After a long while (10+ years) of periodically checking for 2.75"/70mm throw sliders to fill the gaps on the Langevin AM301, I finally stumbled across an auction for unused Duncan Slidelines and decided to procure one for every channel.

Granted, these are 100K lin as opposed to 50K log, but this gives me an excuse to fumble around with changing the law via external resistor AND to finally dive into this unit.

Off with its face!

This explains some of the non-functional channels, some others have fader assemblies that are breaking apart (not pictured, yet).

Better oust these old electrolytics while I'm at it.

Here's a shot of the stock wiring.

Here's someone's mod, I guess. Dual gang to unify two channels across one fader? It does explain why there has been an empty slot staring back at me as long as I have owned this thing. Mind you, I don't think this "fix" is still functional. Was it ever?

The stems on these faders are slightly smaller than the stock Slidelines, meaning I will be going with another sort of cap (I know I mentioned seeking some red Rollo looking caps last time). Onward & upward.

I'm slated to commence on a recording project this evening, so it's high time I get around to recapping the Langevin AM-301.

If anyone reading this has a spare couple of those red Rolo looking slider caps, I'm interested.

Another low parts count device, my favorite!

To the right is an upsized 33-50 (was a 25-25) CDE and 4.7-63 Spragues, but they are nigh on identical in appearance to the Nichicon caps in other values I procured. I miss the days of manufacturers celebrating their independence with unique and ugly colors (you know, when they made the stuff themselves..).

I decided to draw the line at recapping 4 (BEAD), retaining a pair of original (CF) and the pair of previously modified (HG, by an unknown tech at an unknown date) for comparative purposes. I've seen pictures of this mixer as a set, with EQ, limiting, etc, and am speculating that the traces that terminate at the end of the PCB can plug into additional modules (of which I sadly have none).

While the picture does not reflect this, I have recapped the master summing cards seen here. I have not yet messed with the 100-50 CDE Beavers, as to do that in a non-half-assed manner will entail actual disassembly (as opposed to actually reaching over and pulling open the flip up panel). I might be a lazy asshole and clip those caps out, loop the existing legs and install the new caps that way, but just typing that out made me cringe so that's probably unlikely. It will probably wait until I dig in to replace the channel 8 slider, unless malfunction forces me to tend to it immediately.

Power is single pole 48 volts DC. Makes it tempting to implement phantom power, though I could probably build up a small phantom power breakout box to piggyback that 6 pin Jones outlet with a lot less hassle and more ease of use. I do like the abbreviated "cue".

Another week with minimal actual work on the electronics front. Sadly, this seems to be the norm. So, in the meantime here's some gutshot of a Langevin AM301 discrete solid state mixer. As it stands, I have a stupid amount of mixers in my to-fix pile. This one is no exception.


As you can see in this pic, channel cards G & H are different from the rest. They've been modified for more gain at some point in this units history. My to-do list on this involves reproducing that mod on the rest of the cards, a recap and some front panel slider replacement. I've hunted for some faceplate photos of this unit, but nothing I've found meets my quality control, so I'll just have to post some exterior shots next time.

For the moment , here's a component side shot of a standard card, my apologies on the poor depth of field and flash washout in this photo, it is the best of the current bunch:


And a shot of the trace plane: