ADA MP-1 (Pt 1): The War Against Bespoke Obsolescence

Customer update
#amptech #electronicsengineer #guitaramprepair #tubeamp
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Thank you for following me here on KZbin. Bear in mind the purpose of this channel is mainly for customer updates and edification, random and contemporaneous blabbering, and etc. I rarely post "How-To" related content. For more how-to focused guitar amp content, visit @BradsGuitarGarage @PsionicAudio @d-labelectronics @UncleDoug and all the other greats, who are smooshin' it on a daily basis.
Do not attempt to service electrical devices without understanding the risks involved. Tube amps present the opportunity to injure oneself critically or fatally in a multitude of ways. Do not be lulled into a false sense of security based upon the volume of readily available content on the subject matter online.
Soldering Gear: Hakko FX-951
Solder: Kester 63/37
Solder Removal: Chemtronics Chem-Wik | Kotto Solder Sucker
Oscilloscopes: Leader 513A, 508A | 1955 DeVry Wideband
DMMs: Agilent 34401A, Hioki DT-4256
Signal Tracer: Heathkit IT12
Function Generator: Leader LFG 1300S
Signal Generator: 1960 MSU Phys Dept Signal Generator
Chemicals: Deoxit, CRC QD Electronics Cleaner

[@Corporations8MyBaby]

"you're out there playing? ... you take em." .. This is what music and gear are all about.

[@thatampguy]

Preach!

[@countstoneula]

The algorithm knew what I’d enjoy today! Nice work!

[@thatampguy]

I never get that lucky lol

[@TubelabCom]

I bought a used MP-1 off Ebay back in 1994 for cheap. It worked fine for several years before becoming quite microphonic. New tubes did not help. After a maybe a year longer it would just go silent. A well placed whack with the butt of a screwdriver would restore life, often for weeks, but the silence would eventually return. Somewhere in the early 2000's I replaced it with a DIY preamp and the MP-1 got stashed somewhere, and forgotten. My 41 year engineering career ended in 2014 and I had to move everything 1200 miles on short notice. About a month ago I crack open a hastilly packed box from 2014, and there it was, the MP1 had been sleeping for probably 20 years. I connect it between a guitar and a DIY tube amp, hit the switch and get, silence. One good whack, and it ROCKS! the crazy thing is that all my old presets are still in there. Mine has a Zilog CPU chip and a 2.01 sticker on the EPROM. The latest date code I can find on any part puts its build date in 1992. The input jack is the typical Switchcraft open style and does not seem to be noisy or intermittent. The rear panel jacks are a different story, as they are plastic boxes that take a bit of plug wiggling to get a connection. It's sitting on a shelf for now, but I'll probably get it down and dig into it when I clear some other projects off my workbench.

[@thatampguy]

Great post! Those rear jacks will give you hell if you even look at them sideways. Do not make eye contact.

[@TubelabCom]

I had opened the top of the MP-1 many years ago to replace the tubes, and again recently when I found it. I had never taken the bottom off, so after you made me curious, I decided that I would use the pointed end of the screwdriver to take the bottom off rather that the handle to whack it. I was careful not to let those jacks see me taking their picture. Then I slapped both covers back on with two screws each and put the MP-1 back on the shelf. It does look like it would be nearly impossible to find a drop in replacement for those things, but maybe there is something that could be mounted in the hole and connected up with flying wires. There's got to be something out there in the stomp box world......maybe. @@thatampguy

[@johnpierson8398]

Hey my friend, I enjoyed this video. You respect the realities and tradeoffs of working on gear from the 80s. I noticed you are using a CR2032 cell battery for the the memory presets. My research tells me the original used a BR2325 3V coin cell. I believe eitherr will work, they are both 3V cells. Are you in the business of repairing ADA MP1 preamps?.Thanks!

[@thatampguy]

Hi! Thanks for the comment. I like the additional capacity of the 2032! I have been working on these old preamps for about 15 years. I don't take them on often and when I do it's at great risk! I'm on my last donor unit and hope she will give life to the community out there. Lots of guys still using these to put food on the table.

[@Turboy65]

I have one that's way down on gain but works. It needs servicing by someone who knows them well.

[@thatampguy]

@Turboy65 have you changed the preamp tubes? Which city are you in?

[@Turboy65]

@@thatampguy Yes, I put in new preamp tubes. No change. I'm in central FL.

[@theophany1770]

​@@Turboy65me too, I have one and in Orlando. Unfortunately I had a negative experience with The Amp Guys recently probably not calling them.

[@JazzRockswithAdam]

I used to have one of those. I think I bought it used in 1989. It had the switch on the panel to pad it Xdb or switch back to a full blown preamp output. Not sure what version it was. It had a great sound.

[@The_Absurdistt]

Excellent vid. I appreciate your attention to detail and your clean soldering work. Many techs butcher components and take ugly short cuts when doing repairs. How can I contact you for repair work? Cheers.

[@thatampguy]

Sincerely appreciate your comments. I'm all about transparency in this industry. Want everyone to see how the sausage has been and should be made🤣. You can initiate comms via [e-mail]. Cheers

[@socallars3748]

#$&!! hot glue is a pet peeve of mine! Hate that stuff, especially when they use it to mechanically stabilize small electrolytics. The tiny ones get cooked from the heat, greatly reducing their lifespan. I just repaired a Focusrite channel strip, every damn hot glued cap was bad! It's fine for bigger caps, but just use silicone people!

[@thatampguy]

Sounds like Michael's or Hobby Lobby blew up next to that Focusrite haha

[@socallars3748]

May they be haunted by the ghost of Rupert Neve.

[@thatampguy]

@socallars3748 just spit out my coffee lmao

[@braxal6983]

I have an original ADA MP-1 that appears to turn on. I am the original owner. Is there a place in Dallas/Fort Worth I could tale it if I have any issues?

[@thatampguy]

It's going to be incredibly challenging to find someone in your local market that would be willing or even competent enough to work on it, I hate to say. Spare parts have to be on hand when doing even the most mundane types of service.

[@braxal6983]

@@thatampguy That is a bummer. So if it breaks I am out of luck

[@thatampguy]

@braxal6983 not entirely, just make sure you have a good tech network. The main problemsI've seen these revolve around failed batteries and caps. No need to remove PCBs on these with the e caption of those on the tube sub board. Now, broken jacks and other hardware will put you in the hurt locker! Just be gentle!

[@braxal6983]

@@thatampguy Well, The original battery is still in the unit. I think that could be easy replaced by me? IS it hard for me to get out my soldering iron and replace caps? How can I tell if they are no good? I appreciate your help.

[@thatampguy]

@braxal6983 the most difficult aspects of servicing these preamps include having perfect technique with your iron and perfect tip temperature. Either one of these is off and you'll see curled and lifted solder traces. The boards are enormously fragile, so you have to go hot and fast on low and slow. Both cap and battery alike require soldering. Even if you install a battery socket, you'll have to solder it in. Just practice your skills on other things first.