Tube reamer noise/dodgy mains power

Vinnie500 · October 13, 2016, 05:26:03 PM

Hi I made the ROG tube reamer

I really like it but it has bit of a noise problem. On or off there is a loud buzz a mid pitch static. If I lift it an inch off the ground it drops half as loud, a foot of the ground and it is quiet.

I have a gig tonight and would like to use it. So I want to try and get it working without noise or suspending it from the ceiling.

I wonder if anyone has had this problem before or has some idea what might cause this kind of interference.

GibsonGM · October 13, 2016, 06:08:49 PM

Hi Vinnie,

Most likely, a problem like that is caused by a ground not being connected. All kinds of BS result from that. It can happen if a ground wire is broken/missing from a jack, for instance. Or if the ground to the chip wasn't connected.

1) run it on battery, see if that does anything. If you are on battery, never mind

2) So, assuming you've already housed the thing in an enclosure - I'd open the back, check that the jacks are making connection with the enclosure so the whole thing is a ground plane - that is major. Be SURE that your input jack ground wires are making contact with plug inserted, if you're using a stereo jack wired up in the typical on/off config.

3) they DO have continuity? Ok, then check the pin on the IC to be sure it is grounded (usually pin 4, in this universe).

Next, look for the other grounds that need to be connected...check that they are, also the output volume pot.

4) Did it work?

Vinnie500 · October 13, 2016, 06:33:28 PM

Thanks for the reply Mike.

I have checked all the grounding point's you asked about and everything was good. Then I set my gear up in my house as opposed to our rehearsal space, and there was no noise? It only seems to do it with this particular pedal in that particular room. I think there might be to many variables to sort this out in a forum. I'm just going to hope it behaves as well at the bar we playing at as it does in my garage.

But thanks a gain for that check list run down, it made it much faster and logical.

robthequiet · October 13, 2016, 07:08:46 PM

Neon lights and an old wiring fault in the building did that to me once. Also cheap light faders. From the sound of it you might have been right over some AC wires in that one room.

Vinnie500 · October 13, 2016, 07:24:19 PM

Also I get a shock if I touch the bass players strings, something dodgy going on I think

Tony Forestiere · October 13, 2016, 07:42:00 PM

Quote from: Vinnie500 on October 13, 2016, 07:24:19 PM
Also I get a shock if I touch the bass players strings, something dodgy going on I think

Something dodgy, indeed.

Have it checked and be very careful.

GibsonGM · October 14, 2016, 05:48:34 AM

A great investment is one of those plug-in mains testers...please get one! 2 seconds and you know if the outlet is wired right. Sounds VERY much like a hot/neutral reversed at that location...so, what you expect to be grounded (Neutral) in one outlet is HOT. Lots of players were killed in the 70s this way...I had a very nasty experience at a VFW once between my guitar and the mic, and got a tester.

Are these 3-hole outlets or 2?

YW for the 'list'...that would be the pretty standard stuff to check for hissing/noise that's constant (rather than your issue), so keep it handy

Vinnie500 · October 14, 2016, 09:46:28 AM

I spoke to the guys about the dodgy wiring at the rehearsal space and we are going to get a sparkie to take a look, it's a 40's building so who knows what's going on. I can't find a mains tester for New Zealand power outlets, but they look super handy.

These are 3 hole outlets here

duck_arse · October 14, 2016, 11:21:56 AM

you have jaycar in enzed, vinnie?

https://www.jaycar.com.au/power-point-and-leakage-tester/p/QP2000

Vinnie500 · October 14, 2016, 02:22:19 PM

Ah yes of course I should have thought of that! I just went straight to trademe and eBay. Poor old brick and mortar retail.

amptramp · October 15, 2016, 06:54:14 PM

These testers are just three neon lights and three resistors with one light connected in series with one resistor strung between each of hot, neutral and ground. You can build that into an amplifier or a power bar.

Vinnie500 · October 16, 2016, 03:20:12 AM

I just remembered a few months ago a cat snuck into the rehearsal room and jumped up on my lap while I was playing guitar. As I patted it, it moulted and the hairs floated upward and hung suspended in the air level with my forehead (I have witnesses). Maybe this power supply needs an exorcist not an electrician

amptramp · October 16, 2016, 04:44:05 PM

Quote from: Vinnie500 on October 16, 2016, 03:20:12 AM
I just remembered a few months ago a cat snuck into the rehearsal room and jumped up on my lap while I was playing guitar. As I patted it, it moulted and the hairs floated upward and hung suspended in the air level with my forehead (I have witnesses). Maybe this power supply needs an exorcist not an electrician

You could sell it to some Death Metal band as Satan's power supply for a handsome premium.

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Tube reamer noise/dodgy mains power