Upgrading Op-Amps Peavey -10 to +4 converter.

[Christian]

I just purchased a Peavey AMR IA 8410 converter. I want to convert 8 channels of old reels to digital and am worried about the op-amps used in this. Since it came out in 1992 not a good thing. The circuit seems to be a 5532 into a TL072. Has anyone modded this actual device or built a step-up converter like this and what opamps did you like. I am going to try a few 2134's since I have them handy. But am looking for recommendations. Socketed also it will be easy.


Thank you,
Christian

 

[NewYorkDave]

What's wrong with those op-amps?

Most likely, the TL072 is the input buffer and the 5532 is the output stage (it wouldn't make sense to do it the other way around).

Don't assume it sucks just because it's 13 years old and doesn't use the currently trendy ICs. Have you actually used it yet?

Your converters don't have enough front-end gain to accept a -10dBV (-8dBU) input? Are you sure? The signal's probably being knocked down before the input of the actual ADC chip, anyway, since most can't handle high levels. Really, the best approach would be to go directly from the deck into your A/D converter box with no added amplifiers in between. If it's just an issue of balanced versus unbalanced, don't worry about it: running an unbalanced output into a balanced input is not a problem. It's only when you try to go the other way 'round that you might run into trouble.

 

[Christian]

The reason I bought the box was because my converters, the Panasonic WZ-AD96, did not have enough gain for the output of my reel to reel, Tascam 388. Some of the levels might not have been recorded really hot You are correct about the gain signal. Closer inspection of the pcb layout shows that.

 

[NewYorkDave]

I see. Well, if you really feel the need to try an op-amp swap, try a different JFET-input opamp in place of the TL072. I wouldn't recommend replacing the 5532 output stage unless you have the test equipment and methodology to really measure the consequences of the change.