Memory Man with a PT2399

 

I've finally found a circuit worthy of replacing my  Memory Boy -for me. I use delay subtly and especially just like the tone my EHX  adds to my sound, dark, spacious, analogue - just nice. It's not moving for anything less. This has made the grade. I've set it up side by side and been able to get it to sound the same on settings I use, and it has a lot more functionality, and it uses a readily available PT2399 IC.

 

The circuit originates from Madbean - the discontinued "Dirtbaby". In their own words " an honest attempt to recreate a Memory Man with a PT2399". The circuit has been traced on Dirtbox layouts and thanks to him can be found here dirtbox - madbean .

I read up a lot on this one and have modified this some. Added a switchable charge pump to 17v, placed the trimpot on top which does give me some less/more effect options. I've a few component values based on recommendations for a darker tone. Just found my notes I grabbed while researching

NOTES

 So I finished a couple Dirtbabies lately, one for a friend and one for me.

It's simply the BEST PT2399 delay I've built.

I changed C10 (1,5nf instead of 1nf) and C12 (150nf instead of 100nf) for less noise and a very slightly darker tone (still quite bright!)
R4 is about 30k (raising C12 raised the volume also), and R35 is 56k. C14 is a 47uf tantalum (I read in the notes from valvewizard that using a tantalum in that place was better, so I keep doing it with every PT2399 circuit I build)

The first opamp is a BB OPA2134 and the second one is a OP275.

I added a charge pump to run it at 18v (much better in my opinion!) and also added a couple things:
- a tone switch that adds another 1,5nf in parallel with C10 for a much darker delay
- a slam footswitch with internal trimpot accessible from behind, to decide how fast it ramps towards oscillation.

I t's seriously not a difficult build, as long as you take your time to plan everything well.

I'd recommend to socket all opamps and PT2399 of course, but also :
R4 (feedback resistor. In mine, 33k)
R35 (mod rate. In mine 56k)
R37 (mod depth. Kept it stock in mine)
C8 (just in case, cf build doc. Stock in mine)
C9 and C10 (in mine C10 is 1,5nf, helps with the noise, though it cuts a tiny amount of treble response. Still bright enough for me. Far brighter than the analog mode of my Echo Park, which is supposedly modeled after a DMM)
C13 (will alter the way the repeats degrade, keeping more treble in a tape-like way, cf build doc)

And I definitely recommend a charge pump to run it at 18v. So much better in both my builds!! (and that's the reason I use a IR9022 instead of TL062 for the LFO, since 18v is the maximum voltage allowed for TL062)  

I stuck with the 17v charge pump as I've used the TL062 for reasons as above. A vero layout for this can be found on tagboard effects along with many other useful little circuit tools. As with the mods I did use, I suggest socket - experiment once you've got a working thing.

Aside from all the options this pedal offers, the level/volume control is a big pro for me. The memory Boy always give a volume increase which is a pain in the A** . Now I can get unity.

It's not a pedal I would attempt first, there's a bit going on. But I highly recommend to do at some stage.

It is now my full-time delay - main board.

I'm stoked with the look of this one. Continuing on now from the protein look. Adding a bit of colour,

I've found UV cured epoxy, cheap as chips from TEMU, China. It's great. You can tint it, apply it, and when you're happy, cure it. This is my first use of it instead of paint to colour the etching cavities. Still a clear coat on top too.

I picked up some 50k slider pots for an EQ/Boost pedal I'm thinking about next and was able to use one of the extras here. Looks retro. Stole the slider knob off an old Technics HI-Fi Eq I got with my record player.

Making your own Pedz from the shed Rulez :-)