Stagg buzz

[slobluesine]

anyone managed to stop the hum/buzz on their Stagg? mine seems to be getting worse

[Maxcat]

[quote name='slobluesine' post='411169' date='Feb 16 2009, 02:59 PM']anyone managed to stop the hum/buzz on their Stagg? mine seems to be getting worse [/quote]

Dont have any buzz mate. Silent as the proverbial. Is your battery good and the connections sound?

[BOD2]

Check through some of the points in this sticky here

[url="http://basschat.co.uk/index.php?showtopic=194"]http://basschat.co.uk/index.php?showtopic=194[/url]

Might be of some use.

[Floyd Pepper]

Took mine down to the local music shop and they replaced the jack input on the Stagg. Job Done. Apparently he said that he had done a couple of these and since then, its been fine.
Cheers,
Jim

[slobluesine]

thanks FP

[Mateybass]

[quote name='slobluesine' post='411169' date='Feb 16 2009, 02:59 PM']anyone managed to stop the hum/buzz on their Stagg? mine seems to be getting worse [/quote]

I recently came across a Stagg with the hum problems, on closer inspection with a multi-meter, I discovered that the metal plate the electronics are fastened to has no connection with the earth-side of the signal. Coupled with the lack of screening in the cavity beneath the control plate means the electronics are not screened at all.

Fortunately, it's a very easy fix, only requiring some self-adhesive aluminium foil which can be bought on a roll like gaffa tape from a hardware store, a cross-head screwdriver, a scraping implement, pencil and a 10mm spanner. It took me about 20 mins to fix the hum problem. The self-adhesive backing of the foil tape I used seems to be conductive so taping foil on top of other foil doesn't seem to be a problem.

[b]Disclaimer: the following instructions will no doubt invalidate your warranty, if in any doubt of your own competence, seek professional help.[/b]

First, remove the battery to prevent the electrics from letting the smoke out. Remove the electronics control plate and the long plastic back cover from the rear of the instrument. You will probably find a feable factory attempt at foil sheilding inside the cavity underneath the long cover. I removed it all to do the job properly.

There are two channels in the cavity for the wires to run down. Clear the wires away from the cavity the best you can to gain access to the channels. The two peizo leads can be unplugged (they are terminated in mini jack plugs) from the control plate to make this easier, just remember which way round they go back. Take the foil tape and line the whole cavity to include the rebate where the plastic and electronic plates sit. Ensure you follow the profile of the wire channels to make sure the wires will be recessed enough to clear the end pin when retracted into the body. If you don't want to leave anything to chance, line the cavity underneath the jack plate, being careful to allow clearance for the jack socket terminals.

Now that the cavity is fully foiled, lay the peizo wires and the grey signal wire leading to the jack socket into the channels and tape them down with foil tape. The battery wire (red-black lead) can then be taped down afterwards. I did it like this so the audio wires were fully sheilded from the battery wire. Check that the wires are clear from snagging on the endpin by sliding it in and out a few times. It might be an idea to rotate the endpin whilst doing so as mine is ever so slightly bent.

Once you have the whole of the caviity foiled you can then proceed to the electronics plate itself. This is covered by the same black plastic coating that everything else seems to be but unfortunately, it also insulates the electronics earth-side from the metal plate.

Carefully pull off the sub-bass control knob from the control shaft to expose the nut and washer holding it in place. Take the pencil and draw a line around the washer. With a 10mm spanner, remove the nut and washer. You should be able to see the circular pencil line. With an implement to scrape away the plastic coating, scrape inside the circle till you get back to bare metal. When satisfied that you have removed enough of the black plastic coating, replace the washer and tighten the nut. Don't over tighten or you might strip the threads.

On the underside of the metal plate, there are three screw holes along one edge for fastening this plate to the body. The middle screw hole is the one I used for the next step. With the scraping implement, remove the black plastic covering around this hole on the underside (inside surface) to expose the bare metal and extend for about a centimetre or half inch either side of it. The idea here is that when you mount the plate on your body again, the bare metal will make contact with the foil you stuck onto the plate recess.

You should now have a bond between the earth of the electronics and the metal plate. This can be checked with a multimeter set as a continuity checker or on the lowest ohm range. Check for continuity or zero ohms between one of the minijack socket securing nuts and the bare metal near the screw hole you just made.

If it checks ok, plug the peizos back in, refasten the control plate and the plastic cavity covers and refit the battery. Incidentally, the black plastic cavity cover should already have a foil backing on the underside. If it doesn't, foil the underside yourself. Now plug your noiseless Stagg into an amp and enjoy.


Oh BTW, there is a level trim control for each peizo on the electronics, if you lack level on your G-string side (I did), turn the pot nearest the corresponding peizo plug on the board to balance it up.

Hope some of this is useful to other Stagg players.

Edited March 25, 2009 by Mateybass