Probs with my T20mkII transformer

[Goomer]

Hi there(apologies if this is in the wrong section)

I'm looking for some advice as to the possible cause of a problem that's developed with my vinyl rig - LP12/Syrinx PU3/Kontrapunkt b, Ortofon T20mkII step up into MM input of MF X-LPS phono stage.

As of yesterday, for no apparent reason as far as I can tell, one channel plays louder than the other - I've done some lead swapping to ascertain which bit is at fault and I think it's the right channel input on the step-up transformer, as running the Kontrapunkt directly into the MC input of the X-LPS gives a correctly balanced sound, albeit at the expense of sound quality.

I've had a look inside the T20 and all looks okay - no bad solder, leads all connected okay and no charred bits of any kind. Another thing I've noticed is that there is a noticable hum when you touch the plug(on all leads) going into the right input, and also if you touch the front plate of the case - presumably this is connected to the sound imbalance(?).

I'm no electronics wizz, by any means, but I can handle a soldering iron if necessary - can anyone help with tests that I can carry out to pinpoint the problem, or does anyone have a suggestion as to what it could be?

Thanks in advance for any assistance you can provide....

 

[bottleneck]

Originally posted by Goomer
there is a noticable hum when you touch the plug(on all leads) going into the right input, and also if you touch the front plate of the case - presumably this is connected to the sound imbalance(?).

Sounds like an earth-hum to me.

Id try messing about with things like.... attaching the case of the step up to the cae of the XLP, removing/attaching the TT's earth ground wire... basically mess about with earths until it goes away.

Running an extension from a different socket and attaching the XLP to that instead of your 4-way may do it aswell.

Try also touching the wires behind the cartridge to see if it effects the hum - they may be touching each other.

A lot of experimentation and messing about Im afraid!

 

[Goomer]

Cheers for the advice, Bottleneck - I'll give this a go this evening when I get home.

 

[Sid and Coke]

Chris ,
One thing i did find with the X-LPs connected to my Linn LP12 and Rotel pre, If i included the X-Lps in the ground circuit it used to Hum like a bee. The way i got around it was to connect the earth from the Linn to the Rotel direct and just have the signal wires from the Linn>X-Lps>Rotel, this cut out the Hum completely.
HTH.

 

[Goomer]

Cheers Sid - not sure if my integrated has an earthing point but I'll check it out tonite and try your suggestion.

Bye the way, you don't know of any mca-76's for sale, do you....?

 

[Sid and Coke]

Bye the way, you don't know of any mca-76's for sale, do you....?

You can have mine for a Ton . Only joking I'm quite enjoying it at the moment, the CD-4 switch doesn't seen to do anything ? ( i'd keep it flat anyway).
Somebody was selling a T20 Mkii on e-pay the other day, i was temptd for a look-see but it went over my 'Hmmm...?' threshold. Looked ever so slightly tatty too .

 

[Goomer]

the CD-4 switch doesn't seen to do anything ? ( i'd keep it flat anyway).

Hi Sid

Not positive about this, so if anyone can correct me then please do, but I think this is a function which only works with specific CD4 encoded pressings when played back using a compatible stylus profile, so unless you have both of these you won't hear a difference between it being switched on or off. Something to do with the stylus profile means it can pick up detail in the pressing at around 40hz which is then played to rear channels(if you have them), although from what I've read about it, it failed to replay these discreet channels as soon as you got a build up of dust on the stylus tip - no wonder it never caught on....

On the topic of my transformer, I did all the switching and ground testing yesterday to no avail - right channel input on the step up seems to be the culprit. I have one of those digital boxes with the red and black leads for testing purposes so will open the thing up and test the bits inside, hopefully later today.

By the way - how much did the T20 mkII go for? - I've done a search but can't seem to find it

Catch you later....