Hi amigos,
I upgraded the Inductors (MA5173-AE as per TI spec) + OPA1656 on my Aiyima 3151, Tilear 2.1 PCB with full Elna caps.
++ :
I confirm what has been told by Rhing : soundstage is improved, better roundness in the bass and better clarity in the Mediums.
Listening Eric Bibb Live @ FIP in HD Audio it's surprising!
I upgraded the Inductors (MA5173-AE as per TI spec) + OPA1656 on my Aiyima 3151, Tilear 2.1 PCB with full Elna caps.
++ :
I confirm what has been told by Rhing : soundstage is improved, better roundness in the bass and better clarity in the Mediums.
Listening Eric Bibb Live @ FIP in HD Audio it's surprising!
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Hi Dany
Did you check that the changes you made were suited to your loudspeaker impedance in the 10 to 20kHz (coil value + cap value in the output filter)?
Do you have the impedance curve of your speakers?
Enjoy music
Claude
Did you check that the changes you made were suited to your loudspeaker impedance in the 10 to 20kHz (coil value + cap value in the output filter)?
Do you have the impedance curve of your speakers?
Enjoy music
Claude
Hi amigos,
I upgraded the Inductors (MA5173-AE as per TI spec) + OPA1656 on my Aiyima 3151, Tilear 2.1 PCB with full Elna caps.
++ :
I confirm what has been told by Rhing : soundstage is improved, better roundness in the bass and better clarity in the Mediums.
Listening Eric Bibb Live @ FIP in HD Audio it's surprising!
Hi Danny. Just some quick questions. Can you still get the top case on with these inductors as I understood they are bigger than the originals ? Did you also change the Output Capacitors or just the Inductors ? What value of Inductors ?
James.
As per Danny's post, the ref of these coils indicates 7uF.
They are marginaly bigger than what is fitted first place and hence a quite straight forward replacement.
Having said that, I can't outline enough that simple copy paste from "Rhing" isn't a good idea at all. He knew what he was doing and the values he chose where not just as per TI's example (that's merely a coincidence)... but as per TI's calculation sheet. In short, if one wants to play with that, output coils value and output caps value have to be CALCULATED for YOUR speakers. I am quite convinced "Rhing" would have chosen other coil values for his other speakers...
Caps and coils form the output filter of this Class D amp and it works in conjunction with the associated load. In short, you have to know the impedance of your speakers in the 10 to 20kHz band and then calculate various cap and coil combos until you find one that suits you (gives the best possible response and damping).
As "Rhing" stated, TI sheets and calculation tools are quite explicit - as long as you know what you are doing. If simply taking values from other set ups, one goes the risk to completely ruin the treble response. Note though, you might find it "better", but it isn't really HIFI anymore and another debate, taste and colours.
I hope this helps
Claude
They are marginaly bigger than what is fitted first place and hence a quite straight forward replacement.
Having said that, I can't outline enough that simple copy paste from "Rhing" isn't a good idea at all. He knew what he was doing and the values he chose where not just as per TI's example (that's merely a coincidence)... but as per TI's calculation sheet. In short, if one wants to play with that, output coils value and output caps value have to be CALCULATED for YOUR speakers. I am quite convinced "Rhing" would have chosen other coil values for his other speakers...
Caps and coils form the output filter of this Class D amp and it works in conjunction with the associated load. In short, you have to know the impedance of your speakers in the 10 to 20kHz band and then calculate various cap and coil combos until you find one that suits you (gives the best possible response and damping).
As "Rhing" stated, TI sheets and calculation tools are quite explicit - as long as you know what you are doing. If simply taking values from other set ups, one goes the risk to completely ruin the treble response. Note though, you might find it "better", but it isn't really HIFI anymore and another debate, taste and colours.
I hope this helps
Claude
James, the top cover will fit on cleanly as long as the inductor's outer diameter isn't too much larger than the stock inductors. The inductors must also be fully seated on the PCB to provide enough clearance to put the cover back on.
ClaudeG, you are correct. I bought the Aiyima TPA3251 2.0 amp to use with my KEF LS50 speakers. My Klipsch Forte II spekers in my main system has a completely different impedance vs. frequency response between 10kHz and 20kHz.
KEF LS50 Impedance vs. Frequency
Klipsch Forte II Impedance vs. Frequency
After installing the 7uH Coilcraft inductors, the amp sounded better suited for the KEF LS50 speakers. With the Klipsch Forte IIs, the amp still sounded good from the lows through the mid-highs, but the highs were slightly tipped up where my system sounded brighter overall. If I wanted to optimize the amp to the Klipsch Forte IIs, then a similar inductance to the stock 12.5uH inductors would be appropriate.
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Thanks Rich 🙂
I have calculated the filters we want for the RF-8000-F and I will change both coils and caps (the latter because of their value, the former because of their value and quality).
That is if the unit sounds better than a 600$ "reference amp" my friend has purchased last month and is thus deemed tunable / worth investigating 🙂
Enjoy music
Claude
I have calculated the filters we want for the RF-8000-F and I will change both coils and caps (the latter because of their value, the former because of their value and quality).
That is if the unit sounds better than a 600$ "reference amp" my friend has purchased last month and is thus deemed tunable / worth investigating 🙂
Enjoy music
Claude
Hi Claude you re perfectly right. With my 8 ohms speakers, 93DB + ribbon 36-23000 HZ, 2.5 way. This "lucky" tweak seems to fit my speakers.
I used the same inductors as Rhing and just noticed a good improvement... this is subjective opinion once more.
I probably "played with fire"
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Lucky you then... If one day you appear to have your impedance vs frequency curve, we might find out if there are "luckier values" re coils and caps (the latter being non expensive to adjust of required).
Sadly 8 Ohm speakers don't mean a lot, despite recent norms re max possible variations (most manufacturers don't care and it is difficult to respect strictly anyway), not to mention ribbons are special... you are getting close to my beloved magnetostats 🙂
Have fun all of you
Claude
Sadly 8 Ohm speakers don't mean a lot, despite recent norms re max possible variations (most manufacturers don't care and it is difficult to respect strictly anyway), not to mention ribbons are special... you are getting close to my beloved magnetostats 🙂
Have fun all of you
Claude
Thanks for the answer 🙂
Ok I saw it too. I wondered if I searched well because they are much more expensive than 49720 or 1622...
My setup includes a USB Box S+ dac and column speakers. I will receive soon an amp Aiyima Tpa3255 :
AIYIMA Mini HIFI TPA3255 Stereo 2.0 Channel 300W*2 High Power Digital Amplifier Class D Audio AMP For Home Sound Theater DIY|Amplifier| - AliExpress
and I would like to change the op amps..
Is there such a big difference between opa1656 and 1622?
Thanks
Where are you located ??
I have some if you are interested. Are you looking for then on DIL8 adapters or just the SOIC8 chips ?
James.
If you are experiencing "very noisy" with the OPA1656, you did something wrong.
Rob43
Klipsch RP-8000F
Hello Claude
Can you share these values?
I also own Klipsch RP-8000F
Thanks...
Hello Claude
Can you share these values?
I also own Klipsch RP-8000F
Thanks...