ADHD v2 (Fulltone OCD Ge)

MichaelW

Well-known member
Build Rating
5.00 star(s)
So i had planned the day around building a somewhat complex modulation pedal having just built 3 overdrives.

By the time I finally got to my bench it was after lunch and as is my usual practice I start with drilling the enclosure then pick the components. Well, wouldn’t you know it I was missing an On On On toggle , bahhhhh…

I decided to start populating it anyway and then noticed the board is actually spaced for 1/8 watt resistors, this is AFTER i had pulled all the values I needed in 1/4 watt. Double bahhhhh……I checked the clearance and space and decided to go with the 1/4’s since i already had them all pulled and just soldered them standing up. I managed to get all the resistors done then decided to bail since my toggle isn’t going to get here until Monday.

So back to the drawing board, since it was getting late afternoon and I still needed to take Bonnie the wonder dog for her shnork and sniff walk around the neighborhood and visit all her little doggie buds I figured I’d better go with something I could finish this evening. I don’t think my psyche can survive TWO unfinished projects…

Thus, i wound up building @Robert ‘s latest ADHD revision. So humming away happily I drilled the enclosure. No drll template……and when I went to dry fit everything before populating the board I realized I drilled the toggle on the wrong side…..Triple bahhhhhh…..🤬

I wasn’t going to waste a nice Tayda enclosure so I rigged up the toggle off board and came up with a makeshift insulator by cutting up a pot condom and using hot glue. It makes the board fit a little wonky but it worked!

I’ve owned a couple of OCD’s over the years but for some reason they never stuck around. Even though I liked the way they sound. One version I never owned was the Ge version, so I decided to build that.

I have to say I’m pretty stunned at how good this thing sounds. Much better than the retail OCD’s I’ve owned.
It could be that I used some NOS Mullard CV7364 diodes with a very low Vf (.258 & .263).

The classic chewy distortion is all there but there’s a bit of extra creaminess and saturation from the Ge diodes that’s very cool. I’ve heard a lot of people say that the retail Ge version was all hype and didn’t sound any different. I dunno, I never played one. But I’m totally digging my Ge ADHD. And it’s following the same them of the last few Mad Professor drives I’ve built in that it’s a really “chewy” kind of gain. But like the stock OCD you can turn the gain all the way down and use it as a clean boost to push your amp. I’m still not sure I’d shell out the $$ for a retail OCD as it’s not a sound I would use a lot but I’m very glad to add the ADHD to my arsenal over drive sounds.

I used the Tayda gray sand enclosure with a water clear 5mm led. It’s hard for me to see the led in this spot when sitting down so the extra brightness (blinding brightness actually) of the water clear helps.

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I was also missing the correct slider for the buffered bypass selector so I hardwired it with the buffer always on.….cuz…I dig buffers:)

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Fixing my little drilling boo-boo

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Oh I forgot to mention, I didn't have a TL082 and wasn't going to place an order for a single IC. So I subbed a TL072.
I've a read some people say that the 082 are just 072 rejects that didn't meet wafer spec's or something or other.
But they're essentially the same IC with slightly different slew rates and s to n specs.

But the plan is to try some different OpAmp's later today and see if it makes any difference.
Planning to try a 4580D, LM833, hmmm, maybe a 1458 and just for giggles, a 4558.
(Oh and tack solder in those Ge diodes, they're kinda loosey goosey in the sockets but these are staying.

I'll update this post if there's any appreciable difference.
 
Really nice. I read in a couple of different places, they sound good at first, but as they heated up, it went south pretty quick. I’m assuming they’re talking gigging situations.
 
I used some NOS Mullard CV7364 diodes with a very low Vf (.258 & .263).
Beautiful build. Very sober, very refined and uncluttered style !

Never seen these diodes before, I would have thought they're caps... Did you compare with the usual ge diodes, like D9K ? Low Vf means it clips the signal sooner ?
 
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Beautiful build. Very sober, very refined and uncluttered style !

Never seen these diodes before, I would have thought they're caps... Did you compare with the usaual ge diodes, like D9K ? Low Vf means it clips the signal sooner ?
Yah, they tend to saturate more. I’ve compared them before and know what to expect from the Millard/Phillips. I was never one to fuss too much about Ge diodes as long as they were in the right Vf range. But these Mullards have changed my mind.
 
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Does someone have the drill docs for this one? I just ordered the PCB and 5 different types of NOS GE diodes, including the Mullard CV736 (thanks for opening my eyes to these). I want to get a head start on a tayda-printed enclosure, but do not know where to place the pots/toggle switch.

Thanks!
 
Some sounds your ear just needs a good chew on 'em.

man-in-pain-pulling-at-his-ear-from-the-voices-inside-his-head-hence-B7MK97.jpg


This guy lost an ear tooth and can only chew on sounds with his other "good" ear:

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So remember, keep your ears clean — don't listen to too much filthy-mouthed wrap musick or David Allan Coe.


Same goes for your pets, keep their ears clean. This dog's acute high-pitched hearing was luckily saved with proper ear-dental care.

5ypzze8godu41.jpg
 
Does someone have the drill docs for this one? I just ordered the PCB and 5 different types of NOS GE diodes, including the Mullard CV736 (thanks for opening my eyes to these). I want to get a head start on a tayda-printed enclosure, but do not know where to place the pots/toggle switch.

Thanks!
I just measured, and as you can see from my post, flip flopped the toggle to the wrong side...heh.
 
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