thread starter I modded a Boss DR-110 to have extra controls for the sounds, basically just replacing fixed resistors with pots..
Anyhow, there is a tone leaking through the output at all times now.... and it tunes with the hihat/cymbal tuning knob that I added during the mod... I'm wondering if anyone could perhaps guess at what the problem might be? One thing that is perhaps it, but I dont know - none of the pots I added have the 3rd pin (ground) connected to anything.. is this likely to be the culprit? The tone is constant.. doesn't change when fingers contact the metal shafts of any of the pots or things like that.. I can only change it by altering the hihat/cymbal tuning pot... it seems to be the same frequency as the hihat/cymbals tone - and not the noise component at all... so I would guess that it IS that tone part of the hihats, somehow constantly being triggered/allowed through. .. But I actually don't know much about analogue circuits besides basic concepts..
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Where sound is involved, grounding is very important...
pots don't have a grounding pin really...there are only usually 2 connections.
my guess is the wire wrap in teh pot is amplifying a signal or not putting enough resistance in teh circuit... try just removing the pot and putting the resistor back in and if you're lucky it'll go back to normal. pots don't have a grounding pin really...there are only usually 2 connections ?? Every pot I've ever seen has 3 pins.. and everything I've ever read has said the 3rd is for grounding.. BTW, I am not lucky.. I am consistently unlucky.. so I will try, but do you have any other ideas? hahaha they have 3 connections, wiper and 2 terminals. the third is not always used for grounding, but it is common.
yeah 3 pins but usually only two are connected from what i've seen.
I always thought the screw you use to mount it to whatever chassis was the "ground" i've never grounded any pot in any of my bent gear but then again i usually use plastic or wood mod boxes... This very thing happened to me when I modded my TR606. The hihat oscillators are 4 pulse wave generators that always drone at the same pitch. When they are processed inside the drum machine, they run through hipass filters first, so only the higher harmonics are heard. With the crosstalk/bleedthrough issue, you hear these pulse waves mixed, before they are being filtered.
The culprit turned out to be a mod recommended by Robin Whittle which connected an audio input jack to the Hihat's enveloped amp so you could run your own signals through it and get the enveloped signal out instead. It was a switched jack, meaning the entire hihat oscillator mix ran up into the wiring in my breakout box to the jack, then back through the wiring again to the circuit board. Inserting a phono cable into the jack broke the oscillator line and sent your signal to the return line, but you could still faintly hear the hihat oscillators droning, only quieter than before. The jack was not grounded as far as I remember. When I removed this jack, and the wire leading up to it, the crosstalk/bleedthrough of the hihat oscillator mix stopped. Never did figure out exactly what happened, but my guess is some sort of potential difference by sending the oscillator mix out and back, which messed up the electrical isolation of them. If you have anything connected to the hihat enveloped amp, that would be the first thing to check.
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thanks rogerroger,
I have a number of hihat-altering controls, a couple related to envelope decay and such, I will have a play with disconnecting all the hihat controls and see what I can do.... Thanks to my shitty electronics skills when I first did the mod , its a complete bitch to open and rework, but I guess I've no choice soooo.... I had a look at the wiki... I dont understand much in terms of electronics diagrams, but from what I could guesstimate -
does this mean I *should* ground it with the 3rd connection, to make it into a voltage divider? :/ I did have another theory about my own hihat input jack failure.
A few of the wires that go up to pots in the breakout box are part of high gain circuits. If the Hihat oscillator mix signal is hot enough to produce magnetic interference, I'd guess it could bleed into one of those high gain circuits and be amplified. I know I had to ground the pot body for a few of them in the breakout box due to this, so it's plausible this could be related to interference. I don't know enough about electronics to know how to fix it, unfortunately.
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ignore the 3rd lug, ground the body. i have no clue if that will solve your problem, but for this application just ignore the 3rd lug.
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btw the first thing to do is to open up the unit again. if that changes things you're having what might be referred to "the cover problem" :D it doesn't work when you close it... on a slightly more serious note, examine your connections. you either have unsoldered or soldered something by mistake, or things touch where they shouldn't. (oh the pun..)
my guess is that the oscillator signal for the hi hats (which is constant as RogerRoger mentioned) is bleeding into some of your wiring either through interference (most likely) or a solder bridge. try detaching the wiring for the tuning pot and see what happens.
if you're just using the pots to replace single resistors, you don't need the 3rd lug. the third lug is for when you want the pot to act as 2 separate resistors, one between lugs 1 and 2 and the other between lugs 2 and 3.
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thanks zifcak.
I'll open it up when I get some time... for the time being though, I just embarked upon making an arduino sequencer >_> maybe one day i'll put the dr-110 guts inside the sequencer and hook it up with triggers.. that would be cool! Signup to comment
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