[Slater]

I have both amps, and the only thing I'd change about the A5 is the volume knob, I wish they kept the E12A volume knob knurling.

You’re definitely right about the knob! I did come up with a great fix:

https://www.head-fi.org/threads/the...-19vp-p-12-hours.819831/page-48#post-14346913

 

[fokta]

The E12A seems thicker to me, but both have enough power for most dynamic driver cans. I don't believe the power capability of the 990 is that high, so the E12A should do fine there, and I believe it might smooth out it's somewhat accentuated highs. I don't know about the 668's though. I have both amps, and the only thing I'd change about the A5 is the volume knob, I wish they kept the E12A volume knob knurling.

yes, 990 is driveable, need H Gain to get more detail... while 668 no need for gain.
I noticed the colour sound E12A, when using Polaris, when it runs out of battery, so plug directly to DAP... now i need this amp for IEM..

unfortunately I can't compare polaris using A5...

 

[Xyrium]

I'm not sure about what impedance version you have of the 990, but those cans claim to only handle 100mW, as crazy as that may sound. Sensitivity isn't the highest, but impedance is probably the issue if you run out of steam with the E12A.

https://north-america.beyerdynamic.com/amfile/file/download/file_id/3891/product_id/1730/

 

[kutulu32]

Owner of both e12 and a5 . I use for years my mx4pro( ES9018K2M DAC OPA1612 amp) with e12 combo to drive my sennheiser hd600 . After replacing e12 with a5 few months agoi think audio is cleaner and better in general. I think synergy is great.i dont use bass boost ,use high gain and no EQ

 

[a-LeXx]

I think I already mentioned this sonewhere here, is it only me or my unit, I don‘t know, but my A5 sounds differently on low and high gain.

On high gain, it‘s very forward, have that slightly compressed warm sound it‘s famous for. On low gain, the whole presentation becomes much wider, as if there was something going on with the phase, mids become much less in your face, the warms is gone to a large extent... I know it‘s very strange, as a gain switch is usually (don‘t know what Fiio is doing but guess the same as the rest of the world) just a different resistor value for the negative feedback, that shouldn‘t have such a big sonic impact, especially not on the phase....

Anyone also noticing a difference between low/high gain? I don‘t actually believe this is only my unit, as both channels would have to exhibit the same fault simultaniously, very unlikely....

-Alex

 

[kukkurovaca]

I think I already mentioned this sonewhere here, is it only me or my unit, I don‘t know, but my A5 sounds differently on low and high gain.

On high gain, it‘s very forward, have that slightly compressed warm sound it‘s famous for. On low gain, the whole presentation becomes much wider, as if there was something going on with the phase, mids become much less in your face, the warms is gone to a large extent... I know it‘s very strange, as a gain switch is usually (don‘t know what Fiio is doing but guess the same as the rest of the world) just a different resistor value for the negative feedback, that shouldn‘t have such a big sonic impact, especially not on the phase....

Anyone also noticing a difference between low/high gain? I don‘t actually believe this is only my unit, as both channels would have to exhibit the same fault simultaniously, very unlikely....

-Alex

That's interesting. I don't have an A5 yet, but that sounds kind of like the behavior of the high/low impedance switch on my Phatlab Phantasy. (Which also does raise/lower volume, but it's primarily intended to act as a gain switch.)

If it is an impedance thing, then it would be less pronounced on planars if you have any and most pronounced (probably) on multi-BA IEMs.

 

[Voxata]

I also noticed a change when using gain. I preferred high.

 

[artnoi]

That's interesting. I don't have an A5 yet, but that sounds kind of like the behavior of the high/low impedance switch on my Phatlab Phantasy. (Which also does raise/lower volume, but it's primarily intended to act as a gain switch.)

If it is an impedance thing, then it would be less pronounced on planars if you have any and most pronounced (probably) on multi-BA IEMs.

No. A5 has pretty impressively low output impedance (0.x ohm I dont remember) for both high/low gain settings so it won’t mess up with lower-impedance IEMs.

 

[a-LeXx]

The only explanation from the technical point I have is that MUSES02 on low gain (0dB) is strangled to death by the negative feedback, while it opens up with harmonics at high gain, which is an impressive around x5 voltage amplification. Don't know what's the open loop gain of the MUSES02, probably not very high... So, with a x5 factor of the high gain mode the influence of the negative feedback is much less pronounced than at low gain, hence more harmonic distortion can make it's way through, responsible for that warmer sound a bit closer to the tubes (that's also my impression, the A5 on a high gain has indeed a more tube-like than SS presentation).

Edit: was to curious and just checked, open loop gain of MUSES02 is 110dB which is pretty high. Probably around 40-50dB for audio bandwidth... Which means even in high gain there is a LOT of negative feedback... Then I just don't know... The numbers and all the theory contradict what I'm hearing...

 

[a-LeXx]

Ok, after some more testing I can confirm that this tube-like sound at high gain is caused by a larger amount of harmonic distortions.

While at low gain the amp is absolutely transparent, and the only effect of it is a little bit less air compared to a source directly, at high gain this amp indeed creates audible amount of harmonic distortions. It becomes most obvious when listening to vocals. It is also not an issue of an amp being overdriven - the input sensitivity at high gain is specified with 1.15V, and I was even below 0.5V (european ipod touch that cannot otput more than 0.5Vrms because of European regulations).

That‘s pretty unique, I haven‘t seen that badly distorting solid state amp in years. But then again, maybe it‘s done on purpose, because it‘s not a bad kind of distortion, it‘s the one making a sound more euphonic...

 

[Xyrium]

Ok, after some more testing I can confirm that this tube-like sound at high gain is caused by a larger amount of harmonic distortions.

While at low gain the amp is absolutely transparent, and the only effect of it is a little bit less air compared to a source directly, at high gain this amp indeed creates audible amount of harmonic distortions. It becomes most obvious when listening to vocals. It is also not an issue of an amp being overdriven - the input sensitivity at high gain is specified with 1.15V, and I was even below 0.5V (european ipod touch that cannot otput more than 0.5Vrms because of European regulations).

That‘s pretty unique, I haven‘t seen that badly distorting solid state amp in years. But then again, maybe it‘s done on purpose, because it‘s not a bad kind of distortion, it‘s the one making a sound more euphonic...

WHen you say you can confirm it, are you saying you have measurements of harmonic distortion? Just curious, I'd love to see the graph since I have both an A5 and the E12A.

If even order, I suppose this could explain why there is a warmth to the output, tubelike even. It sure sounds sweet to me on a pair of Massdrop EDC 3's.

There are a few speaker amps out there which emulate second harmonics, the Nuprime STA-9 being one of them. I had one, and there's definitely enhanced highs, and a thickening of the mids coming out of it, to my ears, no measurements.

 

[Slater]

Ok, after some more testing I can confirm that this tube-like sound at high gain is caused by a larger amount of harmonic distortions.

While at low gain the amp is absolutely transparent, and the only effect of it is a little bit less air compared to a source directly, at high gain this amp indeed creates audible amount of harmonic distortions. It becomes most obvious when listening to vocals. It is also not an issue of an amp being overdriven - the input sensitivity at high gain is specified with 1.15V, and I was even below 0.5V (european ipod touch that cannot otput more than 0.5Vrms because of European regulations).

That‘s pretty unique, I haven‘t seen that badly distorting solid state amp in years. But then again, maybe it‘s done on purpose, because it‘s not a bad kind of distortion, it‘s the one making a sound more euphonic...

I think it’s on purpose as well. The E12A on high gain doesn’t sound exactly the same. Only the A5.

As you said, the result is very tube-like. If it’s distortion, then so be it - it’s the best sounding distortion I’ve ever heard! It’s like carrying a small tube amp in your pocket. And with a simple flip of the gains switch to low, it turns neutral as you pointed out. Very versatile!

 

[a-LeXx]

Nope, not measured the harmonics, but I’ve set up 2 identical sources with identical content, level matched, and a switch box to choose one of them. One source went into the switch box directly, second one through A5. So, I could compare directly how A5 impacts the sound.

As I said, on low gain it was pretty transparent, no added warmth watsever, just a bit less air, but that’s all.

At high gain, harmonic distortions were clearly audible with vocal music. There was a touch of warmth and a sparkle not present in the source, those are clear signs of harmonic distortion, this is how it sounds, no need to measure... Tonality overall didn’t change.

And I agree that it really does sound good. I‘m too laizy to do a proper measurement, I could have taken this guy to work and really measure everything, but what for? If it sounds like harmonic distortion, then it‘s harmonic distortion, that‘s pretty simple

I actually also have a tube amp, that came with nice russian tubes from current manufacturing. Didn‘t like them at all, sounded like a solid state amp. Exchanged the tubes gor some NOS Philips from the 60th, crazy microphonic and distorting - those put a big smile on my face

That doesn‘t work with everything of course, e.g. with most classical music I prefer the sound to be as clean as possible, so that I can listen to a concert hall‘s acoustics and not to what my gear adds on distortion. But Jazz is a complete oposite, there tubes just shine. And A5 on a high gain setting, although it‘s a real overkill for my mostly used t5p.2

 

[Indrajit]

Hi, I have a Fiio X5iii and a Sennheiser HD 598. I am looking for a sound quality that is more neutral. I have options for 3 amps. I can buy either Fiio E12A, Fiio A5 or Magni 3. Portability or not is not an issue. Only sound quality matters. Can anyone here recommend the best in the mentioned class for the pairing with X5III?

 

[a-LeXx]

Hi, I have a Fiio X5iii and a Sennheiser HD 598. I am looking for a sound quality that is more neutral. I have options for 3 amps. I can buy either Fiio E12A, Fiio A5 or Magni 3. Portability or not is not an issue. Only sound quality matters. Can anyone here recommend the best in the mentioned class for the pairing with X5III?

Why would you need an amp for a HD598? Your X5III should be perfectly capable to drive it alone. Remember, EVERY amp, even the most neutral one, will always affect the sound. So, the best solution is not to use any amps if you don't want to achieve a particular result, e.g. getting some warmth and distortion from tubes...