Getting ready to do wopl 400 build

[roccus]

Actually Joe I only need to replace one right now... the C-1 has 2 phono inputs one for MM cart and the other for MC cart I have an MC cart but the right phono input for the MC section is dead I figure if I have to buy one might as well get a couple extras to toss in my parts bin... so what is the deal with going to the OPA2134 with the browndog adapter... is it because they are quieter than the original type opamp?

That is exactly what is in there now Ray so why would you replace them with the same device?

The RC4136 was designed back in the early 80s as the first quad 741 op amp. For its time, the 741 was a phenomenal general purpose op amp. It is among the worst audio op amp choices however. We used them back then for DC motor controllers, the motors did not care about audio fidelity.

 

[Gepetto]

Actually Joe I only need to replace one right now... the C-1 has 2 phono inputs one for MM cart and the other for MC cart I have an MC cart but the right phono input for the MC section is dead I figure if I have to buy one might as well get a couple extras to toss in my parts bin... so what is the deal with going to the OPA2134 with the browndog adapter... is it because they are quieter than the original type opamp?

Quieter, much lower distortion, better slew rate and actually sound musical. 741's are awful sounding op amps. Why did they use them? They were cheap.

Why the brown dog adapter? The RC4136 has a mongrel pinout that is not compatible with industry standards. The Brown Dog adapter swizzles the pinout to be compatible with the RC4136.

 

[roccus]

Never knew that about the opamps learn something new every day!! the OPA2134's brown dog has are surface mount so the 2 opamps get soldered to the adapters that have pins to solder into the pc board slots

Quieter, much lower distortion, better slew rate and actually sound musical. 741's are awful sounding op amps. Why did they use them? They were cheap.

Why the brown dog adapter? The RC4136 has a mongrel pinout that is not compatible with industry standards. The Brown Dog adapter swizzles the pinout to be compatible with the RC4136.

 

[Gepetto]

Never knew that about the opamps learn something new every day!! the OPA2134's brown dog has are surface mount so the 2 opamps get soldered to the adapters that have pins to solder into the pc board slots

Correct Ray.

 

[roccus]

BillD mod done on the C-1 except the browndogs those wont be here till around Wednesday but big difference already if Ron heard this thing he would probably want it back lol