Digidesign Sync I/O won't power up.Switching supply is dead. New one is $40. After checking the obvious things, I'm ordering a fresh and new guy.Later- Received and installed. Working.For reference, it's a Skynet (yeah) power supply, part # SNP-9034. The Digidesign part had a custom cable loom in place of the male header. You just have to remove the header on the new board, and transfer the old wiring to it. Sending 2 Lomo 19a9s to Gefell for capsule repair.

Studio A's Neotek Elite control room monitor pot noisy.Replaced

greg wrote:Installed a new solid state drive in my newish mac mini today. Holy shit, what have I been doing up until now!Waiting for it to boot!

Installed a new solid state drive in my newish mac mini today. Holy shit, what have I been doing up until now!

greg wrote:FOR SALE:Listing a bunch of surplus parts taking up space in the shop on ebay.Going to be selling a lot of Mallory multi section capacitors, XLR, 1/4", and Edac connector parts. If you want to wire up a studio with NOS connectors, watch our listings...Update for the Reverb listing of on of our reribboned RCA BK11s. This is the last of these we're selling...https://reverb.com/shop/electrical-audio

Oh my god this is better!ATR looks solid (updates above). Cleaned a couple old noisy Noble stereo pots, used as the main control room monitor pot. I'm trying the method I use on the P&G faders, (distilled water cleaning the track, dry, alcohol on the brushes). We'll see if this works, and for how long, if I need to swap the studio b one.Looking at the Digidesign 192 that gave us problems recently when the fan failed. The symptom was output levels jumping around.

thecr4ne wrote:Hey Greg, do you guys use the 4665 Transformers in the Altec 525A psus for the 175s? Thoughts on this vs. going without them?We did have one transformerless supply, but I put one in so they'd be all the same. I think it sounded fine without it, but can't remember. Beyerdynamic M500 -Loose part inside.The diffuser/filter assembly fell off the ribbon magnet. Glued it back on, and replaced the decomposing foam in the windscreen.Schoeps 221b -Broken capsule pin on the amp. Replaced with a springed gold probe pin.

Hey Greg, do you guys use the 4665 Transformers in the Altec 525A psus for the 175s? Thoughts on this vs. going without them?

Neotek Elite-Cleaned some dirty switches.Channel 5 Aux AB always sending to A.I pressed the ground leg on the offending stack, and the problem disappeared. I suspect it's the same as some of the other pots in that the rivet securing the leg to the pot's pcb (or wafer) is losing connection. I tried a number of different pressure points, and the problem didn't come back. It will eventually. Unfortunately, you have to desolder the entire row of aux switches to get this one out. If it comes to it, I might disassemble the pot, in circuit, and do whatever work I can that way. Schoeps 221b-No output.DEAD AC701! The grid is internally shorted to the cathode. A smarter person than me said the mic was probably roughly handled. It doesn't happen electrically. So, I guess let that be a lesson for everyone. Treat like crystal!-Elsewhere NY-Neotek Series IICleaned a bunch of faders, fixed some channels, some by reflowing some broken solder joints on the channel headers, replaced some pots... Lexicon Prime Time delay-Delay would work for a few seconds after power up then go quiet, while the display looked the same (though no input metering).5v regulator was making bad contact with the socket it was sitting in. I cleaned it all out, and bent the to220 legs towards the pins in the receptacle. Worked the rest of the day. Their plan is to recap the main board, so I recommended to them that they solder the regulator directly to the board later.AKG BX20-Noisy Channel 1One of the fairchild dual op amps was oscillating. All the components around it measured correctly, and the oscillation occurred if the channel PCB was in either socket. They plan to recap and replace the amp when they get parts.Slappy delay sound on Channel 2One of the "record" coils measured open when the DC resistance should have been under 300Ω. The fault description in the manual was consistent with what we were hearing too. They're ordering a new one from a guy in GermanyOtari MTR 90 CB120 Remote-Display and functions freak out when buttons are pressed hard.Discovered I could reproduce the problem by wiggling a four pin cable connector on the board with the buttons (on top of the display board). I cleaned and checked the tension on the female socket pins, but the problem could still be there with some force. This cable went to a 5v switching regulator module. The four wires were in two pairs, high voltage-0v send, and 5v-0v return. The two 0v conductors were tied together at the regulator, but not on the pcb. I tried jumpering them together at the pcb header, and the problem never came back.Cleared up some other ground and power distribution issues.

Hey Greg, RE: altec 525A1:When replacing the selenium rectifier, did you just put in 4 diodes in a bridge configuration? I have one of these that just has 2 diodes soldered onto the old rectifier, wondering if this is sufficient. 2:Do you also put a new diode in place of Rect.2? should this be left half wave or bridged?Thanksgreg wrote:Altec 175 dead[color=#004000]Altec 525a power supplies-Replacing selenium rectifiers with modern diodes, and figuring out the right value for a voltage drop resistor for the B+. I discovered, while testing the above mic that a couple of our supplies were providing only 4 volts to the filament. Replacing the selenium fullwave rectifier with silicon diodes brought that up to 6-6.3 volts. The B+ was way to high with the new diode. I have to add a series resistor to it to bring it down. Working on the best value to get the voltages specified in the schematic.More later.