Sunday, 16 December 2012

Cook Spring Reverb

This is the original Cook Spring Reverb design and not the "mark 2". Any spring reverb tank should do just fine...

So strike the above text. The tank type is crucial to get this design to work properly. I have no no idea what sort of tank it should be, so even though this is now verified, you should proceed with caution. The tank you have may or may not be suitable for the design. More accurate information about reverb tanks can be found here: http://sound.westhost.com/articles/reverb.htm



56 comments:

  1. I am going to try this with a 3 spring reverb tank 8FB3A1B. Thanks for posting.

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  2. I have a 2 spring hi-impedance input tank. Will it do?

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    Replies
    1. According to the docs i found, any tank should do just fine :)
      +m

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  3. Replies
    1. :) Copypaste. One of those should obviously be 3. I'll fix it.
      +m

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  4. Miro, did you build one of these yet? I put it together and so far the drive pot doesnt seem to do anything. The top wire is Drive 3 as per the schematic but there is a 47k resistor missing between drive 2 and the 100n cap. I am going to go through the schematic to see if anything else is amiss. It is very quiet and there is only a faint hint of reverb but I havent double checked my board yet to see if I misplaced or missed a component.

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  5. Ok so I was looking at the wrong schematic. Drive 3 is the lower wire. Im changing it now and I'll see if it works.

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    Replies
    1. This is the schem, so drive 3 is where it's supposed to be:
      http://english.cxem.net/amplifier/amplifier37.gif

      I've been through it now, and i can't see anything wrong. Only difference to the schem is the two 100n electrolytics - which probably should be non-polar (hate it when someone uses elko symbol for non-polars). That shouldn't affect it though..
      +m

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  6. Any luck? Is this verified?

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  7. do the rca cables need to be shielded?

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  8. Im checking for discrepancies because my various attempts don't work: 1. Missing 100nF cap in parallel with the 1k resistor off of Q2Emitter.

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  9. Actually I think the .1uF electro cap needs to go up one link on top so it links to ground instead of vref. I'll look more closely before I post again.

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  10. Hi, can i change the .1uF electro cap with capacitors of different capacity, what the effects? (stupid question)can i replace these with non-polarized capacitors, what the effects? Thanks

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  11. Has this been verified? I've got an amp that NEEDS spring reverb!

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  12. I don't think so but I have a verified layout for the stage center reverb on vero. Here is a link

    http://www.diystompboxes.com/smfforum/index.php?topic=99803.msg881659#msg881659

    I ended up adding a volume control it sounds great to me

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    Replies
    1. Wow, looks great! I just posted over there with a question I have about it.

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  13. I Got this Cook Spring Reverb working, But as per Schematic had to Connect the negative end on the Bottom 0.1uF Electrolyte to IC Pin 4 Ground (ie up 1 rail) and At IC Pin 6 Vcc there is a 1.5K resistor connected in series to +ve end of a Red LED that then has its negative end connected to the bottom rail where Drive 1 is connected ie Ground. (The Red Led is not connected to the Red wire LED+ as shown.) Refer to the Schematic to verify. I tested it with a low impedance reverb spring tank 4AB3C1B and also on a high impedance spring reverb tank 1A2-S3FB3A1B. The sound quality on both was not what I expected and is too Tinny for my liking and I definitely did not get the big luscious Hall or even Room Reverb effect. The Drive Knob is also very subtle on my build.

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  14. collected but not working.
    Where then is the sound of distant reverb to the touch before spring thunder.
    Tell me where you can be an error in the circuit? I only found that the capacitor electrolyte 0.1 uF should be higher, but it still does not work.
    help please.

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    Replies
    1. This is the schematic i used:
      http://www.guitarelectric.eu/schematy/Efekty/Echo-Delay-
      Reverb/Generic%20Spring%20Reverb.gif.html#schemat

      I'll check it through again...
      +m

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    2. I think i found the error. The 100n cap (electrolytic) has its negative lead to VCC2 instead of ground.

      I'm updating the layout in a minute. I'll swap all the 100n electrolytics to non-polar one too...
      +m

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    3. Layout fixed. Check the emitter connections of the bottom transistor. The 100n goes to wrong row on the original layout.
      +m

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  15. Replies
    1. Can you post transistor and IC voltages? If i could spot something from those.. I'm fairly certain about the current layout matching the schematic.
      +m

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  16. Hey guys, I seem to be having trouble with this one too. The reverb is there but it's really quiet. I corrected a few mistakes that I made and am now pretty sure my board is correct. Here are the voltages I'm getting.
    Q1-Bottom, Q2-Middle, Q3-Top.
    Battery: 8.5v.
    Q1 E 0.288v B 0.89v C 5.45v

    Q2 C 5.39v B 1.174v E 0.284v

    Q3 C 5.53v B 0.867v E 0.263v

    IC1 1. 1.21v 2. 0.5mv 3. 4.0mv 4. 0.5mv 5. 3.72v 6. 8.29v 7. 4.19v 8. 1.316v.

    Cheers, Thommo.

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    Replies
    1. Updated voltages Battery: 9.90v

      Q1: E 0.447v B 1.051v C 5.4v

      Q2: C 5.30v B 1.043v E 0.443v

      Q3: C 5.37v B 1.027v E 0.420v

      IC1: 1. 1.077v 2. 0.4mv 3. 4.5mv 4. 0.00v 5. 5.00v 6. 9.80v 7. 4.95v
      8. 1.2v

      I'd love to get this one working!!

      Thommo.

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    2. Are you getting signal in the "Tank in"? That should be relatively loud..
      Here's the schematic again:
      http://www.solorb.com/elect/musiccirc/reverb/reverb.gif
      +m

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  17. At the 'Tank in' there is a BEAST of a signal!!! At the other end of the tank the signal is a lot more quieter and very dull sounding. Could there be a problem with my tank? It is quite old...lol. The reverb is more audible when I play through my laptop software etc. It sounds like the tone knob is turned all the way CCW.

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    Replies
    1. Try shorting the TankIn and TankOut. If that lets the signal all the way through, then it's the tank.. Or you could try it as a effect loop by replacing the tank with any stompbox.
      +m

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    2. Or. Try feeding any signal to TankOut. If that works, then it has to be the tank.
      +m

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  18. Tanks for the tips Mirosol!! Yes, I love bad puns!! Anyway I shorted the tank in and out and there is a strong signal. Quite a nice overdrive, I must say!!! The tank it is! That would explain the other reverb circuits not working properly with it. Maybe the transducers aren't working properly anymore.

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    Replies
    1. I figured out the tank is 20 years old!!

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    2. Good to hear. Or bad, if the tank is dead.. But it seems that the schematic and layout are both fine. Do you have any other tank to try this with? I sure want to know if it works.
      +m

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    3. No, it's the only one I have. It's out of a Peavey Express 112 that I stripped for parts a while ago. I don't really want to spend any money on a new tank or fixing up the one I have(if it's possible).
      Any ideas on what I can use the circuit for?

      Cheers, Thommo.

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    4. You could use it as a "SuperOverEngineered FXLoopDriver" for just about any pedals :) I'm still hoping to hear that someone gets this working with a tank before i agree on tagging it. Right now i'm pretty confident that it will work. I'm just not sure it will work with any tank.
      +m

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    5. For the SOEFXLD, do I just connect mono sockets to the Tank In/Out? So they become the Send and Return? I might(for the time being) short the Tank In/Outs and use it as an overdrive!! A new/properly working tank would be great but I can't justify the purchase.

      Cheers, Thommo.

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    6. Yup. That would be the way to go. Don't really know how useful that would be in reality :P
      +m

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  19. I am disapponited with this. it isn't loud, there isn't a lot of reverb on tap... any ideas how to really boost the features?

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    Replies
    1. From what i've been reading about the tanks, the issue could be with the individual tank's input coil.. Which may be the biggest reason why so many have failed on the build before. I originally thought that the "drive" control would take care of it when tuned correctly, but i'm not so sure about even that anymore.

      Good read on the subject: http://sound.westhost.com/articles/reverb.htm

      So the circuit works?
      +m

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    2. Yeah, sounds really nice actually. The issue is there is a volume drop when engaged. I have to dime the reverb to get a decent volume and pot the dry to about noon to get a good mix relative to one another. I was hoping for something a bit more haunting...

      I just got a brand new Mod tone tank (8EB2C1B, Short (9 ¾") 3 Spring Unit, Medium Decay, Input Impedance 800 Ohms, Output Impedance 2575 Ohms) to use for this pedal. I have an older 2 spring tank i can test, I just haven't gotten around to it yet.

      Delete
    3. I'll tag it and add a note about the tanks... So Cheers Jon Q!

      I'm certain that the layout is per the schematic, but it appears that the schematic isn't as valid as i hoped. Or sure, the schem is ok, but the documentation about the suitable tanks is missing.

      You could try adding a simple booster after the output to add more level after the recovery. Don't really know how that'll affect the overall tone, but it could be worth a try. Either of these should be ok:
      http://tagboardeffects.blogspot.fi/2013/01/electro-harmonix-lpb1-with-trimmer.html
      http://tagboardeffects.blogspot.fi/2013/02/zvex-super-hard-on-compact-layout.html

      +m

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    4. So i put a compact LPB-1 after the output and it made the difference, however it isn't a pristine clean sound and it takes a bit of the low end off the sound of the clean signal. I'd like to see a bit more headroom in there. I am thinking about making a SHO and testing it in it's place. It does sound pretty good however, and there could be some uses for it in the studio.

      One drawback is I am guessing a by product of the LPB circuit, it has a dramatic volume drop when I roll off my guitar's volume which means I need to essentially keep it dimed or close to, which isn't ideal.

      Delete
  20. So I built this for a friend and it works, and like others have said not a ton of reverb on tap. Mine is a little dark. Anyone tried running this with 18v?

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    Replies
    1. LM386 can't handle 18V. It has maximum rated voltage of 12V.

      What tank did you use?
      +m

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    2. cool, I was running at 12v and it sounded good. I did try 18v, no issues but no change either. I'm using the MOD 8EB2C1B tank (I chose this one because it's used with the VanAmps Sole Mate Jr), purchased from amplifiedparts.com. My only problem is trying to fix the low end loss. Even with the dry knob at unity, the bass is almost completely removed. It ends up sounding like a treble booster. Got any ideas?

      Delete
    3. This comment has been removed by the author.

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  21. i´m quite new to this, what do you mean by RCA sleeves to ground?

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    Replies
    1. there is usually a metal washer with a tab on it for the ground to be connected to.

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  22. FYI, I got this sounding great. I will let you know what all I changed, but here it is.

    https://drive.google.com/file/d/0ByAgtcHCrdNNaExDTnZtY2tEOUE/edit?usp=sharing

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    Replies
    1. Awesome! Would love to know what changes you did.
      How is the dry signal compared? Do you find the circuit changes the dry tone in any way?

      Delete
  23. Is the component marked as LED in the layout actually the resistor in series with the led? In that case is there any reason why it must be there instead of as part of the offboard wiring? Because this is unusual compared to all the layouts I have used from this site

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  24. This comment has been removed by the author.

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  25. I've built this one for my tank from an old Trace Elliot guitar combo. It is an S3EA1C1B with 3 springs, 800 ohms input and 600 ohms output impedance. While the output is fairly matched, the input isn't at all. Touching the springs gives that roaring thunder i've expected from a spring reverb. Driving it with a guitar signal just puts out a dull sounding reverb, no mids or highs at all. How can i mod the build to get some springy highs into it?? Greetings, Thomas

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  26. Would I add this to the end of my guitar effect chain or beginning? I don't have fx loop

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  27. That is what I thought. I built this with modkit 4EB3C1B tank. Everything works but it cut all my volumes in half on my amp and pedal. If I try to to my pedals up it starts to make a groaning sound.I wanted to try to build this reverb http://www.tangible-technology.com/schematics/fender/hrd/hrd-3.htm but don't fully understand how to read schematic. If anybody could vero this for me it would be great.

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