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colinB
03-05-2010, 20:39
Hope ive put this in the correct forum. Can anyone tell me the best way to check for correct earth on my TT?
I have a lot of static pops as i have mentioned on a previous thread and i have a few cleaning gadgets on the way to try. I would like to check the earth though. I get a hum when the volume turned up to 12 oclock but that could be the transformer but im wondering if its a earth loop?
The TT earth wire is attached to the pre amp and continuity tests are positive but as i understand it this doesnt necessarily mean perfect earth.

DSJR
03-05-2010, 21:04
I was told by Linn that to meet regs one earths the deck to the mains, the arm to the deck and the fly lead to the preamp, or not if there's hum..

In the case of the Techie, the mains lead is twin core, so it might be worth checking to see if the arm-earth is connected to the main chassis (others who know the 1200 intimately will hopefully put me right). the SL-150 of mine has a chassis earth point right next to the tonearm under the mounting plate..

Something else to check is the locality of nearby transformers, in amps etc. Hum at practically ANY volume should be avoided if possible.

chris@panteg
04-05-2010, 08:53
http://i636.photobucket.com/albums/uu82/chrispanteg30/Armtransplant008.jpg


There is an earth tag connected to the arm from the pitch control.

The hum you can hear is almost certainly the transformer inside the deck .

colinB
04-05-2010, 19:55
Im guessing this can only be sorted with an external PSU Chris?

chris@panteg
04-05-2010, 21:56
Yep afraid so Colin, but its well worth doing! you will start to hear just how good this deck can sound:)

colinB
04-05-2010, 22:28
Oh hang on. I just turned up my amp to see if the hum increases when the arm is directly above the transformer when i noticed a crackly hissing sound comming out of the left channel speaker. What the hell is that!
Im going to futher experiment in the light of day tomorrow but im not going to sleep well tonight.

The Vinyl Adventure
04-05-2010, 23:13
I'm sure it will be fine, I got spare parts comeing out my ears if anythings gone awry matey, just let me know and we can see what we can sort out!

colinB
05-05-2010, 20:17
Got my Milty gun tonight and tried it out on a few bothersome LPs and there seams to be a significant improvement.
I then connected my deck to the internal phono stage of my integrated amp and i found very little hum and no hiss on the left channel speaker.
Sounds like the Icon preamp needs a service i guess. Last time it was looked at was when the valves were changed 3 years ago.

colinB
07-05-2010, 17:32
From what i have read from guitar forums my hissing could be a faulty tube.
My amp appears to have 2 ecc 83s and a ecc81 so tonight im going to swap them all around to find out if the problem changes to another channel.

If im about to kill myself could somebody please warn me before hand or make sure my sound system is auctioned for charity.

The Grand Wazoo
07-05-2010, 19:42
My amp appears to have 2 ecc 83s and a ecc81 so tonight im going to swap them all around to find out if the problem changes to another channel.


Be warned that this strategy may not reveal anything depending on the way the dual triodes are configured - Just because there are 2 x ECC83's it does not mean there is one per channel

colinB
07-05-2010, 19:51
Oh. I thought it wouldnt be that simple. Maybe i should just buy a new set of valves then?

colinB
11-05-2010, 18:14
Swapped my tubes around and turned up the volume to 12 oclock and the woofers started diong this wierd puffing in and out !! Packaged the thing up and sent of for repair. May be my loud pops have something to do with the mystery fault.

colinB
12-05-2010, 19:25
Spinning tunes tonight through the phono stage of my roksan integrated.
God it sounds shit:(

colinB
13-05-2010, 13:52
This is starting to sound like a blog but i found out today they have changed my valves.
£100 for three triode replacements:eek:
As they say in my mother tongue, they must have seen yee commin ya dafty!