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Opinions on Power Regenerators and Tube Amps

I have a Mesa Baron tube amp plugged into a dedicated 20A circuit. Turntable, CD player, Preamp, and periferal stuff plugged into a dedicated 15A circuit. At a very high listening level, there is a small buzz in the speakers. I only notice it when there is no music playing and I get close to the speaker. I would like to know your experiences in using a power regenerator with a tube amplifier, and whether this is even a good idea. I guess the expanded question is, in your experience, where in your system are you using regenerated power, and is there really a sonic improvement.
240zracer
240zracer OP
121 posts
 
A bit of news. The little buzz is only when the preamp is on phono, and the phono stage is turned on. Preamp on CD = dead quiet. Ground switches on the amp don't seem to have much effect. So the VPI is grounded with a wire to the ground on the phono stage.....is that good or bad.
nsgarch's avatar
nsgarch
2,524 posts
 
I don't know enough about the VPI chassis to really advise you. Typically, the tonearm leads have five connections: two signal leads (from cartridge left and right) which each consist of a hot and ground conductor, covered by a braided shield connected (along with the ground conductor) to the "ring" of the RCA connector at the phono preamp end. In addition, there is usually a black ground wire bundled with the two RCA signal leads that you connect to the ground lug on the phono preamp. This wire goes into the tonearm and is usually connected to the armwand (if it's metal) in order to shield the internal signal wires inside the tonearm.

If the TT chassis is electrically connected to the tonearm, that should be enough, but if it's separate, then you should run another wire from the TT chassis to the phono preamp ground lug.

What kind of tonearm, cartridge, and tonearm cables are you using, and how do the tonearm cables connect to the tonearm?
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240zracer OP
121 posts
 
My apologies, this thread is moving in two directions now. Nsgarch, the table is a VPI Scoutmaster with a thick, I believe, mdf chassis. Cartridge is a Clearaudio Virtuoso Wood. The head leads go to a junction box separate from the tonearm where the cables and ground are attached. interconnect is Synergistic Looking Glass. Amazingly, the VPI setup says nothing about grounding. It does say to try a shielded a/v interconnect, if there is hum. Don't wanna do that. I am going to read up on Exactpower, although they are sorta expensive.
nsgarch's avatar
nsgarch
2,524 posts
 
I think the Synergistic ICs may be the problem. Are you using the active shielding? Is the active shielding connection at the preamp end or the TT end? (might try reversing it). If that doesnt help, try a pair of regular ICs just for comparison (with the arrows pointed toward the preamp)

I don't think you need to worry about grounding the VPI chassis, which is why the don't mention it.
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herman
2,282 posts
 
It is not normal for a tube system to buzz. Some hiss is normal and maybe a bit of hum but buzzing is not.

Glad to see you have isolated the problem to the phono. Now the hunt is on. Try moving cables around to see if the buzz changes, try it without the turntable plugged into the phono stage to see if it is coming from the phono satge or the table, try grounding the turntable to the phono stage, try it without, try grounding the turntable to the preamp, try different interconnects, try moving the phono stage and turntable, try turning off other things in your house like dimmers and appliances.

You get the idea. There is no universal solution so you just have to keep trying things until you get rid of it.

When I first hooked up my latest phono stage the hum was as loud as the music. After trying umpteen different combinations of things you now have to stick your head in the horn to hear anything.

I am using a power regenerator for the high voltage supplies in my integrated and for my phono stage. It does make it a bit quieter but the main reason I use it is my integrated bias is sensitive to changes in line voltage. For your system it may not make any difference.
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