Refurb of a DOD delay

[Barcode80]

I'm refurbishing my DOD 585 performer, as the delay is great but the board traces are a shambles. i was thinking of replacing the chips, but they are all so obscure that i can'tfind them even on mouser! can someone who is a little more IC savvy point me to some substitutions?

NE571N
MN3005
MN3101
4007UBDC
TL022CP (x3)

these are the numbers on the chips. I know the MN3101 is a timer, but i can't find info on the others.

[Shed_FX]

Hi, the chips you need for the pedal are all available from www.banzai-effects.com apart from the 4007UBDC which is a Inverting-Function Buffer Gate which you may be able to get an equivalent for.

Banzai effects are based in Germany but are set up to ship internationally i got my components delivered to me in the UK in 2 days for about 4euros. Just to give you a heads up the MN3005 costs around 19euros as it is quite rare.

Hope this helps.

Cheers

Shed_FX

[sfr]

TL022 is just a low power dual opamp.  I've yanked dozens of those out of consumer electronics.

NE571 is a compander, Jameco seems to stock them.  Mouser and Digikey don't. Small Bear has a pin-for-pin replacement, the SA571 in stock.

4007s of various varieties I've seen any old place.  Mouser and Digikey and wherever.  I'd imagine any old 4007UB chip would work.

The MN3005 is a bucket-brigade-delay,  also available at Small Bear, as mentioned, it's out of production, so it runs $25US there. 

The MN3101 is a clock driver for the BBD, Small Bear has this as well, around 8 dollars.

[Mark Hammer]

I'm a little curious as to why you want to "replace" the chips.  They do not age like caps do, so why the planned swap?  Or were you planning to build a replica, given your comments about the state of the PCB?

[oldschoolanalog]

Mouser DOES stock SA571s. Part # 863-SA571NG. PDIP16 package.

[Barcode80]

the pedal had some other problems before the pads and traces separated. but yes, i would like to build an extra. it is such an underrated pedal, and i wouldn't mind making my own with a cool enclosure and stuff. and when it is functioning, i use this pedal so much that i wouldn't mind having a backup, or at least a parts backup. especially as rare as a couple of these chips apparently are

i already scanned the pcb and made a transfer of it. since this pedal is totally out of production, i'll keep it around and anyone who has this pedal and has the same problem with the traces, pm or email and i'll send it to you. i've been working on build an archive of these kind of things. i'm not going to publicly post any of these (right now i have the 585, b*ss sd-1, and b*ss bd-2 pcb transfers) as i don't find it ethical, but as much as we all mod our production pedals, i'm sure traces come loose every no and then and i don't mind sending them to people in that case.

so mark, yes i'm going to build a replica. i'm trying to decide whether to use sliver mica or film caps in the replica. the old ones are orange (orange drop?) and appear to be film. i would rather use micas, but given the cost of the chips, i may need to cut back elsewhere. what do you guys think?

[Dan N]

I'd just use decent film caps. If there are ceramic pf value caps in the audio path, maybe you could try micas? Not that big of deal. Ceramics in the clock circuit are fine. Going true bypass would get rid of a slew of parts and tweaking problems. Good luck!

[Mark Hammer]

I wouldn't sweat the caps.  The BBD sampling process and all the required filtering does enough to corrupt the signal that I stronghly doubt anyone could hear differences clearly attributable to cap type.  Plain old "greenies" (although if its DOD it's "yellowies", right?) are fine, and will obviously fit the alloted space.

Note that the NE/SA570 is pin for pin identical to the 571, except that it apparently has better noise specs (the 571 can be considered a budget "replacement" for the 570).  It has always been my experience that they are in such low demand (compared to 4558s which everyone uses) that the cost difference between them is negligible, so wherever you order from, ask for both and get whichever one is available and cheaper..... but go for the 570 if its a tie.

[Barcode80]

AAAARRRGGGHHHH!!!! I am literally halfway through drilling the pcb and my last wire bit just broke. FRUSTRATING! worse still i can't buy them that small anywhere nearby, so i have to order new ones from steve. DOD on hold....

[Barcode80]

okay, a little update. i managed to seat the remaining amount of the dirll bit in the chuck of my drill and finish drilling the board. i made lots of progress, and i would have finished it today but i ran out of some parts (namely a bunch of resistors and caps i need). here are some progress pics:


front view, with flash

front view, no flash

back view, showing power jack

inside, showing pots and back of power jack, in and out jacks

my new board on the left, the old on the right

MODS and/or REPAIRS:
1) installed a multi-pin power supply jack, modified a dell laptop power supply to fit it which supplies the 20v needed to power this hoss.
2) repainted the shell with "hammered" copper finish
3) added LED bezel
4) replaced all 3 pots
5) added numbered holes to top of board for wiring to omit the cheap connector included in original production. wiring will be direct to board.
6) salvaged original chips and trannies. jury is still out on whether i want to build another. if someone wants to show me how to omit the electronic switching i'll make up a new layout and make it available as a clone build.
7) replaced all caps and resistors (the ones i had on hand, will replace the others when parts arrive)
etched a brand new board, adding holes to wire the LED as opposed to the STUPID way the LED was wired to the board originally (straight to the back of the board on its own legs!?!?! definitely a no-no in this particular housing, pads it was soldered to separated numerous times) i drilled holes where the surface mount pads were so i could run wire on top of the board to the LED in the bezel. should keep the problem from occurring again.

compare to the original and tell me what you think. I still have to get the black knurled aluminum knobs i am going to use and i need to get some vinyl/rubber flexible paint to repaint the switch cover.

pics of the original can be found here: http://www.sonicurbs.com/dod585/index.htm

[Dan N]

Sorry to hear about the drill bit. Stuff like that can drive you crazy!

As far as I can tell, to get rid of the bypass you can pull that J113 in the lower left of the schem and bridge the drain and source, and pull the transistor that has its collector going to pin 1 of the NE571 (was that some kind of mute?). After that, all the stuff around the CD4007 can be omitted.

Sounds like you were pretty happy with it just as it was anyway.

Thanks for the nice photos!

[Barcode80]

DANG IT DANG IT DANG IT!!!!!!!!!!!!!!!!!!!!!!!!!

I've been tediously and carefully working on this pedal for a month. i just finished soldering all the parts in and plugged it in, and it isn't functioning and one of the chips is warming up. i promptly unplugged it, but now i'm wondering if this is going to be worth the trouble. might just recycle the parts into a new build, maybe put a pt-80 in there.