AIYIMA A07 TPA3255 Amplifier Measurements and Review - LM4562 (and OPA2134) option

[Mal]

"Midnight Audiophile said:
I use an A07 with a Drok 48v, 10 amp adjustable power supply, and run Dali Spektor 2 speakers with it. I think it performs excellent."

Have you compared it with the standard power supply that comes with the Aiyima? Does it make a noticeable difference? Do you use equalisation or tone controls to bring down any brightness in the Dalis? Or are they neutral out of the box?

 

[Mal]

Listening impressions

I connected the amp to the JBL Control 1 Pro speaker ... and I did not like the sound...

Then I moved the amp to my listening room, connected to my regular speakers
...everything was fine. The sound was punchy, well controlled, with good imaging.

Then I put Beethoven's No.2 Symphony with Wiener Philharmoniker directed by Simon Rattle to my CD player and made a "critical listening". The sound was fine, little bit on a dry side, but no bigger complaints.

In general, the amp sounds fine. I would not take it as my main amp, but as a second amp in the office, workshop or bedroom it would be fine...

OK, so that, again, makes me think my speakers are the main flaw. Are there any easily available(!) small, bargain speakers that play nicer with the A07 than the JBLs and the Wharfs?

 

[Tangband]

Tangband, do you have a link to a reputable sales site for the right type of LM4562's for the A07 or the A04 amps?

I used audiophonics in france , they sell to all countrys in europe.

 

[Joe Smith]

I used audiophonics in france , they sell to all countrys in europe.

This one the right one?
Audiophonics

 

[Tangband]

This one the right one?
Audiophonics

Yes .
You have to buy IC removal tools to , also found at that site.

DIP Extractor Clamp for Printed Circuit Board - Audiophonics

This clamp will allow you to simply extract the DIP components from your printed circuit boards without degrading them.

www.audiophonics.fr

 

[Schlippwhip68]

Can agree on everything you wrote. There are clearly sounddifferences between opa2604 and lm4562. One can almost not find two more different sounding IC:s. The first one is sounding warm and innofensive, and the LM 4562 is cleaner and leaner. Both are musically better than ne5532, in my subjective opinion. The opa2604 is a fet opamp and 4562 is a bipolar based IC.

An interesting fact:
Linn products used opa2604 everywhere during the late ninethies including in the legendary CD12 , but changed to LM 4562 everywhere at 2007 when the klimax DS streamer came out. The different players sounded different. Now they seems to have changed again to opa1612 in many places - maybe a suggestion to try ? I have tried ne5532, opa2604, lm4562 and opa1612 and I prefered LM 4562 in both Aiyima a07 and the tpa3251-based Aiyima a04.

Had another go at the op amps today as I have some time on my hands. I rolled the T6 Pro with the Oracle 02 op amps in the preamp output stage and the opa1622 in the A07. A more refined sound all round than the 2604/4562 combo. Todays opa combo gave tighter bass, clearer vocals, more organic, better instrument separation across the board and more air in the highs. Very nice combo indeed. I have no idea what the measurements are but the sound quality is very good. I also tried the opa2134 pure line and mixed but didn't find it that interesting compared, in fact a little dull, veiled, flat by comparison to the Oracle 02/opa1622 combo which made even the DAC usb on the T6 Pro sound almost identical to the ESS9018 Hidizs S3 Pro dac which so in my opinion giving really good value for money here so kudos to Aiyima! The only difference being the S3 Pro pushing out a touch more bass than the USB on the T6 Pro but that being said the extra bass was not needed as the Oracle 02/opa1622 gave plenty and the opa1622 holding the low end with a tight grip making it a little more punchy in the process. This may not be impressive to many but i am coming strictly from a national minimum wage perspective here, low budget and in remembrance of over 30 years hifi enjoyment and for what this little system will give today would have been untouchable in the 80s and 90s and for this money it really is a treat. I remember spending a lot more than this even on all in one boxes back in the late 80s early 90s that probably would come no where near this on vinyl or and especially cassette as far as sound quality goes never mind pre dab days for radio which in many cases would sound like a single 1khz band most of the time. So this is a thumbs up from the paupers here in the UK, at least the one writing this post.

 

[Schlippwhip68]

I have an Aiyima A07 attached to Wharfedale Diamond 9.0 speakers and they sound far too bright for any comfort. Are you suggesting that the amp might be amplifying high frequences by several DB in this context? I have tamed the sound to bearable levels using a Schiit Loki with high frequency knobs rotated anti-clockwise to max (!) But the sound still isn't great. I was going to change the speakers, but now you have me thinking it is mostly this amp at fault. Now I'm thinking of giving up on passive speakers completely. Companies might be more motivated to get things working if the speaker company can't blame the amp company and the amp company can't blame the speaker company. Also, I really like my KEF LSXs - there everything (speaker, amp, dac, EQ) is all in one box... there is only one company that has to shoulder all the blame (or praise...) How did KEF tame the Class D amps in their LSXs?

It won't be the A07 giving that kind of brightness, could well be the WD 9.1s. You could pop the lid on the A07 and grab a couple of opa2604 (op amps) for a few £ $s, they will give a thicker less bright sound that may well fix the issue but I would still say it will be the speakers. the A07 is not at all know for being a bright or analytical amp, it has quite a full well rounded sound comparatively.

 

[Joe Smith]

Swapped my A07 into my workroom system again, in place of the SMSL AO100. Really nice and with sources running through the NAD 1020 preamp, plenty of power using Aiyima's standard power brick. Currently using with my ADS L420s.

Ordered some LM4562 op-amps today from Mouser just for the heck of it. I may try those in the A04 first and see how they do.

I've pulled the AO100 to do some testing of it with a subwoofer in another room. I doubt I'm going to like the SW, but borrowed one from a friend to try out. I just don't have good rooms to incorporate a subwoofer, even in a simple way, but wanted to give one a try since the AO100 has the dedicated SW outs.

The A07 is still running well with no problems after about 9 months. I never run it very hard, my volumes stay pretty low overall...

 

[Mal]

It won't be the A07 giving that kind of brightness, could well be the WD 9.[0]s...

The OP got "fine" sound from his more expensive speakers with the A07 so I think I'll maybe go down the "replace speaker" route... although my Schiit Loki has brought down the brightness to a level I might be able to live with... the Wharfs are good in other respects... great clarity and quite dynamic...

 

[Mal]

Swapped my A07 into my workroom system again, in place of the SMSL AO100. Really nice and with sources running through the NAD 1020 preamp, plenty of power using Aiyima's standard power brick. Currently using with my ADS L420s.

Early 80s speakers! Maybe I should go vintage...

 

[Joe Smith]

Early 80s speakers! Maybe I should go vintage...

I keep experimenting with low cost speakers, but the two-way ADS I have remain my favorites. Hope to eventually get a 3-way model in the L series, though they are scarce in the Midwest. Most of the rooms in our 1916 home are on the small side, and the furniture and radiators in the larger living room make tower speakers and/or sub placement problematic. For now, I have the ADS 520s on good height-adjustable stands in room corners projecting just above the couch line, so I get pretty good overall sound and there is a nice sweet spot if one is so inclined. Another nice thing about the 80s ADS models are the rubber surrounds on the woofers - no foam rot.

 

[MidnightCarouselRider]

My a07 is hooked up to 1965 Bozak Symphonies. I'm about to get a second and actively biamp them.

 

[arvidb]

I won't stop saying that this amplifier (and similar cheap class D amps) is doing a wrong job in signal amplification. The only usable class D amplifiers so far are NCore and Purifi based ones.

What about the ICEpower 300A2? According to the datasheet output impedance stays below 40 mΩ between 20 Hz and 20 kHz (single-ended). Frequency response seems unaffected by load impedance up to at least 40 kHz. (Of course, powering the thing might be a bit interesting: it needs no less than five different power rails! Nicely priced though at €150 from SoundImports.)

 

[pma]

What about the ICEpower 300A2? According to the datasheet output impedance stays below 40 mΩ between 20 Hz and 20 kHz (single-ended). Frequency response seems unaffected by load impedance up to at least 40 kHz. (Of course, powering the thing might be a bit interesting: it needs no less than five different power rails! Nicely priced though at €150 from SoundImports.)

If the output impedance stays below 0.04 ohm up to 20 kHz, it should be OK. I have not had a chance yet to measure any ICEPower amp, so unfortunately I cannot share any experience.

 

[MiniAudioGuy]

Sounds like most people are rolling both opamp sockets in the Aiyima A07, but can anyone share which opamp socket corresponds to which section of the amp?

I would like to mix and match opamps and experiment with the sound.

I assume one corresponds to the input gain and the other the volume...can anyone share their knowledge here?

 

[pma]

Left/Right channel.

 

[Digby]

I was thinking of using this amplifier with a pair of Behringer B2031P speakers at about 1m distance. I was under the impression this is a good amplifier for such a use. I essentially want something with low noise that is energy efficient, am I wrong about this being a good amplifier for this use? Will someone be kind enough to translate the information presented in this thread into 'layman' language for me, so I can understand whether this amplifier is a good choice for my scenario. Thanks.

 

[TheWalkman]

I was thinking of using this amplifier with a pair of Behringer B2031P speakers at about 1m distance. I was under the impression this is a good amplifier for such a use. I essentially want something with low noise that is energy efficient, am I wrong about this being a good amplifier for this use? Will someone be kind enough to translate the information presented in this thread into 'layman' language for me, so I can understand whether this amplifier is a good choice for my scenario. Thanks.

Translation: for $65 it’s a fantastic amp. Buy it. Try it. (Don’t overthink it.)

If you don’t like the amp, give it to a neighborhood kid and create the next audio enthusiast.

 

[El_Arte]

The noise floor exists, though. Yes, I know it's cheap. If you expect the purest of noise void, $65 won't do it. For now. Or will it?

 

[ethernode]

Thanks @pma for this incredibly useful research; what i do not understand is if this non-linearity can be EQ-compensated ?

In other terms
- does the behaviour change with volume (which would require "dynamic" EQ) ?
- will a regular sweep exhibit the non-linearity ?

Thanks again