The Fiio A5 thread: an upgrade of E12A, MUSES02+LME49600, 800mW, 19Vp-p, 12 hours
Apr 15, 2018 at 8:37 AM Post #707 of 1,039
Yeah dynamic range compression is limited to the source recording and how it was handled during the mix down and mastering. what lexx is experiencing is the Fletcher Munson Curves / Equal Loudness Contours, I think.
 
Apr 15, 2018 at 9:47 AM Post #708 of 1,039
Wow, what a discussion... As I said, looking into the non-loaded FR of the amplifier does not necessarily show the whole picture. Do you guys have a circuit diagram of the A5? I couldn‘t find it anywhere... It‘s very possible to have an amp that will have an ideally flat responce into open and non-flat into a non-linear load... Depends on how the negative feedback / gain control is implemented...

All the cans I‘m currently using tend to bloat the bass without enough damping, particularly the Momentum in a paasive mode and the W5000. As a matter of fact, Momentum in the active mode did not show the bass increase, I forgot to mention this initially... And an active mode in Momentum of course is equal to a flat load seen by the source...

So, actually, based on this, I think this amp will probably indeed not have this bass increase with high impedance HPs, because they usually represent a much flatter load than some of the low-impedance cans...

Ok, I‘ll go listen to my new toy, actually this little Amp is really nice, my W5000 sounds with it almost as good as with the HA5000, I really like what I‘m hearing...
 
Apr 15, 2018 at 11:07 AM Post #709 of 1,039
Increasing the gain also increases the voltage? I think i read that somewhere, just asking if thats a correct conclusion.
 
Apr 15, 2018 at 11:21 AM Post #710 of 1,039
With low gain setting, A5 will have the same ouput voltage as the input voltage, so it‘s basically just a current buffer. With high gain, the output voltage will be higher by a factor of around 5. So, it‘s only needed when higher impedance / low sensitivity cans are being driven...
 
Apr 24, 2018 at 8:38 AM Post #711 of 1,039
After few days with the amp, I noticed the following:

on low gain setting, this amp is doing some nasty things with the phase. The soundstage is pretty wide, but the perception of depth is suffering. This doesn't happen on a high gain setting. There, the width of the soundstage is reduced a bit, but it's becoming deeper and the overall presentation turns to be more holographic. This can be only observed with hps that have very good 3D qualities, very noticeable e.g. with an AKG K550, especially with reference-quality binaural recordings, they become kind of flat on low gain.

Too bad no circuit diagram of this amp is available, and I'm too lazy to open it and reverse-engineer...
 
Apr 24, 2018 at 9:56 AM Post #712 of 1,039
I have an AKG K553 - it doesn't do that for me. Doesn't with the HD800 or HD600 either. Difference between high gain and low gain is the volume (for me). Volume match to within 0.1 dB ..... no difference.

Have you actually tried a volume matched blind test? I'd be curious if you can tell the two apart in a completely volume matched blind test with no external cues?

Could be just my hearing though.
 
Apr 24, 2018 at 10:06 AM Post #713 of 1,039
No blind tests. But I asked my wife who has a very good hearing to listen to those 2 settings and describe the differences (without giving her any hints), and she described this in the same way how I hear it... Volume was every time tuned down to 0 and then slowly increased to comfortable listening levels. I'm very sensitive to phase distortions though, confirmed this many years ago with DBTs...
 
May 18, 2018 at 8:50 PM Post #714 of 1,039
Could be. All i know is, any proximity to my V20 renders my e12 useless with so much noise. T-Mobile. 4G.. I know its not my interconnect, because the amp powered on with only the cans attached still picks up the interference.

As an LG V20 owner looking into possibly getting this amp, does the interference include wifi? I have an LG V20 as JUST a DAP, with no cell service. I just use wifi.
 
Jun 28, 2018 at 11:52 PM Post #719 of 1,039
Just wanted to drop by and say I recently picked up a factory sealed A5 for $90, including one of the FiiO Oyaide stacking cables (which is miles better than the A5s included noodle cable).

I already have the E12A Mont Blanc for my IEMs, and fell in love with its clean Muses02 sound, super long battery life, and friendly layout/form factor. But the E12A always struggled to drive some of my more powerful gear.

The A5 has no such issues, and can drive everything I own (or demo at CanJams) no problem. I don’t mind that it has a bit less battery life - it’s a fair trade off. I do like the beefy knurled knob of the E12A better, but that’s small potatoes too.

I agree with Brooko that FiiO missed a great opportunity to build the A5 with a negative gain setting. Then I’d have no reason to even keep my Mont Blanc, as the A5 would also play nice with my most sensitive IEMs. It could have truly been “one amp to rule them all”.

Just like on my E12, I skinned the top and bottom of the A5 with graphic vinyl in ‘brushed titanium’ finish (which looks identical to the E12A’s stock color and brushed finish). Works much better than the FiiO stacking pads, and it has kept my E12A looking brand new for years now. If anyone wants to see a pic lemme know and I’ll post a few.
 
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Jul 7, 2018 at 8:48 PM Post #720 of 1,039
I have a very simple usability mod for the A5 I wanted to share.

The E12A has an awesome volume knob, heavily knurled, giving your finger a kung fu grip. The A5 volume knob may as well be made of glass - it's slippery and very hard to get a grip on it. Why they didn't use the same knob as the E12A is beyond me.

I was going to just order a different 13mm knob, nicely knurled like the E12A's knob. But upon closer inspection of the stock A5's knob, the red 'stripe' (which I originally thought was painted on) turned out to be a thin red rubber o-ring.

DSCN0007.JPG
stock oring.jpg

Well, all you do is remove the red o-ring (using your fingernail or the point of a sharp object like a sewing needle). Here's what you're left with:

DSCN0006 - Edited.jpg

(Note you DO NOT have to remove the knob itself. I only removed it when I thought I was going to replace the knob. To do this mod, you can leave the knob on.)

Anyways, once the red o-ring is removed, I found a similarly sized (but just a tad thicker) o-ring, and reinstalled it back onto the knob. The results are a nice grippy rubber surface that allows the knob to be turned with ease. A vast improvement over the stock knob!

Here's the finished product:

DSCN0002.JPG

Note how the new o-ring is thicker, protruding from the edge more than the stock red one did. This is what provides the grip for your fingers.

The whole process from start to finish takes <10 seconds. The o-ring like I used runs about $0.01 to $0.02, and you can get them numerous places (I happened to get my o-ring from a case of assorted o-rings I already had laying around). If you can’t find one that fits I an assortment, lemme know and I’ll post the exact size of the one I used.

I saved the original red o-ring in a baggie and stored it inside the A5 retail box, if for some odd reason I ever wanted to go back to the stock red o-ring.

Enjoy!
 
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