TS808 Not working

[ranchak]

I just got finished with a TS808 Clone. I'm using the El Griton 2.2 from Tonepad. I made my own PCB. It doesn't work, which seems to be the case with my projects. I've checked my values, looked for cold solder joints, checked for bridged solder joints. I decided to build an audio probe. I have signal at the input on the board. I have signal through the first cap and into the first resistor (1K). On the output of the first resistor the signal is barely audible. I thought I had a bad resistor so I tested the circuit with a new resistor not wired to the board. I had signal so I replaced the resistor and I still have the same problem. It seems that something is "grounding out" the signal. I'm new to building, but I take my time and make sure that I am careful when soldering. I don't know what to look for next. Any ideas?

[The Tone God]

Read and follow the "DEBUGGING - What to do when it doesn't work" sticky then report back.

Andrew

[ranchak]

Battery Voltage   8.68



        Q1          Q2
G      8.54       8.54
S      7.81       7.81
D      7.80       7.81



Pin 1     4.32
Pin 2     4.40
Pin 3     4.32
Pin 4     0
Pin 5     8.54
Pin 6     4.32
Pin 7     4.32
Pin 8     4.32


I made my mine PCB from the Tonepad site. This is the El Griton 2.2 made as a TS-808. No substitution for parts.

[petemoore]

   Q1          Q2
G      8.54       8.54
S      7.81       7.81
D      7.80       7.81
  The sources should be close to ground, check all ground points, and that the source resistors are correct value and connected to the sources, these Q's aren't biased.



Pin 1     4.32
Pin 2     4.40
Pin 3     4.32
Pin 4     0
Pin 5     8.54  This one is near V+, ?miswire or misvalue somewhere near it
Pin 6     4.32
Pin 7     4.32
Pin 8     4.32
   

[The Tone God]

Pin 5     8.54  This one is near V+, ?miswire or misvalue somewhere near it

Unless OP has misunderstood IC pin numbering...I hope.

Andrew

[ranchak]

Andrew, do you mean I have my pin numbering wrong?

[The Tone God]

Andrew, do you mean I have my pin numbering wrong?

I don't know. It was just a thought as it is weird for pin 8 to be at that level and pin 5 to be at V+. Check this diagram from the DIY FAQ:



Andrew

[petemoore]

  Pin 8 should be at V+ supply, ...battery voltage.

[petemoore]

  Since it's near 1/2v like all the other pins except Gnd. pin4, perhaps a probe slip led the meter to reading the wrong pin as you were noting voltage.

[ranchak]

You guys are right. I have my pin config backwards. Here are the new readings:

Pin 1     4.20
Pin 2     4.27
Pin 3     4.20
Pin 4     0
Pin 5     4.20
Pin 6     4.20
Pin 7     4.20
Pin 8     8.29


I haven't checked the source resistors, I'm going to do that now.

[ranchak]

I found the problem, I had installed J201 trannys instead of 2N3904. Everything works fine. I sure wished I would have checked the trannys last night.