better compressor pedal??

[merlinb]

Well, I do have an oscilloscope, so if you want to tell us more about it...
How should it be biased?

Fair enough! You need to disable the side chain so the FET can be manually controlled.

Easiest way is to short the 100k feedback resistor on U1b.
Set postgain to zero resistance.
Set ratio to zero resistance.
Input a suitable test tone; level is not important provided it doesn't clip. Say, 100mVpk, 1kHz, ish.
Monitor the input and output waves and adjust the bias until the output amplitude is equal to the input.

That's it! For anyone without a scope they'd have to switch back and forth between the effect and bypass, and adjust the bias by ear for equal loudness.

I will try and make a sound clip this weekend.

[roseblood11]

The MXR Sustain Unit is more interesting than the Dynacomp and its derivates. But I couldn´t find a schematic for it. Someone just started a retracing thread over at the other forum...
That would be my first choice for a strong, audible sustain effect.

For decent sound improvement, esp for clean sounds, I really like the Demeter Compulator (see: Baja Compulator). Or have a look at Bajamans Optical Limiter.

[mr_deadmaxxx]

I own a Dynacomp, Orange Squeezer, and a DOD.

My personal favorite is the Orange Squeezer. It warms up the sound a bit and squishes it in a very reactively pleasant manner that works beautifully with clean, whether it be plucking with fingers, using a slide or using a pick. It sounds nice on pedal steel as well. Works great on all pick ups. It doesn't seem to play well with overdrives though, IMHO. It's a fun sounding compressor though that you definitely can hear working when it is on.

Dynacomp sounds like the inbetween of the DOD and the Squeezer. It has a nice squish, but doesn't overly color the tone. Not totally transparent, but not warm like the OS either. It has a fairly fast attack and a long release that is similar to the OS. It works better before an overdrive than the OS due to the limited tonal coloration. I've used it on a number of recordings, but it is never my first choice in any situation.

The DOD is very transparent and is what is currently on my effect board. I just leave it on all the time for live. It is definitely the "Can't tell if it's even on until I turn it off" compressor of the bunch. Works very well in conjunction with other pedals.

If I had the room, I'd put both the orange squeezer and DOD on my pedal board because there are times where I wish I had the OS for clean parts. But for me because I use a lot of overdrive and I want to control the overall dynamics of my playing all the time, the DOD wins.

OS not good for distortion??

[FlyingZ]

OS not good for distortion??

I thought the same

[slideman82]

The Orange Squeezer has a very light tube-ish overdrive that works great with single coils.

I think the same, it's quite clean, but yo better place 2 pots (I think vol and compression), and use a high gain JFET as a j201 or a 2sk117. Also you could try the DOD 280. They are the simplest!

[thedefog]

OS not good for distortion??

I thought the same

I find it makes my overdrive/distortion pedals too farty/boomy on the low end and that the individual note playing is a little on the muddy side for my tastes. That's using a Alnico 2 pro bridge humbucker in a telecaster going into a 68 twin reverb.

[ryanuk]

I suppose when deciding on a build you should read some reviews, try out some in shops, and match your needs and expectations to a pedal. That way you're ound to get close to what you want on the first try.

For me there are kinda 2 types of compression.

First is one thats very sustained, very "squishy", and fattens up the tone i.e. dims the highs and adds balls (not really an expectation from compression I know but useful none the less). It has a pronounced sonic "effect", like the Dyna sound byte on the dunlop site. Personally I associate these squished sounds best clean/jangly tones and chording. If used on a high gain pedal/am channel, I find it cuts too much out of the sound as others have stated.
If this is what your after, I would go for a Dynacomp, Ross or Orange Squeezer.

The other compression I use is more for "feel" than sound if that makes any sense. (Alike many others) I have a comp on all the time. Sustain is set very low - just so you can barely hear the "wall" kick in when you really attack the strings (apologies - cant think how to describe it but hopefully you know what I mean). Volume I set just above unity. I find it evens out the sound and balances out the difference in string volumes etc, especially when I switch from pick to fingers and am playing on the higher strings/higher registers. Im not sure compressors are design to balance out levels across the strings, but it works for me!! These "transparent" compressors translate to distorted and clean base sounds.
For these senarios I would go with a Compulator, Philsophers Stone, Ibanez CP9, Boss CS2/3 or Marshall ED-1 (I hear these are pretty good provided you get one which will last).

My personal favorite is a DOD Milk Box. Its not an popular choice but they are FANTASTIC boxes. You can still buy the odd one for £50. Not sure they still make them.
I believe it shares the same typology as the CS2, CP9 (therefore Ross/Dyna to some extent), however, it covers a lot of ground. It can do the transparent thing, and the effected squishy sounds also. I've also had recent success with a Compulator clone built from a project at f r e e s t o m p b o x e s. This is great great great natrual sounding and versatile optical compressor.

My $0.02, or pence as im in UK.

Ry

[alfio]

For me there are kinda 2 types of compression.

First is one thats very sustained, very "squishy", and fattens up the tone i.e. dims the highs and adds balls (not really an expectation from compression I know but useful none the less). It has a pronounced sonic "effect", like the Dyna sound byte on the dunlop site. Personally I associate these squished sounds best clean/jangly tones and chording. If used on a high gain pedal/am channel, I find it cuts too much out of the sound as others have stated.
If this is what your after, I would go for a Dynacomp, Ross or Orange Squeezer.

The other compression I use is more for "feel" than sound if that makes any sense. (Alike many others) I have a comp on all the time. Sustain is set very low - just so you can barely hear the "wall" kick in when you really attack the strings (apologies - cant think how to describe it but hopefully you know what I mean). Volume I set just above unity. I find it evens out the sound and balances out the difference in string volumes etc, especially when I switch from pick to fingers and am playing on the higher strings/higher registers. Im not sure compressors are design to balance out levels across the strings, but it works for me!! These "transparent" compressors translate to distorted and clean base sounds.
For these senarios I would go with a Compulator, Philsophers Stone, Ibanez CP9, Boss CS2/3 or Marshall ED-1 (I hear these are pretty good provided you get one which will last).

I completely agree on this distinction.
This also explains why I like the Carl Martin: is the only one I found good for both.

[FlyingZ]

OS not good for distortion??

I thought the same

I find it makes my overdrive/distortion pedals too farty/boomy on the low end and that the individual note playing is a little on the muddy side for my tastes. That's using a Alnico 2 pro bridge humbucker in a telecaster going into a 68 twin reverb.

It's the only one I can use with distortion albeit not too often. Just goes to show the many variations in guitar amp combos.

[Mark Hammer]

Some very good comments here.

I think the biggest challenge in producing a "good" guitar compressor sound is that the full bandwidth of the guitar is not equally represented across the lifespan of any picked note or strummed chord.  Most of the treble content is packed into that initial transient that gets pushed down hard, while the content that gets brought back in over time is largely low end.  Were it the case that the spectral content were constant, then you could imagine how to set the various controls that shape the rectification and control signal.  But even if you have an Attack and Release control (and this is not to take anything away from merlinB's excellent design), the Release is addressing different spectral content than the Attack is.

That's not an insurmountable obstacle, but it IS a tough one for all single-band guitar compressors to grapple with.

[Paul Marossy]

The best compressor for me is NO compressor.

[Mark Hammer]

I hear ya, but I will also affirm that, over the years, some of my very best and most luscious and fascinating guitar tones have relied on compression.

[Paul Marossy]

I hear ya, but I will also affirm that, over the years, some of my very best and most luscious and fascinating guitar tones have relied on compression.

I like natural compression from tubes. Whenever I use a compressor pedal, I feel like I am driving a vehicle with a governor on it that takes all the power out of the vehicle. It dampens all the dynamics in my playing. 

I will say that of the ones I have built/used, I think I like the Orange Squeezer best because it's kind of a subtle effect compared to my Boss pedal which is like throwing a wet blanket on a fire. 

[Mark Hammer]

Depends how you want to think of "dynamics".  For instance, I like being able to modulate the sound of the guitar, and how the tone varies with pick attack, without having to have robust volume changes come along for the ride.  Not every single time, to be sure, but at least sometimes.  There is a reason why folks who like to play a clean-as-a-whistle Tele love compressors.  You can get that snap off the bridge without distracting people by an ice-pick through the forehead from the amp.

Will too much compression destroy one's capacity to elicit qualitatively different overdrive tones, via pick attack, whether from an amp or pedal?  You betcha.  But like I say, that's not the only cotext where you might want to use one.

I think they're great for being able to go crazy on rhythm guitar without accidentally over-shadowing a singer.

It would actually be kinda neat to be able to use one foot-pedal to vary both compression and output level simultaneously.  That is, pull pack and the amount of compression increases but the output level is decreased, so you're "there" in the background, but you don't get lost.  Then when solo time approaches, you treadle forward and the dynamics get gradually restored as the volume gets upped.

[Paul Marossy]

Depends how you want to think of "dynamics".  For instance, I like being able to modulate the sound of the guitar, and how the tone varies with pick attack, without having to have robust volume changes come along for the ride.  Not every single time, to be sure, but at least sometimes.  There is a reason why folks who like to play a clean-as-a-whistle Tele love compressors.  You can get that snap off the bridge without distracting people by an ice-pick through the forehead from the amp.

Yeah, they have their uses. I see a compressor as a limiter. I use a volume pedal to control my output level and am very sensitive to how loud I am in comparison to everything else and have been doing this for at least ten years now, so I'm quite used to it. So in that way, I am my own compressor, without any limiting or loss of dynamics in my playing.  

[BoxOfSnoo]

Some very good comments here.

I think the biggest challenge in producing a "good" guitar compressor sound is that the full bandwidth of the guitar is not equally represented across the lifespan of any picked note or strummed chord.  Most of the treble content is packed into that initial transient that gets pushed down hard, while the content that gets brought back in over time is largely low end.  Were it the case that the spectral content were constant, then you could imagine how to set the various controls that shape the rectification and control signal.  But even if you have an Attack and Release control (and this is not to take anything away from merlinB's excellent design), the Release is addressing different spectral content than the Attack is.

That's not an insurmountable obstacle, but it IS a tough one for all single-band guitar compressors to grapple with.

I find with my OS, if I lower my guitar volume a touch - and I have a treble bleed cap - it brightens up considerably.  It's kinda counterintuitive though, if you want to cut through more and have more presence, you have to turn down a bit.

Sorta like getting your best, crispest clean sound by turning on a fuzz pedal

[auden100]

merlin, I was wondering if your ratio pot acted kind of like a blend control in between the effected signal and the clean signal.

I made a Ross comp a while back, and had to add a blend control to it to get back some of my highs. Have you heard a Ross comp, and would you be able to make any tonal distinctions between the two?

Thanks

[Ripdivot]

Well, I do have an oscilloscope, so if you want to tell us more about it...
How should it be biased?

Fair enough! You need to disable the side chain so the FET can be manually controlled.

Easiest way is to short the 100k feedback resistor on U1b.
Set postgain to zero resistance.
Set ratio to zero resistance.
Input a suitable test tone; level is not important provided it doesn't clip. Say, 100mVpk, 1kHz, ish.
Monitor the input and output waves and adjust the bias until the output amplitude is equal to the input.

That's it! For anyone without a scope they'd have to switch back and forth between the effect and bypass, and adjust the bias by ear for equal loudness.

I will try and make a sound clip this weekend.

Hey Merlib I don't have any J112 FETs so what other common FETs would work well in this circuit?

[petemoore]

  Mass on a spring compression...speaker !
  Pneumatic compression...the Enclosure !
  These two can be made so they work together and provide very compression.
 

[merlinb]

merlin, I was wondering if your ratio pot acted kind of like a blend control in between the effected signal and the clean signal.

Not really. It simply reduces the amount by which the signal is attenuated when the FET turns on.

I made a Ross comp a while back, and had to add a blend control to it to get back some of my highs. Have you heard a Ross comp, and would you be able to make any tonal distinctions between the two?

Sorry, I've never heard that pedal in person. My circuit is deliberately designed to be low distortion and wide bandwidth, because I wanted it to be suitable for bass/keyboard/voice etc ('universal'). Maybe the Ross is meant to be a bit more 'coloured' and 'guitar specific'?

Merlib I don't have any J112 FETs so what other common FETs would work well in this circuit?

Anything with an average Vgs(off) of less than 3V. J113 and 2SK30A should work. Be prepared to try more than one sample though, whatever kind of FET you use.