#ca3080

Um, what’s that all about? Yeah I dunno, something. So I was snooping around the internetz (ie, killing time at work when I damn well had other More Important Shit that needed doing) and found a site that hosts veroboard/stripboard layouts for clones of like two hundred pedals or something. Hmmmm this could be interesting, I thought.

For no reason at all, at least not one I can recall, I started my trip through that site at a page about a clone of the Emma Transmorgrifier, which is a compressor pedal that uses an old, out of production, semi-pricey but not impossible to find CA3080 chip. The CA3080 is a special kind of operational amplifier; it’s an OTA—Operational Transconductance Amplifier. I can’t really even begin to explain what’s different or special because I hardly even have a clue myself. In any case, this chip found its way into a number of devices in the music-making arena, like synths, especially in filters. Info I’ve read said that Roland used OTA based filter designs in their SH-1 -5 and -7, as well as the System 700, and anything with an IR3109 which means Jupiters and Junos, and even the JX-3P, and JUNO-106. Later generation Korg MS20s, and various synths that used Curtis filters (OB-8, Matrix-12/Xpander) also used OTA based filters.

The CA3080 didn’t just do filter duty though, as it was evidently also used in VCO and VCA circuits, and for a handful of other synthy guts jobs to boot. But that’s not all! The chip ended up in something like 90% of compressor pedals, which is what I wanted to talk about in the first place. I dunno why but I love compressor pedals, and I especially love using them on things like synths and drum machines and other weirdo gear that they were never designed specifically to play nicely with in the first place. I place the blame for my interest in using compressor pedals this way on Legowelt. I saw him talk about running his 808 through a Boss CS-3 and was like “huh?” That started it. Of course, I have a CS-3, and have modded the flying fuck out of it, and I do use it every now and then, but I was looking for something with a different flavor. Coincidentally, the CS-3 uses a VCA circuit, which gives different results than an OTA circuit. Anyway...

So the transwhateverifier looked neat and not all that hard to put together so why not? After a week all the necessary parts had been ordered (Tayda rocks the house, it’s cheaper for me to order from them and have it shipped here from overseas than to go into Osaka and buy parts). Soon afterward everything had been delivered so it was time to get busy with construction. I’d never used veroboard/stripboard, so I was a tad nervous about the whole affair at first. Making cuts and running links was easy though, and as long as you PAY CLOSE ATTENTION TO THE PLAN, you should have no problems. Actually, the pedal worked from the first time I powered it up so I was very pleasantly surprised. Here’s some photos.

The innards. I cheated and used a nifty little PCB from Tayda that makes all the connections between the stomp switch and the main PCB and the LED and everything. Fucking brilliant. I put Scotch Super 33+ electrical tape on the underside of the veroboard, just in case the line of hot glue there along the bottom that sorta attaches it to the wall of the case there comes undone. Don’t need any shorts. Coulda used longer wires to the power jack. The audio jacks are parts I cannibalized from an Alesis Photon controller keyboard I bought as “junk” when I needed knobs for the ION.

I used clear knobs and an egg-yolk pastelish yellow LED just for shits and giggles. Doesn’t look half bad really.

And lastly here’s a photo of the CA3080 I used. Neat looking old tin can of a chip!

I was so chuffed with my successful build of the compressor that I went right to the next pedal project without hardly pausing to catch a breath. An Analog Bit Crusher!!! Yeahhh!! WHAT?! Analog?! Yep. No idea what the fuck wacko bastard figured this shit out. Two bog standard TL072 op-amps and a sorta hard to get transistor (2N5457) and That. Is. It. One knob. Works like fucking magic. I’ll blab about that one once I get it in a case and all.

Here we have a Ryu vs Ken moment. On one side we have the flaming multi-hit Shoryuken, and pretty boy looks matched with a rockstar arrogance that just jumps out of the screen and infects the player. On the other side we have a disciplined and focused lifetime warrior, complete with reverence, inner calmness, a more powerful hadouken and a tatsumaki-senpu kyaku that avoids projectiles. But pit the two against each other and time after time it is shown to be pretty much an even match.

This time, Instead of Capcom, we have MXR producing the characters: two high-quality and equally non-asian looking whippersnappers just waiting to jump into the fray and wrassle it out, and in this battle I have already selected my fighter--the MXR Custom Shop Custom Comp (In an actual SF match I would choose Ken of course). You will find out that like Ryu and Ken, deep down these two pedals have the same heart and soul.

In 2010, As Street Fighter II was approaching its 20th anniversary, pedal manufacturer MXR (or is it Jim Dunlop?) discovered a stash of legendary CA3080 "Metal Can" ICs, the principal component that provided the legendary tone of the original dyna comp. Being a fervent owner of the standard block M-102 Dyna Comp (it is the only pedal I keep on ALL the time, with low sensitivity and high output) I decided to follow this trend. The 00's standard dynacomps are OK but not great compared to the original dynacomp, which sounded more open and less restricting. For $69.99 new, they are still a good deal, offering a much needed boost to the natural guitar harmonics and increased sustain with enough accompanying noise to make you consider getting a noise suppressor. They also choke your tone and give you too much squish if you max out the sensitivity. All in all, they don't even touch the tone of the original. So, MXR decided to put their supply of NOS CA3080s to work and release a new reissue pedal true to the original 1976 dynacomp specs and tone, completely handwired, and just like the original with no DC jack (battery only) or LED indicator, and of course the fancy script font. It retailed for $174 and like Ken there was a tradeoff for being the cool kid.

People greeted the '76 RI with open arms and loved the tone and lower noise levels, and for the money many even preferred the '76 RI flavor to boutiques like the Keeley compressor. A lot of people were also sending their pedals to Analogman for his mod, which added true bypass, a DC jack, and an internal LED. Falling under the camp of modern conveniences I held out for the rumored 2nd edition of this pedal.

A few months later mid 2010 we get the MXR Custom Comp. Built from the same CA3080 Metal Can IC as the '76 RI, the custom comp includes the DC jack, LED, and internal trimpots for fine tuning the pedal. It isn't handwired, and has slightly cheaper jacks and switch than the '76 RI. Also, much like Ryu, the Custom Comp isn't as flashy as its counterpart, but the guts are the same. It is also much cheaper at $129 compared to $174 for the '76 RI. I've found it for as cheap at $105 new online. Tone? Just as good as the '76 RI, the difference between the two being negligible. So there you have it: two very similar-sounding pedals with different cosmetic features and vastly different price points. Also, as of 2011, MXR no longer manufactures the '76 RI, but the Custom Comp is still in production.