#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.

#15 Alesis io|26 repair & modding

So, i got my hands on one of these Alesis io|26 interfaces for pretty cheap (50 bucks delivered). "Of course", i bought it as faulty (can you see a pattern yet?), with the already "classic" issue of dead Firewire chip (the ubiquitous Texas Instruments TSB41AB2).

I went for it mainly for two reasons. First, because i knew it was based on the TC Applied Technologies Dice II chip, and as such, should have flexible enough mixing / routing options; second, due to the ADAT inputs available. The sort of "added bonus", one might say, were the gain adjustments for the 8 analog (mic/line) inputs.

#14 TC Electronic Studio Konnekt 48 "Dice II STD" replacement / transplant

A couple years ago i got my hands on a faulty one of these. Details of the revival process can be found over here; photos visible only for forum members though. Buuuuut since i'm in a good mood, OVER HERE you can find the link to a Google Drive folder with all the (relevant) photos i had posted on that particular thread - you're welcome...

The last issue i had to take care of, back then, was the (apparent?) shorting to ground that some of the I2S clock signal lines, coming out of the Dice II chip. Fortunately, it has several sets of these clock output signals in use, so between cutting a couple traces and adding some wire jumpers, i managed to put together and distribute a healthy set of clock signals to all the ADC & DAC chips that required them.

PS: It seems that the original link for the schematics of this unit is dead nowadays ("thank you", Music Group?), but for the sake of completeness and posterity, i've reuploaded it right over here.

#13 Fisher RS-1022 rehabilitation and bling-ification

So i had this old Fisher RS-1022 Studio Standard stereo receiver brought in, with one of the fuses in-line with the speaker outputs blown. Fair enough, that was easy enough to replace, they made it quite easy, with the fuseholders being mounted right on the rear panel. The clamps were nowhere near as elastic (or firm) as they might've once been, but with a pair of needle-nose pliers and a bit of creativity, that was no biggie.

Second issue, five of the six lamps that illuminate the tuning scale and the radio signal level were dead. In four of the dead ones, the fillament was attached only at one end, and in the fifth, it was attached at neither end. Interesting little lamps, 6.3v AC, 250mA, in a similar casing as 6x32mm glass fuses. Good luck finding replacement ones (which may very well just end up dying again anyway); these will get replaced with a few white LEDs recovered from a laptop display's backlight.

#11 sE Electronics sE X1 rebuild

It's been a good few years since this mic (sE Electronics X1) came into my possession. As many others i have, i bought this one as faulty. The main problem was, it was noisy as hell (think wind-noise, or the sound of blowing straight into a microphone).

Once i had another capsule to test this with (a temporarily removed capsule from a Shure KSM27), i figured i'd hook it up to the X1 to see whether the capsule was the source of the noise. Nope, the noise was still there. After i ruled out the (stock) capsule, i replaced it with a 100pF styroflex capacitor, for minimal hassle (and risk of damaging a capsule) during subsequent testing of the electronics.

#9 Revisited: Amphion Impact 500 (DB Series DB5004) subwoofer amplifier - DONE!

Got the fresh parts the other week, and installed them all. That, plus rebuilding the two blown and "distressed" traces, respectively.

#6 Canon EOS 400D / Rebel XTi troubleshooting & repair

I got this old EOS 400D from a friend for about 35 bucks. She said it won't power on, even with a fully-charged battery. Might as well have a crack at it, eh?

On the outside it seems to be in pretty good shape. A bit of dust here and there, but hey, it's about a decade old, whaddya expect? Battery checks out fine, reading 8.15v, so that's definitely not it.

As chance would have it, between being offered the camera and receiving it, i did some digging around online, and i came across this little story here (scroll down to the second half of it). Could i (also) be fortunate enough to only need to swap out some fuses?

#4 Dunlop Zakk Wylde ZW45 wah pedal teardown & repair

Ok, this one's a real quickie. One of the guitarists in my band got this wah (Dunlop ZW45 Zakk Wylde Cry Baby Wah) as a gift a number of years ago, and in the last few weeks it developed crackly and intermittent sound (regardless of being on or off).

Initial fiddling with the power / input / output jacks pointed towards a questionable patch-cable, but even that soon stopped working, which then turned my suspicions towards cracked solder joints (rather than the jack sockets themselves).

#3 MOTU 8Pre teardown & gain adjustment pot replacement

On the latest drum tracking session i surprisingly discovered that channel 8 on the MOTU 8pre in my recording rig was noisy and useful-signal-less. This same unit had a similar issue with channel 6 when i bought it (as faulty, with a shot Firewire chip).

Fortunately, when i was about to take care of ch6, i got two replacement pots. When investigating the issue, i had read it's a relatively common occurrence, so i figured that as long as i'm contacting the local MOTU distributor, might as well get an extra / spare one, just in case (especially since i had two 8Pres at the time).