Friday, 9 May 2014

Cornish SS-2

Pete's highly acclaimed Overdrive/Distortion box of the stars.  The original obviously includes the Cornish buffered bypass switching which isn't shown here as it is assumed most people will use the usual 3PDT mechanical bypass.

But if you do want to build it like Pete, then make a daughterboard of the Cornish Buffer.  The input socket connects directly to the input of the bypass buffer.  The output of the bypass buffer then goes to SS-2 input and daisy chains to the 3PDT stomp switch, lugs 1 and 4.  The output from Volume 2 of the SS-2 will go to 3PDT lugs 3 and 6, and the output socket connects to 3PDT lugs 2 and 5.

The third pole of the 3PDT is used for LED switching as usual.

Info from Cornish about his very expensive and much sought after stompbox:
The Pete Cornish SS-2™ satisfies a tremendous void in the Musicians palette of tone colors. Totally different from any overdrive/distortion effect that has ever been previously available; it is amazingly responsive to changes in both Guitar volume and picking articulation. It has the best “bottom end retention” ever heard in an effect, whilst the mid-range is sweet and very transparent. The SS-2™ retains all the tonal nuances of your guitar and is subtle and yet capable of amazing power and sustain. Using the SS-2™ with a clean amp it is possible to progress from subtle overdriven amp sounds, through rhythmic crunch, up to a blues' lead. The tonal characteristics and dynamics of the guitar are maintained even when using this pedal at its maximum gain.







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56 comments:

  1. I'm pretty sure the 510K resistor should be 510R.

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    1. I knew it was 510 ohms too, must have been on autopilot. Thanks for the heads up matey

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  2. In theory, would it be possible to build one of these around a TL072 instead of two LM741s?

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    1. Yes, in fact I was going to do the layout with exactly that, but decided to keep it true to the original because there are a lot of passive components used around the opamp channels and I thought it would spread it out more neatly with the two ICs as per the original. Using a dual channel IC may have shaved off a couple of rows, but it would definitely have been wider and it may have been a struggle keeping it to 21 columns maximum so it would fit in a 1590B.

      You don't have to use the LM741s though if you'd prefer not to. The TL071 is the single channel version of the TL072 and will work perfectly well in this.

      In fact if you were experimental you could omit the ICs in the layout entirely (but keep the cuts in between the pins), solder a TL072 to a separate daughterboard and take wires from the daughterboard to the places where the channels and supply need to connect on the main board and it will work perfectly well. I'd prefer to just get a few single channel ICs myself though :o)

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  3. Would 1n34a be ok as diodes to test it with before my 1n270's arrive from China?

    Tx.

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    1. Yes it will work fine with 1N34As

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  4. Tx Mark. Just ordered everything from Newtone in the Netherlands including 1N34A's. Will socket the diodes.

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  5. Hey Mark, built this last night, works a treat. I noticed just one small mistake on your layout. The cut at the top left is 4 holes in from the LHS, but in the unpopulated pic you have it 5 holes in from LHS. Other than that you can mark this verified.

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    1. Awesome Alan, thanks for verifying. Cut moved and tagged! :o)

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  6. Hi Alan, I hope to start building it Tuesday. How do you like it? Is it a bit like a tubescreamer?

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    1. It's a very nice sounding pedal, not really like a tubescreamer. It sounds just like the gearmandude demo of it on youtube.

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    2. I wouldn't expect it to sound too much like a Tubescreamer, it's basically a souped up Distortion + or OD250

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  7. Love those Cornish switches :) what are they?

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    1. I'm not sure if that's just some sort of heavy duty actuator and he uses relay switching. I haven't seen the guts of the SS-2 so I'm not sure.

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  8. Ok that's good 'cause I don't like tubescreamers very much. Some clips of it made me think that. I am wondering if the Cornish guy really needs the waiting time to build enough of them or if that's just to raise the mythical image of the thing and it's price..

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  9. Mine works fine with 1n34A's. Really like the string definition of the pedal. Goes from very little to very much gain. Tx!

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  10. A a standard 50k lin pot for the gain is not good idea cause in this case all the gain is in the last part of the pot means from 4 to 6 o'clock , this make difficult to microset the gain and of course all the other range of the pot is gainless

    The correct pot is a 50k C reverse log pot

    cheers Michael Analog Design Pedals Greece

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    1. Interesting, I must try swapping the gain pot on mine. Thanks.

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  11. sounds good but it's very quiet, doesn't hit unity until ~ 2 or 3 o'clock. Would changing the value or taper of the pot help? I haven't put in the reverse log to for the gain yet, would that help with the overall volume?

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    1. I'm having the same probleme with mine... and the Gearmandude's demo suggest that it should have quite a good volume boost. Have you solve the probleme? Is your unit noisy?

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  12. I just finished my build. I have two issues, one of which I think may be fixed if I change out the gain pot as suggested by "Info" above. The gain seems to have a rush of effect in the last 5% of turning the pot. It works fine up to that point, but it has an odd effect of going to crazy distortion in that list 5% or so. Does anyone else experience this? Also, I've noticed that the effect isn't "instant on". When I stomp the switch, the effect takes about 1/2 second to kick in. I have found that if I have it on, click it off, and immediately back on, this does not happen. It seems as if it's taking a bit of time for a capacitor to charge. I'm not positive that's what's happening, but it seems to be. Any suggestions to correct this would be appreciated. I wondered if the 91 ohm resistor on the supply voltage is really necessary? That might delay charging the 220uf cap, but I don't know how much an effect there would be.

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  13. The taper I suggest before would solve the gain problem , all the pot would work , after changing the pot with a 50KC reverse log the gain would start even at lower settings and work as the original one,
    The 91ohm resistor is a protection resistor to make the voltage very close to 8.5-9 volt and not more, personally I use a good power bank and not an Onespot type of power so no problem to jumper the 91ohm and have more headroom without noise or other problems

    Cheers Michael Analog Design Pedals Greece

    https://www.facebook.com/AnalogDesignPedal

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  14. I am having major problems with this build for some reason. Think I am going to put it aside for a while (again) and if anyone has any ideas please comment. I checked all the cuts and links (including double links before mounting any components). Also verified all components before mounting. My only difference is I did not have a 2K4 resistor and used a 2K7 (other choice was a 2K2...I figured it was a coin toss. I really took my time with this one which is why I am frustrated. Here is what I have:

    Signal path appears to be ok. I traced with DMM and no shorts. Plug in and I get what sounds like a by-pass signal. No suckage on the signal, but no gain either. It's as if the board isn't even on. Also of note is I really don't hear any differences with any of the pots. Shouldn't at least the volume cut the signal?

    So I pulled the IC's. Checked ground path. Checked power...all good.

    Went back through pinouts, components, cuts, links for the 3rd time. And I really can't find a thing.

    Thanks in advance if anyone has any other ideas.

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    1. From most descriptions, the fault could still be dozens of things and so any advice would be guesswork. To give us a better clue we always need the pin voltages of any IC or transistors in the build. That tells us a lot more.

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    2. Thanks for the quick reply! Mark is it? I should have known better. I just read your fault guide. So here we go:

      Battery not loaded 8.82

      IC1 (IC not socketed) 1 0.0 8 0.0
      2 0.0 7 8.81
      3 2.34 6 0.01
      4 0.0 5 0.0
      IC2 (IC not socketed) 1 0.0 8 0.0
      2 -0.09 7 8.81
      3 2.88 6 -0.08
      4 0.0 5 0.0

      IC1 socketed 1 0.0 8 0.0
      2 4.79 7 8.78
      3 2.31 6 4.80
      4 0.0 5 0.0

      IC2 socketed 1 0.0 8 0.0
      2 4.32 7 8.78
      3 2.86 6 4.31
      4 0.0 5 0.0

      Thanks! Saw you your profile you are in Manchester. Was a tech rep there for Douglas Aircraft for the 92 Olympics. I remember the Beer Keller if it is still there...what a wreck I was.

      Appreciate the help!
      John

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    3. Yes the Bier keller is still there but it moved from when you went and is now in The Printworks which is basically a complex of loads of bars and restaurants. I was in the Bier keller a couple of months ago for a mates stag do.

      Your voltages don't look too bad to me, pretty much what you would expect on pins 2, 3, 4, 6 and 7 which are the ones in use. Have you ever used an audio probe? That would be my next suggestion, probe through the signal path and see where the signal is dropping out, that will show exactly where the problem is.

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    4. Thanks! I'll have to build one later today. I was hoping not to have to go that far, but nothing else is jumping out at me. I'll post what I find.

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  15. Mystery solved. Working later at night is not a good thing. I had troubleshot a bad Tone pot initially (it wasn't really bad..I had just had a jumper between pins 1 and 2 probably from something else, and my eyes aren't what they used to be so I missed it...it would have fixed all my issues straight away). This time however the new tone pot (I didn't check it before installing) had a bad arm and pin 2 was open to both 1 and 3. The audio probe (rigged a quickie) worked great! Gonna keep that one in the mental toolbox. Now to mount this bad boy up and rock a little as a reward! Thanks for the help!

    John

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    1. Actually I do have a question. Why did you end up using cap values that are different from the SS-2 light drive schematic out there? Just curious. Also sorry for the slow start for your national team today. I think we are up Monday. Gonna be a rough road...but hopefully not as bad as Spain's initial performance.

      John

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    2. The values are all the same as the SS2 schematic I've got. If you're looking at the older version of the Toptone schematic there were a lot of errors on it. This is the one it is based on:
      http://freestompboxes.org/

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    3. Do you have this schematic saved? If so could you email it to me?

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  16. I think this is very trebly for me..what should I tweak to remove the treble?I don't want to add more bass I just need less treble

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    1. Try increasing the 10n cap at Tone 3. That's a low pass filter and if you increase that cap value it will lower the cut off frequency so you can cut more high end.

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  17. I like the pedal very much, but at low gain settings it sounds pretty thin. Does it make sense to change the 4n7 (between sustain 1+2 and 3)?

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  18. Hello guys, IC Lm1458 will work fine con this project?

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    1. that should work fine. the LM1458 is a direct substitute for LM741. some info though that i found on DIYSB awhile ago about this. PRR made an interesting statement:

      "The '458 and '1558 are very much like '741 internally except duals, and "improved" (faster yet cheaper). I normally consider them "same", but they are not: one is popular for certain distortion effects, so there must be some small difference."

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  19. The LM741 is a single op amp and the LM1458 is a dual. The 1458 won't work with this layout (different pinouts) but you can try a TL071 or TL081 or another single op amp you have

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  20. Hi,
    Thanks for the great layout! The pedal sounds great but I think I might have a slight problem with the volume. It doesn't make any sound until about 1 (from 1-10, not the usual clock reference) and then has a steady volume until about 9. That wouldn't be a huge problem except that the minimum volume where it kicks in is too loud. I used the 10k pot as outlined in the layout. Any ideas?

    Thanks for any help and the great site!
    Jon

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  21. Hello could you please post a layout of this beast : Cornish TB-83 EKSTRA DUPLEX

    Thank you so much for your website ,

    Cheers ,

    David.

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  22. I have a question regarding the buffered bypass wiring.
    From what I understand buff out goes to lugs 1&4, ss2 out to 3&6 and out socket to 2&5
    So if I'm not wrong both columns of the stomp are doing the same thing, so without led wiring a spdt switch should be enough, buff out to 1, out socket to 2 and ss2 out to 3 ?

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  23. Built this today. I can see why people like these. Sounds great on clean amp! Used 1n34a's. Thnx everyone!

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  24. I happened to purchase a pedal based on this layout and i am happy to see that this very guy has a comment above!!! A friend of mine loved the sound of it, and i am trying to build one for him. I noticed that the builder of it altered the original schematic by adding 3 germanium diodes, two of them in series (or so I think, I am a complete NOOB). Has anyone else tryed this? If so, what kind of diodes were used?

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  25. I don't understand the connection between the buffer, the ss2 and the 3pdt switch.. can anyone post a diagram?

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    1. no reason too. take a look at the G2 layout

      http://tagboardeffects.blogspot.com/2014/04/cornish-g2.html

      there's a layout that shows how to slip the buffer in and wire the switch.

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  26. This thing sounds great!!!!!!

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  27. I built this, and though it does sound pretty good, it has too much treble. I increased the low pass on tone 3 to a 470nF and it still has too much. Is there another area to adjust for this? or should I try a 1uF?

    -david

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  28. Anyone have a reliable schematic for this? Trying to put a layout for my BIY board but this forum thread is just confussing - http://freestompboxes.org/viewtopic.php?f=7&t=16071

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  31. Hi ;

    I have just built this kit from Mklec and I notice that the drive does not kick in until the pot is almost turned all the way. i.e. in the last 10% of the turn it kicks in. not sure if this is the way it is suppose to work...

    Thanks for any information,
    Andrew

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    1. Mine does the same thing, but it's not really a problem for me. I like to leave the gain turned all the way up on the pedal and control the amount with the guitar volume knob. This pedal does "clean up" nicely.

      FWIW, I've seen a few demos of actual SS-2s on the web where the same behaviour is noticeable: a big jump in gain at the end of the pot rotation. If it really bothers you, replace the gain pot with a C50K.

      Cheers.

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    2. Thanks for the reply - I thought that was how it worked,,, I don't really need to move it after tweaking it to my liking...

      Take care,
      Andrew

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