Superlite Turret Board

[WaZaK]

Before making a board for myself, I wondered if the existing layout could be tidied up without detriment.

Can the 27/33K be moved onto the board (between 8K2 and 16uF)? I know the 2nd cap was recently moved and I don't want to spoil a good thing!

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I can still save some space on the board - by slightly rearranging the 2x100K resistors and the 270pF for example.

If it is basically OK, then I will put away my CutnPaste WinCad (Lol), do some accurate measurements and make a drill-through template in p/shop.

[radstringz]

Looks entirely doable to me

jr

[WaZaK]

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Thanks radstringz. That squeezes it up a bit: I think I can get back to the original size for the template. (Not that the physical size matters to me for a scratch build)

[WaZaK]

Sorry - one more dumb question. (Well, 2 actually!)

(a) Is there a special reason for having 2 grounds on the original board, and
(b) Is there any reason why a ground bus cannot be integrated on the board?

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[radstringz]

It's recommended to have separate ground points for the power amp section and the preamp section. There are quite a few discussions here about grounding issues. I suggest you do a search and read the many posts so that you can minimize hum and noise.

A ground buss can certainly be integrated on the board, utilizing the guidelines that will be revealed by your search. Good luck and enjoy your Superlite.

jr

[kd]

I use a ground bar bus for everything I build and have had good luck doing it that way. The ground bus can be integrated into the board with no problem. There are several things that need to be done to make it work properly. The ground bus itself should be grounded to the chassis only in one place and not touch the chassis any where else. It should be grounded to the chassis down by the input jacks, at the preamp. When you solder your grounds to the ground bar, group them up. Solder the first and second filter cap, center taps, EL84 cathode resistor,etc. to the end next to the PT. Ground the last cap(pre-amp filter cap), cathodes, input grounds, etc. together on the other end of the bar near the input jacks. This arrangement has always worked well for me.

Ken

[WaZaK]

Thanks, jr.
Grounds are also critical (and frequently more complex) in the RF circuits I am more used to. I need to get used to the subtleties of these "relatively simple" audio circuits.

It just confused me that the 2 board grounds go to the same point (next to the PT) and felt that if any ground currents are commoned at that point, then a few inches earlier would make little difference. (It apparently does make a difference so I've taken that on board and changed my design to 2 grounds.) Is it an impedance issue with the grounds or something?

Anyway, I'll hunt around for the threads you mention. Thanks again.

EDIT - Thanks kd. I missed your reply. So you ground the preamp section at the opposite end. Interesting. Thanks.