I can HEAR the lights on my TR-808 blinking :(

[DenBaitos]

Troubles in 808 paradise.

I just purchased a 'fully working' 808 in 'perfect' condition with MIDI kit for a lot of money from eBay. The unit arrived yesterday and it is indeed fully working. BUT... I hear a constant buzz tone which is quite loud. You can hear it clearly in the mix, even with individual instrument volumes set to maximum volume. When Iturn down the master volume the noise remains. It sounds quite electrical and is not coming from the 808 sounds itself. When I stop a pattern I can hear the noise whenever a led lights up. So when there is a led blinking, I hear "bzz bzzz bzzz bzzz" on the same tempo the led is blinking.

The noise is coming from the 'HI' of the master out. I am using a normal 1/4" cable.

Anyone an idea?

Thanks,
Maarten

[DenBaitos]

Should be moved to the 'HELP!' section, I suppose. Sorry for that.

[polar69]

Doesn't sound like its truly "Fully working" to me, sounds like a fault.

How disappointing

[DenBaitos]

When I switch the instrument selector to a sound that I don't use in the current pattern (i.e. there are no leds lighting up on the 16 step bar), I don't have the noise. It's really the lights in the 16-step bar buttons that give the noise!

[polar69]

Is it like an earth loop type hum ?

[bhrama]

Might be a power source issue. I had a 909 from the UK (different plug than in the States), and it always had a slight rythmic (BPM) buzz. However the 808 has an attached cord...so thats strange. If it is too much of an issue I'd contact eBay and get a refund.

[Solderman]

I don't know the specifics on the 808, but the TR606 I modded was doing this after I added a few mods. I had to relocate a ground wire that was nearby the entire step LED array before it disappeared. Perhaps whoever did the Midi kit moved or added an unshielded ground lead. I would get your money back unless you know a reputable tech. This kind of thing is definitely fixable.

[Stab Frenzy]

Yeah sounds like a ground problem to me. Run it into a DI and lift the earth and see if that helps at all.

[Solderman]

Ground lift isn't going to help much. This problem is caused by a high-gain circuit picking up interference. It's a proximity problem for unshielded wiring.

[nathanscribe]

I find it unlikely that anybody happy to spend £££ on an 808 would rush into returning it because a 30-yr old drum machine is not entirely perfect. Come on folks. It is, I suspect, as Solderman says, something to do with a high-gain circuit inside picking up interference. I've had it on a 303, 606, EHX pedals etc... It may well be that either a point-to-point wire inside has shifted in transit/use, or someone has had it open to do whatever and repositioned a wire incorrectly on reassembly (this doesn't mean is has been de- & re-soldered, just that it may have been looped over the wrong part of the circuit).

Or it could be that the clock is bleeding through somewhere else. Either way it's not likely to be a major job.

Does the buzzing go away when you use the individual outs? If you can't afford or don't want to attempt a fix, try running the outputs you're using into a cheap small mixer instead. You get some EQ and fx sends into the bargain then. Mix outs on drum machines are a (hoho) mixed blessing.

[DenBaitos]

Nathanscribe> I also have the noise when using the individual outputs, so I would like to keep on using the main out.

When I don't have lights on the bar, I don't hear noises. So that's a good thing. I can always let the instrument selector select a sound that I am not using in a pattern when recording my track.

It's an 808 with Kenton MIDI kit. What I have to test now is if leds are lit up when playing the 808 via MIDI. If no leds light up, I'm fine. If a lot of lights on the 16-step-bar light up, I have a problem and will try to find someone who can have a look at it.

(PS: I don't have a MIDI cable yet, so I will revert to you guys next week).

Thanks for the reactions so far.

[StepLogik]

as nathanscribe said, try just moving the wires around to see if that helps. while you've got it open, check out the midi kit to make sure it was installed per directions and the tech didn't take any shortcuts. pay particular attention to the grounding scheme on the kit - is it grounded precisely where the instructions say? Are the wires clipped to precise length and not wound-up or wadded in the chassis?

do you know if the power supply has been recapped?

[Scories]

My 606 has a similar problem. But oddly, the signal-to-noise ratio gets better when I lower the output level to mid-volume rather than max volume. Maybe you could try it.

[glassofwater]

my 909 has the exact same problem. I'm using a 120-230v converter with it, but I don't think it's that. I've learned to just put it in pattern play mode whenever I record anything, but it's still quite annoying.

[StepLogik]

i gotta wonder if you guys have aging power supplies. if the caps are going bad you can start getting some noise from the digital ground bleeding over into the analog ground.