JLE TPA3255 Build and Modifications

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drMordor

drMordor

Member
Joined 2019
daniboun said:
Soundstage :
I find here the exceptional signature of the TPA325X chips, as I have always claimed on my reviews, the TPA325X is splendid concerning the soundstage. Everything is well separated, the instruments are well detached from each other, I clearly find what I felt when listening to the Drmodor module or even my updated Aiyima TPA3251. No doubt, the TPA325X continues to surprise me.

Mediums :
If I refer to listening to the DrMordor module with the OP Amps Mc33272 and the very good caps Elna Silmic II, I find the combo OPA1656 + Muse UES great too. We feared with Jlester a sound a little "cold, even metallic". In the end this combo works rather well) It's clean, the voices are well detached from the instruments, the mids are definitely good.
Jlester also found the voices were constrained on PFFB mode, I did not particularly feel that way. I also gave a try with the Muse 02 and the voice are clearly more present towards the front of the stage.


Trebles :
As strange as it may seem, I find them a little more nuanced than on the DrMordor module. On my Jazz register in particular, I found the reproduction of the cymbals smoother and more neutral than with its competitor. the highest notes are very well transcribed in general.
Acoustic guitars and other stringed instruments are very well reproduced, the micro details are present and we really feel something very alive when listening; particularly on the highest notes.


Bass :
Here is a point that questions me a little .... I found the bass very well maintained on the DrMordor module and rather pronounced when listening. On the Jlester module, they are less prominent but still present. We have the impression of a more natural rendering on the Jlester module. In both cases, the overall bass rendering is very good : nothing to envy my Hypex Ncore modules for example )


Module sensitivity :

As I often stream via my DAC in APTX HD, I highlighted a big problem with the DrMordor module. The latter is extremely sensitive to this wireless protocol. I sometimes have very audible interference that creeps into my speakers. With the Jlester module I have no problem here) I think the PCB of the Jlester module is less prone to interference, unless the cause of the problem is related to the integrated LLC power supply of the DrMordor module ... Jlester Module is at the top at this level and it is more than appreciable!
Another point, although the DrMordor module is rather silent, gluing my ear to the speakers I perceive from time to time, some noises probably generated by PSU of the DrMordor module. Whereas when I glue my ear to my speakers with the Jlester module, it's less noticeable.
Anyway : it's not really disturbing when listening to my playlist.
I would end this note with a small negative point concerning the Jlester module: I have a slight POP sound when I turn it off but nothing to report when I turn it on…


Conclusion :

I think Jlester has designed a very interesting module. It is clearly a high-end module. It's better than my 3E Audio (I have the RTR module and the finished amp as well).
Given that DrMordor does not reveal any measures concerning its module, we can therefore conclude that the Jlester module should be up to the announced measurements. (let's wait for the ASR review).
I was really looking forward to testing this module and it's done) I really recommend its purchase.

Here are a few items that will help you with to make the right choice : Jlester module with an SMPS LLC PSU will cost you around $200, the XRK audio module will cost you $250 without PSU. The DrMordor Module will cost you around $170 with integrated PSU but without tangible measurements…. PS : I will compare it to my Purifi modules as soon as my Custom Buffer is finished.
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Bro, in my amp you use MC33272? This is good opamp.
New OPA1656 really better old MC33272, i compare this)))
 
D

Deleted member 148505

TICore260BTL mods for noticeable improvement in sound (requires skill in SMT soldering)

Specific for version V1
  • Replace RA7 and RA8 with 2.2 ohm 0603 (already done in V1A and V1B)

For versions V1, V1A, V1B
  • Remove CA3, CA6, CB3, CB6 or replace them with 10pF 0603 C0G

Optional change
  • Replace C11 with 1uF to 10uF C0G (0603 or 0805)
  • Replace C17 with 1uF C0G (0603)
 
B

Brad Pitt

Member
Joined 2020
JLesterP said:
TICore260BTL mods for noticeable improvement in sound (requires skill in SMT soldering)
For versions V1, V1A, V1B
  • Remove CA3, CA6, CB3, CB6 or replace them with 10pF 0603 C0G
Click to expand...
My opinion is that it should be explained by too low feedback pole with 10k//330pF.
Some TI appnote shows that (feedback pole better above 200kHz, then 68pF for 10k (1/2pi*R*C))
Below, phase with 10K/330pF shows 11 degrés dephased at 10kHz.

 
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D

Deleted member 148505

Brad Pitt said:
My opinion is that it should be explained by too low feedback pole with 10k//330pF.
Some TI appnote shows that (feedback pole better above 200kHz, then 68pF for 10k (1/2pi*R*C))
Below, phase with 10K/330pF shows 11 degrés dephased at 10kHz.

https://goopics.net/i/5OGNv
Click to expand...

Yes, that explains the slightly out of phase (or laid back) voice that I am hearing with SLAA788A's 10K||330pF opamp feedback config.

10K||36pF also looks good, feedback pole is just under the TPA3255's operating frequency at 442kHz, with around 3 degrees phase shift at 20kHz.

With 10K||10pF, cut-off frequency is at 1.59MHz with less than 1 deg phase shift at 20kHz (I will be using this config in my upcoming module)

@DrMordor looks like you've used a lower feedback corner frequency, since frequency response that you've posted in Class-D photo gallery starts to roll-off at 2kHz (possibly higher opamp feedback resistor or capacitor on your module)
 

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D

Deleted member 148505

daniboun said:
Jlester also found the voices were constrained on PFFB mode, I did not particularly feel that way. I also gave a try with the Muse 02 and the voice are clearly more present towards the front of the stage.
Click to expand...

I think the constrained or slightly out of phase voicing will depend on the speakers used. This will be "more" evident on single full range speakers as there is no crossover or other complexities to mess with the phase response.
 
4

454Casull

Member
Joined 2004
TNT said:
I think it would be good if you declared what the rest of your system was composed of while doing the evaluation as any deficiency here would have the possibility to alter the perception of your test objects. Also, what is your reference? Do you often listen to non amplified, natural instrument music performances? Also, for us who read this, declaring the songs, and the used format, played to do the evaluation would be informative in order to judge your opinions. You must realise that we have no clue whatsoever what your quality standard, current performance of your sound system and experience in judging sound are.

//
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Honestly, you should just temper your own expectations a little bit. daniboun is out here working hard for all our benefit and you are looking the gift horse in the mouth.

He never mentioned anywhere that he is a certified golden-ear listener with an accredited reference system. If you can't extrapolate his feedback into anything useful for yourself, just ignore what he says and carry on... for myself, I appreciate the work even if it doesn't necessarily match up with quantifiable measurements.
 
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