BAJA Wet Cat analog delay (mini version)

KindaFuzzy · Post by **KindaFuzzy** » 05 Mar 2009, 00:11

That's way neater than mine, looks killer dude. If anyone else wants a half guessing, non-engineer explanation of the calibration, drop me a line.

Fuzzer · Post by **Fuzzer** » 05 Mar 2009, 23:47

Why don't you post it?

KindaFuzzy · Post by **KindaFuzzy** » 06 Mar 2009, 00:25

That's probably a better idea, here are the emails between sfx and I which are mostly about where terminal pin 7 was on the layout:

"I figured it out after looking at a pic of an actual boss dm-2, there's a wire coming off the board labeled 7. It's where F3 and M3 come off the board on baja's layout, so stick your probe on either one of the pot lugs or where the two wires come off the board. I calibrated mine with a 1K sine wave and it was pretty obvious when you have the setting right if you look at the two waves on the dual trace setting on your scope, just keep tweaking till the waves look the same. The max delay time I did by ear, just turn until you can't hear a whine from the clock anymore with the pedal hooked up to an amp. The clock leakage cancel wasn't so obvious, and you could kind of see two waves that moved when the trim was moved, but anywhere in the middle of the trim sweep seemed close enough, so that the two waves overlapped. Mine sounds good even with that setting being kind of a guess.

Hope this helps, this was the first time I've ever used a scope."

This is the second email response when asked about the clock cancel and the dm-2 manual being a little confusing:

"You know what, I'm not sure. The way I did it was just at the wiper of the trim pot, since it's in the middle between the two output pins on the 3005. The instructions seem like a bad translation from Japanese, but I read it to say that you want the clock wave and the output wave to overlap, so that the clock wave is as hidden as possible by the output wave(which would be the clean input wave, "no input read"). I'm guessing the two output pins on the 3005 give off slightly different signals, one "clock" and one "input" and the trim is just like a balance pot between the two. No input read, no clock read, just one balanced output.

But really, I twisted that trimmer while it was hooked up to an amp to see if I could hear a difference, and that one didn't really matter, somewhere in the middle of the trim sweep was fine."

I'll see if I can take some pics of the oscilloscope during each step as sort of a tutorial for others like me that have never used a scope before, maybe I made a mistake and someone with a little more experience can jump in.

KindaFuzzy · Post by **KindaFuzzy** » 06 Mar 2009, 01:47

http://www.flickr.com/photos/35422385@N ... 782147623/

Here's some pics of my scope during pedal calibration. Feel free to criticize and correct, I was just guessing most of the time, I'm a scientist not an electronics engineer. I put an explanation under each picture in the album.

quaternotetriplet · Post by **quaternotetriplet** » 12 Mar 2009, 00:59

hi baja, Are there any sibstitute for sa571n and op275g??.

Post by **abfackeln** » 12 Mar 2009, 10:45

quaternotetriplet wrote:hi baja, Are there any sibstitute for sa571n and op275g??.

You can probably use an LF353N (Mouser part # 512-LF353N), which is what the AP uses, in place of the OP275.

quaternotetriplet · Post by **quaternotetriplet** » 13 Mar 2009, 12:19

I'm a noob. what is the calibration thing??

again sorry

Post by **abfackeln** » 13 Mar 2009, 23:40

quaternotetriplet wrote:I'm a noob. what is the calibration thing?? again sorry

A delay pedal is a different animal than, say, a distortion or orverdrive pedal.

With a distortion/overdrive/fuzz, etc. pedal, you solder your parts, wire it up, plug in and play.

With a delay, there are internal trimpots that need to be dialed in to set the bias to the delay chip, the clock speed (how much delay you actually get out of the chip), and noise cancellation, before you get any delay out of the pedal. That's my "ignorant" version.... someone here could probably explain a lot better...

Not impossible to do without an o-scope, but most likely better results if you do use one.

I'm putting together some instructions on how to set it up (without a scope), that I'll be posting in the Aqua Puss thread in the Boutique Stompoxes section of the forum, as I imagine there's several people (like me) that don't own a scope, and may have never set up a delay before.

quaternotetriplet · Post by **quaternotetriplet** » 14 Mar 2009, 00:53

NIce I'll probably wait for that before ordering the materials. thanks

sfx · Post by **sfx** » 14 Mar 2009, 04:23

This pedal isn't too hard to calibrate actually and you *should* be able to get it set pretty good, even without a scope. (Once you decipher Boss's instructions that is)

Here's some tips, some of this is a rehash of KindaFuzzy posted above...

- The delay knob on the Aqua Puss/Wet cat works opposite compared to the DM-2, meaning you get the longest delay times with the delay knob all the way clockwise versus counter clockwise on the Boss. You can set the related trimpot without a scope by setting the trimmer as to where you don't hear any whine/noise comign from the clock.

- The knobs for the Feedback and Mix are switched when comparing the standard Aqua Puss to the DM-2. Feedback is the middle pot and Mix is one on the far right on the Puss, on the DM-2 these are switched. Keep that in mind when calibrating.

- BBD bias is pretty easy to set manually as well. Center the bias trim to the middle and tweak slightly either way. Once you move past a certain point in either direction the pedal will stop producing delay. The sweetspot is somewhere around center of the trim.

- Clock cancel is the same, I doubt you get this perfect without a scope but the sweetspot again will be somewhere around the center of the trim.

Keep in mind as well that Baja's layout currently has a couple of small errors on it. the two 22n caps by the compander should be 220n and the orientation of Q4 should be flipped around. The pins for EBC are correct though.

Hope that helps... its not so bad.

lautmaschine · Post by **lautmaschine** » 14 Mar 2009, 07:18

Finally got mine wired up today and calibrated by ear.

one thing that doesn't seem right to me is the feedback control. It gets way too wild on me before 12 o'clock. Looking at the Boss schematic, I see there's a polarized .1mF coming off the 2nd lug of the feedback pot. I've put a non-polarized .033 cap as per Bajaman's layout. I might play around with this to see if I can get something more manageable.

JimiB · Post by **JimiB** » 14 Mar 2009, 16:02

pretty sure the .033 is a mistake there - I imagine it was a .33 - there are some clear examples of .22 and the boss used a .1 I would try a .22 and see what happens - also are you using a 10K or a 50K pot?

lautmaschine · Post by **lautmaschine** » 14 Mar 2009, 17:26

I don't have any .22's around, so I stuck in a .1 and it made little difference, if any. Using a 50K linear pot...

Kev77 · Post by **Kev77** » 14 Mar 2009, 21:05

where do you source your parts, im in nz too - any ideas?

bajaman · Post by **bajaman** » 14 Mar 2009, 21:25

capacitor values are correct fior WET CAT (cannot mention real name

) - (not for BOSS DM-2)
22n is now corrected to 220n - refresh your browsers

where do you source your parts, im in nz too - any ideas?

http://www.futurlec.com

cheers
bajaman

rocklander · Post by **rocklander** » 14 Mar 2009, 22:57

Kev77 wrote:where do you source your parts, im in nz too - any ideas?

welcome to the forum Kev...

sfx · Post by **sfx** » 15 Mar 2009, 02:13

Kev77 wrote:where do you source your parts, im in nz too - any ideas?

FWIW Banzai Music in Germany has all the IC's except for the MN3005.

lautmaschine · Post by **lautmaschine** » 15 Mar 2009, 04:49

Mine's just died on me.

Would someone be so kind as to post voltages? I've gone and messed something up here.

Kev77 · Post by **Kev77** » 16 Mar 2009, 08:16

rocklander wrote:
Kev77 wrote:where do you source your parts, im in nz too - any ideas?
welcome to the forum Kev...

thanks brother - i raise my soldering iron in your honour

bbrunskill · Post by **bbrunskill** » 08 Apr 2009, 23:14

Kev77 wrote:
rocklander wrote:
Kev77 wrote:where do you source your parts, im in nz too - any ideas?
welcome to the forum Kev...
thanks brother - i raise my soldering iron in your honour

I'll just chirp in to say 'hello, boys' in a flirty way.