SmallBear Trem Bear build help needed

[gluedtogether]

I have been working on a smallbear trem bear. I think I am very close, but don't get any trem. the led for the ldr doesn't seem to flash at all. Below are the measurements. If anyone has any suggestions, it would be much appreciated.

John lyons was gracious enough to make the layout for me, I added in the parts layout for the board.


Source: http://www.smallbearelec.com/Projects/TremBear/TremBear.html

What does it do/not do?
* LED indicator is functional
Sounds comes out, volume control, but no trem
* LED for LDR does come on at, but I can't get it to flash

Modifications to the circuit?  I have made no modifications to the original schematic.  I bought this as a kit and assembled per directions, using layout from John Lyons

Parts Substitutions? None.  All parts necessary came with kit.

Positive/Negative Ground Circuit?  Negative Ground

Out Of Circuit Battery Voltage?  9.73V

With negative lead from dig multimeter on Ring tab of Input Jack (where black lead from battery connects) -
* Voltage at circuit board end of red battery lead:  9.58V
* Voltage at circuit board end of black battery lead: 0.0V


TRANSISTOR VOLTAGES:

IC 1: TL072P

1 – 4.47   5 – 4.47
2 - 4.47   6 – 4.47
3 - 4.47   7 – 4.47
4 – 0       8 - 8.94

IC 2: TS555CN

1 - 0   5 – 5.53
2 – 2.3   6 – 2.17
3 – 8.3   7 – 5.13
4 – 8.3   8 – 8.42


Q1: 2N7000

D – 7.39
G – 2.33
S - 0.01

Q2: 2N2222A

E - 0.57
B - 1.19
C – 4.7

Q3: MPSA14

D - 0.0
G – 1.8
S - 0.62


DIODE VOLTAGES:

D1: 1N914

A – 2.5
K – 2.2

D2: 1N914

A – 3.1
K – 2.8

D3: 1N4001

A – 8.5
K – 7.9

[John Lyons]

Oh, ok..I see what you were saying now Mike.
I didn't put in a pad for the ground connection. I just assumed that you would connect the ground wire to the board at the ground trace.
Sorry about that!

2n7000 mosfets are sensitive to static. Maybe it got zapped?
The voltage looks ok though I think.

John

[gluedtogether]

I tried putting a new timer chip in, but didn't see any difference. Steve Susgested tracing the schematic and layout which I have started to do and will continue tonight.  If anyone has any tips as to anything else to try, please let me know and I will give them a shot. All a learning experience at this point. I am going to double check I have the switches and pots wired correctly.

Here are some pics of the layout populated. The LED/LDR is not sealed as I was checking to see if I got it flashing. As of now both LEDs light up. All the connections seem to be solid so I am hoping I just have something in backwards somewhere.

[Nitefly182]

Take every component on your board and seat it as close to the PCB as possible. With all those parts sitting way up off the board with long leads you are begging for trouble. You also wont get any trem if the photolens isn't close to the LED and covered so it only sees likght from the LED.

[John Lyons]

The wider spaced resistors will fit flat on the board. I think there are only 4 that need to sit vertical. The 5 resistors that act as R12 are obviously vertical. The diodes and caps should all be against the board.

Can you get a clear picture of the solder side Mike?

The LDR/LED are fine to be uncovered for now as you will need to see if the oscillator is working correctly.
When you figure this out the LED pulsing to the speed and depth settings then you can close it up.

[gluedtogether]

haven't traced yet. That is next. I moved all the components closer to the board as suggested by Nitefly. I will enclose the LED/LDR once I get the LED flashing. I was waiting to ensure that was working before closing it up

John - here are the solder side pics you were looking for

[gluedtogether]

After tracing everything and not finding a problem there, I Found the problem. It was me. i had the tantulum cap backwards. I didn't read the fine print and notice the positive side. that seems to be it. The trem works and sounds pretty good. I still have one of the toggle switches not working correctly, but I can live with that for tonight.

[gluedtogether]

so the trem bear is boxed up, on my board and working wonderfully. I adjusted the value of the resistor for r14 to a higher value. I was gettng a bit of distortion, but that seems to be gone with the change.
John Lyons was good enough to post sounds samples of the pedal on his site. I tried to put together a variety of sounds the pedal was capable of.
http://www.mrdwab.com/john/soundclipspage.html

All the clips were recorded through a silverface pro reverb with Strat. For the distorted clips I used a modded ts-9.

Let me know if there are any questions.