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Mechanical Hum from Class A Amplifier Clayton

Hi All,

Need some advise,

I have a paid of Clayton M300 Monos,

Speakers Tested on were Danley SH50 Horn 100db and Legacy Audio Whisper XD 94db

I noticed one of the mono block has a louder Mechanical Hum and tends to get hotter. The amps are giving off a Hiss sound with some mechanical buzz noise in the midrange drivers.

The other mono block has hiss and slight hum with a much lower Mechnical buzz from the amplifier. What concerns me is the Hiss noise. Its not only a hiss but some buzz mixed into it.

I tried connecting the amps directly to the wall socket and to a AC Regenerator and nothing seems to sort the issue out. Is this normal noise for a Class A amplifier to make a loud hissing noise? My Tube amps have a lower noise floor specially the Bob Carver which are dead silent, The ATI amplifier is Also Dead Silent.
dragon_vibe

Showing 5 responses by jmcgrogan2

jmcgrogan2's avatar
jmcgrogan2
6,346 posts
 
Rtilden, re-read Dragon_vibe's post, the Coda 15.0 only runs in Class A bias up to 100 wpc. The 33.0 that you recommend next only runs in Class A bias up to 15 wpc. He was using the Clayton Audio M-300's, which were 300 wpc of pure Class A power. Coda doesn't have a model that does that. I don't know of any other amp that provides this much Class A power, but I do understand his desire to stay with a pure Class A amplifier. Pass Labs XA200.5 puts out 200 wpc in pure Class A, that is the most that I know of.

FWIW, I do enjoy Coda as well, I am using a Model 11 amp, 100 wpc of pure Class A power is plenty for my application.
jmcgrogan2's avatar
jmcgrogan2
6,346 posts
 
I owned a pair of M-100's a few years ago and thought they sounded excellent when playing music. However, they had a mechanical buzz coming from transformer hum that I never could get rid of, no matter what I tried. Changing cables and cords didn't help, even a PS Audio Humbuster did not work. I eventually gave up and sold them.

If one of your monoblocks is running hotter though, it sounds as if the bias needs to be adjusted too. I would send them back to Wilson Shen to see if he could solve your issues. Good luck.
jmcgrogan2's avatar
jmcgrogan2
6,346 posts
 
Good luck, let us know how you make out.
jmcgrogan2's avatar
jmcgrogan2
6,346 posts
 
That is a shame, though I can not blame you, I know what a hassle it can become. As I posted earlier, I gave up on my M-100 monoblock amps too for transformer hum. These are great sounding amps when the music was playing, but that constant hum during quiet passages eventually drove me to sell them.

Many folks don't have issues with these amps, so they just seem to be very sensitive towards the electrical lines, which is very unusual for solid state designs. I've had issues like this before with tube equipment, but outside of Clayton Audio, I have never had issues like this from solid state designs.
jmcgrogan2's avatar
jmcgrogan2
6,346 posts
 
Pass Labs compares very favorably to the Coda house sound, in fact I wish I could afford the Pass Lab amps. Those 200 wpc pure Class A XA-200.5 monoblocks will set you back over $34K!!! They should sound awesome at that price!!

I haven't heard the MSB amps.
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