I wanted to post my experience with this phono stage and how I removed the buzzing noise from the power supply.
Please see above for stock photo of the model I am referring to, I am not exactly sure, it's not really marked anywhere. Only marking I saw recurring on the board was "VC1". I bought the power supply / phono set in the trading post just a couple of months ago. I had read the audiogon review on the unit and really liked what I read, decided to go for it. One thing mentioned in the review was the noise, but owner of that unit thought it to be his homes power causing the humming noise. I didn't think to ask the seller about the noise. So needless to say when I got the unit I heard the buzz. It was mechanical in nature, you could hear it with everything else off. It was the power supply, would start to buzz when turned on and connected to the phono stage, no music playing. I tried different tubes in the phono, problem persisted. There was an audible tone being generated by the power supply. I wired everything up, listened to it, sounded great! But for me, as good as it did sound, that tone/noise/hum was unacceptable in my system.
So I emailed the seller, he told me to put heavy objects on it, he wasn't bothered that because he sat far enough away. Though that claim makes me skeptical, I would have to be bothered to put heavy objects on one of my components.
When I had first emailed Paul it was regarding what tube was to be fitted at the front slot and which at the rear. I also asked him about changing the loading resistance on the phono stage. The seller told me he had it set to 47ohms, Paul recommended I set it to 100ohms. I never did find how to change that, Paul did not follow up with directions, just recommended setting, if anyone knows I would appreciate if they would chime in. Anyway, he was verify friendly and eager to help. Once I powered it up and found it had the hum issue I emailed him again. He was familiar with the issue, to quote him: "This sounds like one of the mains transformers used in the power supply. The manufacturer I used to use for the mains transformers closed down so I had to use alternative transformers instead. For some reason to do with the construction, the alternative transformers were noisy. I no longer use these transformers in the phono stage power supply and have not found a satisfactory replacement for this type of transformer in the UK". It agitated me a bit to find that Paul was aware, yet these problem units still went out. Paul offered to build me another power supply, for a reduced cost of £485, down from £685, he was going to give me a £200 trade in allowance. Still, that is more than what I payed for the phono/power supply together. I asked him if he would cover this under warranty, but it was past the three years since the original buyer had owned the unit. Have not heard from him since.
I called a friend who is quite the ace with a soldering iron and a pro in the woodshop. Took it over to his place, he was ready to start investigating. Turned it on, heard the hum. Took it out of the case, no hum, was silent. And that's about as far as we needed to go to figure out what the problem was. The case was causing the mechanical buzz of the transformer. I am paraphrasing the explanation my friend gave "the case is shorting the turn on the transformer". Something or another with eddy currents of the aluminum case causing the stress on the transformer. We put it back in the case, hum returned. We took it out, were careful to make sure it wasn't going to short on the table and turned it on. We brought the case close to the top of the power supply. Started to hum when you had them close (same distance as when it is in the case). We tested the same but from the bottom, no effect. So the top of the case was the problem. We ended up just cutting the top off, replacing it with some MDF with notched sides, put walnut veneer on that. Came out looking great!! We turned it on, no hum!! If you put your ear on the wood top, you could hear the transformer buzzing a bit, but only if you put your ear against the case. Beyond that it was quiet. The phono stage sounds fantastic!
In the end I am pretty happy. I got a hell of a phono stage for a killer deal. The part with not having much of any support or documentation on operation is what was not much fun. Don't imagine that is something buyers of new units have to be concerned with, but that is something you have to consider when buying used. Not everyone might be as fortunate as me to have someone they can take problem stereo units to.
I recommend this mod to all who have this phono stage and it is noisy. Because without it you just have a very expensive tone generator, and that has no place in a hi-fi system. Keep fighting the good fight brothers!!
oh and if anyone can help me out with switching the loading resistance it would be appreciated.
