freestompboxes.org

Guess what showed up in the mail today:



Lots of smd, and a mn3007. Sounds very seasick, not as organic as the other vibratos I've done so far, but is pretty cool if you're into extreme effects. Those smd resistors look like they'll be a bit of trouble figuring out values for, but should be doable, any tips would be welcome, and there's more pics in my flickr: http://www.flickr.com/photos/35422385@N ... 693020938/

Thanks KindaFuzzy!

Since I built your Vibrostomp layout, I've caught the vibrato bug

Anyways, this doesn't look too complex. They mighta' coulda' done it without SMD, you think? I'm sure they have their reasons.

nice. i really like this thing.
looking to opamps it may be a small clone derivate

Good call dude, after googling the chips, the tonepad small clone project came up, which I used to trace it, and it's almost an exact copy. It's missing the 22k clean blend resistor which makes it a vibrato, but funnily enough has a spot where it's supposed to be on the board just beside the 4558, so if you don't like the vibrato, you can put a resistor in there and get a phaser. It's also got an added input pull down resistor. I think some of the values in the oscillator are different, since it's a 100k pot instead of the 1M, and some of the resistances from pins 3 and 6 to ground were a little lower, but the stock values should work fine.

I'm glad I had a schematic to trace from, this would have been near impossible without knowing what was supposed to be connected to what.

cool. i'm happy i helped you.
i really like the small clone. i tried removing the 22k resistor but the vibrato it's not as nice compared to this pedal.
i think the speed pot is 100k to keep the vibrato usable.

Really? A small clone? I thought it was a clone of the Boss VB-2.

DWBH wrote:Really? A small clone? I thought it was a clone of the Boss VB-2.

Small Clone modded for vibrato can sound very similar to the VB-2.

Here's a vibrato comparison thread I posted at HCFX a while back.
http://acapella.harmony-central.com/sho ... highlight=

small clone vibrato seems more extreme to me.
whatever, i'm dying to know how it's done inside.
i'd like to mod my small clone

KindaFuzzy wrote:It's missing the 22k clean blend resistor which makes it a vibrato, but funnily enough has a spot where it's supposed to be on the board just beside the 4558, so if you don't like the vibrato, you can put a resistor in there and get a phaser.

So then that would be the Melekko Omicron Phase, I take it?

I think the 22k resistor is the only difference between the two omicron pedals. I don't have a 3007 to breadboard and compare, but I do think the oscillator section has different values than the stock small clone, since the in circuit measurements were a little off, and the 100k pot is there. Here's a pic of the missing 22k resistor:



The boss vb-2 schematic is a little different and uses the 3101. When I traced it, there were resistors and caps where they should be exactly in the same spots as the small clone (with depth mod) on tonepad. Finding the values will be a challenge, since I'd have to unsolder each cap or resistor.

Do you not mean... Chorus? Not Phaser?

I just listened to those clips sonicvi, wicked, and you must have had the depth pot on the small clone set pretty low eh. The malekko gets ridiculously intense halfway and up, super seasick city (which is kind of cool). Otherwise, sounds pretty close to me.

To do the mod just lift the 22k resistor near the spot labled 'A' on the tonepad schematic as mentioned in sonicvi's post on the other forum on page 2. You could even put it on a switch for vibe/chorus.

Scruffie wrote:Do you not mean... Chorus? Not Phaser?

Yep, chorus not phaser, I got the small clone and small stone mixed up.

cool.
i never dealt with SMD, it's not possible to measure those with a standard multimeter?

pietro_moog wrote:cool.
i never dealt with SMD, it's not possible to measure those with a standard multimeter?

Sure, but you have to take them out of the circuit to make sure the reading is accurate. In some instances I think it will work fine, but if there is another resistor in parallel, you'd get wonky number. I suppose you could measure them all, then look at the schematic and back-calculate what the values should be based on their relationships to each other.

Seems like a lot of work, though, when we have a schematic for a circuit that is VERY close to this one.

culturejam wrote:

KindaFuzzy wrote:It's missing the 22k clean blend resistor which makes it a vibrato, but funnily enough has a spot where it's supposed to be on the board just beside the 4558, so if you don't like the vibrato, you can put a resistor in there and get a phaser.

So then that would be the Melekko Omicron Phase, I take it?

ahhhh the ol' "change one component and sell it to em' again" trick. nice.

culturejam wrote:
Seems like a lot of work, though, when we have a schematic for a circuit that is VERY close to this one.

That's what i was thinking. They've got 3207 chips downtown, maybe I'll pick one up and rework the circuit on the breadboard to compare.

After a romantic evening of drinking stout and probing this guy with my multimeter, I think I've got a pretty solid schematic figured out. I couldn't measure the smd caps in circuit, but 99% of the resistor values were exactly the same as the small clone, so it's pretty safe to assume the cap values are the same or close too. Here it is, enjoy:

Did he actually use a Tant?