Optimum gain for Inverted OPA-541 AP

[100db]

Hi,

I read through several threads talking about OPA-541 will give best sound quality at gain less than 10, I don't know if this is for Non inverting configulation only or for Inverting also ?

I did try running this chip using inverted 3875 circuit, gain ~22 and face a lot of distortion at high fequency.

Now I reduce gain to ~9. With out any pre / buffer I need to turn the volume up to 3pm. No more distortion, but look like I'm lossing dynamic.

Shall I try to increase gain up to~15 by using Ri 10k and Rf 150k ?
Or it's better to run this amp with pre-amp ?
( I've OPA627 and AD797 in hand )

Thanks

 

[mike.m216]

Run it with a preamp.

 

[100db]

Many thanks for your suggestion mike.m216 .

One more question

I'm using 25-0-25 Trasformer that give +/- 35.x volt.
Chip is not hot at all, but since I see the datasheet mention that max voltage supply is +/- 35v, I'm not sure that this slightly over voltage will harm the chip or not ?

 

[mike.m216]

It shouldn't be too bad.. but if you push it hard, it will get warm. Be sure to have a good sized heatink!

 

[100db]

Again, thanks for your answer.

I loss one of 541 by connect ground to heat sink that's already isolated from the chip.... Don't understand why

 

[Mrpong]

Don't worry Ball. Let's try LM4780 in parallel mode. Hopefully this little giant (parallel 4780) could shake your room.

 

[100db]

Waiting for 0.1 Ohm resistor from Mundorf to build my BPA200
( or 300 )

But honestly this opa-541 give some interesting sound when use with 12au7 line pre-amp, would like to try with opa-627 buffer but my 541 already death. This chip is quite sensitive... this is the second time that I blew it off