TNC ACM-1200 Microphone Mod

 

ACM-1200 Mic

I purchased a pair of these through the TNC group buy. Again, these are rebadged Apex 460′s (among others) so the same mods apply.  See my DIY Meta for more details.  Overall I would say they sound bright.  The bottom end certainly filled in after initial tube burn in.  That bottom wasn’t exactly the most defined bottom I’d ever heard, though.  This post will be updated to include all of the mods I’ll be doing to these mics. So with out further delay, the mod:

The first thing I’ve done is order new tubes.  I bought a pair of Phillips JAN 5751s from tubedepot.com.  I had them tested for noise and microphonics.  I put them in last night and let them burn in overnight.  The sonic difference was slight.  I would say that the center frequency of the high end bump that this mic naturally has moved down slightly.  The top end isn’t quite as sizzly and there seems to be a slight boost in upper mids. The difference is minute, however.   This week I will order some transformers and caps.

RCA BA-31b Mic Preamp Restoration

I acquired a pair of these early solid state germanium transistor based mic preamps.  They are fixed gain with an easy mod that gives you 6db more when you need it.  The UTC iron on here is also key. From the numbers on the output trannies, I’m guessing these were built in 1965.  I researched the caps that were in there and found modern equivilants.  I’ve so far recapped one whole module and installed bypass caps across C12 (Output) and C6 (Output of gain stage).  I’ll post a BOM when I’m done. (BOM posted in DIY Meta)

Before And After ReCapping.

A Pile of Old Caps

I plugged her in and she purred like a kitten… And not in a good way.  It actually oscillated like a motorboat at first.  I read on Prodigy Pro that these are finicky about output load so I put a 680 ohm resister across the output as per emrr’s recommendation. Oscillation stopped.  Level came up.  The SM57 I was testing with sounded dreamy.  Now I’m gonna get started on #2.

EDIT 10/25/08:

Both modules are done and pigtailed.  I’ve powered them up and have been using them for make-up gain on my passive mixer.  They definitely have a sound to them.  I can’t wait to use them on vocals and overheads.  The next step will be properly mounting them in a Par-Metal case with phantom power.  

More info including a BOM can be found in my DIY Meta.

PM1000

Yes, I’m hooked on DIY. Here’s the latest addition to my studio: Two channels from a Yamaha PM1000 console racked up.

Makin’ Mic Pre’s – The SSL9K 4 Channel Mic Preamp

Here’s my latest endeavor. The SSL9k 4 Channel Mic Preamp. Here’s what I’ve done so far. Power supply, Balancer, and one Mic Pre board are stuffed and ready for testing. The power supply tested at +17.99v, -18.2v and 44.8v so we are looking pretty good there. Next I have to wire up the other two cards, get the gain switch going and plug in a mic and see how it works!

One channel done and mounted.

Close up of Channel 1 and Balancing Amp

More Progress. I fired up channel one.

1. NO SMOKE CAME OUT!!! = AWESOME!!!
2. PLUGGED A MIC IN ONE END AND SOUND CAME OUT THE OTHER!!! = AWESOME!!!
3. IT SOUNDED LIKE CRAP!!! = NOT AWSOME!!!

So there was some troubleshooting involved. After swapping out one of the 5534′s it sounded MUCH better.

Channel 1 wired up.

Gain Switch.

Then I got started on Channel 2. This one went much faster than the first. What took way longer, though, was wiriing all the connectors and switches. Eeesh what a pain! But it’s all wired up. I plugged it back in and Channel 1 still works and Channel 2 seems to be working too. The gain seems roughly the same between both channels. +48 is also working on both channels.

Two channels all wired up.

Two Channels wired close up.

My makeshift front panel. This is temporary.

In the rack.

Logo.

UPDATE!!!
Finally finished channels 3 & 4. Had some issues with thermal shutdown on the power supply but that was fixed with a couple of these:

Couple of heat sinks and now she runs like a top.

Here’s all four channels installed.

Little spaghetti like, but I’ve seen worse.

The Old Studer Speaker Trick!

So I am a believer in the idea that no mix can be called complete until you have given it the once over on the little speaker on the Studer 1/2″ machine. Since I rarely have access to those machines any more, I took it upon myself to find a speaker (with amp card) on ebay and put it together in a little box. It sounds fantastically crappy. Exactly what I wanted. Check out these pics and remember that woodworking ain’t really my bag…

Makin’ Bacon

I’ve been inspired by The Champagne of Blogs to make my own bacon because who doesn’t like bacon??? Bacon makes everything better, and I’m about to have 15 lbs of prime, apple smoked bacon of my very own. Finding a pork belly wasn’t exactly easy. I finally spoke North End Quality Meats where Jimmy said he could order me one. He was funny because the day it arrived, he called me and said he didn’t like the looks of it so he wondered if I could wait one more day until he got a nice fresh one.I left with this:

Notice the spare ribs Still attached

Also from the skin side.

Removing the spare ribs.

Cross section when I split it into 3 slabs

I then rubbed down the meat with salt, pepper and brown sugar. Two of the slabs got maple syrup as well and one got fresh chopped garlic, bay leaves and cracked coriander. They were put in ziptop bags and set in the fridge to cure for 7 days.

The slabs were then rinsed and left unwrapped for a day in the fridge. Then they were smoked with a combination of apple and maple wood.

UPDATE: I regretted the maple wood after the fact. It took away from the nice clean bacon flavor. In my second batch I only used apple wood and it was spectacular.

It ain’t enough to bring home the bacon…. One then must fry it up in the proverbial pan. Mmmmm… Bacon….

UPDATE: As I stated above, I did another batch since this was originally written. The second batch benefited from one less day of curing, a purer (all apple wood) longer smoke and my grandmother’s slicer. The rustic hand sliced feel of the first batch was nice, but nothing beats the control of a real slicer. The first batch had a slight ham flavor to it that I think came from having about 24 hours to long in the cure. That was rectified in the second batch. The second batch is fabulous. All In all, a great project.

Some pics:

Much nicer cuts the second time around.

Daft Punk Was Fantastic

iPhone “thumb surgery” story was a hoax

Cuz if its on the internet, it MUST be true!!!

read more | digg story

Mowo’s New Video!!!

Sooooo cool…

Land Rover Ad…

Finally got a copy of the Land Rover Ad I did the music for.

Land Rover LR3 ad

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