with a noise level of 8.7 uV(A).
Whilst Boxem may be suitably proficient with his designs, I still don't appreciate the use of Hypex PSUs, he feels it is the only safe & suitable to utilise at this point in time, as far as I'm concerned, you Alan are the only game in town for the true discerning individual, your technical prowess is unparalleled when it comes to your Purifi designs 🙂
Thanks for the kind words.
Yes I referred afterwards to the text above the plots. So it is close even though he has rounded up the numbers a bit. 😉
Not sure what Boxem means by "safe and suitable" 🤔. The Hypex PSUs are the wrong voltage, have poor regulation and are known to fail.
Anyway, I have come up with an idea to further improve our buffer. I might be able to get another 2dB out of it.
Alan Marchwrote:
Anyway, I have come up with an idea to further improve our buffer. I might be able to get another 2dB out of it.
That's great to hear, although it's a trifle disappointing that us early adopters of your P482, P481, P282 amps will miss out on these additional performance improvements 🙁
Oniiz86wrote:
That's great to hear, although it's a trifle disappointing that us early adopters of your P482, P481, P282 amps will miss out on these additional performance improvements 🙁
We do have a policy of continuous improvement. It's life in general. If you wait there will always be something better come along.
