11-21-2015, 08:03 PM
(This post was last modified: 11-21-2015, 08:04 PM by 64verberocket98.)
Hello. First thank you for any help you can provide. I am posting first. Searching second. I am so bummed right now it's not good 
Recently I decided to upgrade my 64 R12-R OT with a shiny new Mercury OT-151 (i believe) verified with them. They're super nice btw. Recommend them. But things went wrong.
I followed the schematics and compared it to the Amps original schematic for the secondary side. It shouldn't matter which of the green and black leads go to the speaker and chassis. The original had an outside black and inside green running to the speaker and vice versa going to the chassis. Merury's schematic places both outside green and black leads to the speaker. Which is what I did do. I have continuity through the new OT to the chassis ground and on the positive side respectively.
I also clipped my original leads inside the chassis with a touch of sheath left behind before removing the old one from the circuit. Thus to be certain I re-connected in the proper places. I then replaced wiring one by one. This is just a sanity check but should keep you from making a mistake on something simple.
For the primary side the red wire goes to the diode network fed from the PT and the brown and blue go to pin nine on the output stage respectively.
I have double checked it and tried again.. When I turn on the amp the tubes warm properly and do not blue or red plate. Things look good. But after about 30 seconds. It begins to make this horrible low frequency noise and I pull the power.
At this point I have tried three times. I am afraid to move forward as I don't want to fry anything else. Is this a common issue? If not.. I will call my tech (but I am a tech...) Or could I have a bad OT?
Also for piece of mind, I have thoroughly inspected the chassis to ensure I didn't fold over a component or break another connection several times to no avail. I even tried a different set of pre-amp tubes (that third and last time). Super bummed.. I had the amp playing last night pre install no problems with the tube compliment I used today.
Recently I decided to upgrade my 64 R12-R OT with a shiny new Mercury OT-151 (i believe) verified with them. They're super nice btw. Recommend them. But things went wrong.
I followed the schematics and compared it to the Amps original schematic for the secondary side. It shouldn't matter which of the green and black leads go to the speaker and chassis. The original had an outside black and inside green running to the speaker and vice versa going to the chassis. Merury's schematic places both outside green and black leads to the speaker. Which is what I did do. I have continuity through the new OT to the chassis ground and on the positive side respectively.
I also clipped my original leads inside the chassis with a touch of sheath left behind before removing the old one from the circuit. Thus to be certain I re-connected in the proper places. I then replaced wiring one by one. This is just a sanity check but should keep you from making a mistake on something simple.
For the primary side the red wire goes to the diode network fed from the PT and the brown and blue go to pin nine on the output stage respectively.
I have double checked it and tried again.. When I turn on the amp the tubes warm properly and do not blue or red plate. Things look good. But after about 30 seconds. It begins to make this horrible low frequency noise and I pull the power.
At this point I have tried three times. I am afraid to move forward as I don't want to fry anything else. Is this a common issue? If not.. I will call my tech (but I am a tech...) Or could I have a bad OT?
Also for piece of mind, I have thoroughly inspected the chassis to ensure I didn't fold over a component or break another connection several times to no avail. I even tried a different set of pre-amp tubes (that third and last time). Super bummed.. I had the amp playing last night pre install no problems with the tube compliment I used today.