Wednesday, 15 February 2012

Rothwell Love Squeeze

You don't come across this very often, but this is a fairly original compressor!  At 22 columns wide it will fit in a 1590B, but file the sides down as much as possible for extra space, and maybe use some electricians tape on either side of the box for insulation as a precaution.  I tried to get it down a bit more but that's the price I pay for wanting flat resistors.  Oh and watch for the shared hole at pin 8 of the IC.

Manufacturers info:

The Love Squeeze is a compressor designed simply to sound right with guitars, without any bizarre “pumping” effects and without any noise.
This has been achieved by designing a circuit from scratch instead of adopting the more common approach of using an operational transconductance amplifier (for tech heads, it’s usually the CA3080 chip) or simply copying an existing design (like some American boutique makers have done) and gives the Love Squeeze a sound of its own. Low level signals can be raised by as much as 20dB without boosting high level signals, so when used in front of distortion - either in a pedal or an amp - leads lines can be fattened up without chords sending the distortion into mush. When used with a clean sound the Love Squeeze can be set to just take off the ice-pick attack of single coil pickups for a tone a little easier on the ear. Like reverb (when used sensibly), this is a subtle effect which can go almost unnoticed until it is switched off - then you wonder how you could live without it.



42 comments:

  1. Hi Mark I have just made this. It works as I can hear compression happening but the output is really weak. I've checked the obvious cuts, jumpers, tracks and soldering. Caps and diodes around the right way. I've tried turning around Q1 it does have an effect but just makes a kind of on/off switch of the compression pot. I've Checked the IC is seated correctly. Does it matter how the LEDS are? I have left one + at the top and right one the opposite.

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    1. No as long as the LEDs are top to tail, it doesn't matter which way round they go. If the signal seems weak then it may be worth checking that you're getting continuity to all the points of ground on the board and offboard, and often reflowing the solder can help make a better connection if there is a bad joint somewhere. Can you post a high res front and back pic so I can see if anything else jumps out at me.

      And thanks for the layouts you've verified.

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  2. Works. Tag it.

    I noticed too late that i was out of 3mm red leds, so i put in clear orange instead. Didn't even socket them which i think was a mistake. Anyway, it's as loud as it should be. Not OD loud, but loud.

    There is a first time for everything :) Compression pot's behaviour felt like all the action was in the first 20-50% of the turn, so i swapped B10K for A10K, and the compression control came out much better.

    I reckon that those orange leds may be the cause of this, but attack seems to be a bit harsh. Not as smooth as i hoped. It's still nice non-optical compressor. Currently not as good as Mr. Squishy, but nice nontheless. If i feel like it, i might put in sockets for those leds and try on a variety of different combinations - to see if some other set of leds give out smoother attack. If i feel like doing it. :)

    So. If you have only clear orange leds - i don't recommend this one. Build the Squishy instead :)

    p.s. Only 15 more to go for 200..
    +m

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    1. Nice one matey. I've built a Forest Green Compressor and have been waiting for a pot coming for it which has now arrived, so hopefully we'll have another compressor verified soon.

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    2. I've been wondering if should build some MP/BJF stuff, but they are always using components that are not your everyday stuff - and nothing else seems to use the same components..

      Compressors are great for fattening things up. I'll be building more. I need to do some optical comp soon. :)
      +m

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    3. Bjorn does tend to use some weird E96 value resistors but in everything I've built I've just used the closest thing and they've worked fine. Of course it may not sound absolutely 100% identical to an original, but then he also uses some 5% carbon film in some of his pedals and with cap and transistor variation you may not get two of the originals sounding exactly the same either.

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  3. I notice a mistake of sorts on your layout - the two leds are shown being soldered across two rails (i.e four contacts per LED) which is incorrect - it should be the outer two connections only.
    Hope this helps,
    Philly

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    1. The top and bottom ones are the connections. The second and third rows are part of the LED symbol with DIY Layout Creator which I think is supposed to signify where the wire comes out of the LED body.

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  4. Is there no longer a shared hole at pin 8??

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    1. Well spotted! No I altered it but didn't remove the note

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    2. why did you remove it?!? does this change affect the sound?

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  5. Hi!

    Having a problem with this build.. when i plug in the power i can hear a crackle and the LEDs just light up for a second..the volume pot has no effect and the comp knob just makes the signal louder..

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    1. ok figured out i forgot to ground the volume pot.. now i'm having a distorted sound when i turn up the comp.. did i fry something?

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    2. What type of pickups are on your guitar? A few people have mentioned distortion at higher comp settings which is common in a lot of compressors and so it may be behaving as expected, particularly if you're using higher output singles or humbuckers.

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  6. i have P90s, one thing i forgot to mention is i had no 100pf so i paralleled a 51pf and a 47pf.. could this be the cause?
    i also just replaced the tl072 and the 2n5457 for fresh ones but had no luck..
    when i turn on the effect i cant hear nothing, only after i play a note i can hear the sound fading in distorted... strange

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    1. ok i have to correct myself, the sound just fades in wether i play a note or not..

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  7. i built this one yesterday and it sounds great. when i use it with a bass, if i turn the comp knob a little past noon i get a weird delayed fluttery distortion ONLY on notes on my low E string. i tried running it at 18v and it made it even worse. i also tried different transistors and opamps but to no avail. i ended upsolving it by replacing the lower right 10u electolytic with a 22uf one and it works perfect and didn't seem to change its tone or compression one bit. IMO, it's a great comp, and super quiet.

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    1. Excellent info thanks John. Jeez you must spend ages experimenting with these. Do you just change everything to see the affect or did something else point towards the cap?

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    2. well, since i make my pedals for use with a bass, i socket quite a few of the components so that i can test which values will work best. i already socketed all of the 10u caps so i could compare aluminum electro's vs tants, so since they were so easy to replace, replacing the one of the 10u's with a 22u solverd it. i also tried different diodes (1N270's, BAT41's and 1N134A's)but the 1N5817 was the one that works best in this pedal.

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  8. I built it and it sounds great, but it has considerable amounts of squish and "pop" sound. when picking you get that strat spank and nice compression. I used a 4.7 instead of 5.1 and blue led instead of red. Is that why? I also used 914 diodes rather than the 5817 is that why?

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  9. you must use the proper diodes (both the leds and 5817's)and the correct value resistors. they are an integral part of how the circuit operates. for example, 914's have a forward voltage of around .7 volts, whereas 5817's are at around .2 volts.

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  10. I'll order in a few diodes then, no biggie. Sounds pretty cool as is, but I'm down for a more transparent sound.

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  11. i've found this circuit sounds MUCH better running at 18v... especially with bass and high output pickups. I'd say 18v is NESCESSARY for active bass pickups. now to try a buffered blend circuit in there!

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    1. that's strange, i think mine sounds better running at 9V. i added a true bypassable blend to mine since i wanted to have the option of running the pedal with or without it. here's a pic of it:

      http://johnkvintageguitars.homestead.com/Effects/Compressors/LoveSqueeze-01.jpg

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  12. I'm getting a lot of distortion with this circuit, I made a few part subsitutions, 22r for 33r, 15n for 10n, 39k for 33k, 47k for 51k. They were the closest values I had, but it seems that I may have changed too much, as the comp seems to add bass, darken the tone, and distort as well. Halp?

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  13. IvIark, how would I add an attack control to this circuit?

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  14. I made it three times yesterday with new components at each time to be sure that I made it good.
    And the three ones I made distort the sound. I also tried with another layout (other site).
    I play it with bass guitar.
    Did anyone have this problem and resolved it ?

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  15. Perhaps there's a difference between TL072P (like the original) and TL072CN I put in ?

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    1. That shouldn't matter. The suffix usually denotes things like operating temperature ranges or the packing type the ICs are shipped in so that shouldn't make a difference.

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  16. I changed all components excepted mechanical parts (footswitch, LED indicator and jack in and out). I don't think that should be these parts.
    Anyway, it's a really good overdrive :-DDD

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    1. Are you using it with humbuckers? I've heard a few people say that it clips with higher output pickups so it may be one better suited to single coils

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    2. hmm??? I use mine with a bass and it doesn't clip at all.

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    3. (I've already said that in another topics but... excuse me for my perfectible english...)
      I've got a basic Precision Bass.
      Is it possible that my 3mm LEDs are not good ? I tried different LEDs but they are all from the same seller. I tried the one on the left with catode on top and the one on the right with anode on top and after I tried to do the other way (IvIark, I understood, as you said, that it doesn't matter but my disappointment told me to try this !).
      I tried three different 2N5457 and placed them as shown on the drawing. Is there a good way to put it to have a compressor and a wrong way to have an overdrive ?
      The wire "Comp 2 & 3" goes from the board to the "2" of my Comp potentiometer. Then "2" and "3" of the potentiometer are wired together.
      I didn't take account of the note "Note the 22R/100u shared hole at pin 8" as mentioned above.

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  17. Ok, the problem was with my 3mm LEDS that were clipping too much.
    I replace them and it sounds good but I notice a volume drop even with volume set at max.

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  18. Ive used 2n5459's and 1n4007's are these ok?

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  19. Is there an easy way to add extra compression to this circuit? Mine sounds great, but could use a touch more squish.

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  20. This one REALLY clips with humbuckers - it an average overdrive and even worse I built it wrong the first time in a way that was unfixable (I wasted four hours trying to troubleshoot it, but had it completely rebuilt in under 2 hours). It is just like a first stage in an overdrive (not a bad one).

    Anyway, I want a compressor so maybe I will try a different one. The demo to this one sounded great, though.

    By the way - many of us (siunce early 2015) are hanging out in the forums: http://guitar-fx-layouts.42897.x6.nabble.com/

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    1. Try replacing the lower right 10uF electolytic with a 22uF one (like jonhk said). It worked for me.

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  21. Busy building this but the TI TL072 op amps I bought don't have the notch to orientate them should I assume that writing should then be in the same orientation? Not keen to blow them cause I only ordered two.

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  22. I built this today using MPF102 and NJM4558. Sounded good, maybe a little soft for my taste. 3mm led color doesn't seem to matter. I decided to try different op amps. It sounds better with jfet input, such as TL082. I settled on NJM2082, which definitely broadened the sweep of the compression dial.

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