Wednesday, 17 November 2010

Clark Gainster - compact version

Here's a version of the Clark Gainster for those who don't want to use the massive paper-in-oil caps in the version posted previously.  I only put in the large axial 100u cap because there was a bit of space in the bottom right of the layout and I had some that size.  You can obviously use a smaller radial cap here but there's no scope to further compact the layout because of the other components around it.  Still this will easily fit in a 1590B and so gives an option for a "Small Box" Gainster.




Geiri's demo vid of his supercool build:





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Kit is the 3 knob version 

75 comments:

  1. can you tell me what diodes are used for this circuit? i noticed that the full size version has a picture posted, but i can't make out the diodes. thanks.

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    1. They're used to clip the signal, and they're in the pic of the big box Gainster, just above the silver mica capacitor.

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  2. i did notice the diodes in the picture, i just can't tell what they are. they appear to be silicons of some sort. are they 1n4148's, 1n914's, etc.... or does it not matter, just some sort of silicon? i know they pretty much sound the same, but i wasn't sure if this was one of those pedals that needed a specific diode to give it the juju.

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    1. Yes they're just silicon, 1N4148 or 1N914, whichever you have on hand.

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  3. the 100u electrolytic is not present in the big version. What is its function? Can it be ommited? Thanks!

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    1. The 100u is a power supply filter cap and I'd be surprised if there wasn't one on the original because it can help with unwanted noise, especially in a dirt pedal. I made it 100u because thats a cap I have on hand but you could put in a 47u radial if that's something you have instead. Or you could omit it completely and it won't audibly affect the circuit other than the potential for more noise.

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  4. What IC was or can be used? I have loads of LM386 and JRC4558's?

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    1. Doh how did I miss that? I think the original had an RC4558P, but just use the JRC4558, they're essentially the same thing.

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    2. haha.. I've got some RC4558P's coming anyway for the Lovepedal superlead so i'll try both

      Cheers :o)

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    3. The 4558P sounded really bad in my build (dark gated farty). With the 4558D it sounded really good. When I played a single note however the decay was not perfect at the end. Anybody else had the same experience?

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  5. Can verify this :o).. I had to use a 100pf instead of 120pf (what difference would that make?)

    I'm glad this worked after the Wampler nightmare. And to be honest, this is 10 times better.. sounds more 'amp' like. And the tone makes a huge difference to the sound. Recommended.

    Cheers mate.

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    1. Actually, what component is responsible for bass? and could I add a switch for a little bass boost?

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    2. You could try increasing the input cap, and/or the 47n before the tone control. A 100p in place of the 120p is fine. That's just a filter to kill some highs and smooth it out, but 100p will work fine.

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    3. Ahh that would explain it being quite piercing when the tone is on max.. I've ordered some 120pf so I think that would smooth it out as you mentioned.

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  6. Mark, the links on the images aren't the same. Have a look in the middle. Which one is the correct one, the bottom image or the top image?

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  7. Hi mate, one of the links to the bottom right goes down further than on the populated board above?

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    1. Don't know how I managed that, correction made! :o)

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    2. Funny thing is I made it and didn't even notice the first time! ;o)

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    3. I have one JRC4558DD that I took out of an SD-1 but I think it doesn't work so I put a TL072 instead. Do you reckon there's much of a difference?

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  8. I compared it to the other, bigger, layout and found out which way it's supposed to be so mine works and sounds really nice. Thanks Mark!

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  9. Made this again with no sound. I measured the IC if you wouldn't mind taking a look mate;

    JRC4558P

    1 = 4.61
    2 = 4.61
    3 = 3.32
    4 = 0
    5,6,7 = 4.45
    8 = 8.96

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  10. I just noticed you have the jumpers joined under the IC (how I've done it) but on the populated diagram they're separated mate?

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    1. That's an error on the bare board mate, the top one is right. I must have dragged the link up accidentally before I exported. I'll correct it now

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    2. Nice one mate, At least its an easy fix

      Cheers.

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  11. Will a 120pF ceramic disc be okay? Musikding have only 100pF Silver Mica...

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  12. Just finished the Gainster, but something is wrong :-/

    The pedal works for about a minute, but then the sound almost disappear and become fizzy.
    If I switch off the pedal and wait for a while, the it works again, but for a shorter period.
    Also the LED has been flickering very little, and the died completely. I was a 3mm, and I now changed it for a 5mm, witch is still alive but flickering.
    When I turn on the pedal, the LEDs dims on the other pedals.

    Anybody have an idea about what can be wrong?

    Cheers!
    - Christian

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    Replies
    1. Poor connection somewhere or a dodgy capacitor would be my first thoughts. Reflow the solder and check that you're getting continuity with your DMM at all points of ground including the offboard parts.

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    2. I have now soldered everything again and also found a capacitor misplaced (2N2) - still the same problem, although i took about two minutes before the signal started to disappeared.
      I don't have any replacement capacitors or equipment to measure them. I have a JCR4559D, can I put it in to check if the IC is broken?

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    3. Do you have any other ICs you can test it with to see if that one is causing the issue? Is it socketed or soldered to the board?

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  13. I have a socket for the IC. :o)
    The IC I have on the board is a RC4558P, but I also have a JCR4559D - can I put that one on the board instead of the RC4558P?

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    1. Could the the problem be that I didn't put a resistor on the LED?
      If I disconnect the LED, then everything is fine.. :-/

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    2. lol, I've done that before... yes you should have a resistor on the LED... i use a 2k2 or 4k7 ;o)

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    3. Like this

      http://tagboardeffects.blogspot.co.uk/2012/02/offboard-wiring.html

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  14. Ohh.. I thought it's only to dim the LED..

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  15. Just been tinkering with this... The input cap doesn't seem to make much of a difference no matter what value you place there. The 47n does though. I've made it switchable with a 100n. Sounds awesome! kinda like a 'fat mode' for a strat.

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  16. Hi mate, just want to confirm that nothing has mysteriously changed on this layout? no strange auto updates or anything? I tried making another, twice with the same result. a slight hiss on full volume and nothing else.

    It's probably a one in a million component failure but thought I'd check before my third attempt :)

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    1. No, the last amendment I made to this was when you let me know about the cut placement in the bare board back in June. What voltages are you getting at the IC?

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    2. God damn! 11 IC's later and it works!! I must of got a huge batch of dud IC's... It was that long ago that I can't remember where I got from either...

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  17. Just finished this one. Subbed a 3.3k for the 10k that links pin 1 and 6 for more gain ( quite a bit ). Also subbed a 100n for tone cap. This and my "son of clay jones" are my favorite YATS so far. This one is a bit chimey-er and the SOCJ is a bit darker and "rounder".

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  18. Mark

    Where do you get your PIO caps from? I'd actually like to source some of those and try the PIO version of the Gainster.

    Thanks

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    1. I got them from here:

      http://stores.ebay.co.uk/KW-TUBES

      They're not expensive really and are fun for some mojo builds.

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    2. Awesome! Ordering some today.

      Thanks

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    3. Careful which ones you get. You ideally want the K42Y-2 160V, from either KW or another eBay seller if he doesn't have any. The higher voltage ones can get stupidly large.

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    4. That's exactly what I was looking at for the 100n ( 0.1uF 160V PIO Capacitors K42Y2 K42U2. Lot of 20 ) - thanks for the added info. He doesn't seem to have any 47n though - he has a lot of "PETP" caps that are axial caps, but from what I found through searching, those are mylar. I'll look around ebay for the 47n PIOs and keep the 160~V in mind.

      Thanks again

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    5. I've got quite a lot of the PETP as well and really like them. It may just be a coincidence but the best Meathead I ever made with a mojo layout with PETP caps and I've never been able to make one to touch it using my layouts for more conventional components. It may just be that in that particular build everything else was perfect, resistor values and the gain of the transistors were the ideal match hence the good result, but whatever the reason it has left me with a warm fluffy feeling about PETP :o)

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    6. Good to know. I think I may try a few of both then. Heck, if the leads aren't too thick I'll socket them and see if there is any sonic difference. After more reading, it appears that these make a difference in the tone circuit of guitars too. Going to have to throw some of these there as well. This site is definitely a boon for the tone quest...

      May just have to try the mojo layout for the meathead as well - still one of my favorite pedal builds here.

      Thanks

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    7. If you struggle finding them let me know, I've got some in all the values except 22n so should be able to sort your out.

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  19. Good to go for now. Thanks man. Can't wait to get my order and try these....

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  20. Built this guy up and it sounds pretty sweet. Thanks for the layout! I get my pots from Tayda and as you know they don't do the 25k. I popped a 50k in it's place and it works well, but the very end of pot rotation has some noise. I was wondering if there was a way to add a resistor into the mix to take out that noise, or if I should just replace it with a 20k that they do stock. Would using a 20k in place of a 25k have any loss of high end at full rotation? Thanks!

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  21. Easily one of my favorite ODs. While it definitely has the TS vibe going for it, it's better in my opinion, less compressed and just ballsier as a whole. Highly, highly recommended.

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  22. hi,
    Just finished this one. I used jrc4558d and 1n914.
    The tone is excelent and very amp-like, but the output is very very low in volume. I,v tested grounding and looked for shorts, but evthing seems fine.
    Here are the voltages arround the IC
    1. 4,59
    2. 4,6
    3. 4,18
    4. 0
    5. 0,77
    6. 5,8
    7. 8,49
    8. 9.18

    Could someone compare these voltages with a working unit?
    Thanks so much

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    1. The voltages of the second channel look very suspect to me. Check cuts, component connections and check for unwanted bridges at pins 5, 6 and 7.

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    2. Check you've put the link in that's under the 100u...

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  23. This comment has been removed by the author.

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  24. hey ive just built this and it is working however there is very very little gain, more just like a slightly dirty boost, i would have though it to have more gain? can someone tell me if there should be connectivity between rows 4 and 5? and subsequently between gain lug 1 and 2+3?

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    1. sorry guys disregard, i found a small solder bridge, man they can be unbelievably tiny and yet large enough to stop everything, anyway the pedal sounds fantastic. Thanks for this amazing site, i have built the meathead, the SHOD and now the Gainster in the last 3 consecutive days...i think i have this so called "bug" you guys speak of.

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  25. Could I sub a 20k or 50k pot for a 25k? What changes would this make in the tone?

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  27. In theory, if you add a 50k resistor between lugs 3 & 2 (in this case) of a 50k pot it should give you a 25k one.
    Not 100% sure it would work as supposed to, though.

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  28. I built the 4 knob with the bottom control.only the bottom has know effect on the sound.when I turn the knob nothing changes,is this normal?

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    1. I've only just added that one so you're the guinea pig :o)
      This is the scheme, and you can see the added Bottom control circuit snippet on the right hand side.

      http://i76.photobucket.com/albums/j6/IvIark_2006/Layouts/Schematics/BarberBigBoxGainster-1.jpg~original

      So it certainly matches, but I wonder whether it would be better without the 1M resistor and just having lug 2 linked to lug 1.

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  29. ok I figured it out.take the yellow wire from lug 3 off the level pot but leave the pink hooked up as is.now unhook the aqua blue wire from lug 2 of bottom pot and hook yellow wire there.badda boom badda bing there ya go should work now.

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  30. hi i tweaked to add this bass cut control before going through the comments. anyway, i havent gotton this this work, the bass pot just does nothin...any ideas? i tried both versions

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  31. Same here. The bass pot has zero effect. I even tried 1n to 10uf and still absolutely no change when turning the bass pot from one extreme to the other.

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    1. I don't trust the scheme I did it from, it just doesn't make sense to me so I'm pulling them until I can get more info.

      This is the scheme I did it from and you can see the bass control addition on the right hand side. That 1M resistor doesn't make sense to me. It would make more sense if the 1M resistor wasn't there, and lug 2 of the Bass pot goes straight to Level 3. Then that pot will pan between the two value output caps. Maybe someone who has built one and hasn't had good results could try that to see if it works better.

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  32. Here is a picture of the Gainster that I just finished.http://i1294.photobucket.com/albums/b606/sd_ens/Mobile%20Uploads/image_zps25057b3b.jpg

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  33. Gudday,

    JUst built this, and like someone else above, it's really quiet. If I turn up the amp I can tell that the controls are working as advertised, and it sounds fine, but there's no real output.

    My voltages are:

    1. 4.85
    2. 4.67
    3. 2.34
    4. 0
    5. 0.86
    6. 5.97
    7. 8.56
    8. 9.27

    Any ideas? I've reflowed the joins and checked everything out...

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    1. Found the problem. I was poking around the back of the vero and found if I bridged a couple of adjacent tracks I got output... turned out I'd missed the link that's underneath the big 100u on the layout.

      Works as advertised now.

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  34. Built this and really like it. Simple sounds great! Another one of those simple but good circuits. I am starting to really start to think that there is something to simplicity. Look how many good pedals off the Electra pedal, etc. Anyways, thnx everyone.

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  35. Hello everyone,

    by mistake i bought an jrc4580d (cause i just finished an king of tone w them) instead of the jrc4558. Will that make a big difference, or even stop it from working proper? i read it is a kind of upgrade of the 4558. so i assume it will work....but soundwise?

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    1. dont mind

      tried it
      heard it
      liked it.
      the jrc or njm 4580d is absolutely fine here. nice cream gain, low hiss, good playing response.

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  36. If I want to put the diodes on a dpdt(on/off/on) switch so I can expand my diode options, how would I go about it?

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