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OK, with the schems, I think we're getting somewhere. Please clarify something for me. The supply you pointed us at says it's a +24V supply. The Schems for the M470A show that it wants +24V and -24V, connected to P2-21 and p2-19, respectively. Internally, the modules are regulating that down to +/- ...

OK, the supply voltage stays good even when the modules shut down? A good clue. Have you verified that at both the supply and the module? Do the modules have relays or mute logic or anything? Maybe that's somehow charging up and shutting stuff off after 5 minutes? Which modules are these? Are the sc...

Start here: http://www.uneeda-audio.com/pads/ Balanced or unbalanced? Any more specifics about the overall situation? What's overloading what? The same theory applies to line level signals. Line inputs are often 10K or 20K ohms. Generic line outputs start to get unhappy as the load approaches 1K. Th...

From that datasheet: "Millenium Supply" switch mode power supply Switching supplies aren't all the great for audio work. They're fine if they're matched to what they're driving, but that match has to be fairly close. It's fine for brand-new gear where the designer can carefully match a supply to the...

The solder joints on the power connector are solid and easy to fix, you can see them right below the big cap in the center. Somehow I doubt this went bad. I have access to a scope. How do I see what is wrong or right with it? I really dislike those board mounted power jacks, whe kind where if the p...

If you don't have an oscolloscope, it'll be hard to be certain about what's happening. If the big cap by the power jack was flaky, it could cause what you're hearing: power supply ripple or popcorn noise getting into the rest of the circult. In this case, the power supply lines won't be a constant v...

My recipe: *Buy two of each component you're going to use. *Build one copy of the circuit on a solderless breadboard. Spend some time making it neat & tidy. Don't be afraid to rip up and restart. *Test it thoroughly. *Get a perfboard with the pattern that's like the solderless breadboard. Use the se...

What's your interference environment like? The twisted pairs in the quad cable help keep some of the induced crud out of your audio. Plenty of reading at Belden.com about the benefits of twisted pairs. But if you're somewhere without lots of RF or EMF junk in the air, it may not buy you much. The qu...

This sounds a lot like a MIDI ground loop. You run the pitchbend or modulation, and get zippery pops on the audio outs? MIDI is spec'd so that the receiving device has an optoisolator...inside that isolator is an LED that's effectively a piece of the transmitting gear's circuitry, with no electrical...

I'm actually building a small run of an EQ that I designed myself. It's not a clone of anything, just something that perseverance and experiemntation led me to. It uses passive LCR filters and a transistor gain stage. There are 3 bands, each with 6 selectable frequencies. The highs and lows offer bo...

How do you do component layout? In the old days, people drew on film with markers and used that to make the necessary film to expose a PCB. Look at old Neve or API cards, and the traces on them have a very flowing, organic quality, because they were drawn by hand. Today, in 2006, I use software for...

Just sitting here, I can think of maybe 5 people who own Cubes (60's and 100's), and I know that 3 of them are still in regular use. That those 5 people are involved in completely different styles of music attests to their versatility. It seems like a lot of the little amps I see around today aren't...

There's an MCI 636 on Ebay for $2500. A real aircraft carrier of a board.

Another guess: crummy mic stand that relaxed through the set, and a mic wound up physically touching something, and rattling?

Byron Jacquot

I think GC would do well to start a GC "Pro Shop" and put one in strategic locations, maybe 5 of 'em... NYC, LA, Nashville, Dallas, Chicago maybe?

Your prayers have been answered.

www.gcpro.com

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