super hard on- stuck on full

Started by Bricksnbeatles, January 04, 2016, 10:49:10 PM

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Bricksnbeatles

Hey everybody!

induction

#21
Quote from: Bricksnbeatles on January 05, 2016, 04:17:48 PM
its super loud at 0, then it drops down near unity almost instantly later, so the pot is wired backwards, i switched the wires around but then the pot does nothing, so i went back to how it was and it works, but the taper is all wonky and backwards. I've wired many pedals with no problem, so i don't know why one of the simplest circuits I've done yet is giving me issues...

Quote
gain 1 goes to lug 1, lug 1 bridges to lug 2 and then lug 3 goes to gain 3

To reverse a variable resistor, you just want to change which lug connects to the wiper (ie. connect lug 2 and lug 3, instead of lug 1 and lug 2). Reversing the connections to the board should have no effect on the taper or the direction of gain increase.

Edit: The gain pot wiring in the vero is correct, though. With lugs 1 and 2 connected, gain should increase in the CW direction. So I suspect you are numbering the lugs backwards. If not, you still have a build problem.

mth5044

Quote from: Bricksnbeatles on January 05, 2016, 04:23:37 PM


Unfortunately you can't share gmail attachments. You need to upload to an image site. Unless it's just me that can't see it?

Bricksnbeatles

i got it working. It seems that the diagram was wrong in the way it said to wire the pot. the diagrams for the sho seemed to be split in which way the pot was wired even though they all have the same signal flow.
Hey everybody!

stallik

Glad it's working. Regarding the reverse wiring, it could be argued that it was correct... When viewing the pot the other way up ;)
Insanity: doing the same thing over and over again and expecting different results. Albert Einstein

induction

Quote from: Bricksnbeatles on January 05, 2016, 04:55:16 PM
It seems that the diagram was wrong in the way it said to wire the pot. the diagrams for the sho seemed to be split in which way the pot was wired even though they all have the same signal flow.

The layout is correct as long as you number the lugs correctly. This diagram shows the convention specified by the creator of the layout.


I have seen some SHO schematics and layouts where the pot wiring was wrong, but this isn't one of them.

Bricksnbeatles

Quote from: stallik on January 05, 2016, 05:09:45 PM
Glad it's working. Regarding the reverse wiring, it could be argued that it was correct... When viewing the pot the other way up ;)
what i am referring to however is that to get it to work properly I had to bridge the wiper lug to the lug that went to s on the transistor. And in case anybody is wondering I DID use the correct 5kohm C (reverse log) potentiometer. I suppose its possible that I'm just really tired and my mind isn't working right, but i don't think so. It is a bit confusing when all of your wires are black haha. l'll take another look after i get back home.
Hey everybody!

induction

#27
Quote from: Bricksnbeatles on January 05, 2016, 05:40:03 PM
what i am referring to however is that to get it to work properly I had to bridge the wiper lug to the lug that went to s on the transistor.

This pot is a variable resistor. Reversing the entire pot should have no effect at all. It doesn't matter whether lugs 1 and 2 go to source and lug 3 goes to ground, or if lug 3 goes to source and lugs 1 and 2 go to ground. Electrically, these two arrangements are identical. The only connection that matters (for direction and taper purposes) is whether the bridged lugs are 1 and 2 (correct), or 2 and 3 (incorrect).

Glad you got it working.

Bricksnbeatles

Quote from: induction on January 05, 2016, 05:51:54 PM
Quote from: Bricksnbeatles on January 05, 2016, 05:40:03 PM
what i am referring to however is that to get it to work properly I had to bridge the wiper lug to the lug that went to s on the transistor.

This pot is a variable resistor. Reversing the entire pot should have no effect at all. It doesn't matter whether lugs 1 and 2 go to source and lug 3 goes to ground, or if lug 3 goes to source and lugs 1 and 2 go to ground. Electrically, these two arrangements are identical. The only connection that matters (for direction and taper purposes) is whether the bridged lugs are 1 and 2 (correct), or 2 and 3 (incorrect).

Glad you got it working.
Yeah what I'm saying tho is that for some reason what worked was having lugs 2 and 3 together
Hey everybody!

induction

Quote from: Bricksnbeatles on January 05, 2016, 07:45:52 PM
Yeah what I'm saying tho is that for some reason what worked was having lugs 2 and 3 together

If you're using the lug numbering shown in post 25, then you still have a build problem. If you're happy with the sound and performance, then it's up to you whether you want to track down the problem or just leave it alone, but there's no question that what you're describing is not the way the circuit is supposed to work.

If you're interested in pursuing it, some photos might clarify things. If you're happy with it as is, I'll shut up now.  :)