#84 Cymatic LP-16 teardown & repair

So this Cymatic LP-16 16-channel backing track player came in the other week, from a loyal and "repeat" customer, with the description of "turns on but doesn't output any audio". Additionally, it had possibly been tested also with an AC(!!!) plug-pack. Either way, by the time it got into my hands, it was completely dead. 

#78 Focusrite Saffire 6 USB 2.0 modding (adding a battery)

And here we are, on the third and final(?) part of the modding journey involving this little fella. As presented in the previous post, i managed to "persuade" the thing to power up fully despite not being attached to a computer, only to a USB-connected 5V source. But now, the time has come to integrate what is virtually a "power-bank", within the enclosure, and thus have the Saffire be entirely "self-sufficient", as it were.

#68 Alesis M1 Active Mk2 rehabilitation, part one

Over on the Badcaps.net forums, a thread was started all the way back in 2010, about power supply issues in these arguably "classic" low-cost active studio monitors. It even ended up being stickied just this winter, so it's been quite active and useful. It served as motivation for myself, to take up hunting for faulty ones - not sure if i had gone through three pairs, but at least two pairs i revived and sold off to a couple friends, some 7-8 years ago, and to this day i've yet to hear back about any further issues, so i take that as a good sign. In the mean time, i still contributed with thoughts and advice there, which helped lead to several successes.

Recently, a fellow forum member there got fed up with his failed attempts to revive his pair of monitors, and got himself a pair of new ones. In that context, we struck a deal for the Alesis'es, and a few weeks later, here they are.

#67 Audient iD22 part 2: the repair

 And now, getting back to the issue affecting this unit... As pointed out in the ad, the LT3439 apparently used to have a piddly little heatsink glued on top of it, but it got detached. Now, there's a chicken-and-egg type mystery here - did the heatsink glue fail because the chip overheated in the first place? Or did the chip get fried because the heatsink fell off? Regardless, investigation showed that one of the two switching transistors inside the chip seems to be stuck in a conducting state, despite the transistor itself not being shorted, though. But since it handles all the power for the analog circuitry, it's no shocker (no pun intended) that only the digital ins & outs work. 

#60 MOTU 8M teardown

Well, this one's a "biggie" - i had been lusting after one of these for a few years now, but the price was (and technically still is) on the prohibitive side, retailing at ~$1300-1500, depending where you look. Fortunately though, i've been stalking eBay off and on for one of these, and a used one happened to pop up just the other week, on auction. To my amazement and delight, despite there being at least 6 other "watchers", i was fortunate enough to win it for the opening bid, ie. about half the price of a new one.

#58 Behringer FirePower FCA1616 teardown

Long time no see, eh? Well, what can you do when the new job's kicking you in the rear end? Regardless, new patient on the table this time around - A not-that-often-encountered Behringer audio interface (now discontinued, "obviously"). I took the gamble on it primarily because it was cheap, secondly because i wanted to take a peek under the hood, and somewhat connected to that, curious about if and what "magic mojo" might the touted Midas preamps contain.

#57 Apogee Ensemble Firewire pt.2 - the repair

I was considering making the previous post about the repair as well, but once the teardown part of it was done, i decided it had gotten long enough already, so here's the testing and (hopefully) repair of it, separately.

#54 Recycled backlight LED strip ambient lighting

What with winter drawing closer, and the days (as in daylight) getting shorter up here in the north, one tends to need to turn on the lights more and earlier than in summertime. And since i'm the gathering type, i figured it's about time i put some previously collected materials to (good?) use.

#53 JMicron JM20330-based mSATA to ZIF-ATA adapter power modding

A few years ago, in the quest for more storage space, power saving, weight reduction and eliminating sensitivity to shock, i decided to upgrade my old iPod Video (5.5G) from the stock 80GB hard-drive to a 256GB SSD, with the aid of an mSATA to ZIF-ATA adapter, and some mods to the "aftermarket" Rockbox firmware.

... Except that recently, for whatever reason, it's been kinda flaky, and ended up giving up altogether. To aid with stability, i had also performed some hardware mods on the power supply side of things (as well as on the iPod's mainboard). The rationale behind that, at least in part, was the source of the above-mentioned mods, so i'll need to transplant those to this newer one as well.

#52 Solar A2.7 & Fishman Fluence Keith Merrow, part two

Aaaaand it's back! Not because of technical issues though. Due to chance, and the limited speed of international shipping, only the day after the owner got his guitar back, did the Fishman rechargeable battery-pack get delivered, just only too late to include it in the previous operation. But no matter, this should be far less involved than that.

#50 Philips HTS7201 Soundhub Home Theater (2.1) teardown & repair

This just came in, with the symptom description of "will no longer turn on". Fair enough, sounds like a power supply issue then. Apparently this retailed around $400-ish when new (according to a 2012 review i found online) - not exactly bottom-of-the-barrel, but it's still very much in the mainstream/consumer range, so i'm expecting crap caps to be the root cause. But time will tell.

#44 Ram Audio S6000 teardown & repair (rebranded as LD Systems SP 6K)

A good buddy and neighbour of mine had one of his amps kick the bucket in the middle of a gig (one i was helping out on, as well). On the bright side, noone noticed, only when turning-off time came. The beast in question was one of his two LD Systems SP 6K amps (rebadged Ram Audio S6000).

#37 Presonus Audiobox 1818VSL teardown and troubleshooting (part 1)

Together with the pair of Konnekt x32's (one of which is dealt with in the previous write-up here), i also got one of these Presonus Audiobox 1818VSL's. Also sold as untested, but powered up and allegedly detected by a Mac, so i figured it couldn't have been too far gone (or fubar'd).

The reality of it turned out to be a wee bit more complicated than one might've hoped...

#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?

#28 Active full-range surround speaker project (BN96-12832 & TPA3118)

Since the "unofficial" theme of this blog seems to be repair, recycling and repurposing (more or less), i finally got around to getting knee-deep into this idea, which i started devising quite a while ago - a pair of "slimline" surround speakers.

Disclaimers:
 - No, these are not meant (or supposed) to be "hi-fi". More just for a bit of "ambient noise", if you will, for movies with 5.1 soundtracks. That, and possibly alternative monitoring for checking mixes.
 - No, these are not meant to go terribly loud. Due to, let's call them, physical constraints, they'll be placed at the corners of my sofa (right up against the wall, opposite the TV and the "mains"), so no huge SPL's are required.

#27 Samsung 5V 1A ETA0U81EBE USB travel charger

This one's a quickie, but i figured i might as well document it.

A friend passed me this a few weeks ago, not quite sure why. I don't recall it being mentioned as dead, only not-used. Either way, last night i wanted to charge the battery inside my modded M-Audio Fast Track, in preparation for a local gig next week. Upon plugging it into this thing, the power LED flashed up for an instant, then nothing. I figured it might not like the USB data lines being tied together, as they often are, in chargers; it powered on and worked well with another charger. But that prompted me to crack this one open.

#25 Behringer ADA8000 "Ultragain Digital" revival

I got my hands on one of these Behringer Ultragain Pro-8 Digital a few months ago, as faulty (as in, totally dead) for about 50$ shipped. Having done some preemptive googling before going for it, i was expecting the transformer to be toasted. Sure enough, that's exactly what the problem was - one half of the center-tapped primary measured in the hundreds of kohm, so pretty much open-circuit (as opposed to the 50-odd ohms the remaining good half measured).

Initially i was planning on finding / getting a "drop-in replacement" toroidal transformer, ie. similarly sized physically and power-wise, but with less insanely-high secondary voltages. The stock one, according to some "inspection notes" i found online, seems to have had roughly 2x20VAC windings for the analog +/-15V (meaning the voltage regulators had to "burn off" uselessly much power / voltage), 12VAC for the 5V regulators, and a whopping 58VAC winding for the phantom power regulator. That's about a 50% overkill across the board. One can only wonder just what possessed them to spec the transformer quite like that, especially since it must've been a custom order - you'll rarely find retail units with more than two (identical) secondary windings, and when you do, expect to pay a pretty penny for'em.

#20 SM Pro Audio TB202 power supply repair

<Some sort of continuation from another post>

Buuuuut that brings us to what might as well amount up to the proverbial "elephant in the room" - the power supply. No markings or label anywhere on it - if i didn't know any better, i could almost say it never had any (no adhesive residues or anything). Fortunately, it was held together with four Phillips-head self-tapping screws, so "disrobing" it wasn't unecessarily traumatic. That being said, what greeted my eyes, sort of WAS.