Over Exposed (Exposure 14 & 9)

[Levi_501]

Hi

I am curretly looking to upgrade my pre amp with the afore mentioned Exposure 14 and 9 Power supply. Although a few years old, still regarded by myself and many others as the best active solid state pre amp. Anyhow I shall now get to the chase;

I have connected the 14 & 9 up to the rest of my system, however after about 10 mins of playing I get a very loud hum through the speakers. It only seems to come during vinyl play back, but as I am sure you are aware you drive a system harder to get the same volume for vinyl as you do line level.

I have, disconnected the sub (completley), single amplifing, with different amps, different cables as well as numerous other things !

Any thoughts ? I know some of the earthing on early Exposure equipment was a bit hairy.

System;

Clearaudio Champion fitted with a rewired Incognito RB300 and Clearaudio MM cartridge turntable

Marantz CD63 KI Signature Limited reworked DP Copper plated version CD player

(Rega Cursa pre amp)

2 x Rega Maia power amps (Bi amping)

Kef Reference 2s Speakers

Rel Stadium 2 Active sub

If anyone can suggest any ideas (sensible ones only please !) they will be greatly received.

Thanx

A Very Confused and Fed up Listener !

 

[penance]

Sounds possibly like an earth issue between arm and amp.

 

[Levi_501]

Ok, please go on, the floor is yours !

The tone arm and platter bearing are both earth to the exposure earth binding post.

 

[penance]

well, as you said yourself, if early exposure stuff suffers from dodgy earthing....

Have you tried a different pre?

 

[jimmymcfarrell]

just a thought:
try earthing ur deck to the rega pre-amp or another component, but still connect the outputs of the deck to the exposure and see if this sorts it???

 

[Levi_501]

Jim & Others

Last night I connected the L & R signal wires to the Exposure and the platter and tone arm earths to the earth binding post of the Rega Cursa.

Half way through the second side, it happened again !

Just for completness, I tried it again going into a line level inputs using an external phono stage, it did it again.

Anybody else with a suggestions ? Please !

 

[lordsummit]

Could it be you have a dodgy earth lead somewhere. Perhaps get a multi meter and check the earth leads for breaks.

 

[Levi_501]

Dodgy earth wires ? Yeah I will try that tonight

The Expousres worked in the shop setup and my system was working perfectly prior to adding the Exposures.

I think I will give Incognito a call.

 

[bottleneck]

does the hum increase in volume, or is it the same regardless of volume?

The most likely culprit is earth grounding from your phono source.

The above question will help to tell you if its an earthing problem or another kind of hum.

 

[Levi_501]

Yes the hum increases with volume.

I think you are right it is an earthing problem with the tone arm, but my question is, Why did it not do it with the Rega ?

 

[bottleneck]

try touching the cables on the back of the cartridge one by one with your finger when the phono is selected on the amp, see if the earth of your finger changes things.

Low tech, but it tells you whether its coming from the tonearm..

Try disconnecting the earth lead from the tonearm and leaving it hanging, or if it already is try earthing it.

I am guessing it didnt do it with the rega because it had a different earthing arrangement in the pre.

Low tech stuff I know, but thats me!