Learning About Hardware Digital Stuff

[cpsmusic]

Hi All,

For some unknown reason I've become a fan of hardware digital reverbs and FX units. Most of these can now be picked up relatively cheaply, although many are in various states of disrepair.

So far I've bought and repaired a Roland SRV-330 and TC M300, both of which had power supplies that failed, and both were fairly easy fixes.

My background is music and audio production and I've also worked as a C/C++ programmer. Electronics-wise I'm probably at an intermediate level - I can figure out schematics and have built various bits and pieces although I'm not at the level where I could design something.

So my question is, what's a good way to go about learning the digital side of these hardware devices? I know that's a big question and the technology changed from the 80s to the 90s. Say I was interested in repairing one of the Lexicon units (PCM60, 70, etc.). Is there a go-to textbook for learning about this stuff?

Cheers,

Chris

 

[user 37518]

Learning about repairing and learning about how stuff works are two different things, but I would recommend Morris Mano's "Digital Design" and "Digital Systems: Principles and Applications" by Tocci, Widmer and Moss. Those two books will teach you everything from logic gates, flip flops, memories such as EEPROMS, analog to digital and digital to analog converters, etc..., which is much of the stuff that you will find inside the units of that era. They are also books which I consider very easy to follow, particularly the one by Tocci. Try buying them used, you can get old editions so you don't have to pay full price. You can also get the so-called "International Editions".

P.S. Mods: I suggest moving the thread to the Truth Table forum, since it is really not suited for the Brewery.

 

[tupinamba]

Thank you for this advice, user 37518, I had the same question as cpsmusic, although I have a lesser experience in electronics I guess and I'm also trying to repair a Lexicon PCM60 and would like to understand how it works...
The book by Ronald J. Tocci also exists in French and is available second-hand, which is a good thing! (must have been a bestseller in the 90's... )
I just ordered it for a very fair price...

 

[ccaudle]

Say I was interested in repairing one of the Lexicon units

Do the Lexicon reverbs use a DSP processor (would probably be Motorola 56000 series in that era), or do they have a custom ASIC to perform the calculations?
Custom hardware is much more difficult to get your head around because there are typically no datasheets available, you have to make your best guess about what is going on, and look for generic connections like ROM, RAM, power supply, etc. that you might be able to inspect and infer if something is not right.
If using standard processors you can probably find datasheets to help figure out what is going on (although getting more difficult for parts which were pre-PDF datasheet era).

 

[tupinamba]

Well, I think they use a DSP processor.
Anyway, I have a serious hint about my issue, its is most probably one of the DRAM ICs (I'm posting here about it)