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



Posted by at 08:44
Tags: , ,

66 comments:

  1. Unknown16 December 2012 at 18:41

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

    ReplyDelete
  2. Doron Barness16 December 2012 at 19:59

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

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    Replies
    1. mirosol16 December 2012 at 20:19

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

      Delete
  3. onthetundra16 December 2012 at 20:40

    There are two Drive 2 wires.

    ReplyDelete
    Replies
    1. mirosol16 December 2012 at 20:45

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

      Delete
  4. onthetundra16 December 2012 at 21:48

    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. onthetundra16 December 2012 at 22:14

    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. mirosol17 December 2012 at 17:19

      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

      Delete
  6. Kinski23 December 2012 at 04:03

    Any luck? Is this verified?

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  7. splashsplish28 December 2012 at 02:58

    do the rca cables need to be shielded?

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  8. onthetundra31 December 2012 at 19:43

    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. onthetundra31 December 2012 at 19:46

    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. R.Paolo2 January 2013 at 22:57

    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. Kinski14 January 2013 at 00:32

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

    ReplyDelete
  12. TFletcher14 January 2013 at 18:41

    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

    ReplyDelete
    Replies
    1. Kinski15 January 2013 at 01:41

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

      Delete
  13. Unknown24 January 2013 at 10:20

    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.

    ReplyDelete
  14. Unknown2 April 2013 at 15:49

    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. mirosol2 April 2013 at 18:23

      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

      Delete
    2. mirosol2 April 2013 at 18:47

      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

      Delete
    3. mirosol2 April 2013 at 18:55

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

      Delete
  15. Unknown2 April 2013 at 20:51

    nothing has changed, the same problem.

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    Replies
    1. mirosol2 April 2013 at 21:03

      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

      Delete
    2. Unknown3 April 2013 at 07:23

      rechecked everything, right stand.

      Delete
  16. Thommo28 June 2013 at 07:27

    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. Thommo2 July 2013 at 09:46

      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.

      Delete
    2. mirosol2 July 2013 at 12:58

      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

      Delete
  17. Thommo3 July 2013 at 07:12

    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. mirosol3 July 2013 at 08:20

      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

      Delete
    2. mirosol3 July 2013 at 08:31

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

      Delete
  18. Thommo4 July 2013 at 08:47

    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. Thommo4 July 2013 at 08:59

      I figured out the tank is 20 years old!!

      Delete
    2. mirosol4 July 2013 at 10:02

      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

      Delete
    3. Thommo4 July 2013 at 11:02

      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.

      Delete
    4. mirosol4 July 2013 at 11:32

      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

      Delete
    5. Thommo5 July 2013 at 10:30

      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.

      Delete
    6. mirosol5 July 2013 at 11:18

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

      Delete
  19. jon q8 February 2014 at 22:17

    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?

    ReplyDelete
    Replies
    1. mirosol9 February 2014 at 04:35

      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

      Delete
    2. jon q11 February 2014 at 15:49

      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. mirosol11 February 2014 at 18:04

      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

      Delete
    4. jon q15 February 2014 at 23:07

      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. Unknown4 April 2014 at 16:05

    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. mirosol4 April 2014 at 19:12

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

      What tank did you use?
      +m

      Delete
    2. Unknown8 April 2014 at 20:32

      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. Unknown8 April 2014 at 20:36

      This comment has been removed by the author.

      Delete
  21. Alcatéia23 April 2014 at 15:36

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

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    Replies
    1. Unknown23 April 2014 at 15:51

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

      Delete
  22. Unknown23 April 2014 at 15:59

    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

    ReplyDelete
    Replies
    1. Kinski24 April 2014 at 01:59

      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
    2. Unknown26 April 2017 at 13:35

      hey Joshua, what did you do to make it sound great?

      Delete
  23. Unknown30 May 2014 at 20:55

    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. Unknown30 May 2014 at 20:56

    This comment has been removed by the author.

    ReplyDelete
  25. Unknown2 September 2014 at 15:37

    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

    ReplyDelete
  26. j20 November 2014 at 03:44

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

    ReplyDelete
  27. j20 November 2014 at 12:34

    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.

    ReplyDelete
  28. BaddRiddim6 December 2016 at 15:01

    I'm gonna try this. but to let you know i build reverbs that are used with 4ab tanks(8ohm) input, and if i use a 190ohm input tank, se signal is much lower. I'd try lower impedance input tanks for this. generally the conventional guitar tank has a 8 ohm input, and usually, lm386 are used to drive little speakers

    ReplyDelete
  29. Unknown21 March 2017 at 19:20

    Does anyone know of an easy single knob reverb build? Something for a novice? Thanks in advance..

    ReplyDelete
  30. Tsvetan Popov24 February 2018 at 17:22

    I got this running fine with a 4fb reverb tank (1200 ohm input impedance, 2200 ohm output impedance). I put a small 220 to 6v transformer from an old power supply, wired secondary to the tank out, and primary to the tank input to match the impedance, it works like a charm. Also I switched wet and dry stages by wiring the input jack to the 'from tank' and the output of the reverb tank to the input, I found it works much better this way (the wet and dry controls are the other way around). The reverb sounds much Fuller and the dry sugnal is smoothly controlled. I used 2N5088 transistors. Thank you for this build, it sounds great as a spring reverb should, surfy and drippy at high settings, musical and responsive.

    ReplyDelete
    Replies
    1. Tsvetan Popov24 February 2018 at 17:26

      Sorry for the incognito post, couldn't sign in for some reason, my name is Tsvetan Popov from Bulgaria.

      Delete
    2. Tsvetan Popov24 February 2018 at 17:33

      Also I did some more cuts, and added additional jumper to link the 'new' input stage with the stage before the 386 chip, and changed the gain of the 386 chip by removing the capacitor and resistor in the gain loop to reduce the overdrive in the drive stage

      Delete
    3. LaSuze8 January 2021 at 17:32

      Hi Tsvestan, thanks a lot for your feedback. i'll try your modification soon. but i have a question for you. i got a Belton BL3AB31B tank which has only 10ohm input impedance (and 2575ohm output). what must i do for matching the impedance?

      Delete
  31. Zac2 January 2019 at 20:05

    Hi,

    I know this layout is quite old so there's a chance noone will reply, but i've tried building this and i'm not having any luck.

    The clean signal passes through fine but I'm not getting any voltages on the IC chip and not getting any reverb.

    I've switched out the IC for another LM386 and for a JRC4558 just to see if it was a faulty chip and there's still no voltage - I'm not sure what the issue could be as the power is jumpered to pin 6 and I'm getting power at the 9v input.

    I took some readings of the transistor voltages to compare with others who had posted and they seem off :

    Q1 - bottom, Q2 - middle and Q3 - top

    Battery 8.2v

    q1

    c - 6.58
    b - 0.71
    e - 0.12

    q2

    c - 2.67
    b - 0.86
    e - 0.24

    q3

    c- 5.27
    b - 0.86
    e - 0.26

    ReplyDelete
  32. Elf Hands Customs6 February 2019 at 02:30

    what is the input impedance and output impedance actually at? wonder if I can get this to work with the new blue accutronics tanks without a transformer

    ReplyDelete
  33. Mathijs11 June 2019 at 15:39

    Just for those who were struggling with the loss of low end:
    the decoupling caps serve as high pass filters. increasing their value (I used 0.47uF) will give back the low end BUT seems to also give some rumbling in the sound, probably from leakage after a note is played. Its a tradeoff. I advise to only do the Input and Dry 3 caps (the ones that are back to back) in the "dry" part of the schematic.

    ReplyDelete

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