dr boogey problem

[firko modor]

Hi to all willing to help,

I made the dr boogey from this well known site http://gaussmarkov.net/layouts/drboo/drboo-perf.png
Built the pcb myself and connected all the elements on the board

Now after connecting the power to the board i got voltage readings on only 3 trimer's  (TRIM 2 and 4 which can be adjusted,while the voltage
on trim 1 it is always 7.9 volts no mater how much i try to adjust the value)
On trim 3 i am not getting any voltage reading at all

Truth be told I used 2 resistor in series to get 2 M ohm's    and  1N4007 instead of 1N4004
Also i am using a  ac-dc converter that has an output of 8.2 V and that is the only difference to the original

I haven't found any shorts,or elements put wrong

I tried to put a normal resistor in place of the trimer 1 (50 K Ohm) and got 5 V but still nothing on trim 3
Also replaced the trim 3 with a normal resistor and still nothing

Please help me i want to boogey 

[lonewolf]

do you have 9v on pins 1 and 2 of the trimmers? are all the electrolytics oriented right..I would look for some broken traces or something shorted ..check for continuity along the 9v rail to the trimmers..use a magnifier to look for a hairline crack,etc

[jmwreck]

I would like to ask something different on my build. there is a very low output on my pedal and I have noticed something, I measured the 9v and Ground (DMM at Resistance settings) for connectivity which there should be no connection for both, but I do get a resistance in there. I tried to pull out all the Jfets and the 9v & Ground connection is gone. I wonder if those Jfets created those connections, or is it really suppose to be like that?

Using the Jfets that I have pulled out, I measure it using the same setting above, from D & S, I've also got a reading.

[PRR]

> I measured the 9v and Ground (DMM at Resistance settings) for connectivity which there should be no connection for both

There is usually "some" conduction across the circuit's power connections.

With BJT transistors it may be very very slight (high resistance) until you apply some voltage (more than an ohm-meter).

> all the Jfets

Ah. An unbiased JFET may be like a 300 ohm resistor. You may have another 10K of actual resistance in series with each JFET. So a several-JFET circuit is likely to look like a several-K resistor.

[jmwreck]

schematic


layout

Ive made my own perfboard layout, can you help me verify it? I have made the second build last night and still no sound, I was thinking of the j201 to be the problem, since I just removed them from the first build and mount it to the second.