An interesting tweak from Kevin at KAB USA...

[Marco]

Guys, I received an email the other day from Kevin, outlining the fact that during his experiments with the Technics, he found what he considered to be a flaw in the current grounding within the T/T. Here’s what he wrote:

Wanted to mention, that I have been working up a 16rpm mod for the 1200, basically a half speed mod. So that is 16.66 and 22.5 in addition to the stock 2 speeds. This is for half speed mastering of really warped discs, and of course, talking story books, bible readings and sermons all of which were issued at 16 rpm.

This will be followed by a half speed mod with 50% variable speed. That’s really for DJ's.

In doing this mod it revealed an interesting flaw in the ground current distribution scheme. And that is really what I was contacting you about. You can improve the performance of the main control chip IC201 by adding an additional ground wire. The wire goes from C217 to the bottom leg of R104(one of those 3 big standup green resistors in the lower left of the board.

I have attached a couple of pix. The normal ground for that chip has to wind its way all the way around the board and at some points the traces get mighty thin. Left stock, there is about 22mV of ground noise on the ground for IC201. Adding the direct ground wire eliminates that noise. It can only help.

Pics, as mentioned:








Knowing Kevin, he’s probably onto something. So who fancies having a go at this mod and reporting back the results?

Marco.

[Wakefield Turntables]

Have we got measured proof that the extra earth wire will removed 22mv of noise?

Secondly, is 22mv of ground noise really apparent on listening sessions?

Thirdly, I'd like the opinion of people like Nick Gorham, Paul Hynes on the subject just for an independent opinion.

[Mr Kipling]

Does he still keep in touch with Roland?

[Marco]

Have we got measured proof that the extra earth wire will removed 22mv of noise?

Secondly, is 22mv of ground noise really apparent on listening sessions?

Thirdly, I'd like the opinion of people like Nick Gorham, Paul Hynes on the subject just for an independent opinion.

Sure, and perhaps that will be forthcoming. However, my view, if you’re handy with a soldering iron, is simply to try it, see if you can hear a difference, and then judge things for yourself. Kevin knows what he’s doing, and as knowledgeable as the people you’ve mentioned no doubt are, he’s been modifying the Technics longer than any of them!

In terms of the claimed noise reduction, I suspect that he’s measured it, otherwise why would he come up with that figure?

Kevin’s the man who started the whole Technics modification ball rolling, so when he recommends something to me for the Techy, I usually sit up and take notice. I'll certainly be trying the mod myself next time I’m down at Duncan’s or Anthony’s.

Marco.

[Andrei]

I trust Kevin, and will give it a go. But when? I have leftover super dooper silver wire that was mined from Mt Ararat and can use that.

[Marco]

Cool. Let us know how you get on Andrei

Marco.

[struth]

I trust Kevin, and will give it a go. But when? I have leftover super dooper silver wire that was mined from Mt Ararat and can use that.

Was it stripped from the Ark?

[Andrei]

Was it stripped from the Ark?

Yeah that's right Grant. It was in the navigation system.

[ChrisKemp]

Very interesting and I'll will follow this thread! And I'm with you there, Marco. When David write something like this, I too sit up and listen

[Marco]

David, who he?

Marco.