Which compressor?

[Greenballs]

So, when I was a kid learning how to play guitar, write songs and be in a band I used to dream of recording in hi-tech, expensive, recording studios while I tinkered around with my Fostex X-18 4 track. Having done a bit of that I slowly came to realise that the best music isn't always created and recorded in such state of the art environments and so at the ripe old age of forty COUGH COUGH COUGH, I've decided to get the band back together again and record something low tech and low budget but with enough energy and attitude to compensate for its sonic shortcomings, if my back will hold out long enough, that is.

The reason for this preamble is that one of the pieces of kit that I've decided I can't do this without is a compressor, hence my trawling the interweb tonight for a cheap quad comp that will enable me to compress overheads and bass guitar etc... The cheapest I could find was a second hand Samson for £80, which seemed like a decent enough piece of kit for the money but which then got me thinking, is that cheap and nasty enough and could I build four compressor circuits for less than £80?

My first thought was that the Orange Squeezer +++ might do the trick, plenty of control and a fairly low parts count, but then again maybe the Keeley four knob comp might be more suitable despite the higher parts count? Or maybe something even simpler than the OS+++?

My question is, have any of you ever recorded with a stompbox compressor on anything other than guitar/bass guitar (drums and vocals particularly) and if so, what was the comp and how did it go?

[GGBB]

What is your goal here - decent quality on a budget or using something that you build yourself? You should be able to find used gear for well under $100 that would seriously outperform the typical guitar pedal compressor. E.g. https://reverb.com/item/62037484-presonus-acp-22-stereo-compressor-limiter-church-owned-cg00l9q.

[Greenballs]

What is your goal here - decent quality on a budget or using something that you build yourself? You should be able to find used gear for well under $100 that would seriously outperform the typical guitar pedal compressor. E.g. https://reverb.com/item/62037484-presonus-acp-22-stereo-compressor-limiter-church-owned-cg00l9q.

Obviously, I'd like the final recordings to be listenable but by the same token I like the idea of working within the limitations of what I already have available to me and what I can realistically afford, with inflation in the UK at over 13% currently (don't get me started on that situation...). There's a strong DIY ethos with this project and I thought it would be nice to extend that to the kit used to record it. I'd love to be able to build four 1176's but I'm afraid the parts count is a little high to make it viable (also, the first nine words of this sentence), hence my looking towards less complex circuits.

I may well buy a rack mounted comp but thought this idea worth exploring and throwing out there to see if anyone has experience of using stompbox comps in unconventional ways.

[amz-fx]

I wrote several articles about compressors that you can see at:

http://www.muzique.com/lab/compz.htm

tl;dr - build a Dynacomp clone. The Orange Squeezer requires selecting a jfet that has the right properties to make the compression work well, and that can be a little tricky. The Dynacomp needs a CA3080 chip, which has limited availability, but it can be found at several of the pedal parts suppliers.

Best regards, Jack

[merlinb]

The Dynacomp needs a CA3080 chip, which has limited availability, but it can be found at several of the pedal parts suppliers.

LM13700 also works fine.

[Greenballs]

I wrote several articles about compressors that you can see at:

http://www.muzique.com/lab/compz.htm

tl;dr - build a Dynacomp clone. The Orange Squeezer requires selecting a jfet that has the right properties to make the compression work well, and that can be a little tricky. The Dynacomp needs a CA3080 chip, which has limited availability, but it can be found at several of the pedal parts suppliers.

Best regards, Jack

Thanks for the link Jack, I read all three parts with interest. I found it interesting that the Orange Squeezer, despite its reputation for being quite a subtle compression effect by comparison, is the same type of circuit as the Dynacomp, which by reputation is a little more 'pumpy'. However, my main takeaway was that your Q&D 2 Compressor sounds to me like it would be the best of all worlds! Although, it looks like SMM2166 chips are thin on the ground these days and I've been unable to source a replacement/equivalent chip so I just might take your advice and go with the Dynacomp using the LM13700 as merlinb suggests.

[merlinb]

I found it interesting that the Orange Squeezer, despite its reputation for being quite a subtle compression effect by comparison, is the same type of circuit as the Dynacomp

Orange squeezer is a minimalist FET compressor, I wouldn't call that the same type as the Dynacomp which uses an OTA?

[Fancy Lime]

Or, to toot my own bassoon, this thing:
https://www.diystompboxes.com/smfforum/index.php?topic=128094.40#msg1251519

A FET-based limiter similar to the dynacomp or DOD250 in character. Doesn't need FET matching or selecting and has no hard to get parts.

Andy

[Greenballs]

I found it interesting that the Orange Squeezer, despite its reputation for being quite a subtle compression effect by comparison, is the same type of circuit as the Dynacomp

Orange squeezer is a minimalist FET compressor, I wouldn't call that the same type as the Dynacomp which uses an OTA?

According to Jack's article, both are peak limiting circuits (as oppose to peak compression circuits a la the Keeley Comp Pro referenced in the same article) which is what I was referring to. Yes, they might have different ways of getting there but the effect ultimately does the same thing by the same means.

[moosapotamus]

The LA Light is a bit of a blast from the past...
https://www.diystompboxes.com/smfforum/index.php?topic=30106.0

The circuit is quite simple and it was designed specifically with vocals in mind, while also capable of doing a stand-up job with instruments as well. The links in the post linked above are broken (posted before my .com was ripped off), but they are updated on this page...
http://moosapotamus.net/fatNpretty.html

For recording, I would go with Johan's original and simpler design, LA-Light, rather than my modded stompbox version. The transistors are J201. Looks like synthcube's smallbear parts shop may have some.
https://synthcube.com/cart/index.php?route=product/search&search=j201&description=true

[/memories]

[Greenballs]

The LA Light is a bit of a blast from the past...
https://www.diystompboxes.com/smfforum/index.php?topic=30106.0

The circuit is quite simple and it was designed specifically with vocals in mind, while also capable of doing a stand-up job with instruments as well. The links in the post linked above are broken (posted before my .com was ripped off), but they are updated on this page...
http://moosapotamus.net/fatNpretty.html

For recording, I would go with Johan's original and simpler design, LA-Light, rather than my modded stompbox version. The transistors are J201. Looks like synthcube's smallbear parts shop may have some.
https://synthcube.com/cart/index.php?route=product/search&search=j201&description=true

[/memories]

Cool! Thanks very much for that, I'll definitely have that on the breadboard over the weekend. I take it the op-amp can be one of several options or is there a specific op-amp that Johan used/works particularly well?

[moosapotamus]

I used NE5532 in my stompbox version. TL072 or similar would probably do as well.

[Greenballs]

I used NE5532 in my stompbox version. TL072 or similar would probably do as well.

Thanks!

[moosapotamus]

Also, I probably used a VTL5c3 for the vactrol, but other similar or 'roll-your-own' should work, too.

[Greenballs]

Also, I probably used a VTL5c3 for the vactrol, but other similar or 'roll-your-own' should work, too.

Thanks for the info, I'm going to start with the roll your own variety but its good to know there's a back up plan if I need it. And if I wanted to add a VU meter to show gain reduction where might be the best place to hook it up?

[moosapotamus]

Johan's last revision had a VU meter. I must have lost the scheme in one of my past traumatic hard drive crashes. But I was able to dig it up on the wayback machine...
http://moosapotamus.net/images/LA_Light_last_one_001.gif

Also this...
https://www.diystompboxes.com/smfforum/index.php?topic=64291.0

[GGBB]

I just might take your advice and go with the Dynacomp using the LM13700 as merlinb suggests.

In that case, maybe Merlin's Engineer's Thumb is a better choice than a Dynacomp.

https://www.diystompboxes.com/smfforum/index.php?topic=97123
http://www.valvewizard.co.uk/engineersthumb4.html

[Greenballs]

Johan's last revision had a VU meter. I must have lost the scheme in one of my past traumatic hard drive crashes. But I was able to dig it up on the wayback machine...
http://moosapotamus.net/images/LA_Light_last_one_001.gif

Also this...
https://www.diystompboxes.com/smfforum/index.php?topic=64291.0

Thanks mate. Am I right in thinking that Johan replaced the Jfets with a second opamp? Also, there's two LEDs and two LDRs there, how are they arranged in practice? All lumped together or separated in pairs?

[Greenballs]

I just might take your advice and go with the Dynacomp using the LM13700 as merlinb suggests.

In that case, maybe Merlin's Engineer's Thumb is a better choice than a Dynacomp.

https://www.diystompboxes.com/smfforum/index.php?topic=97123
http://www.valvewizard.co.uk/engineersthumb4.html

Yep, its definitely on my list of compressors to try.

Currently my list is:

Engineer's Thumb
LA Light
Q&D 2 (I managed to source two SMM2166 chips).
Level Lacquer V3.7

[moosapotamus]

Thanks mate. Am I right in thinking that Johan replaced the Jfets with a second opamp? Also, there's two LEDs and two LDRs there, how are they arranged in practice? All lumped together or separated in pairs?

An additional opamp was added for the VU meter, so adding a dual opamp (or replacing all with a quad) leaves one spare opamp which looks to have been used to buffer the bias voltage. It appears the Jfet stage was simply removed and not replaced with anything.

There are some comments about the LEDs and LDRs in that old thread that I linked to. My interpretation is that they need to be lined up and placed as closely together as possible. But read for yourself and see what you think.