Designed a board for etching, re:Neve B002 polarity relays...
Kevin replaced the gain pot on that Traynor TS-10

Fender Pro Jr. crackles loudly when adjusting Volume pot.
Cleaned both Fender Pro Jr. gain pots with tuner cleaner.

Ordered and returned two versions of Parallels that won't work with my computer. I need to buy version 6 apparently.

Soundfield control unit in Studio A intermittently spiking in level, distorting oddly.
First bit of inspection, can't find any bad connections, or components. I suspect it is a bad pot or switch, which usually causes headaches. Need to bench test it.

Replaced a shorting connector in one of the Furman boxes.

Josephson 609/e22s prototype cutting out when mic'ing loud sources.
After comparing to another, I confirmed there was difference. Off to Josephson.

Work on the Neve B002
Used a heat transferable etch resist system called press and peel
This is the weird heater plate I bought at some garage sale. It's the first time I've used it and it worked great. Better than using an iron.
Etched, and drilled the polarity reverse board. Seen here is my awesome pcboard drilling jig-
Started rewiring of the mixer dude. Stuffed it. Cleaned the gain switch on Chan 3 (was noisy).

The other mic was a Beyerdynamic M201 with a torn diaphragm.

-Elsewhere-

Stock Neotek Series II Oscillator dying after 2-3 seconds, in a bomb dropping, pitch drop.
Tried replacing the (coincidence) XR2206 chip, no fix. Replaced the Fet, and capacitors in the circuit (shot-gun style). It now works great.

Same console- Mono function not working, though led lights up.
Someone installed too big of a capacitor at the base of a transistor which switches the fet circuit mono-ing the signal. Replaced the cap with the right one.
Same console- Echo return intermittently functioning.
Remove and resoldered molex headers. They were really poorly lined up.

This is my first post so..... I will most likely screw something up. I'm going to post a couple of the things I did in the tech room.
Nov. 7th
Weird MXR pedal that has been kickin' around the tech room is a complete mystery. The name of the pedal has been scratched off and the circuit board doesn't have any info that leads to an MXR schematic. It has a XR2206 function generator chip on it with two simple op-amps. could be a tremelo, still investigating.
Hot Cakes distortion/overdrive pedal has some really nasty sounding pots. exercised the pots quite a bit to no avail. broke down and sprayed some tuner cleaner in the pots and it works perfectly now.
packaged up a Josephson mic to get repaired.....and another mic but I can't remember the name of the other. Greg will remember. More to come...... soon.
Kevin

Magic Wolf wrote:Weird MXR pedal that has been kickin' around the tech room is a complete mystery.

If that's what I think it is, it's Pedal X, made by mister bill. It's a modulation pedal that goes from tremolo to ring modulator, but it also has enough output gain to act as an overdrive. Pretty awesome for head asplode noises.
I've actually been wondering where it went.

Greg Rules!! 2011!!Hide the pedals!!!! Hide the cat!!!

Beyer M201 is back and working.
3 Coles 4038s are back, re-ribboned.
RCA 74 Jr. has a stretched ribbon. I am going to use it on a loud guitar or drums and try to blow it out completely.

STC 4038 s/n 236 dropped.Cage dented (top mounting peg broken off), magnet doesn't look cracked, ribbon flat (coincidence).
I'll ship it off with the next shipment of 4038s.

AKG C-24 making popping noises on one capsule.

Studer A820MCH blacksides-
Channel 4 has dc spikes when recording tones, monitoring off the repro head. The spikes are not recorded. When it happens, channels 1-3 are effected in weird ways, muting, changing level, etc.
Problem followed the repro card, when I moved it to channel 8, including the side effects to channels 5-7 suggesting some corruption of the CMOS bus to the set of 4 channels ("bus converter 4 ch" board distributes the CMOS in sets of 4 channels). Replaced all the chips that are connected to the bus. In the past, a bad chip has caused similar problems-
not better
Replaced all the amplifiers, starting with the ones directly related to the signal path- nope
Removed IC 6, which would prevent any possibility that the sync repro signal path could be leaking into the repro path- nope
The board has been recapped already.
One clue, the sine wave starts to distort and triangulate just before the pop occurs.
Working with a spare until there's another free day in the studio to test more ideas.
I'm going to get my heat gun and freeze spray and really torture the board under a scope.
Later-
Other issues probably related to this occurred. Occasionally, channels' outputs would mute while recording. They would still properly record the signal while muted, then playback with no audio missing. This led to me replacing the "Bus Converter MCH 1.820.717" for channels 1-4, and then "Multichannel Bus Driver 1.820.723". The glitches went away.
Since both those boards comprised mostly of logic chips, I decided to shot gun the lot. After rechipping the Multichannel Bus Driver, the transport would hiccup during play as if someone nudged the shuttle wheel. It would also sometimes lose tension at stop, as if someone pressed the "unload' button. I checked the board closely for any cold solder joints or tiny shorts between the traces and pads. I also checked the power supply drop diode (5.6v enters the board through a diode in series to drop the voltage to 5.0v), and the 3 SAL capacitors. The voltage drop on the diode was .15v, which ended up feeding the board around 5.45-5.5v. Even though this seems minor, I replaced the diode, and the supply dropped to a solid 5v. C2 was slightly lower than spec so I replaced that as well. Tested on a free machine, and it worked without issue. When I can, I'll put it in the source machine to see if things are good there.

Nate Dort wrote:I figured. I think I've actually posted that part number in another thread around here, but never bothered to order one. I actually work for Harman, but I have no contact with the AKG folks, so they might as well be a separate company.

Maybe you can get an employee discount!
Email me if you need the guy I contacted.

Collecting ribbon mics for a reribboning shipment.
Digidesign 192HD Studio B-Input 11 has snappy spike noises.
Tried all the usual things to trouble-shoot. Replaced the AD card (8 channels).
Fighting with a studer reel hold down "adaptor" that has froze. There's a replacement "adaptor" on the machine it came off of.