Search found 6 matches

by Amperex
Tue Nov 19, 2019 11:38 pm
Forum: Technical
Topic: OR120 mod
Replies: 25
Views: 40101

Re: OR120 mod

hello, yes, I KNOW this is an old thread, I'm replying to it to set the record straight on a few things for future gents to be able to sort out their amp easier. I used to be "Amperex" on the OFG and the plexi palace eons ago, and Im the one who "suggested" to remove the 220K resistor to ground bef...
by Amperex
Tue Nov 19, 2019 11:22 pm
Forum: Technical
Topic: OR120 mod
Replies: 25
Views: 40101

Re: OR120 mod

I just remembered that jerry blaha said WA used step-ups in america when touring, and when they recorded "new england" at criteria in florida, to keep the voltage constant.
by Amperex
Tue Nov 19, 2019 6:54 pm
Forum: Technical
Topic: OR120 mod
Replies: 25
Views: 40101

Re: OR120 mod

thanks LD...I also wanted to know also how your handling the voltage with his amps...at 240 in europe the voltage is correct, but using the same amp here in the US on the 115 tap, the voltage will be at least 30 volts higher and not sound right and need a re-bias for instance this 73 or120 I just go...
by Amperex
Mon Nov 18, 2019 4:34 pm
Forum: Technical
Topic: OR120 mod
Replies: 25
Views: 40101

Re: OR120 mod

Hi Angelo Funnily enough I have recently been working on Andy's amps. At present he has two 1970 OR100s on tour with him, he is using the original that he bought new in Denmark St (stolen and later returned) and another that Mark is using. I have also just restored an ORST (50w), that is in the unh...
by Amperex
Wed Nov 13, 2019 9:35 pm
Forum: Technical
Topic: OR120 mod
Replies: 25
Views: 40101

Re: OR120 mod

thanks for posting guys...there's so many different variations way back then, that I dont disbelieve what your saying, but its not my experience...however I havent been in any GT-100's, only early mattamps ala wishbone ash and orange pics only/text...I also dont know which amp you mean when you say ...
by Amperex
Sun Nov 10, 2019 12:35 am
Forum: Technical
Topic: OR120 mod
Replies: 25
Views: 40101

Re: OR120 mod

hello, yes, I KNOW this is an old thread, I'm replying to it to set the record straight on a few things for future gents to be able to sort out their amp easier. I used to be "Amperex" on the OFG and the plexi palace eons ago, and Im the one who "suggested" to remove the 220K resistor to ground befo...