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VPI Classic 1. Defective or design flaw

I am the mostly proud second owner of a VPI classic 1, serial number 2187, purchased new from Galen Carol audio in san antonio about 4 years ago, Lyra Kleos front end. There are at least 2 situations where a very loud hum is produced. If you connect the ground wire from the grounding block near the tone arm base to the normal(?) grounding screw on the phono stage and when the power cord is plugged into the Phoenix Engineering speed control products(i have the eagle and the falcon and it happens with both). The table is quite pleasant too listen too outside of these circumstances and i have no problem not connecting the grounding wire but would like to think i did not waste my money on the eagle/falcon units. There is certainly plenty of info on the web about minor hum issues with this line but i have not found anything like this. The speed control units work with no hum on my much older VPI HW19 MK III and that table does not produce any issues when its grounding wires are properly connected to the phono stage. I have 3 phono stages in house, a recent solid state and a vintage and recent tubed unit, the problem occurs with all 3. Any advice or theories would be appreciated. As for now will continue to listen and hope. Thanks, LS
trytone
8 responses Add your response
dill
2,531 posts
 
Ask your question over at the VPI forum, maybe Harry or Mat will chime in.

http://vpiindustries.com/forum/index.php
stringreen's avatar
stringreen
6,470 posts
 
I would try using a "cheater" adapter (easily bought at Home Depot for less than a dollar, which would allow you to turn the plug 180 degrees and/or even eliminating the ground lug.  You will find the offending circuit....just patiently experiment.  I don't know the Phoenix stuff intimately....make sure you can eliminate the ground, or plug reversal without damage.  When you find the problem, if a ground has to be eliminated, I would remove the wall plug, and disconnect the ground wire...those cheaters can make the sound grainy, but you don't care...you're just trying to find the ground loop. I would mark the wall outlet with a small piece of paper saying the ground was altered.
czarivey
5,946 posts
 
It's clearly a defect.
The only hum you should hear is when the ground wire is completely disconnected while tonearm wires connected to input of your phonostage.

trytone OP
113 posts
 
Stringreen thanks for the reply. My former guru has talked to me about growing nds and hum and ground loops and cheater plugs before. What I am not cetain about in your reply is where the cheate plug goes, on the vpi power cord at the wall outlet? Many thanks
stringreen's avatar
stringreen
6,470 posts
 
Trytone.....I suggested the cheater to find where the ground loupe is. Try it on the turntable first (I doubt it will help there)..... also try it on your other black boxes until you find the culprit. In my system (Ayre amp, preamp, Universal silver disc player, Vandersteen speakers (which plug into the wall), and dedicated headphone amp)...if the headphone amp is not plugged in, I get a hum (with the 2nd preamp output connected).... You just have to wade through the system ....the joys of audiophiledom.  Plug the 3 way plug you are testing into the "cheater" which allows you to reverse the plug (turn it 180 degrees) and/or eliminate the 3rd ground wire (the rounded metal spade on the plug...as opposed to the 2 flat ones (one wider than the other).
trytone OP
113 posts
 
The cheater plugs i have around here tend to have way too tight a connection for the plug to go all the way in but i can look for some new ones. As far as the culprit goes I thought it had to be this table since none of the other three around have any hum issues at all
dorkwad
548 posts
 
I had a Classic fairly soon after they came out and it had a turn on thump that which I called Harry W. about.   He had me switch a capacitor to one with a different value and the problem was solved.  Call Harry.  He is very good at diagnosing the problem and more importantly, at providing the necessary fix.
borzetta
3 posts
 
Hi,
I too had a similar hum problem when I switched out my Rega RP6 with my new VPI Scout ( 2016 ), using the Phoenix PSU Roadrunner Tachometer. After trying to isolate the hum problem and various scenarios for eliminating the ground loop I had no success. I did find the culprit however, it was the wall wart power supply to the PSU. I removed it from the system and the hum went away-dead quiet. I made the difficult decision of selling it, I opted for the quiet! The last readings I was getting from the PSU / Tachometer set up was a pretty steady 33.333. So I'm assuming the Scout is spot on. I hear no pitch derivations and every recording I play sounds just like I always heard it. I hope this helps. I'm not suggesting you do the same but I can say that I just enjoy the music now and I'm not obsessed with micro speed variances that I will never hear.
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