|27th September 2021, 05:52 PM||#51|
Join Date: Dec 2018
If you , or any other , want to read loads of opinions about different op-amps read this thread :
Shui Yuan Audio TPA3255 Modification Thread
|27th September 2021, 06:25 PM||#52|
Join Date: Dec 2001
Location: Fürstenwalde, Germany
They said it is best to have the Open Loop Gain and Phase VS Frequency function of the TDA7293 and that LM4562 and OPA1656 are great opamps.
(I mentioned that I tried both in our prototype)
So not much information given which is OK.
As each opamp probably needs an individual compensation that´s quite a task but doable.
Take your favourite opamp and compensate measuring THD each time you progress.
Most opamps we talk about here are quite capable BTW but an old 741 probably won´t do.
That doesn´t mean much though as I haven´t measured THD as I stated before. In its current state the controlling opamp might be so slow that the error correction is only barely working.
See graphs from the project linked in post #42.
One of the chosen controlling opamps hardly improves the THD in comparison with a single/non-composite TDA7293 which means that either the opamp is not capable enough to do error correction or it isn´t properly compensated.
So yes, early but maybe not so early.
And again, this is not a circuit to wildly swap opamps in.
You will have to perform another stability evaluation with each swap (and following changes in compensation) and measure THD.
And yes, as Mike said, this is a hobby and time for it limited.
If you can measure THD and want to join the testing club I could share the gerbers for the prototype. I need to ask FauxFrench first though as this is his circuit.
Last edited by joensd; 27th September 2021 at 06:49 PM.
|Thread||Thread Starter||Forum||Replies||Last Post|
|An open source layout for LM3886?||00940||Chip Amps||346||1st September 2021 09:19 AM|
|Newbie TDA7293 Parallel Build Board Layout||CakeorDeath||Chip Amps||7||8th May 2017 04:16 PM|
|[Open source] TINA The total open source Audiophile Player based on Beaglebone Black||DragonWar||PC Based||7||18th December 2016 02:31 PM|
|Open Source, Open Architecture!||zenmasterbrian||Digital Source||185||23rd February 2007 10:35 PM|
|CD player Drawer open close open close open close||qguy||Digital Source||7||23rd November 2006 08:58 PM|
|New To Site?||Need Help?|