Yamaha P3200 - IC replacement

[dannval]

Hello! I'm looking for a suitable replacement (or upgrade) for M5238A input op amps in my Yamaha P3200 that I recently bought. It seem that both of them are fried. Will OPA2134PA work?
The amp will be used in my studio to power my main monitors (Tannoys), so if there is a possible upgrade I am into that!

I've attached the P3200 schematic if needed.

 

[duncan2]

I have used those chips-- OPA2134 and they work okay and yes they are standard 8 pin DIP and will slot right in .


Big improvement in noise & distortion just check they work okay with the existing feedback.

 

[dannval]

Thank you! Will look into that!

 

[jean-paul]

OPA2134 are fine opamps only not in this device as they are unfit to use with +/- 18V continuously. I would look out for other JFET input opamps that can withstand +/- 22V (more or less the following grade in max. PSU voltage).

Another solution would be to replace the 7818/7918 for 7815/7915 but voltage drop is quite large and it is not according the design.

 

[dannval]

I have NE5532 on hand. Will that work?

For starters I will check that everything else is working. I want to measure the voltage coming out of the voltage regs just to be sure. A friend also suggested to measure the two diodes before the ICs. I will post results shortly.

 

[dannval]

Ok, found the problem (at least the start of it). I have -18.4V into pins 4, but just +290mV on pins 8 where i should expect +18V as well. Thank you all for chiming in!

I will change both regulators and the filtering and report back if the ICs are good of they need change as well!

 

[jean-paul]

NE5532 are bipolar types. You better replace them for JFET input opamps of good reputation that can have +/- 22V. You could do this even when M5238L are OK as they are mediocre sounding.