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Test performance of AOP Burson/SPARKOS/SONIC994/1612, .....

JohnYang1997

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#21
The first and obvious conclusion: we must avoid the audiophile Burson Audio V5.
V6 vivid measured superb tho. I have them measured ln violectric v200 and gain stage of o2. At least -120db thd performance. Noise is roughly around 3-4nV.
 

JohnYang1997

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#23
Wow the Burson V5 is really bad, indeed. Sparkoslabs SS3602 is surprisingly good!!
That looks like distortion cancellation to me. The distortion somehow out of phase to the test equipment and causing lower distortion. There is no way that lme49720 has that high distortion but somehow beaten by a discreet opamp.
 

trl

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#24
In what stage have you used these opamps? I/V, LPF, output buffer?

Funny thing, SS V5 used in the gain stage of my Objective2 has lower noise than the original NJM2068 and the same 2nd and 3rd harmonics (3.3X gain). Also, SS V5 and SS V6 has the same harmonics as NE5532 and LME49720 when used in I/V of my ASUS Essence One (MUSES01 instead has higher 2nd and 3rd harmonics).

Also, SS V6 Classic I'm using it with great success inside my HPA-3B headmap. Very low harmonics (<100dB away from the fundamental), extremely low background noise (much lower than LME49860 when high-gain is used, can't explain why).

I really think it's up to the circuit used for testing, gain used, PCB quality, power supply and decoupling used. A detailed review with measurement details could be found here: https://www.head-fi.org/showcase/bu...d-opamp-v5i.21562/reviews?page=3#review-18921.
 

JohnYang1997

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#27
Just read that link and some other pages from the website.
First of all, their approach is really good and should have great results. But I don't think they are honest. The two pole compensation is not unique, i consider them very useful. Also not only they don't even have distortion measured in the datasheet, they only compare to the opamps have not as good specs. They use bjt as input but proceed to use opa627 for comparison? Not even opa827, let along ad797, ada4898, lt1129/1028, opa1611 etc. Two pole compensation can easily be realized by two opamps cascading. Common use is jds el amp and atom. And that type of circuit has never been secret.
Ps: some above apply to burson too. But i think they at least both make good products. Just some radom rant, don't take it too serious.
 
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#28
That's a fair point.
Is cascading opamps topology common in many products? Or just the smart ones use them?

I give him points for explaining the design objective and process.

Also what about the loop gain and bandwidth thing he mentioned?
 

JohnYang1997

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#29
That's a fair point.
Is cascading opamps topology common in many products? Or just the smart ones use them?

I give him points for explaining the design objective and process.

Also what about the loop gain and bandwidth thing he mentioned?
It's common knowledge. What they said in that page are correct. Nothing wrong about that. And I agree that their approach will give awesome results. Just the attitudes made me somewhat uncomfortable.
Cascading two opamps tho. Tbh, single opamp will already give super low distortion into high impedance load. Normally we only need to add a current output stage to boost output current like lme49600 used by jds and neurochrome, I use tpa6120 in the feedback loop. Some other would use ada4870 or lt1210 etc. These type of configuration allows the use lf two pole compensation to ensure stability with high ol gain.

That's not a smart approach to engineer. Because that's too expensive. The use of twin transistors and the occupation of high area will definitely limit the use of their product. For some specific application it "might" work 11/10 of what others do for 1/20 of the price of other products.
 

maty

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#31
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#32
Output Linearity 600 Ohm +20 dBu Residual Spectrum:

AD797 (noisefloor @ -130 dB, 2nd harmonic @ -89 dB)
AD823 (-110 dB, 2nd @ -53 dB)
AD825 (-108 dB, 3rd @ -49 dB)
AD826 (-108 dB, 3rd @ -47 dB)
AD829 (-125 dB, 3rd @ -68 dB)
AD845 (-110 dB, 2nd @ -79 dB)
AD8599 (-130 dB, 2nd @ -68 dB; lot of spurious harmonics @ -70...-80 dB)
OP275 (-118 dB, 2nd @ -52 dB)
Audio-GD OPA-Earth (-122 dB, 2nd @ -40 dB)
Audio-GD OPA-Moon (-115 dB, all @ -40...-50 dB)
Burson Audio Discrete OpAmp Mk II (-120 dB, 2nd @ -40 dB)
LT1128 (-132 dB, 2nd @ -75 dB)
LM833 (-120 dB, 2nd & 3rd @ -75 dB)
LM837 (-120 dB, 2nd @ -70 dB)
LME49860 (-123 dB, 2nd @ -90 dB)
SGA-HVA-1 (-128 dB, 2nd @ -110 dB)
SGA-LNA-1 (-136 dB, 2nd @ -64 dB)
SGA-SOA-1 (-128 dB, 2nd @ -60 dB)
SGA-SOA-2 (-128 dB, 2nd @ -62 dB)
Signetics NE5532 (-115 dB, 2nd @ -58 dB)
TI NE5532 (-115 dB, 2nd @ -59 dB)
TI NE5534 (-120 dB, 2nd @ -68 dB)
Sound Skulptor SK25 (-114 dB, 2nd @ -89 dB)
Sound Skulptor SK99B (-133 dB, 2nd @ -97 dB)
OPA211 (-129 dB, 2nd @ -80 dB)
MC33078 (-119 dB, 2nd @ -40 dB)
OPA551 (-115 dB, 2nd @ -64 dB)
OPA627 (-120 dB, 2nd & 3rd @ -79...80 dB)
OPA827 (-120 dB, 3rd @ -86 dB)
OPA2132 (-115 dB, 2nd @ -62 dB)
OPA2604 (-110 dB, 2nd @ -46 dB)
RC4580 (-118 dB, 2nd @ -55 dB)
TL071 (-115 dB, 2nd & 3rd @ -40 dB)

For +20 dBu the best opamps are bolded, also good-enough opamps have been underlined. For 0 dBU about the same opamps are having about the same place in the list. Interesting that solid-state "opamps" (SGA-HVA-1 & SK99 & SK25) are measuring extremely well and the well-known LME49860 (LME49720 and NE4562) is just a tad lower in performance. +20 dBU means lot of gain, so these opamps should perform admirable when used in voltage amplification gain.
Is there any chance if you could measure Sparkos, OPA1611, Burson Vivid and Classic opamps? Or if @amirm could do a review based on some most popular models? :)
 
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