TPA6120 as a preamp..

[Dxvideo]

Hi all,

I wonder if a TPA6120 can be used as a preamp module for a gainclone or etc. amp?
Its a current feedback amp and has very low THD at high iimpedance loads (like 10K). With this way, we can have a very cheap and high quality preamp with a headphone output (splitted with a relay). Of course with a 2 or 3X gain stage (with OPA2134 or LM4562) and an attenuator just before TPA...
Any comment or advice?

 

[peranders]

The answer is yes but 12 uA as input current may casue you some trouble. Despite that it is wonderful. I have used it in my headphone amplifier.

 

[Dxvideo]

Right,
But I will use a buffer stage (may be with 2x gain) before it like yours. You use TPA as inverted and your buffer stage is non inverted and the total phase response will be as inverted.. Is there any speacial reason for this? Because I plan to use all non inverted..

 

[peranders]

It's no problem if you want to have a non-inverting amp.I used inverting mode because the distortion will be 10 times lower (in theory). Since I already wanted to eliminate the 12 uA problem I could also use inverting mode with 1 kohms input impedance. The TPA6120 demands rather low ohmish resistor values in the feedback.

 

[Dxvideo]

Ten times is a good ratio! I think its worth to try..
But I am planning to put a potentiometer before TPA.. And the TPA will work as DC coupled like yours. In this case it will be problematic..
Do you have any advice about that?