Orange Squeezer Problem

[mveitch]

Ive built the orange squeezer on a breadboard, but im having a few problems.  Im using the schematic on Tonepad, and have used 2N5457's for the JFETs and a 1N1418 diode. Im also using either a RC4558P.

The output of my squeezer, to my ears, is just a large boost thats a bit dirty.  The level of the boost is a lot louder than the bypassed signal when the level is turned all the way up, and it does distort. I was expecting a cleaner, more compressed sound.

As a test to see whether the diode/100K/4.7uf/FETs feedback chain was doing anything, I unplugged the diode. This had no audible effect on the output of the pedal. This suggested to me that there is a problem in this area, though I *think* my FET voltages are ok.

So:
1) Will the 1N1418 work in this circuit, or does it attenuate too much of the signal?

2) Ive read a lot about how subtle this effect is, but surely it shouldnt just sound like a boost. Am i right to assume that unplugging the diode should have a audible effect on the output?

3) Ive also read conflicting views on the trmipot. My 10k trimpot does cut the signal if its too low. If I raise the trim resistance the circuit does turn on, but after that point there is no audible difference. Some people report that the compression effect reduces as the trim resistance goes higher, some say it makes no difference. SHOULD it make a difference?

My 'boost' does actually sound quite nice, but im not convinced this is what the circuit is actually meant to sound like. Can anyone put their finger on what might be wrong in my circuit? Any help would be appreciated.

matt

[seanm]

I've also been working on the Orange Squeezer. I found the distortion too harsh, so I replaced the opamp with a clean boost. (See schematic for Blue Squeezer below.) This is a very mild boost unlike the boost you can get from the original. This is probably the only pedal I can take the volume part 9:00

I used a 1N34A for the diode. All FETs are 2N5458. All lines connect.

I found the compression way too subtle. If I "pull the diode" I can hear a change, but I think that live this would be completely lost.  I am starting to think that the OS is really a "fat distortion" rather than a compression pedal. YMMV.

[rockthebass]

i had the same problem with my breadboarded orange squeezer, recently.  i thought i didnt build it right, but i guess i did afterall.  man, these pedals are confusing  

[col]

Are your fets in the right way round? I put mine in the wrong way at first and it gives a very distorted boost and it made no difference if I removed one. I realised I'd got them the wrong way round and it works OK now.

[MartyMart]

I've built two "OS"'s the first was a perfed "Tonepad" version and the second was a vero version by Torchy.
Both worked perfectly, even though I had a few minor resistor value
changes and a couple of errors on my vero version:

Vol trim pot set at about one third of its travel = Unity gain
"Comp" trim pot.... Low settings were cutting the signal completely, this is
a known issue, then I had about 3mm of useful trim, which went from
subtle comp just on "peaks" to very unsubtle "hard" compression.
After this point the OS became an overdrive pedal !!
So it "does" work but the range of "trimpot" movement was very small so
just a little "touch" with a tiny screwdriver was making adjustments.....
If you have an "overdrive/booster" all the time, then something is wrong
or as mentioned the tranny is reversed, or perhaos your adjustments are
just too big !
Re-check all the wiring and try an audio probe to see where the signal
gets to within the circuit.

Marty.

[seanm]

So it "does" work but the range of "trimpot" movement was very small so
just a little "touch" with a tiny screwdriver was making adjustments.....

This could be. It is hard to adjust and play at the same time

[seanm]

A second thought.... For those who got it working, what FETs did you use? Is the circuit really sensitive to 2N5457s to work right?

[MartyMart]

2N5457's  

Marty.

[McFuzz]

maybe  see if you can find some fets with low HFE. try to match them as close as possible.that might help to curb the dirty.

[mveitch]

Hi guys, thanks for the replies.

This pedal is turning out to be a bit of a pain Glad to hear im not the only one. I am pretty sure that my FETs are in the right way round. I compared the voltages to those reported on GGG and they are prett similar. The only deviation I seem to get is that on th Gate of Q1 I measure close to 0V, rather than 0.6V (my DMM goes to 2decimal places too).

And here's an admission. My trimpot is actually not a trimpot as such, im just using a standard 47k/or fixed resistors between 0-10k. My rationale for not using a trimpot was that a) i dont have one yet, and b) in past posts people hadn't indicated that the sweetspot was that small on the trimpots range. MartyMarts post is leading me to think that im being too hamfisted with the biasing. ill go order a 10k trimpot right now, and let you know what happens.

I hope this pedal sounds good when its done.
matt

[mveitch]

Ok, i went back and replaced my makeshift trimpot with a better makeshift trimpot. This time I used a 4k7 pot in the hope that i would find the sweet spot within its range. And im proud to announce that i have found the sweet spot!

The problem with my 47k pot was that a minute rotation of the pot would cause the circuit to go from off to very much on. It completely missed out the sweet spot! Sometimes i would here it but just thought it was the transistors not kicking in properly so i would turn it a bit more and then wonder why the circuit sounded like a dirty booster.

I found that by using the 4k7, the 'sweet spot' becomes a lot larger. Turning the pot, I found that the circuit goes from being on, to quiet,compressed and clean, to a bit louder (still clean), louder still (clean) etc. Unfortunately I dont have the 10k pot, but putting a fixed 10k resistor in gives me that dirty boost/no compression.

It is a very subtle effect and there isnt much sustain, but im going to experiment with the mods.

Hope this thread helps someone else.
thanks
matt

[MartyMart]

Ok, i went back and replaced my makeshift trimpot with a better makeshift trimpot. This time I used a 4k7 pot in the hope that i would find the sweet spot within its range. And im proud to announce that i have found the sweet spot!

The problem with my 47k pot was that a minute rotation of the pot would cause the circuit to go from off to very much on. It completely missed out the sweet spot! Sometimes i would here it but just thought it was the transistors not kicking in properly so i would turn it a bit more and then wonder why the circuit sounded like a dirty booster.

I found that by using the 4k7, the 'sweet spot' becomes a lot larger. Turning the pot, I found that the circuit goes from being on, to quiet,compressed and clean, to a bit louder (still clean), louder still (clean) etc. Unfortunately I dont have the 10k pot, but putting a fixed 10k resistor in gives me that dirty boost/no compression.

It is a very subtle effect and there isnt much sustain, but im going to experiment with the mods.

Hope this thread helps someone else.
thanks
matt

Naughty Naughty !!
You should always say if you have "subs" in your build   :roll:
Of course a 47k fixed resistor will NOT do the job af a 10k trimpot
and ....... neither will a 4k7 pot  .... tut  tut  ......   :wink:

Marty.

[sovtek50]

I built 3 of them so far, and while some other projects had me crying, all of them OS's worked fine, apart from some minor difficulties with the first one.
Of course it has to be a 10k trimpot, and the sweet spot comes just after doesn't-work-at-all-position. I can't call it a subtle effect, though. The compression is very well audible, works best with clear sounds and is somewhat magical, it's true. That's what makes the reputation of this beautiful little box.

[rockthebass]

has anyone gotten any good results with the j201's from Aaron?  because thats what im using.  my only other "sub" is a 2500pf cap instead of the 2200pf

[mveitch]

sorry marty/everyone. :oops:

I just hadnt expected such a small range over the sweet spot from what everyone had said in the past. I still hope that this thread has some use to someone else.

After playing around with it a bit more, i actually also agree that the effect is very non-subtle. I guess its because its not immediatly clear what the effect does, but when you start varying the attack of your picking you realise that it does a very good job of compressing, without giving the sustain that other compressors do.

anyway thanks again.
matt

[rubberlips]

I was going to start a new topic and ask people what they thought of the OS but it looks like its hear. Just finished it and had to same problems with it, and I found the effect very subtle. So for the trimpot, what value do most people turn theirs to? I chucked in a 20K trimmer and left it halfway at 10K to turn down.

Pete

[mveitch]

I think you have to put a 10k trimmer in for definite. I did the same thing as you, but worse by putting in 47k.  I personally found, with the 2n5457s I was using, that I could find a sweetspot at about 3/4 rotation of a 4k7 pot, so I guess about 3k. But i think that 2n5457s and other fets vary a lot so you d have to experiment.

I would definitely recommend using a 10k instead of your 20k, just because of the better accuaracy you'd get, if nothing else.

matt