Melcor EQs and Preamps: AE-20, GME-20, AML-27

[amplexus]

Here's one of my 4 pairs of AM-27's. This one has 990's, the rest have various flavours of 2520 (Whistle Rock, Red Dots and Fabios). I also threw CAPI H pads on the outputs of this one. The other pairs have fixed 15dB pads on the outputs just to tame them a bit cus they're so damn hot, and makes em hard to drive into the sweet spot.

Originally all my cards had the monolithic 5003 Op amps. I still have a pair of them, tho one is suspect.

This isn't my cleanest racking job- I actually have plans to move all 8 channels into a single 2U enclosure at some point. They're currently all being powered from an upgraded Soundcraft CPS450- overkill I know...

 

[mjrippe]

Very nice work! I have four of those MAP 5004 amps that I bought from someone here - maybe you?

 

[amplexus]

Very nice work! I have four of those MAP 5004 amps that I bought from someone here - maybe you?

Not me... I sold 4 of mine back to the guy who i grabbed the cards from- another local tech who i've known for years.

They'll look nicer when I do my 8ch box... I'm going to do an actual backplane for them, variable output faders on each.. will be killer once i get around to it!

 

[FIX]

API tried that in the early days, doing direct transistor dies onto ceramic. They were problematic so they went back to discrete, as did MAP.

 

[3nity]

Awesome thread.
Few years back I had 4 am-27 I was gonna rack but I sold them to finish some other projects.

 

[amplexus]

Reviving this thread as I've finally actually gotten round to re-racking all my pairs into a single 3U system.

Took a while to get all the requisite components together and sorted. The control panel PCB ended up being a huge pain as I sent to fab without double checking the hole size on a footprint the first time round and so the holes were too small for the rotary switches . An expensive mistake since this ended up being a 4 layer PCB.

But it's done, and other than a couple little glitches I still need to fix I'm quite happy. This actually ended up being quieter than they were in the dual hand wired racks. 3d printed the brackets for the card supports and the mounts for the backplane PCB.... investing in a good 3d printer has turned out to be a real lifesaver!

If anyone has any AM-27 modules they wanna unload, I'm in the market for another pair!

Also if anyone has modules they want to rack, I now have 4 free dual module racks all wired and ready to go... just add power supply!

View attachment IMG_1916.jpeg

 

[amplexus]

Will post this in the schems section as well but in case this is helpful- A full schematic traced from an OG MAP AM-27. This unit has the MAP5004 hybrid op amp and will support other 2520 footprint devices.

 

[zzzzz]

Will post this in the schems section as well but in case this is helpful- A full schematic traced from an OG MAP AM-27. This unit has the MAP5004 hybrid op amp and will support other 2520 footprint devices.

View attachment 129034

All of your work looks amazing, great work!

I was going to say that This might be of interest to you, but I’m seeing now your MAP AM-27 cards have a different pin out than my AML-27 cards