D
Deleted member 148505
Right temperature + good tip + flux work well for soldering tiny SSOP sized ICs.
I only use wick for removing solder on the iron tip (or when cleaning the PCB trace when a component was recently removed). The iron tip itself will adsorb excess solder from the IC legs.
I use T12-BC2 tip for soldering small ICs.
Then wet tissue paper for removing charred particles from the tip.
I only use wick for removing solder on the iron tip (or when cleaning the PCB trace when a component was recently removed). The iron tip itself will adsorb excess solder from the IC legs.
I use T12-BC2 tip for soldering small ICs.
Then wet tissue paper for removing charred particles from the tip.
Attachments
D
Deleted member 148505
LT3462 is expensive, you can use a cheap buck converter for generating negative rail.
https://training.ti.com/how-turn-buck-converter-inverting-regulator
https://www.onsemi.com/pub/Collateral/DN05004-D.PDF
There is a basic part on JLCPCB for that application.
https://training.ti.com/how-turn-buck-converter-inverting-regulator
https://www.onsemi.com/pub/Collateral/DN05004-D.PDF
There is a basic part on JLCPCB for that application.
D
Deleted member 148505
Correct we need to limit the power dissipation of the regulators, we can also reduce the voltage of switching regulator to around 100mV higher than the dropout voltage of TLS205 to reduce power dissipation.
D
Deleted member 148505
Oh no, I think there's no SOIC8 package alternative for it.
Version 2 will be the same except for some optimized trace routings and dedicated TPS7A49 for TPA3255.
Since you are using +/-12VDC rails for the opamps, I think you need to add a voltage limiter (like in my_ref fremen) to avoid overvoltage on TPA3255 inputs (specially in non-PFFB mode)
Absolute max for the input is only 7V peak to peak
Version 2 will be the same except for some optimized trace routings and dedicated TPS7A49 for TPA3255.
Since you are using +/-12VDC rails for the opamps, I think you need to add a voltage limiter (like in my_ref fremen) to avoid overvoltage on TPA3255 inputs (specially in non-PFFB mode)
Absolute max for the input is only 7V peak to peak
Effectively, it is cheaper ...
To solder, i missed to say that i did a mistake on routing. I designed SOIC8 pads instead of VSSOP.
Lester, should you tease your next input stage topology for the Board V2
D
Deleted member 148505
It is ok without protection if you are sure that the input will not make the output of the buffer opamp higher than 7Vpp.
12Vpp at the input of OPA1637 will make both input_A and input_B get 12Vpp too. 7Vpp absolute max is per SE input. Only around 2.5Vrms is safe input if the amp is in non-pffb mode.
------------------
Anyway, what's the input impedance of your OPA1637? Would you add additional buffer at the frontend or it is not needed?
Nice and fast implementation btw.
Not clear if the maximum is common or differential mode. Asked yet in TI forum ...
I choose 2k for the opa1637. It is really the minimum to avoid voltage divisor with the out impedance of my DAC.
I will build the overall Amp next week to install it the living room and will compare with my old (quite good) amp.
I choose 2k for the opa1637. It is really the minimum to avoid voltage divisor with the out impedance of my DAC.
I will build the overall Amp next week to install it the living room and will compare with my old (quite good) amp.
Not have enough time to build my amp this week ...
About protection :
Audio science review mesured the max level at 5.4Vrms. Then peak is 5.4*1.41=7.61v.
But Zout of DAC is 187ohm and Zin of mine TPA is 2k. This voltage divisor is 0.91 ratio, then the peak become 7.61*.91=6.92V, close but below absolute max rating of 7V of the TPA.
About protection :
Audio science review mesured the max level at 5.4Vrms. Then peak is 5.4*1.41=7.61v
.But Zout of DAC is 187ohm and Zin of mine TPA is 2k. This voltage divisor is 0.91 ratio, then the peak become 7.61*.91=6.92V, close but below absolute max rating of 7V of the TPA
.
You own one of them too? It’s my reference amp (EVO A mod) I compare all the Class Ds to. They have to sound as beautiful as that LM3886 amp.
Cheers,
Pete
Hi amigos,
Here my quick review related to Jlester TPA3255 module (many thanks to Jlester by the way). As first sight, the module seems very well made and exudes quality.
It is clear that Jlester attached particular importance to the design of the board and there is a nice symmetry in the implementation of the components.
For a quick comparison with DrModor TPA3255 module :
Some measurements to compare :
JLESTER TPA3255 :
THD+N 5W , 1Khz : 0.0016%
5W 8Ω: 0.0007% THD
10W 8Ω: 0.0008% THD
5W 4Ω: 0.0012% THD
10W 4Ω: 0.0014% THD
Sinad 5W / 4R : 95
PURIFI :
THD+N 5W , 1Khz 0.0006
THD+N 100W 20-20Khz 0.00017
THD+N 10W 20-20Khz 0.00029
Sinad 5W / 4R : 108
SNR : 131DB (ASR shows 128DB)
BOSC Starkrimson Gan :
THD+N 5W , 1Khz : 0.0004%
THD+N 100W 20-20Khz : 0.0092%
THD+N 10W 20-20Khz 0.0025%
Sinad 5W / 4R : 105
SNR : 121DB
ALLO TPA3255 (to be confirmed) :
THD+N 5W , 1Khz 0.00014
THD+N 100W 20-20Khz 0.0097
THD+N 10W 20-20Khz 0.0091
SNR : about 117DB
DrMordor TPA3255 :
N/C : No measurements for the moment…
XRK TPA3255 :
THD : 25W, 1khz : 0.0017%
THD + N : 25W, 1khz : 0.0037%
THD 10W / 8R : 0.0012% THD
As you know I own lots of TPA325X modules (+ Purifi and Ncore) and and now that the theory is set, let's stick to a "human" listening.
I think I have acquired a lot of experience since I registered on this forum, it goes without saying that this review implies a part of subjectivity in my assessments). Now that the basics are laid, here's what I can tell you about the Jlester module
Setup :
Jlester TPA3255
OPA1656 (will check with Genuine Muse 02 Op amps later).
PFFB : ON
SMPS LLC PSU @44V @350W (600W peak)
AC EMI / RFI special filter
Twisted cooper cables
Full Alu case with
Source : HD Audio Playlist
Streamer : LG V30
DAC : Double AK4497 / Dual Linear PSU
Speakers : Top end DIY Floor Speakers 93DB / 2.5 Way with Ribbon tweeter.
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.
Here my quick review related to Jlester TPA3255 module (many thanks to Jlester by the way). As first sight, the module seems very well made and exudes quality.
It is clear that Jlester attached particular importance to the design of the board and there is a nice symmetry in the implementation of the components.
For a quick comparison with DrModor TPA3255 module :
Some measurements to compare :
JLESTER TPA3255 :
THD+N 5W , 1Khz : 0.0016%
5W 8Ω: 0.0007% THD
10W 8Ω: 0.0008% THD
5W 4Ω: 0.0012% THD
10W 4Ω: 0.0014% THD
Sinad 5W / 4R : 95
PURIFI :
THD+N 5W , 1Khz 0.0006
THD+N 100W 20-20Khz 0.00017
THD+N 10W 20-20Khz 0.00029
Sinad 5W / 4R : 108
SNR : 131DB (ASR shows 128DB)
BOSC Starkrimson Gan :
THD+N 5W , 1Khz : 0.0004%
THD+N 100W 20-20Khz : 0.0092%
THD+N 10W 20-20Khz 0.0025%
Sinad 5W / 4R : 105
SNR : 121DB
ALLO TPA3255 (to be confirmed) :
THD+N 5W , 1Khz 0.00014
THD+N 100W 20-20Khz 0.0097
THD+N 10W 20-20Khz 0.0091
SNR : about 117DB
DrMordor TPA3255 :
N/C : No measurements for the moment…
XRK TPA3255 :
THD : 25W, 1khz : 0.0017%
THD + N : 25W, 1khz : 0.0037%
THD 10W / 8R : 0.0012% THD
As you know I own lots of TPA325X modules (+ Purifi and Ncore) and and now that the theory is set, let's stick to a "human" listening.
I think I have acquired a lot of experience since I registered on this forum, it goes without saying that this review implies a part of subjectivity in my assessments). Now that the basics are laid, here's what I can tell you about the Jlester module
Setup :
Jlester TPA3255
OPA1656 (will check with Genuine Muse 02 Op amps later).
PFFB : ON
SMPS LLC PSU @44V @350W (600W peak)
AC EMI / RFI special filter
Twisted cooper cables
Full Alu case with
Source : HD Audio Playlist
Streamer : LG V30
DAC : Double AK4497 / Dual Linear PSU
Speakers : Top end DIY Floor Speakers 93DB / 2.5 Way with Ribbon tweeter.
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.
Last edited:
D
Deleted member 148505
Hi Daniboun,
Thanks for the review! For the module that you bought, I used VER2923-682KL and 0.68uF output capacitors for the output filter.
Resistors on opamp buffers are manually matched (0 to 3 ohms difference).
PFFB circuit uses C0G caps.
Gain is lower as it is using 18K ohms feedback resistor.
Your build looks good! One thing that worries me is if the switch that you used is rated at 240V.
Input impedance is 10K ohms so you need buffer before it, or 10K ohms potentiometer.
Regards,
Lester
Thanks for the review! For the module that you bought, I used VER2923-682KL and 0.68uF output capacitors for the output filter.
Resistors on opamp buffers are manually matched (0 to 3 ohms difference).
PFFB circuit uses C0G caps.
Gain is lower as it is using 18K ohms feedback resistor.
Your build looks good! One thing that worries me is if the switch that you used is rated at 240V.
Input impedance is 10K ohms so you need buffer before it, or 10K ohms potentiometer.
Regards,
Lester
Hi Jlester,
Thanks for the feedback.
For the switch I answered you by MP : no worries.
You made a nice module, I really like it. Yesterday we did a listening session with a friend of mine, he was impressed by the precision and dynamics of this module whether at low volume or at high volume.
You might give a test with some OP Amps Muse 02, it is really worth the while.
Thanks for the feedback.
For the switch I answered you by MP : no worries.
You made a nice module, I really like it. Yesterday we did a listening session with a friend of mine, he was impressed by the precision and dynamics of this module whether at low volume or at high volume.
You might give a test with some OP Amps Muse 02, it is really worth the while.
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.
//
//
You're right, TNT. Did you read about my Setup ?
I have been a drummer for years I played in many projects ... my father is a guitarist and harmonist and I think I have a pretty good ear)
I am going to update the Playlist so you can know.
I specified that I had to deal with a part of subjectivity ... but the measures being announced that gives an idea.
Anyway , here my HD audio Playlist for testing. it covers a lot of registers and it's my reference playlist for my tests now :
Drum STOP No good (Steve Smith)
Ceremony (Fiona Joy)
Sunny (Laura Fygi)
Raindance (Tony Elman / Mike Marshall)
Ain't no Sunshine (Philippe Chrétien)
Beat (Tingvall Trio)
And I love him (Laure Fygi)
Van Gogh (Fausto Mesoleila)
Homecoming ( Hans Zimmer&Lisa Gerrard)
I have been a drummer for years I played in many projects ... my father is a guitarist and harmonist and I think I have a pretty good ear)
I am going to update the Playlist so you can know.
I specified that I had to deal with a part of subjectivity ... but the measures being announced that gives an idea.
Anyway , here my HD audio Playlist for testing. it covers a lot of registers and it's my reference playlist for my tests now :
Drum STOP No good (Steve Smith)
Ceremony (Fiona Joy)
Sunny (Laura Fygi)
Raindance (Tony Elman / Mike Marshall)
Ain't no Sunshine (Philippe Chrétien)
Beat (Tingvall Trio)
And I love him (Laure Fygi)
Van Gogh (Fausto Mesoleila)
Homecoming ( Hans Zimmer&Lisa Gerrard)
Last edited:
