• The Vendor's Bazaar forum is for commercial offers and transactions. Only unmoderated members can post here.

    diyAudio provides this forum for the convenience of our members, but makes no warranty nor assumes any responsibility. We do not vet any members. Use of this facility is at your own risk. Customers can post any issues in those threads as long as it is done in a civil manner. All diyAudio rules about conduct apply and will be enforced.

Amplifier Modules and PCBs For Sale

  • Thread starter Thread starter Deleted member 148505
  • Start date Start date
Status
Not open for further replies.
Jump to Latest
#1,124
Here's Sylph-D200 with TPA3255 chip, PFFB (power supply is 38VDC)

Right channel is A+B, Left Channel is C+D

I need to upgrade my soundcard interface's power supply since the noise floor is high. After I upgrade it, then I will be confident to publish the result.

Early publishing of full measurements might contain inaccurate data.
 

Attachments

  • TPA3255 5W 4 ohm Lch.png
    TPA3255 5W 4 ohm Lch.png
    40.8 KB · Views: 225
  • TPA3255 5W 4 ohm Rch.png
    TPA3255 5W 4 ohm Rch.png
    41 KB · Views: 218
#1,129
10W 8 ohm left and right channels

Notice that A+B channel has lower THD on higher current output.

Although it's also possible that the wiring/connections are the culprit.
 

Attachments

  • TPA3255 10W 8 ohm A+B.png
    TPA3255 10W 8 ohm A+B.png
    40.5 KB · Views: 217
  • TPA3255 10W 8 ohm C+D.png
    TPA3255 10W 8 ohm C+D.png
    40.5 KB · Views: 107
#1,131
It's SMPS. Using smps300rs and lrs-350-36 get the same thd result.

The sensitive part now is the wiring. Alligator clips to faston terminal produces worse result than using female faston tabs. That's why I also check the output current via clamp meter to verify if I'm getting solid connections to the dummy load.
 
#1,132
TPA3255 8.9Vrms/1.1Amp output has lower THD than most cheap soundcards lol

If we measure it at 8 ohm 1W, or lower output current, the measured THD will get into 0.0003% territory.
 
Last edited by a moderator:
#1,134
Hello
very good, but what does your sister think?🙂
For the measurements you know the solution, a shielded cable soldered to the test point with shielding as close as possible, an oscilloscope probe without the wire grip also works well, but it is very restrictive, it is class D!
Regards
Roger
 
#1,135
bobo le chat said:
Hello
very good, but what does your sister think?🙂
Roger
Click to expand...

Still tuning and configuring the sound so I'm not asking her for review yet.

I'm rotating the modules so that I can compare their differences.

As expected, the removal of front caps made the Sylph-D200 sound more transparent, so the source player / DAC and song material should be of higher quality as it exposes minor details in sound.

TICore260BTL with single supply opamps is 'thicker' sounding, it adds some bloom and slight haze to the sound. Sylph-D200 is clearer and more hifi.

TPA3251 sounds more organic, but it might be just my bias lol.

Difference is not drastic, you will just notice it by A/B testing the two.
 

Attachments

  • snip.jpg
    snip.jpg
    398.7 KB · Views: 362
  • snip2.jpg
    snip2.jpg
    122.9 KB · Views: 362
Status
Not open for further replies.
Top Bottom