You should give muses8820 a try. I find them to be more lyrical than the OPA 1656 (which are still very rich & articulate in their own right). I use browndog adapters from cimarron technologies and mount the op-amps myself but they do offer a number of dual op-amps that are already mounted.
SOIC-8 to DIP Adapter - BrownDog Adapters - 970601.
Cheers,
Pete
I own the Muse 02 which is better than the 8820, I found them a bit more warmer but not as good as the OPA1656.
I got caught in the 'hype' when reading a few posts here and ordered a Aiyima A04 from the ebay Aiyima store. Will probably take a long time to reach Sweden.
I have done this a couple of times before, and ordered some 'hyped' class D amps, but have always been disappointed with the sound, and they ended up in the 'scrap box' or as presents to friends. The only DIY amp that really impressed me so far has been a class a JLH, which I think was further improved after some tweaking.
Now I have taken the time to read through this thread, but I found no measurements, and also that the PFFB is not implemented in the Aiyima A04. That gives me a hunch that these will disappoint too..
Has anybody added the PFFB to the Aiyima amps? Are there any measurements on them (FFT spectrum at different power levels and with different input signals)? Looking at the TI spec sheets indicates mediocre performance, and I suspect a Chinese low cost implementation will probably have worse performance. When I say mediocre, it's not about a THD number at 1kHz, I think a falling spectrum is more important too, and low distortion at low output levels.
I have done this a couple of times before, and ordered some 'hyped' class D amps, but have always been disappointed with the sound, and they ended up in the 'scrap box' or as presents to friends. The only DIY amp that really impressed me so far has been a class a JLH, which I think was further improved after some tweaking.
Now I have taken the time to read through this thread, but I found no measurements, and also that the PFFB is not implemented in the Aiyima A04. That gives me a hunch that these will disappoint too..
Has anybody added the PFFB to the Aiyima amps? Are there any measurements on them (FFT spectrum at different power levels and with different input signals)? Looking at the TI spec sheets indicates mediocre performance, and I suspect a Chinese low cost implementation will probably have worse performance. When I say mediocre, it's not about a THD number at 1kHz, I think a falling spectrum is more important too, and low distortion at low output levels.
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I'm sure you have looked this over carefully...
www.ti.com/lit/an/slaa788a/slaa788a.pdf?ts=1599205799757&ref_url=https%3A%2F%2Fwww.google.com%2F
Rob43
@Rallyfinnen
It's not "the end" so to speak, but it is very good value for the money.
The Aiyima amplifier I bought was very good, and you'd have to spend significantly more money to get a little bit better performance.
It's not "the end" so to speak, but it is very good value for the money.
The Aiyima amplifier I bought was very good, and you'd have to spend significantly more money to get a little bit better performance.
@Rob43
Well, I skimmed through it..
It does seem to improve distortion with 5-6dB, about the same amount as the gain is reduced, and FR is more load independent. However it's not easy to see which harmonics are affected most by the feedback. I like FFT's of distortion, but most spec-sheets don't show the distortion spectrum.. Some clues from the 'steps' in the upper end of frequency sweeps can be seen I think, like 10k step should show the amount of 2nd harmonic, and so on, to my understanding.
Adding PFFB would require quite some rework though, but should be doable..
Well, I skimmed through it..
It does seem to improve distortion with 5-6dB, about the same amount as the gain is reduced, and FR is more load independent. However it's not easy to see which harmonics are affected most by the feedback. I like FFT's of distortion, but most spec-sheets don't show the distortion spectrum.. Some clues from the 'steps' in the upper end of frequency sweeps can be seen I think, like 10k step should show the amount of 2nd harmonic, and so on, to my understanding.
Adding PFFB would require quite some rework though, but should be doable..
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@KaffiMann
I really only have one 'system' which now has the JLH amp, and that's what I was looking to replace for better precision in bass, but without losing too much of the other 'goodness' in the mid/treble. I suspect that will fail.
I have built/tested/tweaked a number of class A/AB/D amps, and none of them have been a better compromise than the JLH when it comes to subjective SQ. It also measures surprisingly well. It's low on output power, but it's generally enough for my needs.
I really only have one 'system' which now has the JLH amp, and that's what I was looking to replace for better precision in bass, but without losing too much of the other 'goodness' in the mid/treble. I suspect that will fail.
I have built/tested/tweaked a number of class A/AB/D amps, and none of them have been a better compromise than the JLH when it comes to subjective SQ. It also measures surprisingly well. It's low on output power, but it's generally enough for my needs.
New amplifier TPA3251 by DrMordor :
- Alu H2000 black case
- XLR inputs
- Wuth caps
- Elna Silmic II
- TPA3251
- PFFB +
- OPA1642
- SMPS Connex PSU LLC / Softstart
- Alu H2000 black case
- XLR inputs
- Wuth caps
- Elna Silmic II
- TPA3251
- PFFB +
- OPA1642
- SMPS Connex PSU LLC / Softstart
Hi guys,
I bought the latest version of the Aiyima04 TPA3251 amp with ARC caps.
I swapped the caps out for Panasonics (on Dr Mordor's learned advice) and the NE5532 op amps for LM833s.
I'm now thinking of swapping the op amps out to these China made Discrete dual Op amps:
Audio Discrete Dual Op Amp HiFi Operational Amplifiers OP-AMP replace NE5532 358962406201 | eBay
Do you think that these might be no good, not a fit or just plain overkill for the amp?
I bought the latest version of the Aiyima04 TPA3251 amp with ARC caps.
I swapped the caps out for Panasonics (on Dr Mordor's learned advice) and the NE5532 op amps for LM833s.
I'm now thinking of swapping the op amps out to these China made Discrete dual Op amps:
Audio Discrete Dual Op Amp HiFi Operational Amplifiers OP-AMP replace NE5532 358962406201 | eBay
Do you think that these might be no good, not a fit or just plain overkill for the amp?
OK, thanks Doc! 🙂
Anyway I found these on ebay already soldered onto DIP8 board.
They are chinese, so not so sure if they might be fake? 😕
1PCS OPA1656IDR OPA1656 OP1656 ON DIP8 SOCKET | eBay
I can only afford these at the moment
Anyway I found these on ebay already soldered onto DIP8 board.
They are chinese, so not so sure if they might be fake? 😕
1PCS OPA1656IDR OPA1656 OP1656 ON DIP8 SOCKET | eBay
I can only afford these at the moment
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At that price they better be real and not fakes... I believe some here already posted some trustfull links for these... can't help, I did mine DIY
You changed the PS caps... did you notice any change in sound?
Claude
You changed the PS caps... did you notice any change in sound?
Claude
Please change those 10uF Fake nichicons (4x) to ELNA SILMIC II, another set of 10 uF TK caps also. You will sure notice the difference.
https://www.mouser.sg/ProductDetail/Elna/RFS-35V100ME35?qs=HV%2FSjD3ivR%252BgiKy0fOOcuQ%3D%3D
Like this
Haha, yes.
For me, there was clearly an audible change when I swapped out the ARCs for the Panasonics, mainly in terms of it now sounding a lot smoother than before, without losing any of the detail I had with the ARC caps in place. The bass now sounds tighter.
However, I seem to have lost some maybe wrongly earlier perceived "transparency" though there is now a lot less of that Class D glare.
Overall good caps as Dr Mordor suggested and IMHO they worth a try. 😉
Yes, there was an audible change, and I think for the better overall - tighter bass with no loss of detail although maybe a slight loss of wrongly perceived "transparency" due to less of that Class D glare (good or bad this, Im not sure..haha)
For me, there was clearly an audible change when I swapped out the ARCs for the Panasonics, mainly in terms of it now sounding a lot smoother than before, without losing any of the detail I had with the ARC caps in place. The bass now sounds tighter.
However, I seem to have lost some maybe wrongly earlier perceived "transparency" though there is now a lot less of that Class D glare.
Overall good caps as Dr Mordor suggested and IMHO they worth a try. 😉
Yes, there was an audible change, and I think for the better overall - tighter bass with no loss of detail although maybe a slight loss of wrongly perceived "transparency" due to less of that Class D glare (good or bad this, Im not sure..haha)
That's photo ref from this site.
Mine I changed those 4x nichicons to Elna Simlic II 10uf 25v (35v no stock in mouser that time)
changed 5x black caps to Nichicon UFG 10uF 50V.
Will share photos later. haven't taken photos at the time of changing.
Regarding SQ wise, I can say Deep bass & clear highs, compared to before.
No more muddy like before.
Only my ears, as measuring equipments.
I changed the PS caps also to Panasonic FS 2700uF 35V, at the same time.
EEU-FS1V272 Panasonic | Mouser Singapore
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🙂🙂
I changed mine to Panasonic 1800uf 35V, with ripple current of 3.8. I'm wondering if the additional uf in your caps makes any audible difference, as the ripple current of the Pan 2700uf is slightly lower than the Pan 1800uf? Better bass response maybe?
Will likely try this mod later, thanks!🙂
I changed mine to Panasonic 1800uf 35V, with ripple current of 3.8. I'm wondering if the additional uf in your caps makes any audible difference, as the ripple current of the Pan 2700uf is slightly lower than the Pan 1800uf? Better bass response maybe?
Will likely try this mod later, thanks!🙂
By the Way, I am using Genuine NE5532AP (replaced the supplied, so called FAKE NE5532).
Have LM4562 and OPA2134. Yet to test. now waiting for my tpa3255 components to arrive.