#49 Joyo ZoMBie, part two - analysis and repair

It took the best part of an evening and a couple hours the next day, but i managed to lift the schematic for the whole preamp board. I also recreated the board, but that was mostly for sanity-checking. I used all the same component designators, but didn't bother measuring all the dozens of small ceramic caps, because there's only SO far i'm willing to go...

#47 Joyo ZoMBie guitar amplifier teardown

My bandmate got his hands on this Joyo ZoMBie about a week or two back; it was sold as faulty. No idea how or why, but there's something dicky with the tone control - on some power-ups it works fine, but sometimes quits working (ie. sounds like the setting got stuck at some random point along the travel of the knob), no matter how much you twist it. Power cycling sometimes helps, but inconsistently, and even if it does, it just "gives up" again, sooner or later.

#43 Focusrite Scarlett 18i6 teardown

As it turns out, i hadn't done (or at least documented) a teardown of this little guy, even though i've been using it for the last two years or so. Even though, as it turns out, i bought this a few months after starting this blog. Either way, i just put it up for sale (due to upgrading to the Scarlett 18i20 i inspected the other week). So i figured i might as well snap a few photos before it goes to its next owner (whomever that may be).

#39 M-Audio Profire 2626 teardown and repair

Ebay strikes again - this time, a pretty damn cheap (to acquire) M-Audio Profire 2626 Firewire audio interface. I maintain it's still the cheapest way, to this day, to get 24 inputs and outputs to and from a computer. Most other 1U (rackmount) interfaces will give you 8 mic preamps but only one bank of ADAT. The ones with two sets of ADAT I/O will cost you a pretty penny, though.

Either way, this was sold as "not detected by the computer", so my bet's on the Firewire chip being toast, "as usual". Can you see a pattern emerging here?

#38 Focusrite Scarlett 18i8 (1st gen) teardown

Yet another "sold as faulty" eBay catch - a nice little(?) Focusrite Scarlett 18i8 USB audio interface. Which turned out to actually have nothing at all wrong with it.

Admittedly, i went against the first commandment of teardowns (ie. "Don't turn it on; take it apaaaah't!.."), but only because it was the first troubleshooting step, and it used the same drivers as my Scarlett 18i6 "daily driver".

#35 Focusrite Saffire Pro 24 DSP teardown and repair

Yet another sold-as-faulty eBay catch - a nice little Focusrite Saffire Pro 24 DSP Firewire audio interface. The listing said:

"I bought this online and it is not working or it is not compatible with my computer. My computer is not recognising this audio interface. So I am selling it as not working."

 Fine by me. The photo of the back showed the Firewire port as looking quite pristine, so it wasn't a case of connector-inserted-upside-down. And for the price i won the auction for, it was worth the gamble. A frontal photo did show it powered up, so at the very least, it wasn't dead.

#32 M-Audio (Avid) Fast Track C600 teardown & repair

This little bugger, an M-Audio / Avid Fast Track C600, was listed as faulty on eBay - description said it would no longer power up, regardless of it being bus-powered or having its own external power supply connected. Got it shipped for 30eu / $30, so why not?

#21 SM Pro Audio TB202 dual tube preamp / channel strip modding & upgrade

<Further developments can be found in parts two, three and four>

I'll admit, this was a bit of a lucky catch, in that it was mistakenly listed in the wrong eBay category, but one i "stalk" for good deals on certain faulty bits of audio gear. It was up for auction, there didn't seem to be much demand for it, and i ended up winning it for a mere 21 euros. About as much as the shipping for it ended up costing, oddly enough.

But still, even for some 40-odd bucks, not a bad little unit. Two channels, a (bare-bones-ish) compressor on each (1.5-10:1 ratio, 1ms/5ms attack, 500ms/1500ms release, at least according to the specs in the manual), as well as 3-band EQ (80Hz shelving / 1.8kHz bell / 8kHz shelving), and there's a tube / valve involved in the circuitry as well. If nothing else, i figured it would do nicely as a bass DI (or even an overdriven preamp, once some internal re-wiring is figured out and done).