Thursday, 19 July 2012

MXR Dyna Comp

No effects layout site would be complete without this one, and even if this isn't the most sought after compressor there are quite a few more fashionable ones which are based on this, and so I thought it would give a good basis for mods and tweaks, and adapting to the Dyna Comp-esque variants.  The layout is easily 1590B friendly, even with a few extra columns and rows for mods.

Info from the manufacturer about the original:

MXR Dyna Comp Compressor Guitar Pedal - One of the most popular compressors of all time, the MXR Dyna Comp is the secret weapon on many stars' pedalboards. This box will produce that percussive, clicky sound on a clean guitar that you've heard on so many pop hits. It also adds smooth sustain to lead lines.









57 comments:

  1. Cheers man! What does the trimmer adjust? Just wondering if I should use a normal pot for it since I have a few 2k pots laying around.

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    1. It allows you to adjust the input level if you're getting too much noise

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  2. Hello Mark, Can this pedal be use on bass?

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    1. Billy Sheehan suggested trying it in one of his books, so it sounds like it would be ok.

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  3. What's that the trimmer is for?

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  4. Damn. I need to get a bunch of CA3080s. Quick googling didn't give out any pin to pin alternatives...

    Ross comp up next? ;)
    +m

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    1. Hee hee, you know me too well! Actually when you look at the differences between the Dyna and Ross I honestly don't think there is a lot of point in doing it. The only real difference is a 10K resistor used between Q1 collector and supply, but that's a unity gain buffer anyway so it wouldn't make any difference. Apart from that the Ross just has a few extra 1u caps as filters, but I just can't imagine them making much of a difference. Especially as I already modded the dyna comp for extra supply and vbias filtering.

      I only had one CA3080 and so just ordered 4 more from Polida on eBay. Check them out, I seem to be buying lots from them at the moment and they have some fantastic prices.

      http://stores.ebay.co.uk/POLIDA-ELECTRICAL-H-K-LIMITED/

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    2. Yep. Now i have at least 3 compressors quite high on my to-do list. :) (prolly get back home next week..)

      I'm familiar with Polida. They do have all the right chips and other components for the right price, but... Some of my orders never came in and some took more than 45 business days. When i asked them why do their packages take 45 business days and every other hongkong seller get their goods in northern europe in two weeks, the answer was "prease wait another 10 business days"..

      Quite sad in my opinion. All their goods are with free shipping and they offer only registered as alternative for 3,50 usd. Which is usually always higher price than the current order..

      But. I guess i'll need at least 10 of 3080s :)
      +m

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    3. Yes the orders do take a while to come through and the last one I placed he requested that I pay the extra $3.50 because it was a higher value than usual. But they do always arrive eventually, and I'm never in that much of a rush for anything that I can't wait.

      The germanium diodes from him are a real bargain.

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    4. I guess it's best to buy more than one item from Polida at the same time and request combined shipping - and then pay that 3,50 extra...

      I'm not in that much of a rush with any order, but 45 business days is just ridiculous in modern world. At lest if compared to Tayda. Every order gets here always in less than two weeks - and that's calendar days :)

      I did ask polida why they don't have web shop like tayda does, but they didn't answer..

      They have other stuff with real good prices too.. I got my batch of LM308s there and i'm currently waiting for 1N5817s - very, very, very reasonable price for bigger batches... :)

      By the way.. Thanks for all the compressors! Must build them all! :D
      +m

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    5. There are a few Chinese and Hong Kong based seller who take a similar sort of time. I get the impression that the cheapest post comes over on a paddle boat.

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  5. Hee hee, "Dyna and Ross", sounds like a Motown singer.

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  6. will def do this soon enough.. just finished etching millenium pcb's for the first time ever... jeez, been struggling so hard. made em on a 100x160mm board sp i got 20 pcs, atleast half of them is useful. the other half went up in blue liquid haha, etched to long.

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  7. Yeah. Tag it.

    Got my small package from Polida today, the 3,50 is really worth it. Took only two weeks instead of free-postage's eight to twelve.. :) Let's just say i won't be running out on 1N60Ps anytime soon..

    First class compressor indeed. Round and fat. Instant funk :) Quite similar to Ross, with just nuances in difference.
    +m

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    Replies
    1. Awesome verification day! :o) Cheers mate

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    2. :) Sadly, there ain't many interesting unverified left...
      +m

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  8. A bit out of focus, but that'll do..
    http://mirosol.kapsi.fi/varasto/boxes/DynaComp.jpg
    +m

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  9. Cant get a peep out of mine...is there a significant difference in 3080 and 3080e ??

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  10. Cant get a peep out of mine...is there a significant difference in 3080 and 3080e ??

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  11. +1
    Is there a real difference between 3080 and 3080e?

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    1. Yes there is. CA3080 works in temperatures from -55 to +125 degrees celcius, while CA3080E works only in temperatures from 0 to 70 degrees celcius. Other than that - no difference.
      www.intersil.com/data/fn/fn475.pdf
      +m

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    2. Then there's the CA3080A, which is the super-high-end metal can version. I've got one of those in my 2-knob Keeley clone.

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  12. Just finished building this the other day and can't get to work. Only sound comes through when hitting the strings hard and it sounds like it barely makes a noise. I cut all my lines again to make sure of no shorts and verified all parts locations and directions. All wires are hooked up correct. Any ideas? I am using the CA3080E chip. Thanks for any help in advance.

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    1. All IC and transistor voltages will be needed for us to have an idea

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    2. I measured my voltages last night and this is what i ended up with
      IC
      1 = 0v
      2 = 3.4v
      3 = 3.4v
      4 = 0v
      5 = 0.7v
      6 = 1.9v
      7 = 8.1 v
      8 = 0v

      For the transistors, below is the measured values starting from top left of vero layout and going counterclockwise (values are C,B,E)
      Q1 = 8.1/0.1/0
      Q2 = 8.1/7.2/7.5
      Q3 = 7.2/0/0
      Q4 = 7.2/0/0
      Q5 = 6.4/1.9/1.6

      Thanks again for any help and for all you guys do with posting these layouts!

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    3. Scratch that fellas. After digging and digging through my build, i noticed i had one wire out of place. Moved it and it fired right up. Works great!

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  13. Hey,

    I just built the comp and have a little problem.
    It is working, but I have to fully turn up the volume to get bypass volume. When sensitivity is turned up to max I get a short peak and then it suddenly drops down in volume but you hear the comp working when your guitar fades down it tries to compensate by turning up the volume.

    Any ideas?

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    1. Hey Andreas,
      I doubt you monitor this so many years later, but I just built one and have similar results to you. I need the volume at full to just barely get parity with bypass volume. The compression really works however with large swells and sustain being added back to the signal some seconds later. I wonder what other people have experienced with effected volume vs. parity volume?

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  14. Hey guys,

    Built this a week ago and I'm having a llittle trouble with it since then. First fire up just gave me a pretty heavy disortion, similiar to a wrong biased transistor or a electra distortion. Changing all of the 2N5088s made it a bit better but I have to turn the volume down to get a clean signal out of it. Double checked all the resistors, caps and soldier joints, but nothing.
    Turning the trimmer just slightly changed the distortion. I'm using a CA3080EZ chip here.
    Is this noise usual with this circuit or is something somehow wrong biased on my board?
    Using a wall wart with 9.25V output, voltages are just a bit higher than the ones shown above.

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  15. Hi guys, I am having a problem, when I engage the effect der is just an occasional distortion sound. And it isn´t even constant, its just if I wiggle around with the cables or touch the copper side of the board. I checked for bridges and didn´t find any.
    I also swapped the trannies and IC and it didnt change.

    Here are my voltages:

    Q1:
    E: 2,3
    B: 2,7
    C: 9

    Q2
    E: 6,3
    B: 7
    C: 6,3

    Q3
    E: 0
    B: 0
    C: 9

    Q4
    E: 0
    B: 0
    C: 9

    Q5
    E: 8,4
    B: 9
    C: 9

    IC
    1: 0,1
    2: 4,7
    3: 4,7
    4: 0
    5: 8,4
    6: 9
    7: 7
    8: 0,2

    The IC and Q3,4,5 dont look like they have correct voltages.

    Please help me on that, I drives me nuts.

    Thanks in advance.

    John

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  16. Hi Ivark,
    Can you put layout for MXR Custom Comp. I'm interested what is the difference between Dyna Comp and Custom Comp.
    Thank you in advance,

    Pedja Serbia

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  17. Hi just built mine and not a single sound coming out when engaged. I used a CA3080e IC. Is this ok? Also this may be a silly question but where does sensitivity 1 connect to? Thanks!!

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  18. Hi all.
    What if I use a 2K2 trimmer instead of the 2K?
    Thanks a lot

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    1. Wont make any difference at all buddy. Its what I use on all my Dyna Compressor clones (built 4 so far all with the 2k2) And if you don't want to use a trimmer just use two 1K resistors - one end of each goes to pin 1 and 3 and the other ends go to pin 2, like a voltage divider if that makes sense?

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  19. HI there. Really having some trouble here. When I activate the pedal. It is giving me signal, but not effect signal. It's almost as if there isn't even a circuit board there. HELP.

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    1. well i found that problem. i forgot a cap. now that its added, i dont have any signal at all when the pedal is on.

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  20. can i use a different IC instead of a ca3080?

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    1. You can make a daughterboard using the LM13700. It's essentially 2 3080's in one chip. I've used the board here with great success. So just make a board and fly wire to the pin connections on the layout.

      http://tagboardeffects.blogspot.co.uk/2012/10/emma-transmorgrifier.html

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    2. hi ciaran...why about lm13600. can i replace lm13700 to lm13600?

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  21. i found 2 errors in this vero :
    the 2 x 100uf caps is : 10uf for the right and 1uf for the left no?

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    1. Not sure if they are errors, looks like they're straight across the power rails so are probably just power supply caps, wont hurt if they're 100uFs, but I'm sure the experts will soon tell us!

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  22. The left 100u isn´t filtering cap.

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    Replies
    1. Yes...it is. Filtering the 56K/27K divider (Vref)

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  24. Hi chaps,
    Just wondered if I could ask your advice - its working, and doing what it should do, but it's got a high pitched whine that changes only slightly when the output is on 0 or 10, and gets louder/changes pitch when the sensitivity is at 10.
    Just wondered if anyone had any suggestions, or has had the same thing happen?
    Thanks,
    J

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  25. I just bought an old dyna comp on craigslist and got it for a real nice price. found out why when I got it home and listened to it under headphones. It has a soft crackling noise that gets louder the longer you don't put any signal through it. once you are playing the noise seems to mostly vanish or at least it gets quiet enough that I can't really distinguish it under my bass. I have found several threads of people having this exact issue with old dyna comps. this is the most detailed discussion of the issue I have found: http://www.diystompboxes.com/smfforum/index.php?topic=84367.0

    Suggestions included replacing the CA3080 and also replacing the transistors. but I more suspect resistors or capacitors. Does anyone here have any experience with this issue before I go deconstructing my dyna comp?

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  26. Hey there! This is my first build off this site. This may be a total amateur question but I'm not seeing where to wire Sens 1 to the board. Am I missing something?

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    1. it's not used. if you see in a layout a wire to a pot lug isn't mentioned or it's not mentioned in the build notes then it's not used and you can ignore it.

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  27. So I wired everything up and the led is turning on but I'm not getting any signal and sen 3 starts to heat up and when I turn the knob the wire gets hotter and the led gets brighter

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  30. Which way do install the IC on the Vero board for the MXR dyna comp . Its my first build with a IC circuit . I know these IC s have a half circle sign on them but for this build I don't know which way it needs to go . Please help Thanks Stu

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    1. Its ok I spotted the half circle on the diagram.

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