Build Your Own Clone Message Board

Hello,

I've checked everything a few times over but don't see anything obviously wrong so far with my work. I get a fine clean signal, leds all work and pulse in what I assume is a correct fashion. Footswitches work. Tried two different power sources.

If I turn the blend knob all the way to wet, all I hear is a very faint and fizzy effected signal. Adding a tad bit of dry signal basically just gives me dry only, since the wet signal is so faint. At first I thought there was no wet signal at all, but now I can actually discern a very faint and fizzy wet signal when the dry is cut out at full clockwise turn of the blend pot.

Here are pictures of the top and bottom of the board so far:

Try removing and reinstall the PT2399 chips from their sockets (reseating them). Verify there is 5 volts DC on pin 1 of each PT2399, and try swapping their positions.

If you have any pedals with known good PT2399s, swap them out.

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MasterDelayer/Reverbrador/Ampaholic/TopJacker

Interesting. I have 5v (4.8 on my mm to be precise) on each PT2399 IC. I switched them around and had wet signal once, so I put it back in the case and retried...no signal. Took it out of the case again...no signal but the faint fizzy original. I think I'm going to order a couple replacement PT2399s just to try that out.

Intermittent problems like that usually suggest faulty solder joints/connections.

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*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

So I do notice something of interest. When I touch two of the 4.7uf Aluminum Electrolytic capacitors, I get a buzzing sound like if you touch the end of the input jack. Could these components be bad or inserted wrong? None of the other ones do this.

Remove the two PT2399 chips. Insert jumper wires between pins 14 and 15 of each socket. Does the blend knob now have "wet" signal? The wet signal will now have no delay or modulation. It should have a small amount of the high frequencies filtered out.

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

Only very weak non-effected signal with the jumpers in.

Then the problem probably isn't with the PT2399 chips. Try removing the 571 from its socket and jumpering pins 11 and 7. What does the wet signal sound like now?

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

Thanks much. Doing that gives me wet and dry signals that are almost identical. No effect/modulation.

Now try jumpering 10 and 11 together and 2 and 6 together on the 571 socket. Make sure the PT2399 chips are installed.

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

10 & 11: Very faint dry signal
2 & 6: Very faint dry signal, plus oscillating static that appears to maybe coincide with the top-right LED pulsing.

Jumpering 10/11 and 2/6 at the same time gives weak dry signal with the fizzy/static effected delay signal mixed in.

Thanks for all your help btw. I just wired up an audio probe. Are there some specific spots I should try probing to see where the signal chain is breaking down?

Based on the signal bypassing you just did, we can assume that the problem is somewhere between the send and return of the 571 compander chip, and possibly including the 571 itself. If you have a signal tester, that's a huge help. Put all the chips in their respective sockets and test in this sequence:

1. Pin 10 of 571
2. Pin 11 of 571
3. Pin 16 of IC3 PT2399
4. Pin 14 of IC3 PT2399
5. Pin 16 of IC4 PT2399
6. Pin 14 of IC4 PT2399
7. Pin 2 of 571
8. Pin 6 of 571

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

HYG. I labelled the PT2399s based on orientation since I couldn't discern which one was the IC3 and which was IC4

1. Pin 10 of 571 -- dry signal, good volume
2. Pin 11 of 571 -- dry signal, slightly weaker vol/thinner tone
3. Pin 16 of IC3 (horizontal) PT2399 -- no signal
4. Pin 14 of IC3 (horizontal) PT2399 -- effected delay signal
5. Pin 16 of IC4 (vertical) PT2399 -- very faint delayed signal
6. Pin 14 of IC4 (vertical) PT2399 -- slightly louder but still faint distorted delayed signal
7. Pin 2 of 571 -- fizzy delayed signal
8. Pin 6 of 571 -- very weak fizzy delayed signal

Would you say the signal coming out of IC3 at pin 14 is a good delay signal? Good signal level? Not distorted?

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

Yes, good delay/reverb effected signal on pin 14.

Swap the chip that you have in the IC4 socket for the chip that you have in the IC3 socket. Is the sound coming out of IC3/pin14 still good?

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

Yup! Still good.

Hmmm....well that means both of your PT2399 chips are good, which is disappointing because that means we don't know what your problem is yet. Please take voltage readings of the IC3 and 4. Please take readings first with the chips out of their sockets and then with the chips in their sockets.

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

Measuring at pins 1&4 on the PT2399s I get 005 on both. Measuring at pins 4&13 on the 571 I get 009.

I also went ahead and ordered two new PT2399s and a new 571, and I get same results with the new ICs, so I think you're right that the ICs themselves are fine.

Mmmm....I don't think you're taking those voltage readings correctly. Also, I need to see the voltage readings for all of the pins, 1 through 16 of both the PT2399 chips. I need to see readings with the chips in their sockets and I need a set of readings of the empty sockets. I'm not really concerned with the 571 at this time, so you don't need to post those readings.


Please let me know if you need assistance with how to use a multimeter. If you do, please let us know the make/model of your meter.

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

Here's the multimeter I'm working with.

Set the DC voltage range to 20. Leaving it on 1000 doesn't give you enough sensitivity to see fractional voltages.

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“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Readings with Chips Inserted

IC3 (horizontal) PT2399

1 - 5.00 9 - 2.50
2 - 2.49 10 - 2.50
3 - 0.00 11 - 2.50
4 - 0.00 12 - 2.50
5 - 2.84 13 - 2.50
6 - 2.50 14 - 2.50
7 - 0.69 15 - 2.50
8 - 0.79 16 - 2.50

IC4 (vertical) PT2399

1 - 5.00 9 - 2.50
2 - 2.49 10 - 2.50
3 - 0.00 11 - 2.50
4 - 0.00 12 - 2.50
5 - 2.89 13 - 2.50
6 - 2.50 14 - 2.50
7 - 0.25 15 - 2.50
8 - 0.69 16 - 2.50

Readings with Chips Removed

IC3 (horizontal) PT2399

1 - 5.00 9 - 0.00
2 - 0.06 10 - 0.00
3 - 0.00 11 - 0.00
4 - 0.00 12 - 0.00
5 - 0.00 13 - 0.00
6 - 0.00 14 - 0.00
7 - 0.00 15 - 0.00
8 - 0.00 16 - 0.00

IC4 (vertical) PT2399

1 - 5.00 9 - 0.00
2 - 0.09 10 - 0.00
3 - 0.00 11 - 0.09 <-- These three would start around 0.30 and then level off at 0.08-10
4 - 0.00 12 - 0.09 <--
5 - 0.00 13 - 0.10 <--
6 - 0.00 14 - 0.00
7 - 0.00 15 - 0.00
8 - 0.00 16 - 0.00