This is AIYIMA.
We have tried to change the chip to OPA2134PA and LM4562NA on A07, the sound improved a lot, especially when LM4562NA is used.
As stated a few months ago we decided for "the fun of the exercice" to go for quite a long list of mods regarding the Aiyima A04.
Current lockdown and distance are not helping progress at all but at least it gives me currently some time to start posting.
Now to the questions: where do you want my posts to be located?
Here, on this thread, as I did in the past (so just following what I started), or rather in this new thread, apparently dedicated to this unit?
Aiyima A04 TPA 3251 measurements, and maybe more
Note that I am asking the question as double posts are not permitted (and I won't have time to follow multiple threads in case of questions), plus there won't be any measurements and all reports will be based on the owner's findings - I am not interested in owning such a unit... but nevertheless decided to buy one for my own mother (international opera singer), so it must have some sonic value
Pick you choice and we get started on mods...
Claude
Current lockdown and distance are not helping progress at all but at least it gives me currently some time to start posting.
Now to the questions: where do you want my posts to be located?
Here, on this thread, as I did in the past (so just following what I started), or rather in this new thread, apparently dedicated to this unit?
Aiyima A04 TPA 3251 measurements, and maybe more
Note that I am asking the question as double posts are not permitted (and I won't have time to follow multiple threads in case of questions), plus there won't be any measurements and all reports will be based on the owner's findings - I am not interested in owning such a unit... but nevertheless decided to buy one for my own mother (international opera singer), so it must have some sonic value
Pick you choice and we get started on mods...
Claude
Few month ago I discussed with Amir from ASR and we had to put the AIYIMA Tilear 2.1 to the test (with OPA1656 + Inductors update).
Unfortunately this could not be done ... However I would appreciate that a person living in the USA with this model could get in touch with ASR so that we go to the end of the process ... Any volunteers?
Unfortunately this could not be done ... However I would appreciate that a person living in the USA with this model could get in touch with ASR so that we go to the end of the process ... Any volunteers?
OK, given the overhelming response... I guess I will keep posting here.
Note sure it is still of interest to anyone, but I will get started and depending on feedback will bother posting... or not. No offense at all, I do perfectly understand this section may probably be less DIY than some others.
Note sure it is still of interest to anyone, but I will get started and depending on feedback will bother posting... or not. No offense at all, I do perfectly understand this section may probably be less DIY than some others.
Short summary of my past posts, sorry for the blunt bullet points statements and, no, I won’t start a debate :
- 6 months ago I discovered that trustfull people got interested in that little unit, had a look at its layout, gave some possible hints re tuning/mods and advised amongst other things on OPA1656
- Got no interest at all in the unit personaly other than considering tuning it being a potiental puzzle / game
- Meanwhile one of my best friends wanted to give it a go, saving a 50y old amp by changing all its internals, I advised giving that unit a try, and he even decided to go bi-amping directly. He considered all this as a fun project/game we could play together, tweaking bits and if it goes pop then at least we would have had some fun. He has other amps and quite some training re music, but wants to learn about amps…
- Out of the box the unit confirmed that it was indeed good VFM. However, in our POV and direct comparison with another recent amp we use « meanwhile », it could only compete with modern amps up to say 500E. As in the past, my conclusion was the best VFM Class D amp can compete with 5x more expensive A/B amps, which is already great, but the small units aren’t giant killers (and not suited to my needs in a my main system). A midfi Onkyo played overall on level or better, not to mention features, conectivity, built quality. In bi-amp mode with a good PS, despite the high efficient Klipsch RP-8000F that are intended to be paired with it, things got indeed surprising more level with the Onkyo, perhaps even bettering it slightly now (see previous posts for all details).
- We decided to have some fun and see if we could still keep that 5x VFM « rule » while tweaking the units. We decided to go as far as spending on parts roughly as much money into the amps as they cost and to see if the end result could compete with modern traditional « over 1000E "VFM" amps ».
- The beauty of having 2 identical (and identicaly sounding) amps to start with, plus a clever layout allowing to go very quickly single or biamp or to switch from one amp to the other within seconds gives us the opportunity to compare the value and differences of the tweaks we are doing (one amp moded with the last tweak, the other won’t)
- We hope that way to be able TO OUR EARS to assess the benefits of each mod, the sonic trends of each mod and to give future tweakers hints of what mods are best VFM or in what direction to adjust their sound. Indeed some mods are really no brainer and easy to implement, while others will be firsts I believe
- As for us, we want have some fun and see / hear how far that little unit can reasonably go. Oh, and I purchased a unit for my mum as quick back up to her main amp that failed, so it can’t be that bad
Claude
- 6 months ago I discovered that trustfull people got interested in that little unit, had a look at its layout, gave some possible hints re tuning/mods and advised amongst other things on OPA1656
- Got no interest at all in the unit personaly other than considering tuning it being a potiental puzzle / game
- Meanwhile one of my best friends wanted to give it a go, saving a 50y old amp by changing all its internals, I advised giving that unit a try, and he even decided to go bi-amping directly. He considered all this as a fun project/game we could play together, tweaking bits and if it goes pop then at least we would have had some fun. He has other amps and quite some training re music, but wants to learn about amps…
- Out of the box the unit confirmed that it was indeed good VFM. However, in our POV and direct comparison with another recent amp we use « meanwhile », it could only compete with modern amps up to say 500E. As in the past, my conclusion was the best VFM Class D amp can compete with 5x more expensive A/B amps, which is already great, but the small units aren’t giant killers (and not suited to my needs in a my main system). A midfi Onkyo played overall on level or better, not to mention features, conectivity, built quality. In bi-amp mode with a good PS, despite the high efficient Klipsch RP-8000F that are intended to be paired with it, things got indeed surprising more level with the Onkyo, perhaps even bettering it slightly now (see previous posts for all details).
- We decided to have some fun and see if we could still keep that 5x VFM « rule » while tweaking the units. We decided to go as far as spending on parts roughly as much money into the amps as they cost and to see if the end result could compete with modern traditional « over 1000E "VFM" amps ».
- The beauty of having 2 identical (and identicaly sounding) amps to start with, plus a clever layout allowing to go very quickly single or biamp or to switch from one amp to the other within seconds gives us the opportunity to compare the value and differences of the tweaks we are doing (one amp moded with the last tweak, the other won’t)
- We hope that way to be able TO OUR EARS to assess the benefits of each mod, the sonic trends of each mod and to give future tweakers hints of what mods are best VFM or in what direction to adjust their sound. Indeed some mods are really no brainer and easy to implement, while others will be firsts I believe
- As for us, we want have some fun and see / hear how far that little unit can reasonably go. Oh, and I purchased a unit for my mum as quick back up to her main amp that failed, so it can’t be that bad
Claude
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Off we go with the list of mods we intend to do. We have the parts lying around since months, but distance (this HIFI system is not in the main house) and lockdown don’t help. At the end, my friend will carry out the less critical mods while I hope « when the Gov permits » to go for the potentialy trickier ones.
The 2 amps are internaly indentical and do sound indeed identical. I believe people here call them green boards or so. We found the volume pot to be a weak point and, as we wanted a remote control and a single volume control for both amps (remember bi-amping is the goal at the end as that sounded better) we decided to go for an external pot. We have yet to remove the existing tiny low quality pots and go for a straight signal path instead and tell the difference, at this stage the baseline are the original amps with an additional Alps blue pot (not the best sonic choice by far in my experience (I am using a Black Beauty since 3 decades and a Tocos since a year, would love to give the MUSES a try), but reasonable choice if you want a motorised physical pot and not spend fortunes). Oh, and the amps are fed by a Meanwell SMPS, LRS-350-24. This adjustable unit allows to go up to 29V (not that we need all that power in bi-amping mode) and has a much lower ripple / better specs than the next unit with 36V. And with 350W it has enough power to drive 1 or 2 units. Personaly, I wouldn’t trust anyway much output power from these small units given their tiny internals…
Now that you know the baseline, here is the list of mods we intend to do, in random order, some are even easy to perform and reversible :
- Fit a home made filter between SMPS and power amp(s), various configurations
- Increase the PS capacity with external caps… just to give it a try given we will get some unused desoldered PS caps ;-)
- Replace the existing op amps with OPA1656 (I have many other “flavours” ready to go in case of final fine tuning, but that’s clearly our first choice)
- Replace the volume pot as we feel that’s a potential bottleneck
- Install Polypropylene DC blocking caps and get rid/bypass the relevant electrolytics at the entry of the op amps and between op amps stages
- Replace the electrolytics at the output of the op amps stage with 1uF WIMA MKS quality caps, as that should do the trick with the (roughly) 24k power amp input impedance that follows
- Bypass various PS electrolytic caps with either Murata 0.1uF (C0G, had to go for 0.082uF in fact due to the 0.1uF being in back order) or 2,2uF X7R quality caps
- Replace the 2 big electrolytic PS caps with high quality low ESR ones
- Bypass the 2 big PS caps with quality 2x2.2uF X7R caps each
- Replace the 4 output filter coils with quality coils (Coilcraft) having other values matching the LS impedance
- Replace the 4 output filter caps with quality caps (real Epsons, as I suspect the ones in the unit are fakes) having other values matching the LS impedance
- Resolder various locations starting with the awful output connectors
I believe that’s it. Parts are already lying here since ages or now at my friend’s who left Thursday night in hurry due to the lockdown with a TODO list, sadly on his own due to lockdown and distance instead of us getting started together on Saturday as intended. Of course any comments or ideas are as always welcome for potential future additions to that list.
Let’s see if we do it all and if nothing blows up J
ALL FINDINGS AND RESULTS ARE / WILL BE IN OUR VERY HUMBLE OPINION, TO OUR EARS, AND NOT WILLING TO GET INVOLVED IN ANY DEBATE.
Claude… and Gilles
The 2 amps are internaly indentical and do sound indeed identical. I believe people here call them green boards or so. We found the volume pot to be a weak point and, as we wanted a remote control and a single volume control for both amps (remember bi-amping is the goal at the end as that sounded better) we decided to go for an external pot. We have yet to remove the existing tiny low quality pots and go for a straight signal path instead and tell the difference, at this stage the baseline are the original amps with an additional Alps blue pot (not the best sonic choice by far in my experience (I am using a Black Beauty since 3 decades and a Tocos since a year, would love to give the MUSES a try), but reasonable choice if you want a motorised physical pot and not spend fortunes). Oh, and the amps are fed by a Meanwell SMPS, LRS-350-24. This adjustable unit allows to go up to 29V (not that we need all that power in bi-amping mode) and has a much lower ripple / better specs than the next unit with 36V. And with 350W it has enough power to drive 1 or 2 units. Personaly, I wouldn’t trust anyway much output power from these small units given their tiny internals…
Now that you know the baseline, here is the list of mods we intend to do, in random order, some are even easy to perform and reversible :
- Fit a home made filter between SMPS and power amp(s), various configurations
- Increase the PS capacity with external caps… just to give it a try given we will get some unused desoldered PS caps ;-)
- Replace the existing op amps with OPA1656 (I have many other “flavours” ready to go in case of final fine tuning, but that’s clearly our first choice)
- Replace the volume pot as we feel that’s a potential bottleneck
- Install Polypropylene DC blocking caps and get rid/bypass the relevant electrolytics at the entry of the op amps and between op amps stages
- Replace the electrolytics at the output of the op amps stage with 1uF WIMA MKS quality caps, as that should do the trick with the (roughly) 24k power amp input impedance that follows
- Bypass various PS electrolytic caps with either Murata 0.1uF (C0G, had to go for 0.082uF in fact due to the 0.1uF being in back order) or 2,2uF X7R quality caps
- Replace the 2 big electrolytic PS caps with high quality low ESR ones
- Bypass the 2 big PS caps with quality 2x2.2uF X7R caps each
- Replace the 4 output filter coils with quality coils (Coilcraft) having other values matching the LS impedance
- Replace the 4 output filter caps with quality caps (real Epsons, as I suspect the ones in the unit are fakes) having other values matching the LS impedance
- Resolder various locations starting with the awful output connectors
I believe that’s it. Parts are already lying here since ages or now at my friend’s who left Thursday night in hurry due to the lockdown with a TODO list, sadly on his own due to lockdown and distance instead of us getting started together on Saturday as intended. Of course any comments or ideas are as always welcome for potential future additions to that list.
Let’s see if we do it all and if nothing blows up J
ALL FINDINGS AND RESULTS ARE / WILL BE IN OUR VERY HUMBLE OPINION, TO OUR EARS, AND NOT WILLING TO GET INVOLVED IN ANY DEBATE.
Claude… and Gilles
Some quick pix of the initial built at various stages. Cables shown and other bits here were back then temporarly devices on hand just to make sure... it all could fit and work.
Meanwhile it all looks of course much neater with better routings and a perfectly closing lid if needed, but that’s not what you are interested in and it will be improved even further anyway once we have tested all we wanted ;-)
This Pioneer amp of the 70s used to belong to Gilles grand father and has some sentimental value. Repairing it would have cost more money than changing all internals and I must say I don’t trust most repairers down here, not to mention that old unit was anyway probably on its last legs re sound and life expectancy of its components. IMHO a very nice idea of Gilles to save it this way…
Claude
Meanwhile it all looks of course much neater with better routings and a perfectly closing lid if needed, but that’s not what you are interested in and it will be improved even further anyway once we have tested all we wanted ;-)
This Pioneer amp of the 70s used to belong to Gilles grand father and has some sentimental value. Repairing it would have cost more money than changing all internals and I must say I don’t trust most repairers down here, not to mention that old unit was anyway probably on its last legs re sound and life expectancy of its components. IMHO a very nice idea of Gilles to save it this way…
Claude
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Good one! I think some people get carried away in their own words.
Man, this thread is about a chip not about your (not you dr.)musings and modifications. Be respectful and open your own. Maybe somebody wants to read your novels.
That thread rocks
Aiyima TPA3251 Modification Build Thread !
It is technicaly minded and in the right hands, so from now on I will post there!
Claude
Aiyima TPA3251 Modification Build Thread !
It is technicaly minded and in the right hands, so from now on I will post there!
Claude