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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
dnath's avatar
dnath
33 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.
essentialaudio
1,147 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
6,770 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
65 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.
lewm
6,770 posts
 
The company you found, is it in California? If so, they're a really good source.
I feel remiss in not thinking about the electrolytic capacitors. By all means, they need to be replaced if still OEM. One can only hope that damage has not already been done to one or more of the FETs.

Last year I bought a Klyne 6LX. I built a new outboard supply for it using an overkill toroid from Antec, and I replaced all the lytics on the audio chassis with ELNA Silmic IIs. I also upped the values of the PS filter caps. Lots of bang for the buck.
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