Internal opamp of T-amp, any tweaks? - diyAudio
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Old 4th July 2008, 09:15 AM   #1
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Default Internal opamp of T-amp, any tweaks?

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?
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Old 4th July 2008, 09:43 AM   #2
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I thought that you increased the feedback resistor to increase the gain?
Ri; Av= 12(Rf /Ri )
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Old 4th July 2008, 09:46 AM   #3
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Sorry, my mistake.
You are right, that should be lower the input resistor.
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Old 4th July 2008, 09:53 AM   #4
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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
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Old 8th July 2008, 03:01 PM   #5
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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.
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