MXR Dist+ Schematic

[kojjum]

Does anybody sit on a original MXR Dist+ schematic? I have a later version in for repair, block logo, LED and 9V adapter connector. I have replaced some parts that were broken but the unit is still grounding the output tip when in use. I have looked at some of the schematics found on the Internet but my unit have other values on all resistors for example. If it's one of the ceramiccaps it would be nice to see what value it once was.

//jens

[Mark Hammer]

Is it possible that the solder lugs on the jack have different connections than you think?

[kojjum]

Looking at the circuit in daylight I start to wounder if I'm colorblind nighttime. Everything on the PCB match the schematics floating around the Internet. I will change all resistors and caps and OP-Amp and se where the problem is. As you can se on the images the original opamp has been fried. Also the diode on the 9V feed was broken so I have replaced them with new parts. The circuit is still dead and shorts tip to ground when activated. Not sure why yet but it might be the new 741 that is dead. Will measure it tonight and get myself some more to test with. Can I repalce the 741 with any other op-amp?




//jens

[kojjum]

Done with it! The +9V supply to the IC was dameged on the PCB. Verry hard to find but with a multimeter it's qiute obvious.

//jens

[stm]

Usually when a PCB fries it becomes conductive in the burnt area.  You should check that with a DVM or ohm-meter.

[the_badcliff]

The 741 is a single opamp, and I don't believe it would have the same pinouts as the dual opamps people around here tend to use (RC4558 type, TLO72, NE5532)

However, I know from working with the Tube Reamer that you can directly sub a NE5534 in for a 741.  Probably quite a bit less noise too.