[carlmart]

Sounding different, and not worst, from the Burson is promising.

Looking forward to what the differences turn out.

 

[Rick_B]

We look forward to your tests. I heard this space-like opamp is bright sounding. I guess you'll find out if it's true or not.

It almost seems, especially on Head-Fi, that one person's "bright" is another's "transparent"...same with bass response.

I did not notice this opamp sounding too bright, too brittle, too distorted in the treble region whether using my SR225e's, He-400i's, or really any other set I tried with it.

I also like to reserve my judgement until a piece of electronics has been run in for at least a week, I've been playing this hi-fi game for over fifty years and it never ceases to amaze me how much some electronic gear can change just by being run in...

 

[leeperry]

I did not notice this opamp sounding too bright, too brittle, too distorted in the treble region

According to Scott Wurcer(the designer of the holy AD797), opamps have no sonic character and it's all highly dependent on how they are used and especially if they are not oscillating. To EE's we're clueless idiots rolling opamps blindly.

 

[Ivan TT]

Similar tune from Douglas Self:

With horrible inevitability, the very popularity and excellent technical performance of the 5532 has led to it being criticized by subjectivists who have contrived to convince themselves that they can tell op-amps apart by listening to music played through them. This always makes me laugh, because there is probably no music on the planet that has not passed through a hundred or more 5532s on its way to the consumer.

 

[carlmart]

The objective vs subjective discussion is never ending when talking with most electronics engineers.

It seems they do not want really to hear or maybe are afraid that something comes up that they can't explain.

No surprise they still say amps have no sound of their own, so opamps should all sound the same too, as long as their specs are the same. The specs tell the truth, not any golden ear.

Fortunately not all EEs think like that, like Nelson Pass or Walt Jung.

 

[imran27]

The objective vs subjective discussion is never ending when talking with most electronics engineers.

It seems they do not want really to hear or maybe are afraid that something comes up that they can't explain.

No surprise they still say amps have no sound of their own, so opamps should all sound the same too, as long as their specs are the same. The specs tell the truth, not any golden ear.

Fortunately not all EEs think like that, like Nelson Pass or Walt Jung.

I am an EE

But I have myself heard different opamps sounding different.

Heck even the bypass capacitor across the opamp power rails affects it's sound, the magnitude of change depends on the stage it is being used in (I/V, LPF, Gain)

 

[carlmart]

Of course you did! I didn't say all, just most.

 

[imran27]

Btw,

I would like other opinions as well on bypassing opamp power rails and how it affects sound with respect to different capacitors like Nichicon PW/VZ, Panasonic FM, UCC KZE, etc.

To my ears, Nichicon VZ sound like tubes, Nichicon PW sound like extremely reference and extended, point blank precision, UCC KZE sound like a middle ground of the two: like a tube+SS hybrid.

Haven't tried Panasonic FM yet.

 

[raoultrifan]

The objective vs subjective discussion is never ending when talking with most electronics engineers.

It seems they do not want really to hear or maybe are afraid that something comes up that they can't explain. [...]

Everything will be seen with an audio analyzer or a scope and a good ADC + ARTA & RMAA software. You need to compare:
- impulse response with both tested opamps
- freq. response
- freq. roll-off with square signal
- phase shift/timing with square signal
- SNR, THD, IMD, FFT harmonics as well

With some opamps 2nd or 3rd harmonic will be higher and this might have little influence on output sound. Same happens with IMD when multiple signals are applied, with some opamps there will be a "skirt" or more harmonics or higher THD and this will also influence the sound.

Some very important aspects would be: channel separation (inject audio signal only onto one channel and do some tests) and CMRR & PSRR, because a poorly designed PCB and/or schematic, combined with an opamp having less than 90dB CMRR/PSRR could create some oscillations or high frequency signals on output (lower harmonics of these signal might get into the audible range).

I am an EE

But I have myself heard different opamps sounding different.

Heck even the bypass capacitor across the opamp power rails affects it's sound, the magnitude of change depends on the stage it is being used in (I/V, LPF, Gain)

I do really like this one: http://www.analog.com/media/en/training-seminars/tutorials/MT-101.pdf. From my own experience I realized that as long as the opamp is not delivering high current output, a 0.1-1uF ceramic or MKP combined with an 10-100uF electrolytic or polymer should do well on most designs, but when speaking about output buffers, then a 10-20uF tantalum might also help, along with a 0.1-1uF ceramic or MKP (for high-power speakers buffers a combination of 0.1uF MKP with 4.7uF ceramic and 1000uF electrolytic should do well). However, it's very important to check with a scope for ringing and oscillations on V+/V- & GND, measured directly on opamp's rails; choosing higher values when bypassing an opamp might do more harm than good.

 

[leeperry]

IME Pana FR really acts as a magnifier showing the ugliness in the circuit, be very afraid coz it will hurt ^^

Some forums claim that trebles are bright, shrill yada yada but don't shoot the messenger. Wherever I put it it sounds PHAT but of course any crappy link will blow up to your ears.

 

[FritzS]

Everything will be seen with an audio analyzer or a scope and a good ADC + ARTA & RMAA software. You need to compare:
- impulse response with both tested opamps
- freq. response
- freq. roll-off with square signal
- phase shift/timing with square signal
- SNR, THD, IMD, FFT harmonics as well

With some opamps 2nd or 3rd harmonic will be higher and this might have little influence on output sound. Same happens with IMD when multiple signals are applied, with some opamps there will be a "skirt" or more harmonics or higher THD and this will also influence the sound.

Some very important aspects would be: channel separation (inject audio signal only onto one channel and do some tests) and CMRR & PSRR, because a poorly designed PCB and/or schematic, combined with an opamp having less than 90dB CMRR/PSRR could create some oscillations or high frequency signals on output (lower harmonics of these signal might get into the audible range).

Have you or anyone tested an audio analyzer or a scope and a good ADC + ARTA & RMAA software: LM6171, LME49710, AD843, AD847, LT1056, LT1022, OPA602AP, TLE2071, OPA627, Supreme Sound Opamp V5 S, AD797?

In my headphone amp WNA MKII now I use AD797 with best experience. All other I listet above I tested in this amp too.

 

[raoultrifan]

I did, but in differente devices same opamps may perform very different. Most differences were noticed in SNR improvement, but sometimes when doing FFT I saw different values for 2nd and 3rd harmonics (I was usually tested for 1KHz sine).

 

[carlmart]

Unfortunately such differences will probably not show in simulations, except for THD perhaps.

 

[raoultrifan]

Signal to Noise Ratio was the most noticeable.

 

[Rroff]

Btw,

I would like other opinions as well on bypassing opamp power rails and how it affects sound with respect to different capacitors like Nichicon PW/VZ, Panasonic FM, UCC KZE, etc.

To my ears, Nichicon VZ sound like tubes, Nichicon PW sound like extremely reference and extended, point blank precision, UCC KZE sound like a middle ground of the two: like a tube+SS hybrid.

Haven't tried Panasonic FM yet.

I've tried a lot of different capacitors both film types and aluminium electrolytics and combinations bypassing both at the op amp and obviously for filter earlier in the power supply.

Generally I don't notice much difference unless specific opamps benefit (probably due to being more stable or otherwise resulting in conditions they are happier with) but I do find that general purposes capacitors tend to result in what I call a "80s/90s" sound for want of a better way to describe it while some of the more expensive/specific purpose stuff seems to be a touch more refined and then you get some outliers that are definitely causing some degree of distortion (or the opamp just isn't 100% happy with them there).

Certain types and combinations do seem to make the sound a little narrower and some seem to widen the soundstage somehow and then there are some slight oddities like the Panasonic FM while otherwise an excellent capacitor (I use them a lot for power supply filtering) seems to result in a bit of congestion somewhere at a certain frequency or frequency and the Nichicon FG seems to have a bit of a bump somewhere around 500Hz that results in a little bit fuller sound which isn't always desirable but not necessarily a bad thing. For bypassing close to the opamp the Panasonic FC is a better bet than the FM as it seems largely transparent in impact.

Same with the old Elna Silmics that get raved about - to my ears they seem to have some kind of DSP like impact on the sound resulting in a wider and more "3D" sound but it certainly is distortion rather than truer to the original (probably somehow attenuating ~4.5KHz slightly though I'm not sure how that works via the use of a bypass capacitor) - but again not necessarily a bad thing as it can be quite pleasing for general listening.

For a "reference" like sound - very neutral if a touch "flat" but as transparent as possible I've ended up using Cornell Dubilier MLQ series in the power supply filtering stage 2x 470uf per rail and Nichicon KZ close to the opamp with 2x 220uf rail to ground and 10uf rail to rail and then some of the new WIMA 0.1uf polypropylene rail to ground at the opamp pins. For a more fun sound I swap out the 10uf for either a 0.1-0.22uf film cap or a 10uf Elna Silmic II - though it isn't earth shatteringly different.

The Nichicon PW also seem pretty good close to the opamps as you mentioned but I've not used them extensively - they've got good ESR, etc. properties in the ideal range for using in audio application like this - especially if they are sitting between a regulator and the opamp.