ADA MB-1 tube bass preamp

About 5 years ago or so, I purchased a bass preamp from my bass instructor/mentor/friend, Rusty Springfield. The ADA MB-1 was a real masterpiece of engineering, and had both a tube portion as well as a solid state portion that could be mixed together for that “perfect sound”. This unit had seen a lot of use, as Rusty used it in his travels with the Big Apple Circus, and it survived roadies, tent dust, and endless use. So, when I decided I wanted to do a little home recording, he was willing to sell it to me for a good price.

All was well until about a year and a half ago. For some reason, the little guy would just stop working and dump its programming. If I could get it to work, bumping it would upset it again. I searched for a place to repair it, and after much procrastination, took it in. The guy said it would cost around $60 bucks just to bench it, and then he still didn’t know if it could be fixed. And, since ADA had been out of business for some time, he didn’t know if it’d be worth looking at.

So, I went online. There were places that could repair and service it, but it was still going to be pretty expensive. So, for the time, I gave up, and chalked it up to “well, I got good use out of it while I had it”.

Fast forward to last week. As you know, I’ve started a new job, and in the course of 5 months, I’ve learned a lot about hardware, and much has been demystified. So, armed with these new learnings, I decided I had nothing to lose by at least taking a look at the preamp and see if it could be fixed. Worst case, I’d need to replace some parts. The guys at work could probably figure out what I didn’t know, so the prospect was good in my mind. So, I opened up the case and looked around. Lots of chips and lots of other electronics that I have no clue about. So, I decide that maybe a chip is loose. I start poking around with my fingers on all the chips that are mounted on sockets. There was a lot of creaking and flexing of the mainboard, until finally, one of the chips I pushed on gave a little. Hmmm, it seems it was loose after all. So, I plugged it in, and, “voila!”, the preamp ran through its normal POST, then warmed up the tubes, and displayed its normal screen. Needless to say, I was ecstatic. I immediately plugged in my bass, and there was nothing but sweet, sweet music 🙂