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

Leon

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Mar 5, 2018
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Hello everybody,

I read on several forum the advantage to use specific AOP for the final stage of DAC or Amplifier. Several reference are used on forum.
It could be very interesting to test their performance:
- SNR
- Bandwish
- slew rate
-....

I suggest the following reference
- 994Enh Discret OpAmp SONIC IMAGERY LABS
- SPARKOS LABS SS3606
- AOP 1612
- LM4562
- Burson

What do you think

Cheers
 
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Unfortunately, I have no adequate tools/oscillo to achieve the test.

If an expert could be done these tests and comparaison it will be very great and useful for the community

Thank you
 
I do plan to test the Topping D10 with some op-amps members have donated. So let's get through that and assuming that is a good platform, we can test other op-amps.
 
I was able to test the following BURSON op-amps: SS V5, V5i, SS V6 Classic, SS V6 Vivid.

In Objective2 gain-stage I prefer the SS V5, with the hybrid V5i or with SS V6 there's a hiss noise when moving the volume knob and also the thump noise when switching the gain is higher. So, best one from BURSON for O2 seems to be SS V5 dual; also, no oscillations could be found (tested with 10 Mhz scope and with several input signals at various amplitudes).

For Matrix M-Stage HPA-3B (also for 3U will be the same) I found the SS V6 Classic as being the winner (although, with OPA1652 the background becomes even darker). V5i could only be used for higher gains, but approaching the unity gain it started to emit a hiss...around 40-50% of the music was covered by V5i's generated noise. Tested with 4 different op-amps, same result; didn't even bothered to measure this noise with a scope. SS V5 was just too hot and not recommended, also it can't accommodate this device's voltage of +/-18V.

For I/V the best one would be the SS V6 (the best from above, not from the market! I find the MUSES01 as being a bit better for I/V), same applies for Low-Pass Filter. Also, the internal noise is quite low and comparable with very low noise op-amps. However, given their relatively big size they can be prone to EMI/RIF influences (I've seen that in PLAY and HPA-3B, but this can be also reproduced in other devices too), so shielding could be a good option.

For output buffers their output DC-voltage could be a bit higher sometimes, I'm speaking of 1-3 mV when hot, but while being cold (in the first couple of minutes of operation) their output DC could be even 5 times higher. What it matters is the DC-voltage on headphones plug, so if your headamp has DC-servo circuit or caps in the signal path then BURSON op-amps could be very well be used in output buffer of your DAC/preamp/etc.

What I like to the above op-amps:
- they are solid-state and not integrated chips, so quite a good upgrade for audiophiles that are looking to get rid of integrated op-amps
- they might sound better when used in voltage-gain and LPF indeed, but not sure why...I've ran some FFTs, but I'm unable to see an strange harmonics generated
- they look fantastic and sound appealing and there's also the impression of very well done small electronic equipment

What could be improved:
- their max. operating voltage could be increased to +/-18V or even more...+/-22V, like their SS V4 used to be in the past; this will ensure maximum compatibility with most existing products
- their height it's just too high and can't fit in some devices
- output DC-voltage could be lower

P.S.: I should be able to find some screenshot I did with V5 and V6 op-amps on O2, HPA-3B and PLAY, so if someone insists I should be able to provide some.
 
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Sine-waves and square-waves are looking identical with all opamps I've tested (SS V5, V5i, SS V6 Classic, SS V6 Vivid), just the output sound seems to be a bit different: imaging and musicality seems to change a little bit. However, I found some scope shots with SS V6 Classic inside the Matrix HPA-3B that show no evidence of oscillations or strange signals up to 10 MHz. That means they're compatible with HPA-3B, at least you can lower it's internal PSU voltages from +/-18V to +/-15V or +/-16V (otherwise, please stick to the original LME49860, OPA1652 or other audio opamps able to sustain 36V voltage between V+/V- rails).

MATRIX_HPA-3B_SS-V6_01 copy.png MATRIX_HPA-3B_SS-V6_02 copy.png

However, swapping opamps seems to be more dependent on the surrounding circuitry, their quality and PCB layout, than the opamp itself. Same opamp could sound more open and with a darker background when tested in equipment #1, but may sound with a much closer scene and with a bit of hiss-noise when installed in equipment #2. So, it's all about compatibility between the tested opamp and the actual circuit from the audio device.
 
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.
 
I'm impressed how well the SK99 does measure in both unity gain, but also in voltage-gain (+20dBu). Not sure it's good for I/V stage, but for voltage amplification and output buffer seems perfect. Too bad it's lot of DYI needed to use it in DIP9 sockets, especially if duals are needed.

SK99.png


Lot of power in there, I wonder if it will be stable inside Objective2; however, there's definitely not enough room inside, but design and implementation seems on pair with how it measures. Not sure it worth the trouble and price difference vs. the AD797, but still worth a check for DIY-ers.
 
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I was recently reading http://nihtila.com/2017/01/12/pcm1794a-leftright-channel-differences/, so today I did a test: swapped the 4 x MUSES01 to 4 x NE5532P in my ASUS Essence One MKii. I was curious how these 8 opamps are measuring in the I/V stage of this DAC, because in A/B test with identical Essence One, just opamps swapped, in 10 out of 10 tests the device with MUSES01 in I/V sounded better, with a bigger scene, even the details seemed better and cleaner.

ASUS_E1_1KHz-48KHz_Headphones_MUSES01_IV_MUSES02_LPF.png

MUSES01 in I/V stage (MUSES02 in LPF, MUSES8820 in buffer)


ASUS_E1_1KHz-48KHz_Headphones_NE5532_IV_MUSES01_LPF.png

NE5532P in I/V stage (MUSES02 in LPF, MUSES8820 in buffer)

Seems that with the cheap good NE5532P the THD+N decreased from 0.0067% to 0.0026% vs. the much more expensive MUSES01. Second harmonic decreased with about 16dB and the third one with about 2dB; background noise remained identical, very low actually.

Measurements done directly on headphones-output jack (MUSES8820 + LME49600).

P.S.: 50 Hz and its harmonics are below -130dB on the RCA plugs, not sure why on headphones-out these get up to -120dB, perhaps it's from my measurement cables.
 
Worth mentioning that the same MUSES01 opamps, when used in the I/V stage of my Burson PLAY combo, has the 2nd harmonic below -100dB.
So it's really up to the surrounding circuitry and the way it was implemented.
There's probably no best all-rounder opamp out there, just recommended opamps, based on manufacturer's datasheet.
 
So far. I tested lt1128 is best for gain stage opa827 for output stage. opa2156 can have better performance under 1khz but high frequency distortion rise up a little bit.
 
Not quite the best thread to speak about new opamps, but OPA2156 is really new to me (and to market too). It seems to be based on the OPA1652, which I'm using it with success inside my Matrix HPA-3B in the gain-stage, but with less THD and less noise too.

A comprehensive comparison between OPA1612 and OPA2156 (and other opamps) could be read here: https://quantasylum.com/blogs/news/opa2156-hifi-in-cmos.
 
Not quite the best thread to speak about new opamps, but OPA2156 is really new to me (and to market too). It seems to be based on the OPA1652, which I'm using it with success inside my Matrix HPA-3B in the gain-stage, but with less THD and less noise too.

A comprehensive comparison between OPA1612 and OPA2156 (and other opamps) could be read here: https://quantasylum.com/blogs/news/opa2156-hifi-in-cmos.
Well I actually did more extensive measurements in more applications. Basically the only downside i can see is the voltage noise performance, which can be improved by paralleling but not to the 1612 level that would be non realistic.
In nested feedback circuit my measurements showed better performance in higher frequency (which is weird but consistent results). In o2 output stage, 827 is still better but 2156 has more current both are better than 1612. In other stages I believe most opamps may perform similar.
 
Measurements (graphs) by jalejos: LM4562, LME49720, MUSES01, Burson Audio V5, Sparkoslabs SS3602 and Silicon Imagery Labs 994 Enh Ticha

https://www.diyaudio.com/forums/vendor-s-bazaar/281361-hypex-ncore-nc500-build-post4737441.html

Version 2. Original design, modified by Richard


LM4562


LME49720


MUSES01


Burson Audio V5


Sparkoslabs SS3602


SIL 994 Enh Ticha


Version 3 smd

LM4562


LME49720


MUSES01


Sparkoslabs SS3602


SIL 994 Enh Ticha

Measurements made with APX 525 with software APx500 V3.4 at 1KHz.
 
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