AudioNervosa

Systemic Development => Analog Devices => Topic started by: James Edward on March 21, 2010, 11:22:43 AM

Title: High Pitched Sound From My VPI Classic/Cambridge Phono Section
Post by: James Edward on March 21, 2010, 11:22:43 AM
I have a very high pitched sound that appears AFTER I play a record or two. When I first turn on the system and select the phono input, it is quiet. When I lift the tonearm at the end of the record, it sounds like a dentist's drill. I can modulate the sound a little by touching the tonearm wire.
I am using a Dynavector 10x5 cartridge, and a Cambridge 640P phono section. All interconnects are shielded.
The noise is the same with the CD player on or off.
Any suggestions appreciated...
Title: Re: High Pitched Sound From My VPI Classic/Cambridge Phono Section
Post by: richidoo on March 21, 2010, 01:21:41 PM
Good one, Mr Rubik.   :-k

No tubes, right? Phono preamp and TT sharing safety ground, at least same circuit? Try disconnecting your phono ground wire, or moving it to another location, or tightening it. Experiment.

A cart will change sound after half hour of "warming up," maybe that has something to do with this.

That's all I got man, sorry.
Title: Re: High Pitched Sound From My VPI Classic/Cambridge Phono Section
Post by: James Edward on March 21, 2010, 02:20:03 PM
Rich,

I do have a tube preamp, and hybrid amplifier. But the only source affected is the TT.

I must hang my head in shame, though, about the ground. I will hook one up and see if it solves the problem. Although, I've heard grounding issues before, and they never sounded like this.
Title: Re: High Pitched Sound From My VPI Classic/Cambridge Phono Section
Post by: richidoo on March 21, 2010, 02:29:19 PM
I used to have problems with buzzy hum with my old Bellari tube phono preamp, it actually sounded better without the ground wire connected! It was a common problem for many owners of that pre. Long gone now, thank goodness. 
Title: Re: High Pitched Sound From My VPI Classic/Cambridge Phono Section
Post by: James Edward on March 22, 2010, 12:26:05 PM
The ground wire wasn't it, though it got rid of a hum heard only at full volume.
Proximity to other equipment wasn't it either...

I switched out the Cambridge 640P with a Rotel RQ-970, and the problem went away.
So, whatever interaction they had just wasn't good, or the Cambridge is defective.
Also, the turntable on/off switch does not THUMP through the speakers when using the Rotel.

Thanks for the response...
Title: Re: High Pitched Sound From My VPI Classic/Cambridge Phono Section
Post by: richidoo on March 22, 2010, 12:41:04 PM
Hey, glad you figured it out James.   :thumb:
Title: Re: High Pitched Sound From My VPI Classic/Cambridge Phono Section
Post by: mikecole on March 27, 2010, 06:58:19 AM
Go to this thread on Steve Hoffman forums to read about a similar problem. The last post is probably the most relevant:

http://www.stevehoffman.tv/forums/showthread.php?t=188406&highlight=10x5+640p (http://www.stevehoffman.tv/forums/showthread.php?t=188406&highlight=10x5+640p)

Mike
Title: Re: High Pitched Sound From My VPI Classic/Cambridge Phono Section
Post by: James Edward on March 27, 2010, 03:20:56 PM
Mike,
If I could say it like they do on the Guiness commercial: "Brilliant!'
I had a nagging feeling it was something about my setup, but it
appears to be a known problem.
Thanks!
Title: Re: High Pitched Sound From My VPI Classic/Cambridge Phono Section
Post by: mikecole on March 29, 2010, 05:04:13 AM
No problem, James. The only reason I saw that thread was that I was looking for a new phono stage for my 10x5. I ended up with one from a small company called Vista Audio. It is their Phono-1 and it turned out to be a *very* nice phono stage.