ribbon mic transformer comparisons

antichef

antichef

pornk rock
I've got a kid's birthday party this weekend, so it's not looking too good for my comparison of the Lundahl 2912 and the Edcor RMX1 in the TnC ACM-3, but to prove I'm getting closer, here's a (decent, for a change) pic:

acm3-n-trannys.jpg

stock tranny, Edcor RMX1, Lundahl 2912 (w/ghetto output lead extensions, and ready for action)
(this is actually the dead RMX1 that Edcor quickly and graciously replaced - a working one is currently installed in the mic - they said not to bother sending the dead one back -- is it even worth while to try and dissect/fix it?)

To anyone who's been following these threads: have the samples been helpful? I'm pretty much limited to guitar related sounds -- can't sing at all, and don't have quick access to anyone who does. I have some other instruments, too, but I'm primarily a guitar player.

I prefer to keep using this re-amping technique, because it's so easy to supply the exact same sound source before and after a mod, but if anyone has any comments as to the music itself (lots of dynamic range, lead licks, heavy riffs, etc.? I've got a bunch of amps, too, from small '50s tube to large 80's tube) I'm open to that. I can either use that Amazing Grace one again or record a new one based on any input.
 
Now there's a good helpful pic. Good shot.

K & K is still out of stock on all ribbon mic transformers. Should be in next week though. I just hope I don't drool into the guts of my ACM-4 while doing the swap ;)
 
chance -- yes, absolutely - do what you like with the picture.

You'll notice how much larger the RMX1 is than the others. It's a very snug fit in the ACM-3. The 2912 is maybe smaller in volume than the stock one, but its length is what prevents it from sitting in the mu metal chamber in the ACM-4. I'll probably have to put some cotton balls in the ACM-3 to keep it from clanking around.

I'm still open to suggestions for the sound, but if I don't get any I'll use the same sample (both for laziness and consistency's sake :) ).

After the test, I'll probably leave the Lundahl in the ACM-3, and then put the Edcor in that Nady RSM-4 that I got (the other working Edcor is in my ACM-2) - then I'll have two lollipop style ones with the Edcor trannys and I can try some stereo recording.

And I sort of think I know how the test will shake out - you can't say that either the Lundahl or the Edcor is better, because they're so different sounding. The Edcor seems better for heavier, more aggressive sounds, and the Lundahl seems better for smoother (jazz, laid-back blues) sounds. I know I'll have a hard time using a non-ribbon on an amp after all this.

Oh, and for the record, I did have to retention the ACM-2, the ACM-3, and the Nady RSM-4. Doing it to the Nady mic was the hardest, because the ribbon was glued down on both ends, it seemed like. I sort of had to bunch up the unglued portion of one end of the ribbon under the clamp to get it work.
 
OK - despite the kid party, and the impending Superbowl, I was able to swap the transformers in the ACM-3 earlier today, and do a before and after, with some pictures.

skylarkandbird.jpg

first, (as demonstrated by my lovely 15-mo-old assistant, who got a temporary tattoo at her older brother's birthday party) here's the hardware for my before/after - the reamp track was recorded with the pictured guitar - an Antoniotsai SG clone modded with Gibson P-94 pickups. The track was then played through the displayed amp - a 1962 (I think) Gibson Skylark. This amp is very bright sounding, maybe too much, so I thought it would be a good choice to show the difference between the two.

edcor-lundahl.jpg

I got to work when I could -- here's the guts of the ACM-3, with the Lundahl partially in place. Simple enough for even me to work on it. The biggest challenge, as it turned out, was to tease the transformer and leads down the body of the ACM-3 enough to grab them from the bottom end, so that I could solder them to the XLR pins. In fact, I broke one of my ghetto output lead extensions trying it, and had to strip the white output lead a little to resolder it -- this was a nightmare. The output leads on the Lundahl are dainty, and the insulation is really tough. It took a few tries, and this was the most frustrating part of the job. Except that then, I had to try and fish the thing down through the body *again*....

edcor-lundahl2.jpg

Ah, but this time I had an idea -- I took a 3x5 index card and fashioned it into a tube, and then arranged the transformer and leads the way I wanted in that before curling it closed and stuffing it through the body of the mic. That way, I was able to pull the card out of the far end, and grab the extended output leads gently enough to pull them where I could solder them. That picture is a little too bright to see (I'll try darkening and re-uploading it).

I'll post the samples in the next post, to make them easier to find.
 
and here are the samples - each a 24 bit wav file, about 15 megs:

before -- Edcor RMX1 in place:

http://www.recursor.net/e-l/ACM3-Edcor-Skylark.wav

You can hear my wife yelling in the background - she was upstairs trying to study, and I had the amp volume on 7, which is pretty loud, even for that little thing.

after -- Lundahl LL 2912 in place:

http://www.recursor.net/e-l/ACM3-Lundahl-Skylark.wav

One thing is worth pointing out that you won't be able to tell from the samples -- both transformers seem dead quiet -- all the noise is coming from the amp (and the yelling :) ).

The rest of the chain is the same as the previous posts - 5' XLR cable into BLA-modded MOTU Traveler with BLA Microclock, gain at +20 (pad off, so I guess that means gain +40), into Logic Express 8, dry, of course.

I'm lucky to have made it through another modding adventure with a still-working mic and no serious burns. Next will be to put that Edcor into my Nady RSM-4, so that I'll have something of a match with my ACM-2 (which currently has the Edcor and sounds great to me). Then I can do some stereo recording with those lollipop ribbon mics.

Superbowl's on, so I stopped short of putting them in a mix, like last time. If anyone wants to hear that, let me know and I'll do it a little later.
 
antichef said:
I got to work when I could -- here's the guts of the ACM-3, with the Lundahl partially in place. Simple enough for even me to work on it. The biggest challenge, as it turned out, was to tease the transformer and leads down the body of the ACM-3 enough to grab them from the bottom end, so that I could solder them to the XLR pins.
Click to expand...

If you give it a slight whack with a hammer, the XLR connector shell should push upwards through the body, IIRC. One of mine was pretty tight. The other one pushed through with just my thumb. YMMV. In any case, it should slide all the way through the body and out the top. Makes it a lot easier to replace the transformer if you can solder the guts together completely before you assemble anything. :)
 
dgatwood said:
If you give it a slight whack with a hammer, the XLR connector shell should push upwards through the body, IIRC. One of mine was pretty tight. The other one pushed through with just my thumb. YMMV. In any case, it should slide all the way through the body and out the top. Makes it a lot easier to replace the transformer if you can solder the guts together completely before you assemble anything. :)
Click to expand...
Heh, yeah I guess that would make a big difference :o. I'll definitely go that way next time.
 
antichef said:
Heh, yeah I guess that would make a big difference :o. I'll definitely go that way next time.
Click to expand...

I'm about 95% sure that is correct for both the ACM-2 and ACM-3, but I'm not 100% certain, so take that with a grain of salt. If you pull out the connector and look in the tube and it doesn't show any obvious cut-in section where the connector sits, then I'm remembering correctly and it should push through the other way.
 
Lundahl 2912

I've used the Lundahl transformer before and was pretty impressed with the quality. Have you ever tried any Cinemag transformers?
 
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