Tremshifter issues

[mr-nad]

Hi all,
finally got the tremshifter finished, but alas, no input signal.

The trem and filter are both working, you can hear it scoping through and the pots are providing everything thats needed. just no guitar signal. bypass is fine.

I used marks offboard wiring diagram and used vero on the pots to connect the wiring to. (first time i have tried this, and mightily effective with the pcb pin potentiometers)

the readings from the ics are

iC1 - 1 4.38, 2 4.44, 3 4.22, 4 0.00, 5 8.86, 6 4.34, 7 4.38, 8 4.19
ic2 - apart from pin 4, all other pins are fluctuating between 2.22 and 8.34
ic3 - 1 between 4.04 and 6.92, 2 between 5.19 and 5.76, 3 between 4.76 and 5.03, 4 0.00, 5 8.86, 6 everywhere in 5v, 7 same as 6, 8 same as 6 and 7.

all strips i have made sure there is no bridging (i've used a junior hacksaw down all strips)

I'm really lost as to what i can do next

Anyone with any ideas

Thanks Dan

[cylens]

just in case: have you wired the LEDs for visual feedback? they need to be wired to complete the circuit

[mr-nad]

Hi, yeah, the superbrights are connected up with the ldrs and the external leds are connected up to give visual representation of the rates and depth of both the tremolo and the filter.  It's weird because the feedback from it not being in an enclosure, you can hear the tremolo and filter working. Just no signal when you play guitar through it.

[mr-nad]

Hi, yeah, the superbrights are connected up with the ldrs and the external leds are connected up to give visual representation of the rates and depth of both the tremolo and the filter.  It's weird because the feedback from it not being in an enclosure, you can hear the tremolo and filter working. Just no signal when you play guitar through it.

[cylens]

the signal path in the tremshifter is quite simple, you should probe the circuit and you'll clearly see/hear when you lose the signal... it happened to me many times just having forgotten one cap somewhere...

do not hesitate to post a picture of the board, a "fresh" pair of eyes might help

[mr-nad]

Excuse the messy wiring. I haven't got an enclosure for it yet and was using cardboard as a fascia for the pots and switches.

[Synsound]

I compared it to the layout and all of the components seemed to be positioned properly from what I could see. Of course there are some blind spots in the photo (mainly hidden by the LDR/LEDs.
I usually find the mistakes in my builds to be hidden in plain site. Here are a few things I've come across that might be worth a look.  Going over the solder side with a magnifying glass I've come across leads that were never soldered like a missed socket pin. Cold joints that I found metering for continuity, not only on the strip but at each joint. Components that are off a bit in placement( didn't see any here). Bad joints at wire points, seems like if the shielding gets melted it can slip through the hole and create a bad joint. Double check for continuity at all off board connections and functionality of the switches
When I built this circuit I went over it for hours. I set it down and came back to it a week later to realize I had my input wire off by one row. I was on the brink of scrapping the whole thing.
My best advice is to take a break when hoe feel the rage and come back to it ( a couple times if need be) I would say that of the circuits I've had problems with, 95% of them were a silly mistake and were fine after a quick fix.
Hope you find it.

[cylens]

same here...

you should definitely probe it:



pin 2, pin 1, pin 6 and pin 7 of the top left IC should give you a good indication of where your problem is

[cylens]

I'll open my tremshifter later today to check voltages, but 2 remarks here:

I think you mislabelled your IC pins: it's 1 to 8 from top left pin, but counterclockwise: pin on top right is pin 8

something else: for IC2, you say that apart from pin4, all voltages are fluctuating: you should have a steady 9V-ish on pin 8, otherwise, check your double link here (check for continuity between all the ICs pin n°8)

[mr-nad]

I'm off to work in a mo, but I'm going to give it a good look over when I'm back.
I checked the data sheet when I probed the ics. Following it counter clockwise from 1 to 8.

It could be some of my soldering, my iron tip has disintegrated over the past few days, it was a sharp point but that has disappeared. I know there are no bridges between the strips as I went over all of them when I finished soldering up.

It's just frustrating that everything is in place as it should be. You can hear the tremolo and filter working. The leds are doing what they are supposed to,

I thought I was being a little over ambitious for my experience in building pedals, but I took my time over it to make sure I done everything right.

[cylens]

well actually that would be a "good sign": you should have roughly 9V on all pins 8 and on the first IC, pins 3&5 should be at roughly 4.5V: they are connected by a jumper

if you don't have these numbers, check the 2 following 100k resistors: the one just at the right of IC1 and the one at the left of IC1

[mr-nad]

ok so all ic pin 8s are just below 9v
and pins 3 and 5 are around the 4.5v mark with a little bit of fluctuation.

[mr-nad]

i think i have found the issue. where the input lead is put into the circuit i had an issue with the placement of all of the components and jumpers on the left side. i had place everything one strip too high. i just had a fresh look at the back and noticed where the input wire goes in, there is no strip left between the solder and the next solder joint. soldering iron is heating up and i will give progress as soon as ive soldered that piece up.

if that is what the problem is, i am gonna feel so n00bish

[mr-nad]

surprise surprise. it was what ive just said about.

i'm feeling really pleased with myself now, ive just made myself a pedal with only the most minor of hiccups.

[cylens]

that's great news, enjoy this wonderful circuit!

[mr-nad]

I will enjoy a lot more once i have an enclosue for it. theres quite a bit of rf interference with it.

[mr-nad]

and thank you, your pointers were a massive help

[motterpaul]

Major congratulations - as I recall this is your first build (yes/no?) and it is a very big project - not easy at all.

[mr-nad]

Hi Paul. It's my first big build. I have made a few minor boards, (green giant, bazz fuss, mini muff) with varying degrees of success.



I'm gutted I can't box it yet. Finances are strict until June as I'm globe trotting in may. I guess it will sound even more awesome once I get it grounded.

I have since built the cave dweller ed1 with first time success and boxed it. Just unhappy with echo tail length/volume. Could be down to the pots I used.

(Sorry about the delay in replying, work has overtaken my life this week. I forget what the mancave looks like. Might pop my head in there tomorrow when I finally have a day to myself)