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EA tremolo help?

Started by aran.e666, December 18, 2014, 11:03:53 PM

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aran.e666

So since im a guitar pedal loveri thought I would build a tremolo, problem is ive plugged it in and get a wierd buzzing noise but, the pulsing led works with the speed etc. Yes I know, very breif description but I will go into more deatil if anyone can think, maybe its grounded wrong or a solder bridge (all ready checked lots). Thanks

P.s I will send pictures of the build and take transistor voltages...

Aran
Guitar is love, guitar is life.

Leevibe

Hard to say without pics or a better description. Does it cleanly bypass your signal? Verify that your guitar is connected to input, amp to output, and not vice versa. It's such an easy mistake to make, especially when the pedal is guts-up.

mgwhit

Quote from: aran.e666 on December 18, 2014, 11:03:53 PM
Yes I know, very breif description but I will go into more deatil if anyone can think, maybe its grounded wrong or a solder bridge (all ready checked lots).

You've got the order wrong here -- we can't think until you give us the details. ;)

Follow the steps in the Rules for getting tech help thread and several of us will be happy to help.  Good luck!

aran.e666

Ok so it does bypass. That tells me that the in/out are working. Also do you thing that it could be that ive used box caps instead of mylar on some? I will send pics when I get back from school. Thanks

Aran
Guitar is love, guitar is life.

aran.e666

Guitar is love, guitar is life.

aran.e666

Guitar is love, guitar is life.

garfo

There's a single sided version of the DBD called sea urchin laying around, why don't you etch your own board and go from there. I've built two already and work nicely. Something that could have happened is that the pt2399 is  avery sensitive chip and can easily fry, a socket is suggested.

midwayfair

Quote from: garfo on December 19, 2014, 01:46:44 PM
There's a single sided version of the DBD called sea urchin laying around, why don't you etch your own board and go from there. I've built two already and work nicely. Something that could have happened is that the pt2399 is  avery sensitive chip and can easily fry, a socket is suggested.

wrong thread, dude. :)

Leevibe

#8
Quote from: aran.e666 on December 19, 2014, 08:02:29 AM
Ok so it does bypass. That tells me that the in/out are working. Also do you thing that it could be that ive used box caps instead of mylar on some? I will send pics when I get back from school. Thanks

Aran

The fact that it bypasses means that at least part of your switch is wired correctly. That's good. You could still have your cables reversed, or reversed leads between the switch and the board though. The only reason I bring up reversed cables is that I routinely make that mistake. :)

Your caps should be just fine as long as they are the correct values. In fact, your box caps could well be mylars unless you know different.

Is the circuit boxed? If so, a gut shot might help.

aran.e666

Okay so I cut the in/ out wires and the pcb in/out wires so I could test easier and there IS paper behind the board to stop shorts.

Aran
Guitar is love, guitar is life.

midwayfair


aran.e666

Ok. Should I get the transistor voltages? Thanks

Aran
Guitar is love, guitar is life.

aran.e666

This pedal is odd because when I touch + pole on audio jack it intensifies the buzzing and now all trans pins read around -1v and slowly drop to -0.00?
Guitar is love, guitar is life.

mgwhit

Quote from: aran.e666 on December 19, 2014, 03:01:35 PM
Ok. Should I get the transistor voltages? Thanks

Yes, please.  Remove your board from the enclosure and connect the board's +9V pad to a +9V power source and the ground pad to ground.  Clip your multimeter's black lead to ground and probe the pins with the red lead.  Post the results here like so:

Q1 E: ?V, B: ?V, C: ?V
etc.

Quote from: aran.e666 on December 19, 2014, 03:41:58 PM
This pedal is odd because when I touch + pole on audio jack it intensifies the buzzing and now all trans pins read around -1v and slowly drop to -0.00?

If you're really getting 0V on every pin you're either not getting power onto the board, the power rail is cut before it hits the transistors or there is a short to ground (possibly through a resistor, hence the slow bleed), but I'm not 100% sure what you're actually doing.  Try measuring the transistor voltages the way I've explained and let's see what you've got.

garfo

Quote from: midwayfair on December 19, 2014, 01:48:17 PM
Quote from: garfo on December 19, 2014, 01:46:44 PM
There's a single sided version of the DBD called sea urchin laying around, why don't you etch your own board and go from there. I've built two already and work nicely. Something that could have happened is that the pt2399 is  avery sensitive chip and can easily fry, a socket is suggested.
Shite, too many posts open at the same time got me confused, anyway, there is an EA tremolo at General guitar gadgets as well as Tonepad I believe. They're both ready for etching. I've made the GGG version and honestly I like this tremolo better than the Tremulus.

wrong thread, dude. :)