Repairing Zappa's Delay

[dano12]

Through various circumstances, an old non-functioning ADA Digitizer 4 was delivered to beavis labs by a friend who claimed it once belonged to Frank Zappa. We've all heard those stories.
But then he showed me the box:



I am a *huge* zappa, so the allure was both immediate and overwhelming.

Opening the box:






Next step, remove the top cover. I worked as slowly and carefully as possible. I mean this is a piece of history. Top pop'd. Look at this beast, straight out of the 80's engineering design school.


And check out the close up for extra geekery points:


That chip on the bottom right? A Zilog Z80! No crap! That was the microprocessor that powered my first computer, the brilliant Sinclair ZX81, along with just about every other first generation "PC" out there. We are talking dawn of time here folks.

So, onto the first triage of repairing this beast. I popped and reinserted every chip that was in a socket. Then on to the wire headers. Each one was pulled, shot with a gentle dose of contact cleaner and the reseated. Finally the PCB holding the buttons display and buttons was given an initial cleaning.

Then I fired it up. Holy Crap! All the lights work. Plugged in a guitar, the VU meters responded accordingly, and then into the amp. I got an awesome 80's chorus setting. Other than that, no luck in changing functions, slots or banks, but not bad for the first pass.

Here is my son Frank Vincent (that's right, as in Frank Vincent Zappa) trying to walk the through the presets.


So I could get one preset to play, all other functions were still dead.

After some more spelunking, I traced down a cold solder joint on one of the wires going up to the header on the button/display pcb. A quick reheat.

Now it is 100% functional. It sounds incredible, there is a wild amount of LFO sweep available, the delay time goes up to 1024 ms, and there is a built in phase switch. Unfortunately, the lithium battery back died sometime back in the lat 90's so any presets used in the Muffin kitchen were long gone. Shame about that part.

I gotta tell you dudes, it was quite a thrill to resurrect (with my minimal hacker skills) a piece of history.

Needless to say, tonight was a good night at beavis labs. The true sorrow will be having to send it back to its owner.

[Eb7+9]

 


funny, I was just watching We Don't Mess Around ...

[mth5044]

It would be a cryin' shame if you don't clone that...

[Boogdish]

Whoa, way to go Dan!

[Ben N]

I am a *huge* zappa, so the allure was both immediate and overwhelming.

That would be ZOOT allure, non, mon ami?   

[mth5044]

Oh man, Frank Zappa turned that knob. Frank Zappa changed that preset. Frank Zappa played through that! Wild.

[ayayay!]

Dano this is the coolest man!!!!  You must be on an amazing high right now.

You are what you is and you's is one lucky son of a gun.  Congrats! 

[Ben N]

Oh man, Frank Zappa turned that knob. Frank Zappa changed that preset. Frank Zappa played through that! Wild.

I could see Frank having twiddled the knobs and presets, or some other such Zappanian usage. But just "turned"? I don't think so.

[mnordbye]

Not to encourage you, but i think you should steal it. 

Naah, cool find, Dan!

Magnus Nordbye

[Electron Tornado]

Do you have a schematic? Can you post it?

Do you have a layout for it?

Can I get Press 'N Peel Blue in sheets that big?

Does anybody sell PC boards for it?

Are there any kits available?

Does anyone have any mods?

Etc....   


Typical questions all asked in a single post. Bandwidth saved, hooray! Now don't I feel...

[drewl]

Good for you.....I was just reading up on some Zappa stuff with the passing of JimmyCarlBlack...."The Indian of the group"

Alot of  those early rack units can be had for cheap nowadays, and I've got a pile of junked ones I've pulled out of the trash I use for parts etc.

[noelgrassy]

Wow what a piece of history. Great job too.

I still have one of those and it was working when I removed it from my rack.

[David]

Now what you need to do is dump the program in the Z-80 and run it through a disassembler so the source code is available.

[Filament]

Who's Frank Zappa?  Is he related to Dwezil Zappa?

[GtrmanMoe]

Frank is Dweezil's father.

Frank = Pure Genius.  The music, the lyrics, the arrangements, all of it...nothing short of amazing.  Just my $.02.

[Der Groovemeister]

Wow man!

Maybe Nanook rubbed it!

+1 on the stealing! Just say to the owner that you couldn't fix it, that it just blew up. 

Arf arf

[~arph]

How do you know it was Zappa's if the box came from hollywood 

[dano12]

How do you know it was Zappa's if the box came from hollywood 

The guy who bought it directly from URMK is  good friend of mine. If he says that's what happened, that's good by me. Plus, he paid $150 bucks for it and ended up _giving_ it to friend #2 who brought it to me for repair. So that far in the story chain is good for me.

I suppose there could be have been some elaborate scheme wherein somebody at Barfko/Swill deceitfully put some else's ADA unit in a Barfko/Swill box and shipped it from the Barfko/Swill address just to screw with all of us. I don't see that as really likely for a unit that was sold for 150 bucks.

[Apehouse]

I could see Frank having twiddled the knobs and presets, or some other such Zappanian usage. But just "turned"? I don't think so.

So true! He's couldn't even use a bicycle correctly at age 22:
http://www.youtube.com/watch?v=8e3I0iagWXU

I looooooove Zappa!!!

[~arph]

Ah a google of barfo swill made the assumption clearer.. I never heard of barfko swill before..