New Project - Deluxe Memory Man Converting To 9V & 3205s

[Scruffie]

Hey all,

Undertaking a bit of a big one here... I want a EHX Deluxe Memory Man and they're pretty pricey these days so I thought i'd convert it to the available V3205 chips and run it off 9Vs.

Just one or two questions... Does anyone have a good example of converting Delay chips that I can look at and do I need to change anything from the 4047 Clock... had a look at the datasheets but i'm not sure on it.

Gunna be veroing this one so I don't want to debug the layout and my incorrectly converted schematic 

P.S. speaking of which does anyone know the authenticity of this schematic? I've been through alot of the threads on schematics and I know there's bad ones but there's no definitive answer as to what's right http://www.freeinfosociety.com/electronics/schemview.php?id=381

[roseblood11]

...Don´t you think you´ll end up with a EHX Memory Boy/Toy?

Maybe it would help to buy one, take a few gutshots, compare it to a DMM and then send it back?

[Scruffie]

Yeah I will (except for a few missing options on those) but I feel like building it myself! (Otherwise i'd just buy a Memory Boy or Toy and where would the fun in that be)

Hmm, the new models are all SMD, i'm not sure my eyes would cope with tracing it out and i'm not sure about the returns policies for opened gear...

Shouldn't be too hard to convert anyway, the 3205 will need different supply voltage to the 3005 but other than that it'll probably just be a couple of value changes around the BBDs, I just wanted to see it done so I could have a guess as to what values might need changing.

Then I just need to know about altering the clock output of the 4047 which I assume like a 3205 needs a 3102 and the 3005 needs a 3101, i'll have to change it slightly.

Edit: Also from gut shots i've seen of the Memory Boy, the design is quite different, for a start there's a 4011 and several quad op amps and even a LM13700.

[Scruffie]

Wait... nevermind, i've found someone that's attempted this project befores schematic so my questions have been pretty much answered!

Thanks anyway... now to sit and cry over a giant sheet of vero layout paper while I torture myself for some reason.

[cathexis]

I'm looking forward to this! Keep us posted on the progress of your torture! 
LARS

[Scruffie]

I'm looking forward to this! Keep us posted on the progress of your torture! 
LARS

Haha, well I started it last night... it's pretty tortuous, i'm having to compare 3 schematics at once as I do it (One's right but too blurry to read, one's right but has different values and added stages because it was a modified project and one's got the readable right values but is wrong)

I've just about done the Power & LFO section but i'm not sure if they're horribly wrong... regretting this undertaking  Hey Cathexis, fancy doing a vero layout for me?

[Scruffie]

Right... i've decided i'm gunna do it in stages so, so far i've done the Power, LFO & Clock section and that's looking like this if anyone fancies checking it over, that'd be very handy, I would not be suprised if some of it is completely wrong.



The Side got chopped off though it goes in order (The Blue lines going off the edge)
- 9V
- Vdd
- Vcc
- Vref
- Gnd
-SPDT B
-SPDT A
-SPDT C

Parts List (Just the missing ones):
R6 - 910k
R7 - 910k
R8 - 120k
R9 - 7.5k
R10 - 27k
R11 - 27k
R12 - 5.6k

C3 - 1uF Tant
C7 - 4.7uF Tant
C8 - 1uF Tant
C9 - 2.2uF Tant
C10 - 1nF
C11 - 1nF
C12 - 240pF

[cathexis]

Hey Cathexis, fancy doing a vero layout for me?

It'll be a while until I get back to doing layouts, rough patch right now. But I'd be glad to check your work. Post the schematics you're using or PM them to me, and I'll take a look!
LARS

[cpm]

i've tried before

my quick recommendations:

power, lfo, clock: pretty straightforward, just adapt for negative ground. I consider using a buffer for the clock if more than 2 3205 are used, but may be useful either way if it helps to keep the clock sharp clear for better performance.

opamps: buffers, mixers, filters... sanitize the biasing and ground references for your +9v
gain through stages must be adapted to the 3205 levels (whis is lower thatn 3005). I kept the gain down on the compander stage and that was good enough.

3205s, you'll need a dedicated power voltage with a 780x regulator.


the bad part is that you are fighting against the lower voltage of the 3205s, which can yeld to higer s/n if not treated carefully.
To get the max out of them, i'd think:
- for each delay chip: use independent bias trim, output balance trim, (and probably a dedicated Vg too)
- some filtering between delay stages, instead of a whole filter at the end
- run the 3205 at 7 or 8v. it goes to the limits of s/n (as showed in datasheet)

but that would get you with a design different from a memory man, thats what i was working on some time ago but left it behind being busy with other projects.
Ang having now the memory boy, toy, etc, that may even be a little redundant

by the way... the new memory boy plus (or whatever) looks very nice !! looks like it has everything we had on our diyer's minds

scruffie PM me if want more detail of what i had on the work

[Scruffie]

Ahh... yes, I was hoping it would run almost as usual but with just a reduced headroom and maybe a bit noisier at worse... if it's not going to be the same basic design (I was expecting to have to change a bit once i'd got it boarded, but not completely) then the new Memory Boy products suddenly become alot more appealing...

This being the case... I might just do a vero layout for MN3005s as a challenge, not that i'll probably ever find any to build it up with.

Then again, a new dual chip analog delay based around the principles of the Memory Man could still be fun, I just wouldn't work hard at a good vero for it at present, I may PM you in the near future, Cheers 

Hey Cathexis, fancy doing a vero layout for me?

It'll be a while until I get back to doing layouts, rough patch right now. But I'd be glad to check your work. Post the schematics you're using or PM them to me, and I'll take a look!
LARS

Hope things aren't too rough and you get through them  Well if you're still interested in a 3005 layout i'll send you the schematic and Continue on with this vero, although at a reduced pace as I wont be building it up... atleast anytime soon *Crosses fingers that Cool Audio for no reason out of the blue reproduce the 3005* but that'd be appreciated if you wanted to check it (no idea if you have any 3005s on hand or not?)