Tuesday, 14 April 2020

Cornish SS-3 Soft Sustain

*Edit 200914*
New smaller layout.
Schematic is avaiable HERE






25 comments:

  1. Awesome, thanks for posting. Is this based on the Aion schematic? If so I think the divider of the 180k @ pin 7 of IC1 and the 150k to ground should be swapped.

    Also the 1k6 in column 18 (L-P) right of the 220n, might need the south leg moved up 2 rows (N). Should connect to the output of the 220n, and Hi Cut 3.

    ReplyDelete
    Replies
    1. Hi there. thanks for the headsup. I will sit down with the schematic and layout in a couple of days to check out the corrections.

      Delete
    2. I did a new layout from scratch since I wasn't happy with the size. Feel free to take a look if you see something out of place.

      Delete
    3. Hi Fuzzhead, I built the pedal and the output is very quiet, To the point of everything turned up i can only just hear sound. Also when the sustain is turned down to zero there is a high pitched screech. I have no bridges that shouldn't be there and no cold solder joints. Im about to see if replacing the chip or the transistor fixes the issue at all but otherwise im not sure. Any other Ideas?

      Delete
  2. the screech happens when the sustain knob is zero to about 2.5-3

    ReplyDelete
  3. new chips and transistor make no difference

    ReplyDelete
    Replies
    1. I've double checked it and compared it to the schematic and I can't find any errors. But I have a finished board on my desk, just need to wire it up. Will report back.

      Delete
    2. Just fired up my build and it works fine. With gain and volume controls turned up it well above unity level. I have no issues with the gain control, it works as it should.
      You probably have a solder bridge or a misplaced component somwhere. I usually "triple check everything I 've triple checked" to make sure that everything is in the right spot as well as resistor values. You can also try another gain pot?

      I think it sounds pretty good, especially with single coils, with humbuckers it can get quite dark and mushy. Ideally I would use a dual 10kC pot for Lo Cut control since the action is at the last half of the rotation.

      Delete
  4. Did you wire the ground from the Power socket to the ground of the input/output jack? I did and got no sound then unwired it and it was a bit noisy and no effect present, even turning knobs didn't do anything

    Sorry for all the headache and noob questions

    ReplyDelete
    Replies
    1. No worries, we've all been noobs and still is sometimes:-)

      I connected the ground wire to my test rig which is grounded via a DC jack to input and output jacks. I Think you might a have short somewhere on the board, possibly a solder bridge....
      An audio probe is a very useful tool when debugging, you can identify the spot where the signal stops.

      Delete
    2. Just wondering if I should get a signal on the parts that link to ground? So far I have tested from the input to IS1 Leg 3 and on the parts that link to ground i get no signal on the ground side. I also lose signal at IC1 (should pickup signal leg 6 if I am reading the schematic right, I tested all other legs and i had no signal) so I might need to try a new IC1.

      Delete
    3. I can't see any components that is connected to ground from pin 3, only 10nF cap that is connected to the input buffer and a 1M resistor that is connected to voltage reference.

      Delete
  5. Sorry i should clarify, I have tested up until IC1 pin 3 and then lose the signal.

    When i test components connected to ground, should I get a signal on the ground side?

    ReplyDelete
  6. I looked up the Schematic and i have no signal after IC1 Pin 3. I also switched the probe to be input and plugged into the output jack and from IC2 pin 6 I have got sound but not before that. I have tried 4 ICs in IC1 place and no difference. any ideas on other things to check while i wait for new ICs or to check if the ICs are good?

    ReplyDelete
    Replies
    1. First I would check the jumper that is connected to pin 2 and 100k and 220pF cap that that is connected to pin 6. It is a feebcack resistor and cap that sets the limit for the gain in the first op amp. Check the cuts sorrounding 220nF cap right to IC1 as well. Also 470nF connecting to pin 2 as well as the resistor connecting to the Sustain pot. And make sure that lug and 2 is properly grounded. Those components determines how much boost and which frequencies being boosted at the first gain stage.

      Delete
    2. Tested ICs in another pedal and they work fine. So i tested again and lost the signal after IC1 pin 3 the swapped the leads around so my probe was the input and went backwards and lost signal at pin 6 of IC2 ( had signal at pin 2 of IC2 as it loops round from pin 6 on the schematic). Any ideas what to look for?

      Delete
    3. I put my multimeter to lug 2 of sustain and the ground of the input jack and got the buzz right thru to say it was grounded. The link from pin 6 to pin 2 via 220pf and 100k resistor looked good to me but I still have no output at IC1 pin 6. Cuts around 220nf looked ok as well.

      Delete
    4. Ok, have you meassured the voltages of IC1?

      Delete
    5. Just measured them and they read as follows
      1) -0.11 8) 0
      2) 0.5 7) -0.11
      3) -0.05 6) 0.57
      4) -0.11 5) -0.11

      Delete
    6. It seems that you a have a power issue....pin 7 should be close to 9v. Are you sure you have a 100ohm resisor between pin 7 and D3?

      Delete
    7. I think that'll be it. looks like its going to pin 8 will fix that and get back to you.

      Delete
    8. Man i need to quadruple check everything 10 times lol the resistor 1 pin out mad all the difference. thanks heaps for all your help fuzzhead

      Delete
    9. Great! Glad you got it workin'. I've been there and still is sometimes, a small mistake can end up a board in the bin....

      Delete
    10. So I tried to make another and made sure I kept an eye on the above errors of the previous one but found some new errors :/ this one the Voltages are too High on IC1, they read:
      1)0 - 8)0
      2)7.23 - 7)8.78
      3)0 - 6)8.15
      4)0 - 5)0

      I did use 470nf Tantalum caps on this one instead of a green cap could this make an issue?

      also for some reason i am getting signal on Pin 1 of IC 2 where Im not on the other one I built. and no signal on Pin 7

      Delete
    11. So i did some more tests and I have signal up to the 10nf cap before IC1 and then From IC1 pin 6 to the out put. so could be a faulty 10nf cap but still open for ideas

      Delete