Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Class D Switching Power Amplifiers and Power D/A conversion

What is wrong with TPA3255?
What is wrong with TPA3255?
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 10th November 2017, 05:58 PM   #161
vizeta is offline vizeta  India
diyAudio Member
 
Join Date: Sep 2012
I was not aware about the difference and ordered this board at cheapest price available. Though the list was for blue board but I received a black board
  Reply With Quote
Old 10th November 2017, 08:13 PM   #162
JacobEO is offline JacobEO
diyAudio Member
 
Join Date: Mar 2017
A clear disadvantage to PFFB in the TPA3255 would definately be the need for a zobel resistor during open load configurations I'd say.

The improvement in idle noise would maybe be worth the extra components however.
  Reply With Quote
Old 10th November 2017, 09:19 PM   #163
DPH is online now DPH  United States
diyAudio Member
 
Join Date: Dec 2008
Location: Portland, OR
However you need to increase the gain elsewhere to make up the difference. Just make sure whatever's doing that is quiet. (Unless you have excess gain in your system already, then you're good to go!)
__________________
Happy DIYing, Daniel
(This space is occupied by the artist formerly known as Derfnofred)
  Reply With Quote
Old 10th November 2017, 10:31 PM   #164
lithoc is offline lithoc  Malaysia
diyAudio Member
 
lithoc's Avatar
 
Join Date: Jul 2005
Location: Seremban2
Quote:
Originally Posted by vizeta View Post
I was not aware about the difference and ordered this board at cheapest price available. Though the list was for blue board but I received a black board
Have you tested it?
Does it have pop sound when power up and shutdown?

Does it sound good?
  Reply With Quote
Old 12th November 2017, 10:58 AM   #165
vizeta is offline vizeta  India
diyAudio Member
 
Join Date: Sep 2012
Nope! I have already received TI EVM and connected to Mean Well SMPS. I am planning to not use it and sell it locally.
  Reply With Quote
Old 13th November 2017, 12:02 PM   #166
doctormord is offline doctormord  Germany
diyAudio Member
 
doctormord's Avatar
 
Join Date: Oct 2007
How would PFFB improve idle noise?
  Reply With Quote
Old 13th November 2017, 05:47 PM   #167
DPH is online now DPH  United States
diyAudio Member
 
Join Date: Dec 2008
Location: Portland, OR
PFFB -- If you can get away with the lower gain, the idle noise will decrease accordingly. If you have to turn up the gain elsewhere to make up for the PFFB, you're basically back to square one.

* I'd think this would matter only in the most extreme of sensitive speakers and/or ground loops. The former would be important for sound reinforcement (who needs this many watts PLUS super sensitive speakers for domestic hifi?!) and the latter should be addressed, not blamed on the amp itself.
__________________
Happy DIYing, Daniel
(This space is occupied by the artist formerly known as Derfnofred)
  Reply With Quote
Old 13th November 2017, 06:36 PM   #168
voltwide is online now voltwide  Ireland
diyAudio Member
 
Join Date: Jan 2010
no, that is not the hole truth. Idle noise can be reduced due to the fact that input referred noise of TPA3255 is something like
65uV/Gain = 6.5uV.(rms)

There are lots of OPAs with significant lower input noise.

Following this, you can reduce gain of TPA3255, compensate gain loss with a preceeding OPA and achieve a lower output noise at the same total gain.

In my private test setup I did demonstrate this achievement.
  Reply With Quote
Old 13th November 2017, 10:08 PM   #169
DPH is online now DPH  United States
diyAudio Member
 
Join Date: Dec 2008
Location: Portland, OR
Of course, Voltwide, I guess I should have provided the caveat that an inverting, 10k input impedance NE5532 (like the EVM but changing the feedback resistor) will have higher noise than the internal gain structure of the TPA3255, albeit marginally. Plenty of ways to go lower both on input impedance or switch over to something like an OPA164x (suggested due to DI process lowering CM distortion and jfet-input) and have a very high input impedance non-inverting topology. A direct swap from the NE5532 on the EVM to a OPA2209 would also lower the noise appreciably.
__________________
Happy DIYing, Daniel
(This space is occupied by the artist formerly known as Derfnofred)
  Reply With Quote
Old 16th November 2017, 02:37 AM   #170
ccss is offline ccss  United States
diyAudio Member
 
Join Date: Sep 2017
Quote:
Originally Posted by KaffiMann View Post
I couldn't find any additional information about it, but in the pictures it looks like there is no earth ground (marked "NC", not connected, on the board), which means you could use it with a 2-prong power cord, but might need to be careful about grounding of input devices for your amp or you could have noise. Typical RCA outputs/inputs are earth-grounded but it depends on the source.

Also, it does not appear to be adjustable, which I guess means you get 48V and only 48V? For tpa3255, I like to run at 51V. And there's no PFC mentioned.

Last edited by ccss; 16th November 2017 at 02:56 AM.
  Reply With Quote

Reply


What is wrong with TPA3255?Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
TPA3255 - all about DIY, Discussion, Design etc. lms Class D 462 1st December 2017 10:46 PM
My 1st Class-D Amp -TPA3255 with PFFB JohnnyInBris Class D 17 6th October 2017 07:25 AM
FS: TPA3251 TPA3255 2.0 BTL Amplifier doctormord Swap Meet 11 13th August 2017 08:14 PM
TPA3255 Amplifier for Car Audio System GABRIELITEDEVIL Class D 6 1st January 2017 10:37 PM
Wrong Voltage / current on BoZ... or Wrong Measuring ? gionag Pass Labs 8 14th May 2008 12:24 PM


New To Site? Need Help?

All times are GMT. The time now is 09:59 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio
Wiki