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HELP HELP - VENDETTA RESEARCH SCP2A FAULTY

I recently purchased a Vendetta Research SCP2a phono stage - before i go on I am 100% certain it was sold to me without any faults, and that it may have been something else that was the problem -
HOWEVER!!!
I have a major problem
I used a step down transformer as recommended by John Curl so that I could run it off UK voltage which is 230.
I got a great sound out of my right channel - as it happened I only wired the ground to the left channel.

I checked the fuses (1 Amp) - but to be sure I went and got some replacements and put them in.

Once back on again there was a very faint signal out of the left channel alone - I replaced the fuses with the originals - just in case - same thing.

I tried it this morning - absolutely no sound at all -
I got a decent step down transformer from Maplins so that there would be ample overload protection.

I have emailed John Curl and await a response - I have also furiously e-mailed a few audio electricians in the UK - does anyone have an idea what the problem may be?

Alternatively is there anyone you know who may be able to resolve this?

Thanks

Lohan
parrotbee
parrotbee OP
103 posts
 
Hi Lewm
You have read entirely correctly:
- I lost signal entirely when I went back.
I opened the amp up - no burning smells - not sure about loose wires
I am confused due to having heard something from the right channel initially.
Spoke to a guy called Ben Jalopy from Highend audio repairs in NYC and he thinks it is most likely a capacitor issue.
If this piece of kit wasn't so rare I would probably do the work on it myself, but I think I have roped a good technician into dong the work.
My real fear is losing the original fets if they are damaged - I am told they are the best thing about this phono stage...
finger crossed...
dnath's avatar
dnath
38 posts
 
The Vendetta does need extremely closely matched JFETs which are no longer made.

IMHO I would only let John Curl work on the unit.
bpwalsh
1,197 posts
 
Dnath is correct. These NOS JFETs from the 70s have been unobtainium for a long time, and John Curl is one of only two or three people who matched them by curve tracing them.
lewm
12,530 posts
 
There is a company on the West Coast, the name of which escapes me, that carries a lot of supposedly no longer available transistors, including FETs. I was able to buy the full complement of transistors needed for my 1980-vintage Beveridge amplifiers from them. I will look for the name later today, but you may find it by simply doing a google search on the needed FET, if indeed you need a FET.
parrotbee OP
103 posts
 
Hi Lewm - I think I have found the 'unobtanium' company. Trust me it was a flipping pain in the backside to find them - I felt like a stalker tracking posts by John Curl on another site. I spoke to a chap called Ben Jalopy - a pretty decent guy who reckons that it is most likely the old Panasonic electroytic caps that have gone bad. He reckons Elna replacements are the way forward.
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