Audio Project Amplifier Speaker Loudspeaker Kit
diyAudio.com diyAudio Forums Archive > Top > Amplifiers > Class D
 
Internal opamp of T-amp, any tweaks? - Click HERE for Original Thread
ChuckT
Is there anyways to tweak the internal opamp of the t-amp. This internal opamp is found in most t-amp chip and are normal set at unity gain.
I found that by increasing the gain to 2 (I reduce feedback resistor from 20K to 10K), the sound improve a bit.

Anybody had similar experience?
Lostcause
I thought that you increased the feedback resistor to increase the gain?
Ri; Av= 12(Rf /Ri )
ChuckT
Sorry, my mistake.
You are right, that should be lower the input resistor.
Lostcause
Less feedback is always a good thing but you increase the chance of noise. I certainly have noticed an improvement when increasing the gain =>2 but I take great care to shield all my inputs.... I hate hiss, no matter how faint;)
ChuckT
quote:
Originally posted by Lostcause
Less feedback is always a good thing but you increase the chance of noise. I certainly have noticed an improvement when increasing the gain =>2 but I take great care to shield all my inputs.... I hate hiss, no matter how faint;)

Only 2x, not much increase in gain, so noise is not a problem.
If you are serious about noise, then reduce the feedback and input resistor, increase the input cap, and put a good buffer in front.

BTW, I found the 5V pin for the internal opamp can change the sound a lot. I put 2 Blackgate hi-q 47uf/6.3V directly on the two pins, more bass, better mid. Probably because the old decoupling only has 1 0.1uf ceramic for both pins.

Page generated in 0.019800901412964 seconds with 17 queries,
spending 0.00678945 doing MySQL queries and 0.01301146 doing PHP things.

Powered by: Search Engine Indexer and vBulletin
Copyright ©1999-2008 diyAudio.com