Saturday, 22 September 2012

Anderton Super Tone Control

I think this will be popular with quite a few people, especially those who want to get the most of their dirt pedals and fine tune the frequency response more effectively.  I think this would go to make the perfect distortion pedal if you put your favourite dirt circuit with this in a dual effect box, particularly with an order switcher so you could put the tone control before or after the dirt.  The IC is supplied with +/- 9V and I have altered the circuit slightly to use my preferred method of doing this with a ICL7660S to provide the bipolar supply.

Note that the original is advertised as being capable of accepting a supply from +/5V to +/-18V.  However, the ICL7660S can accept a maximum of only 12V and so I would suggest keeping the supply at 9V if you use the suggested charge pump IC.  That still gives you an 18V swing which I expect would be more than adequate for this, but if you would prefer to use an 18V supply for additional headroom then you could use an ICL7662 which is rated for up to 20V although these may be more difficult to find and certainly more expensive.

Info about the original project from the author:

Deflnltlon: Offers flexible control over tone by creating several different response options. Low pass response boosts low frequencies and attenuates high frequencies; high pass response boosts high frequencies, and attenuates low frequencies; bandpass response boosts a specific frequency range; and notch response attenuates a specific frequency.

The "state variable" filter is a type of filter used in several synthesizers to control timbre; this circuit is a variation of the state-variable filter that has been optimized for tone control purposes. It offers considerably more sonic flexibility than the tone controls found on most instruments and amplifiers.

. Variable resonance control changes "sharpness" of the sound
. Easily resettable to fiat response
. Low-pass, high-pass, the band pass outputs alre individually mixable via an onboard mixer to create highly complex responses
. Useful as recording studio or PA equalizer
. Operates at low level or line level






Modified with additional volume control.



53 comments:

  1. Hi Mark, do you if there it is a difference between ICL7660SCPA and ICL7660SCPAZ?

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    1. Oh and if you want to get a few in on the cheap then try these:

      http://www.ebay.co.uk/itm/251066447875

      I've bought from here and although they take a while to arrive they were fine.

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  2. This looks really interesting, a must do during the weekend!
    Thanks as always mark!

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  3. I've been looking for something like this for ages! This would be excellent on bass, as this sort of similar to the preamp in the old Vigier and Alembic basses.
    Anyone know where I can buy 10k log concentric pots? With one of those, I could conceivably put this into a 1590B.

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    1. http://www.taydaelectronics.com/10k-ohm-linear-dual-taper-potentiometer.html

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    2. Sort of. I know about that 10K dual linear for the frequency, but what I was thinking was a concentric (stacked) pot for the high/lowpass , so I could just have one pot instead of 2. It seems the only people making concentrics are the ones for the '62 Jazz Basses, which are 500K/500K... so I could conceivably put some resistors in line.
      Oh parts sourcing, you never fail to amaze and simultaneously confuse me!

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    3. Sorry I misunderstood. But yes they're be great for this, if you find a source let us know

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    4. http://www.smallbearelec.com/servlet/Detail?no=1213

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    5. Awesome. You could even used one of those for the Frequency pot too. If you turn both concentric pots together it simulates the dual blend type pot, but means you could also control both side independently as well. It should easily fit in a 1590B with these providing they aren't too deep.

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    6. now that the requests section is closed, i am just gonna put this here. you should tag the layouts with the transistors/IC part numbers, just so if we happen to have a certain part lying around, we can search for what we can build with it. i realize it's probably not feasible for the massive backlog of layouts (a hundred thanks, again) but it would be helpful in the future.

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    7. Yes it would be really useful but the size of the task has always put me off. I suppose to make it simpler I could cut it down to something like:

      Single IC
      Dual IC
      Quad IC
      Transistor
      JFET
      MOSFET

      and maybe add more unusual parts like:

      Vactrol
      LDR
      Regulator etc.

      Because for the vast majority of these layouts you wouldn't have to use the part specified, lots of alternative dual opamps could replace a JRC4558. I'll have a think about the best way of doing it.

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    8. @Mark: No problem! I should have been a bit clearer.
      @Nicholas: Oh yes! That'll do nicely!

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  4. bah, built the board and about to make the pots wiring i realize that im out of 10k logs, got linears, also all i have is dual 100k ones. wanted to verify this one, give it ago and change pots later on maybe?

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    1. Linear will be fine, 100K probably won't be, but you never know! At worst you may only find useful range out of the last 10 or 15% of the pot rotation and so you won't get the fine tuning resolution you would out of the correct value pot. But you'd certainly know if it was working.

      One of the reasons I hoard so much is because I hate the idea of wanting to build something and finding out I haven't got a part. 500 pots may be taking it a bit far though! :o)

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    2. you can never have to many of them, y stash is about 150 i guess in mixed values. i could always try the resistor trick on the 100k dual one.

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    3. Yeah it could get a bit messy with it being a dual pot though with resistors all over the place, plus you have to make a few daisy chains to the Frequency pot (although you could make it last in the chain so it only has 1 wire going to each lug).

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  5. HI,

    Is the ICL7660S from Musikding ok ? ( http://www.musikding.de/Active-parts/Transistors/Voltage-Regulators/ICL7660S::1132.html)

    Thanks in advance.
    François

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  6. Thank you very much lvlark.

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  7. Damn. I thought i had dual 10ks, but i don't..
    +m

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  8. Do you know how I could implement an input so I can control the filter frequency with an EP2 pedal from Moog ?
    Here what the Moogerfooger's manual tells about the pedal inputs.
    'All pedal control input jacks are 1/4" tip-ring-sleeve phone jacks. The sleeves are grounded and the ring terminals are supplied with +5.7 volts which is current-limited to about 0.5 milliamperes. The tip terminals receive the variable voltages from the pedals.'

    And here is a pdf that show the details about the pedal itself.
    http://www.teaser.fr/~amajorel/ep2/

    Thank you in advance. And sorry for my ignorance.

    PS : And I wonder if it could be possible to create a generic circuit for implementing that kind of input control on everithing (Drive, tone and whatever we have on a pedal...) :)

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  9. Finished this tonight, holy off-board wiring batman.

    Sounds pretty cool so far, was very clean sounding. Will try it with my amps and other pedals tomorrow.

    The resonance pot seems to be backwards, fully clockwise gave me no resonance, all the way down it's max. It also seems to jump from "off" to "some resonance" pretty abrupt.

    It definitely can boost the signal quite a bit, a master volume control will be easy to add to the box.

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    1. Excellent, thanks for verifying Michael, let us know what you think after using it with your other gear.

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    2. It sounds great! Incredible EQ possibilities after a fuzz or overdrive, but just as cool before one, just like you thought. I played with it for a few hours now and feel I just scratched the surface with the possibilities (before, after certain pedals, and all the interactive eq weirdness it does).

      It can get very synth like, esp with the resonance switch on with some fuzz/dist before it, it doesn't self oscillate, but almost.

      The internal mixing as described is a little weird, causes a lot of interaction between the controls.

      Like I said before, it can get much louder than unity, so unless you want a boost I would add a volume control in the box.

      This is a cool tone shaping effect, I recommend building it.

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    3. Thanks for the feedback Michael, I've added an additional layout with an optional volume control based on your thoughts about it.

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  10. Maybe you could add a 2K2 resistance beetween column 3 (from left) / line 1 and line 7 (from up) plus a cut column 4 / line 7.
    So we could have a direct Led + output ?

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  11. Hello,
    I'm building it with a meathead on the same veroboard with a pre/post switch.
    It's my first 'custom' project. I'm a little bit anxious with the switch wiring. Especially considering the ground connections. No hum and other noises with a wiring like that ? Are there things I should change or should I change the entire circuit ? :)
    http://imageshack.us/a/img685/6817/andertonmeathead.jpg

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  12. So I built it and after several days of carrefull wiring, of course...it doesn't works :)
    Bypass and leds ok with both meathead and filter (I'm so proud).
    The sound pass thru the filter but the controls doesn't respond or in a strange way. The res. does nothing except a noise when fully clockwise, the volume make some strange plops and I can have very nice distorsion sound with the band knob :p...
    No sound with the Meathead. (I used BC108).
    No hum with both.
    Do you see something wrong in my wiring schematic please (Link in the previous message) ? Or should I concentrate on the vero ?
    And the useless gui for the fun here ;) http://img37.imageshack.us/img37/2666/photorvxq.jpg
    (

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    1. Your layout looks ok at first glance but it is quite small and so I may be missing something. I'd strongly recommend testing both circuits independent of switching first. If you don't know whether the board works when you're doing the offboard wiring, then you're just adding another potential point of failure into the equation to make fault finding more difficult.

      Check the voltages of all the transistor and IC pins on both boards. That should give us a clue.

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  13. Thanks lVlark for your quick response. I knew it was dangerous to wire directly but as a newbie into soldering I know I can destroy a delicate veroboard while soldering two time on the same hole :) I will check it again tomorrow following your advices.

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  14. Now the Meathead works...BCE is not EBC :p (I'm this kind of people dangerous for himself and everyone around when equipped with a simple screwdriver)
    The problem persist for the filter (I tried to replace both ICs without success).
    I will check outboard wiring tomorrow.

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  15. Hello,
    I've checked the wiring which is ok with my layout. I cleaned the vero tracks one more time. But still wrong.
    One clue maybe : If the Low and High are not both fully clockwise (Almost fully), there is no sound going out. (The band knob has no effect.)
    Any ideas ?

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  16. If I only wanted one or two filter types, would I just leave their respective pots disconnected? I'm building this for bass, so I think the highpass filter isn't really that necessary.

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    1. Yes it's no problem just leaving out the pot

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  17. the only thing i can hear is a loud buzz, no signal passes through the pedal, and the 100 uF cap became really hot after a few seconds...
    any hint?

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  18. My version coupled with a DAM Meathead in a box, with a switch to change the order of the effects.
    [IMG]http://imageshack.us/a/img16/7417/img1619m.jpg[/IMG]
    and the verified offboard wiring [IMG]http://imageshack.us/a/img96/4113/projetfuzzavecfiltre3.jpg[/IMG]

    Thank you ;)

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    1. Nice, the pre post has a lot of applications. Mark is this something you could mak a generic layout for in the off board wiring section? Booster,distortion pedals in the xotic + line do the ordering thing and it sounds great.

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  19. Can anyone please clarify exactly how are the spst switched wired?

    I'll probably use two spdts and just use the middle and one of the outer lugs, but how exactly does this work? Sw1/sw3 wire to one pole, another pole to ground?

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  20. that's sw1/sw2, of course. :)

    I'm not sure this would work since on/on and off/off would be possible so switch recommendation (preferrably Tayda) would be much appreciated.

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    1. A SPST switch can only be on/off, there is no other possible arrangement as it only has 2 lugs and so the contact is either made or broken.

      If you can't find SPST switches you could use 2 position SPDT and just use the middle lug and one of the outer lugs.

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    2. Thanks for a quick response!

      So we are basically on the same page, what threw me off was you saying "2 position SPST" on the schematic, that's pretty much same as saying "SPST" (given that single throw is what it is, either made or broken)?

      That "2 position" thing made me think whether there may be 2 actual switches (with some implied wiring schematic). :)

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  21. This is such a cool pedal for shaping tone. I finally found the elusive sound I have been trying to recreate from Spirit's 1968 LP, "The Family That Plays Together". Resonance, squeal, and endless feedback sustain at my fingertips!!! Lots & lots of off-board wiring but in the end... more dials to tweak and make everything sparkle. Go with the additional volume control version. This is a highly recommended build!

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  22. I like it! I'm having a high pitch whine but I think it's due to the IC: It's 7660CPA and not 7660SCPA. Can it be? I'll try to get the correct one...

    Thanks!

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  23. Yes you will need the one with the "S"

    The one you have is not suitable for audio applications as it operates at a frequency within the range of human hearing (resulting in an audible high pitched oscillation).

    The correct chip should be easy to find pretty much no matter where you live

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    1. I´ve build this ting - ok. But after 5 minutes play with my equipment it makes laudly "britzel". If I turn on LowPass-Pot it will be lauder. I have change the IC7660 and TL074 - but not result. I also change the 100uF cap - nothing.
      What can it be?? What can I do??

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    2. Solved, - a bad connection an a pot!
      Dirtyness!!

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  24. Hi Mark, curious why C5, the 10uf output cap, was omitted from the layout? What's it's purpose? Static protection for the IC?

    http://www.mrdwab.com/john/CA-super-tone.jpg

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    1. I assume it would be for DC blocking? Otherwise it's there to be an output cap, but omitting it means that there's unlimited frequency response? If there was a cap there, it would limit the frequencies in a certain way depending on the value of the cap. I think. Me just speculating.

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    2. I just had a look at the schematic I did this from which isn't the same as yours and the only think I can think is that the cap symbol looks like a plug and socket symbol so I think I probably just thought it was showing the output socket.

      Doh :o)

      It's a quick easy mod so I'll do it now. Without it I would expect it to be noisy because it won't be blocking the DC from the opamp.

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  25. How can this be moded to get a better bass response? i would like to get my lows lower or deeper.

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  26. Hi IVIark,

    Just built this using an old cry-baby shell. I filed away a bit to squeeze the double gang pot into the mounting bracket. It took a bit of work to get the pot mounted as short threaded, but got there in the end. Luckily, the sprocket from original pot fits on the Alpha long shaft almost perfectly. Maybe a half mil of play, which is noticeable, but manageable.

    I didn't feel like drilling any extra holes in the shell (it was a fuzz-wah, so had a switch each side and a pot on one) so used trim pots for the hi, lo, band and volume. I could only get my hands on 25 turn trims at short notice, but I mainly use the band with a tiny bit of hi mixed in, so fit for purpose. After wiring it up I noticed I reverse wired the frequency pot(s). Great for the hi pass on it's own, but bit tricky otherwise, so went out and bought a 4pdt toggle, and wired in a reverse switch. Almost mandatory addition if you mount in a sweepable enclosure, but has to be a linear dual gang. I use it like a wah in front of dist/fuzz. Less funky, more brutal filter sweep.

    Build pics here - http://s126.photobucket.com/user/williamthesweet/library/Anderton%20Super%20Tone%20Control

    I used a MAX1044 and the bipolar power supply design from gaussmarkov - minor changes to your layout -
    1 - added 2n3906 and resistors to extra 3 rows below original layout and a link from collector to the top row where your 9v in is. Cut rows as needed to route 9v into emitter and 6.8k to input jack ring and 1k between base and emitter.
    2 - replaced 100uf and 47uf caps with 220uf.

    No other changes needed, all cuts and links in your layout work with this power supply design.

    Many thanks IVIark - muchly appreciated!

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  27. Hi, I have anderton's book and i built this circuit, with this layout three times (two for me one for a friend, we use em for dub mixing). Here's my issue: when res level pot on low level, hi here a anoying beeeeeeeeep behind the sound. I'm using vintage polystiren caps for the 68p (like advised in the book). Finally i decided i did'nt need the res at low level so conected sw1 and sw2, and that was ok. but today i've built one for a multi fx box i'm building, and that one beeps even on hi res level. I checked and tried everything. In the book anderton says if you hear squeels or oscillation, shield the res pots wires, that didn't work eather.
    Anybody got an idea???
    And by the way, is ther a way to plug some control voltage for freq control (lfo) on this unit? On the original layer there is a way to add a module to make an envelope filter by controling voltage(i'll have to look at that one day).

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