How to bias Orange Squeezer?

[carrejans]

I recently build an Orange Squeezer. I never used a compressor before.
I want to know the best way to set the trimpot right.
I have used a 30-turn 20k trimpot.

So the purpose of a compressor is to have a uniform volume. Lower volumes will be boosted; and higher volumes will be damped. Right?
So, I probably have to strum my guitar from soft to hard, while turning the trimpot, I guess. And then listen where it has the most uniform volume?
I already tried some different settings. But sometimes the squeezer acts like a booster, sometimes as a distortion device.

My main question is; how should I put the other pot (gain or volume), while testing? Should I put it at half, or at maximum?
Should the volume be te same, with the effect on and with the effect off, when the volume pot is at half?

What do I have to hear, to know I'm at the sweet spot?
One end of the trim has almost no sound, the other end has a massive volume boost.
Do I need to be just before the volume boost?

Thanks...

[carrejans]

BTW, isn't it possible to measure a voltage somewhere after the JFET, or somewhere, to set the trimpot right?

[petemoore]

  Fine question, and I recalled well enough to leave well enough alone at 8k2 a couple weeks ago, this OS is fine ever since.
  A couple squeezers told me the difference between 10k and a jumper is difficult at best to detect or undetectable/unimportant.
  So the latest one got rid of the 10k, if it ever causes problems I can always +/- Rvalue there, no need to, but maybe I got luck 2 times with 10kpot there, 1 time with fixed R.
  The compression is slight and the sound is fine.
  As with trying to 'hear' the 10k adjustment, the compression tends to be subtle.
  There are stronger and fast compressors {Dynacomp for instance}.
  Very strong-simple and slow compressors [LDR is easy to make slow enough to include attack peaks/duck/rise up slowly, nice for a 'sustainey/attackey distortion].
  The OS is 'delicate' sounding, and adds a touch of distortion, very nice...if it's an only boost or luck has it or it finds it's 'niche'...like pushing but not shoving a cleanish distortion [ok tube output/speaker] while keeping it from entering 'unwanted' territory, boosting...anything, with a bit of slack at the top-peaks of output. 

[chi_boy]

I had a very hard time adjusting mine, but finally found this:

http://www.diystompboxes.com/smfforum/index.php?topic=48102.0

After setting it as Mark suggested I was happy with the result.  Your milage may vary and such, but it worked for me anyway.

Cheers,
George

[shadowmaster]

The trouble I had with biasing my OS clone build was on not knowing how should a compressor sound like much more on not knowing on how should an Orange Squeezer sound like.

I listened carefully to the OS sound clips available on the internet and still I was not really able to determine what does a compressor sound like. What I noticed on those OS sound clips were boosted signal and some tone coloration. I started to wonder, "Is that really what they mean about compressed sound?" This is a big mistake on my part. Knowing the description of the OS being a subtle compressor, I never bothered to listen to other compressors that does medium to heavy compression.

Fast forward. I bought a Line 6 Toneport and was one day tinkering with its effects that emulates those classic stompboxes. Tinkering with the compressors opened my ears on what a compressed sound is like. What I was hearing was like a mixed sound of a pop and the note of the guitar. I was like, "Yeah that's it. That's the sound of a compressed guitar."

So one day, I took out my OS again and was ready to give biasing another try now clearly knowing what does a compressor sound like.

Below are the steps that I did from what I remember.

1) I set the volume knob fully counter-clockwise meaning full blast on the volume.

2) Next, I used my middle pick-up and digged hard one string, one note near the bridge of the guitar while dialling the bias trim pot and doing this over and over again until I heard the cleanest compressed sound. This step was advised by someone on this forum. I forgot who. Thanks to him anyway.

3) Lastly, I did chord strumming and heard distortion so I slowly backed off the trim pot until I can hear only a little touch of distortion. I also switched to other pick-up configuration still needing to adjust the trim pot with the goal of hearing the least amount of distortion with chords. I finally settled on a setting that to me is favorable with all my available pickup configurations

[FlyingZ]

So they don't breath badly I set them where chords maintain unity and single notes get a slight boost. At 1/2 volume the lightest compression without thumping.

[Philippe]

An OS might be considered more an 'effect' than a conventional compressor. Adjustment is pretty much subjective.

Volume/gain should ramp upwards as the exterior control knob is turned clockwise (obvious of course), but here is where it can get kind of tricky.

As you turn the internal trimpot higher, the inherent 'bloom & swell' intensifies. Some call it a 'sea-sickness' sort of vibe. Distortion naturally increases as the external control knob is turned up.

A lower internal trimpot setting reduces this characteristic & the effect becomes bit more transparent, maybe a little smoother & natural to some ears.

A good usable range is around !0 o'clock to 2 o'clock on the external control knob with 10 being unity gain & moving past 2 kicking in the mild distortion.

BTW, best to set your amp at a clean volume level while doing the internal adjustment.

[igerup]

On my OS build unity gain is with the volume on max. If I set the trimpot according to that japanese schematic Mark found, that is. Probably due to  me using a different J-fet as Q2.