Wow! A lot of action I didn’t know about. Okay, no 4 ohm speakers. I had to step away from electronics for a bit, my wife just gave birth to twin girls and I had to spend quite a bit of time before hand prepping a nursery and just overall preparing. Of course after they were born I didn’t have time for much else. My wife has now gone back to work and I’ve become accustomed to being a stay at home dad and can get back into my groove. Anyways, it was perfect timing as I was waiting on arrival of the filter caps.
Alright, got the new filter caps in place along with the RCA 410s and 2N3439s that were sent by Iaatsch55. I am ready to bring it up on the isolation transformer/variac/DBT supply. Do I just follow procedures from the 700 manual since it has a 700 power supply? It appears there is no method of bias adjustment, it’s just set by transistors. Only trimmers being for input and output offset which I assume would be adjusted according to the waveform on the oscilloscope? I just want to make sure I bring this up correctly, so any pointers would be great. I’ll obviously go through the testing procedure, but are there any specific areas I should check?
Also, even with an 8 ohm load I’ll suggest a fan. We did discuss adding a protection circuit like the one from watts abundant, but he isn’t too keen on putting too much money into this amp since he can’t white oak it. So we discussed series fusing on the outputs to protect the speakers.