Amplifier Modules and PCBs For Sale

[Deleted member 148505]

Really excited to see the progress. Too bad I probably won't go for it even if it's way better than your TPA3255 already (I would have to buy another SMPS).

The board is still the same, just lower gain, lower rail voltage and TPA3251 PFFB config. If the benchmark is at 10W, I would have used TPA3250 config.

 

[commstech]

Nice! It has very good specs. Hopefully Roger will be able to compare the improvement on residual noise of his SMPS.



What cap did you use? While mixing out Silmic II and Muse caps I found out that most of the 'bloom' sound comes from Nichicon Muse, though in some opamps, the bloom sound is not so noticeable..

I am using Elna CE-BP bipolar caps . I love the Nichicon Muse too but my local shop here does not have 10uf in bipolar or non-polarized version. Muse, nichicon gold , Elna silmic at the shop were all 22uf minimum. At least I know my problem has been solved. I shall order muse 10uf to replace if I do not like the Elna CE-BP sound.

 

[Deleted member 148505]

I am using Elna CE-BP bipolar caps . I love the Nichicon Muse too but my local shop here does not have 10uf in bipolar or non-polarized version. Muse, nichicon gold , Elna silmic at the shop were all 22uf minimum. At least I know my problem has been solved. I shall order muse 10uf to replace if I do not like the Elna CE-BP sound.

I see, I plan to create a relay based, speaker protection board for single supply amps. So that 22uF can be used without problem.

 

[Deleted member 148505]

Hello
I went from a lrs350 power supply to a Connex 300rs power supply, minimum mains connector ditto aux power supply, only positive point the dimensions of the 10cm * 10cm card and aux power supply, listening big disappointment, sound without dynamics, workshop direction, to the oscilloscope, the HF residue and peaks, change capa 2200uF / 63v by Nichicon HW, the same as on the TPA card, only a small HF residue remains, listening I find the sound with the lrs350, to hear in a few days
Best regards
Roger

Tested the LRS-350-36 + TICore260BTL right now in my QA400, the noise floor is clean. 65kHz switching freq is around -100dBV. At 34USD on mouser, this is really value for money.

 

[bobo le chat]

Hello
I will try to do some tests on the LRS and Connex this afternoon ... if I have time.
Looks

 

[AlexScan]

bobo please respond at my MP...

 

[AlexScan]

For my futur TPA3255 i will use this SMPS630-S:

SMPS for Audio Applications | Page 2 | Audio Science Review (ASR) Forum

For 110$ this is the best one, specialy designed for TPA3255.

 

[Deleted member 148505]

For my futur TPA3255 i will use this SMPS630-S:

SMPS for Audio Applications | Page 2 | Audio Science Review (ASR) Forum

For 110$ this is the best one, specialy designed for TPA3255.

Looks heavy duty, does it have ripple+noise measurements?

 

[Deleted member 148505]

Trying out OPA1656 on Muse + Elna Silmic II combo, it is cleaner sounding than LME49860. Sounds promising. I will try it out on module with all Silmic II caps.

 

[AlexScan]

Looks heavy duty, does it have ripple+noise measurements?

No... I request to Cresnet the measurement but he not answer to me...

 

[Deleted member 148505]

This Elna Silmic II is better sounding in my bedroom compared with Muse. Good for nearfield listening, I had the speakers beside me.

 

[turion64]

Lester, my experience with using Silmic IIs, and reiterating ppppp’s comments, is that they take a long time to settle in before their true character kicks in. I feel they work in some circuit placements but not all (I’ve never liked them in direct signal path either) but yet drMordor’s board uses them (in the signal path) and they don’t seem to have the muddying effect I’ve normally heard using them. Of course speaker character and other signal modifiers in the path, before the amp, will certainly change each evaluators experiences.

I’m looking forward to seeing what your amp is capable of. I just got it yesterday. SE input & output.

Regards, Pete

 

[bobo le chat]

Hello
Test of noise
MW LRS350 36V / Connex smps300rs48V (with 2*UHW1J222MHD 2200uF/63V)
The two power supplies are charged by a 220 Ohm resistor
LRS set to 40V
smps300RS on 46V

LRS


LRS 0.2V 5uS


LRS 0.2V 20mS

Connex



0.2V 20mS


0.2V 10mS


0.1V 1uS

The Connex output capas have been changed, I no longer have any data with the original condos (2*Samxon LP 2200uF / 63V)

The sound is now very good with the two power supplies
Thanks JLester
Best regards
Bobo

 

[turion64]

Hi Lester: any recommendations on rating and type of SMD cap to use on your op-amp adapter? I’ve searched around the forum but couldn’t find whether that information was shared.

Thanks,

Pete

In my experience when a DIP-8 socket becomes loose after you do opamp rolling, sensitive opamps tend to oscillate (I experienced it with Myref-rev C LM3886 boards) I prefer the opamp to be directly soldered on the PCB.

There's plenty of real estate under the PCB so might as well add a bypass cap and a LED light. Pins 4 and 8. They are not soldered by the factory so you can opt to get the adapter with only OPA1656 installed.

The adapter PCB, the pins, and the DIP-8 socket are all gold plated types to avoid corrosion. Can't settle for less.

 

[Deleted member 148505]

Hi Lester: any recommendations on rating and type of SMD cap to use on your op-amp adapter? I’ve searched around the forum but couldn’t find whether that information was shared.

Thanks,

Pete

Hi Pete, I'm using 100pf 0805 (0603 is also ok) 50V for my LME49860

Hello
Test of noise
MW LRS350 36V / Connex smps300rs48V (with 2*UHW1J222MHD 2200uF/63V)
The two power supplies are charged by a 220 Ohm resistor
LRS set to 40V
smps300RS on 46V

LRS

View attachment 899355
LRS 0.2V 5uS

View attachment 899358
LRS 0.2V 20mS

Connex

View attachment 899359

0.2V 20mS

View attachment 899362
0.2V 10mS

View attachment 899363
0.1V 1uS

The Connex output capas have been changed, I no longer have any data with the original condos (2*Samxon LP 2200uF / 63V)

The sound is now very good with the two power supplies
Thanks JLester
Best regards
Bobo

Thanks Roger! Lower ripple+noise of LLC type SMPS is confirmed.

 

[Deleted member 148505]

TPA325X 36V PFFB Budget Version

Budget version of TPA325X post filter feedback that will run on 36V and will defeat many expensive systems.
ETA is mid January, 2021

Specs

Target SINAD @ 5W 4ohms = 95dB, or 0.002% THD+N
36V PFFB Mode = TPA3250
Dimensions = 147 x 100 x 40mm
Output inductors = Codaca 17A (PCB can still accomodate VER2923-103KL)
Tank capacitors = Lelon or Samyoung 1200uF
Main Chip = TPA3251 running as TPA3250
Heatsink = 100 x 30 x 30mm
Opamp buffers = LM4562NA

Features removed from TICore260BTL to lower down cost
- removed SCR transient overvoltage protect
- removed ENIG gold plated surface finish
- replaced TLS205B0 with LM2940 (same as EVM)
- replaced opamp decoupling electrolytics with SMT type
- replaced with TPA3251

Attached picture of what the end product will exactly look like:

 

[Deleted member 148505]

SMPS300RS has arrived, It's tiny, I can use smaller chassis for this.

 

[Deleted member 148505]

Regarding SMPS300RS, I think the negative out terminal is too close to AC fuse, I'm afraid it might pickup some interferences. I'm also losing confidence on the 5mm pitch AC terminal.

Also they've dipped the whole board in insulating varnish / conformal coating bath, so the terminals including the faston tabs are now insulated lol. I have to replace all terminals and fuse holder, good thing I have all the parts here.

Primary side cap Aishi 100uF 400V, 22mm diameter, 10mm lead spacing.
Secondary side cap is Nichicon 2200uF 50V, 22mm diameter, 10mm lead spacing.

 

[AlexScan]

Change the caps Lester, maybe the nichicon is good but it's not standard audio cap (and Aishi is a cheapest brand)

You can put large 25mm caps for both I think

 

[Deleted member 148505]

Change the caps Lester, maybe the nichicon is good but it's not standard audio cap (and Aishi is a cheapest brand)

You can put large 25mm caps for both I think

Yes I will change it, it has the same performance as meanwell on my soundcard THD measurements.

Also on balanced mode I can't lower down the THD even if I'm using 6.8uH coilcraft VER2923. Possibly the problem is limitation on my setup rather than the module itself. Good side about balanced input is that the 'even harmonics' are dominant., on SE the 2nd and 3rd Harmonics are almost equal.