Harmonic Percolator- Tagboard.. switch wiring?

fig said:
Why do I have this sudden craving for turrets?
Click to expand...
You know you want it!

Turret I like working with particularly this type which is more tag than turret and it don't break the bank

It is sometimes a pain trying to get long leads through the holes especially with axial stuff, I cut one side in half, slide the longer one in then the shorter one if there's more than one lead in the same tag I don't solder till I've got them all in

I'll then just tack solder to hold in place and remelt to position everything, I use croc clips a lot with tag especially with wires

With this one for the weird 750K I suddenly thought use 1/8th watts for a nice small tepee series job, so you do learn as you go I'll do that in all future builds if I need an oddball value
 
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Mcknib said:
Right finished building it and tested on my test box

It worked perfectly those transistor voltages are accurate

I used a 2N404 hFE 100 very little leakage and a 2N3904 and built it stock

From my readings on this circuit

Most folks say it should be a low hFE germanium but this works fine with a highish hFE for a germ

I tried it using humbuckers and single coils didn't notice any difference albeit my humbucker isn't particularly hot

Hopefully you'll find your problem soon because it is a good sounding pedal with lots of sustain the switch is a good addition it does sound a tad dark till you flick it

Anyway here it is for reference you may see something comparing it to yours

I do use the holes to secure the wires so you'll see them going down here and there green is in, yellow out, red 9v, black ground with the brown ground bottom left jumpered up to the main grounds on the underside
View attachment 13374
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Don't rub it in man lol
 
This might be a dumb question but do all grounds need to be connected to each other?
like the grounds on one side of the turret need to be connected to the other, etc?
 
To actually answer, there needs to exist continuity within the ground plane...so yes, by hook or by crook all grounds lead to the same place (in most cases).

btw, that is NOT a dumb question.
 
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As long as they all go to ground on the power supply you can have as many seperate ground wires on your board as you like but as @fig said they all need to be connected to your power supply ground ( the same place) on the DC jack or battery ground connection.

Us older dudes will remember star grounding where your wiring looked like a dead octopus

You'll get it sussed I've done many tag builds so it wasn't a conscious rubbing it in

but......

nah, nah nuh nah nah
 
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Okay well I am going to try adding a ground from one side of the board to the other which would connect all grounds together. I'm also going to test my voltages on the multimeter and see what it comes out to!
Thanks again for the input. I will report back later
 
Here's the underside of mine where you can see the brown jumpers connecting all the grounds

That may well be your problem with over voltage making your trannies oscillate

20210707_172254_copy_310x249.jpg
 
Mcknib said:
Here's the underside of mine where you can see the brown jumpers connecting all the grounds

That may well be your problem with over voltage making your trannies oscillate

View attachment 13378
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I think that was it. That was the one wire I was missing.
I like how you went under the board. I will have to remember that the next time I do one of these.
Off topic, where do you get your boards?
I ordered one from the UK
 
Thanks that site looks pretty good if you want to do the vintage look tagboard

Those Allen Bradley 1/8 and 1/4 watt resistors ain't too bad

That eBay seller's the guy that runs this site Mark Hindes

This store has expired

markhindes.easywebstore.co.uk
 
Update- adding the ground wire did indeed stop the oscillating. However, the pedal still doesn't work. If I turn the volume and harmonics up all the way it is spitty and very very quiet compared to the bypass tone. So, would this mean that the transistors are in the wrong way?
21DF469D-CA03-4509-BE8E-639EA711DE1B.jpeg
Based on the diagram I have seen for the 2N404A it should be (left to right) Emitter, Base, Collector. I actually tried moving it around in some different ways and it didn't really do anything.
BBC28C08-FEA5-4267-8FEB-B50A0D11F6B7.jpeg
based on the data sheet for a 2N3904 this should also be correct (left to right) Emitter, Bass, Collector.

I did double check the board and it looks like all the parts are in the right spot.

I'm really stumped. If these transistors are in the correct way, I would have to be missing something else obvious
 
You've got the transistor pinouts correct and from your previous pics and posts you have the 2N404 base pin bent over to the left followed by collector and emitter so that's the correct way to solder it in left to right B,C,E

What's the voltages on your C,B,E transistor pins

It's difficult to trace everything with the big caps in the way can't see the 91K for example

It does sound like your transistors aren't biasing correctly I don't know whether 70K difference in having a 680K instead of 750K feedback resistor would cause mis biasing to that extent

You could try lifting a leg of the 680K out and adding a 67K in series ie tepee them together
 
Mcknib said:
You've got the transistor pinouts correct and from your previous pics and posts you have the 2N404 base pin bent over to the left followed by collector and emitter so that's the correct way to solder it in left to right B,C,E

What's the voltages on your C,B,E transistor pins

It's difficult to trace everything with the big caps in the way can't see the 91K for example

It does sound like your transistors aren't biasing correctly I don't know whether 70K difference in having a 680K instead of 750K feedback resistor would cause mis biasing to that extent

You could try lifting a leg of the 680K out and adding a 67K in series ie tepee them together
Click to expand...
I took the build out of the enclosure last night, but I didn't have time to take out the multimeter. Hopefully today I can check all of my parts and voltages
 
This may also be a silly question- the electrolytic cap I am using here- I believe its non polarized.. that wouldn't cause any issues would it?
 
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Alright so classic mistake. Resistors in the wrong spot... and one of legs of the GE tranny came off. So, I'm going to order another one.. and some smaller caps since these 640's are the definition of overkill.
Thanks so much for all the help. I'll report back once parts show up
 
Yeah just use green mylar! I too fell into the trap of using vintage looking axial stuff for my first tagboard efforts

I only do that now if it's requested

You can use any PNP germanium in there if you've other types kicking about in your parts bin and of course any cap of the correct value

I don't normally tepee resistors like yourself I'll just use the nearest value but coz I'd read this is a bit of an oddball I decided to do it
 
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