3/24/04
Problem-
Studer 820MCH (blacksides) channel 2 sync output not there on two occasions

Solution-
Recapped all five audio cards after I found a bad bipolar cap on the NRS control card. That card is where the output signals are switched and routed to output amp.
Any time I recap a card I'll also carefully remove all the ICs and clean their sockets with alcohol.

damn EA sucks ! all machines are messed up ! I'll never ever record anything there !

-smiley-

Upkeep schmupkeep!

4/7/4
Is been a while. How's everybody?

Problem-
Lexicon Prime Time has noisy faders. I need to find replacements. I can't retro-fit another fader because there is no room.

Recapped a more studer cards.
Looked for parts.

greg wrote:Problem-
Lexicon Prime Time has noisy faders. I need to find replacements. I can't retro-fit another fader because there is no room.

Hey Greg,

You're probably already aware of this guy, but in case you're not, try www.jimfabiano.com. He specializes in older Lexicon pieces.

Chris Garges
Charlotte, NC

4/8-9/4
Repaired cables and snakes.
Worked on my compressor project.
Tracked down some 14"reel flanges.

Problem-
Sytek mic preamps occasionally have a DC charge on the input with the phantom power off. This caused a "snap" noise on a ribbon mic when I pugged it in.

Solution-
I talked to Mike Stoica who told me that the electrolytic bypass capacitors that appears on each channel after the phantom switch and before the 6.81k drop resistors were probably still charged. When I patched it in at the patch bay the voltage was discharged through the mic. There isn't much current there so the mic doesn't get zingged to bad. However the way to keep this from happening is to switch off the phantom power a few minutes before disconnecting the mics. This will discharge the caps through the mic's electronics.

Problem-
Neumann SM-2 to GML mic preamp channel 4 to M-S Decoder To channel 22 Elite input out the 2-mix caused and oscillation at around 30K to appear.

Solution-
I recreated this arrangement and played with the settings to try to cause this problem. No luck.

Problem-
GML channel 4 set to 55dB gain or higher being "unstable" with the Sony c37p. I will ask what "unstable" means exactly.

Solution-
I recreated this arrangement as well with no problem.

4/12-13/04
Lexicon Prime Time- Cleaned faders and connectors, and looked for replacement faders. I called Jim Fabiano but have not got though to him yet. Thanks for the recommendation Chris. I seem to remember him not having parts for the Prime Time when I talked to him last though.

Problem-
Drawmer 201 dual gate doesn't work on the left channel.

Solution-
Filter pots for the sidechian were dirty and intermittent. I cleaned them so they work now.

Yamaha 1010 delay- Ordered a new power transformer. We bought it from Europe so it had a 220 - 240V transformer, that couldn't be switched to U.S. voltage. I powered it up with our variable ac transformer to see what voltages we needed (+-18V and +8V).

greg wrote:Thanks for the recommendation Chris.

No problem.

Chris

Last few days

Problem-
Ampex 351 #8 has a high hum it's output.

Solution-
Hum located after the first gain stage. You could hear the hum at a consistent level with the gain pot in any position. The problem was in the power supply board. The filter cap C-16 was measured under spec. When I added a cap in parallel to raise the C-16 capacitance, the hum went down significantly. So I replaced the cap.
There are some corrections that I need to do for the schematic. I'll post them on the 351 topic.
Problem-

4/23/4

Problem-
Ampex 351 #s 8, 6 and 2 have intermittent pad switches. The signal would cut out when you wiggled the switch knob. These are a type of C&K rotary switches that were originally installed. They aren't reliable.

Solution-
Replaced them with the new Grayhill switch (as mentioned in the 351 modification posts).