The Timestep Bearing

Hi Anthony

The hum you are describing ' i believe is almost certainly due to the internal transformer in your techy ' .

If or when you get an outboard psu like the timestep ' when fitting ' whip out that lump form your techy's innards ' and no more hum ;) .

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Originally Posted by chris@panteg

Hi Anthony

The hum you are describing ' i believe is almost certainly due to the internal transformer in your techy ' .

If or when you get an outboard psu like the timestep ' when fitting ' whip out that lump form your techy's innards ' and no more hum ;) .

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I thought of that, but there is a hum when the turntable is off, and when the tonearm is completely removed from the turntable's body.

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Originally Posted by therockst4r

I thought of that, but there is a hum when the turntable is off, and when the tonearm is completely removed from the turntable's body.

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Anthony -

Have you got electrical continuity between the earth wire leading from the arm and the body of the arm itself?
If that's OK then a new arm may not necessarily solve the problem, because it could be caused by an earth loop in your system or a preamp problem.
It's also possible, as you say, that the interconnect cables are defective in some way.

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Originally Posted by jonners

Anthony -

Have you got electrical continuity between the earth wire leading from the arm and the body of the arm itself?
If that's OK then a new arm may not necessarily solve the problem, because it could be caused by an earth loop in your system or a preamp problem.

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I believe I have continuity; the earth wire is properly attached to the arm. I doubt the preamp is the problem as that gets a lot quieter when I unplug the turntable's RCA plugs from it. As for a ground loop problem in the system I have no idea how to solve that.

Well guys, I'm still waiting for my Mike New bearing to arrive. Can't wait to get it installed and post some testing results. For those of you teetering on the brink of buying a Jelco 250ST, it is a tremendous arm for the money. I've used mine with a Denon DL-160 (high output mc) and Audio Technica AT33PTG (low output mc) and the Neglex arm lead. Excellent tracking, settings that don't drift and a feeling of solidity to its mounting and bearings. It doesn't look a million dollars like the 750, but I can live with that.

I seem to have ticked all the prerequisites for changing the bearing (including a brilliant phono stage) so my Techie is ready and waiting.

Silly question, but some power amps earth themselves through the screen of the interconnect and if pre and power are both earthed, you'll have a hum loop even if it's at a very low level. In my system, everything is earthed to the preamp, which has a solid connection to mains earth. The only problem I have is the SUT picks up hum from nearby transformers and I've found it difficult to site it carefully.

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Originally Posted by DSJR

Silly question, but some power amps earth themselves through the screen of the interconnect and if pre and power are both earthed, you'll have a hum loop even if it's at a very low level. In my system, everything is earthed to the preamp, which has a solid connection to mains earth. The only problem I have is the SUT picks up hum from nearby transformers and I've found it difficult to site it carefully.

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Oh, I never thought about the amp causing the problem, luckily I am getting a new amp in a few days, so when that arrives I will retest my turntable.

Keep the deck away from mains transformers..

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Originally Posted by DSJR

Keep the deck away from mains transformers..

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I tried moving the tt further away from my other components; however, this did not help at all.

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Originally Posted by MartinT

Well guys, I'm still waiting for my Mike New bearing to arrive. Can't wait to get it installed and post some testing results. For those of you teetering on the brink of buying a Jelco 250ST, it is a tremendous arm for the money. I've used mine with a Denon DL-160 (high output mc) and Audio Technica AT33PTG (low output mc) and the Neglex arm lead. Excellent tracking, settings that don't drift and a feeling of solidity to its mounting and bearings. It doesn't look a million dollars like the 750, but I can live with that.

I seem to have ticked all the prerequisites for changing the bearing (including a brilliant phono stage) so my Techie is ready and waiting.

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Hi Martin

I think i am pretty certain ' the 250st is the arm for me ' i did really fancy a 309 , but its a lot of money and i have in the past owned the 10 inch version , but why not the Jelco .

I think you will be amazed with the bearing upgrade ' give it some time to bed in ' mine seems to be improving all the time ' today i was listening and i was struck by how calm it seems now ' the lack of noise ' this is important as it allows you to hear more low level detail , present techy arm excepted of course.