DIY-Racked DR-609 build...

[SjorsDahmen]

I can measure AC in and out of the input transformer. After the the resistors and diodes, on test point F and H there is no AC but there is 650mV DC. On the input pins of the interstage transformer there is 3.6V DC. there is nothing on the output pins of interstage transformer. Are these measurements normal/correct? These measurements are taken with the setting written in the 1st step of calibration with 1 khz sine wave connected to input.
Hi Ateshk,

I’m also in the middle of a DR609 build, and I’ve experienced the same problems you did. With my unit it had something to do with a few transistors on the opamp cards that had problems. Be careful to keep the trimpot on the opamp cards all the way down, until the calibration process, or it will run really hot and damage components. I do get signal in and out of the unit now. I couldn’t measure anything at the interstage transformer, might be because the signal is very low there. I started calibrating my unit, and the limiter section is actually working perfectly if I leave the wiring for the compression section unplugged. As soon as I plug in the control B wiring, the reduction meter jumps to -20 db and stays there no matter what I do with the controls. Did you manage to get yours working?

 

[ateshk]

I can measure AC in and out of the input transformer. After the the resistors and diodes, on test point F and H there is no AC but there is 650mV DC. On the input pins of the interstage transformer there is 3.6V DC. there is nothing on the output pins of interstage transformer. Are these measurements normal/correct? These measurements are taken with the setting written in the 1st step of calibration with 1 khz sine wave connected to input.
Hi Ateshk,

I’m also in the middle of a DR609 build, and I’ve experienced the same problems you did. With my unit it had something to do with a few transistors on the opamp cards that had problems. Be careful to keep the trimpot on the opamp cards all the way down, until the calibration process, or it will run really hot and damage components. I do get signal in and out of the unit now. I couldn’t measure anything at the interstage transformer, might be because the signal is very low there. I started calibrating my unit, and the limiter section is actually working perfectly if I leave the wiring for the compression section unplugged. As soon as I plug in the control B wiring, the reduction meter jumps to -20 db and stays there no matter what I do with the controls. Did you manage to get yours working?

I still have all the problems.
I unplugged everything; A, B and even the opamp. I sill get 14-15V on the meters and no sound on the output. Is there a way to test the opamps? With which transistors did u had problems? How did u check the transistors? Please let me know.

 

[jeroenvdv]

Ahh crap I have got R44 shooting out smoke whenever I plug the amp340 in. I've done as suggested, ccw turn on the trimmer installed on the amp340 board (all the way left - maybe I need to bring it up a little??). Or is it a trimmer elsewhere on the board that I need to sort too? Damn I'm all out of 10r resistors now haha

Did you ever find the problem with the R44 resistor going up in smoke? Same issue here. Amp trim fully counter-clockwise, but R44 went up in smoke immediately after plugging in the amp.

 

[veve]

Hi guys,
I'm close to the end of the wiring and I'm waiting the Carnhill transformers.
I hope calibration will be fine!

Cheers

 

[Whoops]

I ADVISE EVERYONE AND ASK EVERYONE TO NOT REPLY TO THIS TRHEAD,
doing so it's supporting Tat Purusha (DIY-Racked owner).

Purusha stole from many members in this forum and was very disrespectful towards this community,
that lead to Purusha being banned from this forum forever.

DON'T LET THIS FORUM BE THE SUPPORT FORUM FOR PURUSHA PRODUCTS

Purusha continues to steal projects from this forum and selling them in his own name for profit,
it's his responsability to support the projects that he sells not GroupDIY.

DON'T SUPPORT A THIEF

 

[dudewithabeer]

Did you ever find the problem with the R44 resistor going up in smoke? Same issue here. Amp trim fully counter-clockwise, but R44 went up in smoke immediately after plugging in the amp.

Thanks mate, yeah that's where i was checking and even though i'd turned the bias down i was getting smoke out of r44, but don't have the same issues when the 340 isn't installed, so need to do a bit of troubleshooting.

Sorry to add to this but I’m in the same boat blowing 44 resistor out. And same diagnosis as well only when the op ano is plugged in. I got this kit from a reverb seller and had no idea about the owner. Unfortunately I’m stumped and could use help. On what this fix for the 44 resistor is.