Compressor recommendations?

[LaceSensor]

Hi

I want a simple to build and use compressor, that wont overtly colour my sound, just add sustain, and if possible not diminish any attack (preferably add some if thats possible?)

Any recomendations?

Thanks

[midwayfair]

Hi

I want a simple to build and use compressor, that wont overtly colour my sound, just add sustain, and if possible not diminish any attack (preferably add some if thats possible?)

Any recomendations?

Thanks

What's your guitar, Lace?

I have ... a few ... suggestions.

[jtn191]

I haven't played/built as many as Jon but I'd recommend a Ross style compressor. Sounds good and it's not optical. Keely's 4-knob compressor is based on the Ross.
I played a friend's "custom compressor"...sounded sweet; opened it up and found out it was most likely a Ross compressor with Attack pot.

[oldhousescott]

The Orange Squeezer and variants are pretty neutral sounding. If you could mix in some direct signal, that would help keep the attack.

[RobA]

I've got a BBE compressor that's Ross clone with an attack knob. I like it. The OTA to make these are a bit pricey now though.

I have an EHX Black Finger compressor that I love. But, it would probably be a pain to do as a DIY. It would be cool to have the sound of the thing minus some of the EHXiness of it though.

[LaceSensor]

Hi

I want a simple to build and use compressor, that wont overtly colour my sound, just add sustain, and if possible not diminish any attack (preferably add some if thats possible?)

Any recomendations?

Thanks

What's your guitar, Lace?

I have ... a few ... suggestions.

I have a bunch of guitars but it needs to work with a JMascis Jazzmaster and a Corgan Stratocaster as thats what I mostly use for band duties.

cheers!

[LaceSensor]

might look into an orange squeezer with a blend then
I have some ca3080s if thats what they use...?

[Effectsiation]

Orange Squeezers use 4558s, the Dyna/Ross ones use CA3080s.

The Orange Squeezer is a pretty simple (read: low part count) build, I think everyone should build one, because even if they aren't your cup of tea for a compressor they make a great "warm boost". The only non-standard part on them is the 1N100 diode, but all reports say that any Germanium diode gets you the same sound. Although, Effects Connection (also on eBay) sells them if you decide you want them.

DISCLAIMER: I still haven't gotten around to building a Dyna/Ross, but I have a Boss CS-2, which I believe is the same circuit (and it's been my favorite "stock" compressor for years).

[midwayfair]

This is kind of a long post, but hopefully it'll be informative.

I use FET comps almost exclusively, usually an Orange Squeezer life. FET comps (Orange Squeezer, Rothwell, my Bearhug) have an extremely fast attack and generally have a short release. They tend to round off the edges of the notes, and the decay rarely is long enough to carry over between notes. But once your signal crosses the threshold to really get some compression, it reacts like tube amp sag: it's the "duck and swell" effect. (I like to refer to Orange Squeezers as a tweed emulator because of this effect.) I don't really recommend a FET design in your case. You say in your original post that you want it to "not diminish any attack" -- basically, you probably need something with a slightly longer attack. The good FET comps tend to sound very transparent. They typically don't compress very hard, also (there's an exception to this at the very end of the post). You may want to make one -- they're cheap and easy -- just to compare, but it's probably not the ideal choice in your case.

Ross and Dynacomp type compressors tend to be more in the "sustainer" camp. It's a very specific effect, where long runs of notes are compressed to a very similar dynamic range, and longer notes will have a lot of percieved sustain as the hold cap drains. Despite what most posters in this thread has said, I highly recommend against a Ross type compressor specifically. OTA chips are noisy, and the Ross's feeback design essentially puts the OTA in the audio path and all that noise it makes is amplified. This is why people complain that compressors are "noisy." I know a bunch of people are going to come on and say that the noise isn't that bad ... and it's not compared to something like a high-gain overdrive ... but once you hear a compressor that doesn't make it's own noise, you can't stop hearing what the Ross is doing.

MerlinB's Engineer's Thumb does literally EVERYTHING you can do with a Ross or Dynacomp, but does it better and uses a quieter OTA chip (the LM13700) AND puts it in the feedback loop in a feed-forward design, so the only way to increase the noise is to increase the total amount of guitar signal, and by then, the original signal is amplified so far above the noise floor of the chip itself that you can no longer hear the noise.

But I specifically recommend against them in your case. Dyna/Ross Comps also tend to have an extremely long decay and shoot for a fast attack. The attack is not as fast as a FET compressor usually, but it's similar. However, because these designs tend to compress harder, they really don't leave your attack untouched. You'll have the first note in the run with a noticeable attack and then everything after that will be compressed. You can shorten the decay, but the resulting "pumping" is horrible.

Finally, there's optical compressors. I saved this for last because I really think it's the best choice for you. Start with the Afterlife. For the most part, it doesn't get any better in optical compressors, despite (or because of?) the simplicity. The behavior of the compressor is very good; there's almost no carry over between notes, which generally means that your attack will never be messed with unless the compression is just set too high for any given guitar. Optical compressors have a limitation, though: although you can play with the threshold and decay, the attack is limited by the vactrol itself.

Fortunately, all vactrols have a slightly sluggish attack that generally makes them sound pretty natural. The very front of the note (usually a couple wave cycles) gets through to the amp because the vactrol just can't turn on fast enough to catch it. If you pick a vactrol with a faster turn-on time, and it may actually enhance the attack just slightly because it'll turn on harder at a point where the original note is naturally still louder, giving the illusion of some extra "pluckiness" when it ducks the signal a little. I've used the VTL5C1 instead of the VTL5C3 and this seems to work out in practice. The 5C3 sounds the most natural to me overall.

So that's my primary suggestion: An Afterlife built with a VTL5C1.

I have another recommendation, but it's a little more work. I built this recently (and will be posting a demo later today):
http://circuitsaladdotcom.files.wordpress.com/2012/11/mosfet-compressor1.gif

The actual behavior of the compressor is spectacular, and it's also pretty unique (I've never seen a MOSFET as the variable resistance element before). It's capable of even extreme compression without losing a natural-sounding attack (it's VERY punchy), and the decay never carries over across multiple notes the way it does in something like a Ross/Dynacomp. The only issue is that it has some pretty hefty perceived treble loss and therefore it DOES darken your tone a little. Unfortunately I didn't breadboard it ahead of building to try and find ways to solve this, but I think you can put a cap across R1 and maybe also increase R3 and R4. I would need to experiment. I think if this issue were solved, it would be a contender for best in show.

[midwayfair]

DISCLAIMER: I still haven't gotten around to building a Dyna/Ross, but I have a Boss CS-2, which I believe is the same circuit (and it's been my favorite "stock" compressor for years).

CS-2 isn't a Ross. It's actually a really cool circuit. RO Tyree broke it down here:
http://www.diystompboxes.com/smfforum/index.php?topic=99682.0

Lace, I forgot to mention in my post that this thing also exists:
http://www.smallbearelec.com/servlet/Detail?no=234

I have one at home and breadboarded it, but I haven't soldered it up yet. It sounds good, very tweakable and it has a built-in gate. It's actually meant for microphones.

[LaceSensor]

Thanks for that it was a useful read.
I already have the Flatline compressor, but at the time I made it I didnt have germanium diodes, so used 1n4148s haha, it works pretty good though. I also rolled my own vactrol for that. This was over a year or so ago.

Maybe I will make another one, properly.

[GermanCdn]

Build the Flatline/Afterlife with a Vactrol, the difference is quite noticeable.  It's a great comp.

My personal go to always on compressor is the Barber Tone Press, don't think there's a circuit in the DIY realm for it yet.

Just finished boxing up Jon's/Josh's Bearhug comp, very nice compressor as well, and the beauty of it is it doesn't require any parts you wouldn't normally use for 90% of build out there (i.e. no 3080's or Vactrols.