Is there an Oktava MC-012 tube mod?

C

ChoobieWoobie

New member
My search has turned up a "dorsey mod"..doesn't include a tube mod. I heard a sample recording that used the dorsey mod, and it sounded a tad boomy.

I also found a place called oktavamod.com...the guy mentions using tubes, but i dont think he offers them yet. I'd do the mod myself but i have no clue on what components to replace..plus there's a 99% chance that i'd screw something up anwyways due to my mechanical ineptness. On a similar note, I have seen some mc-012 compatable capsules..including a lollipop. I might pick up one when I get some more cash. Anyways if anyone knows what components i'd need to replace, what kind of tubes i'd need, or if there's any place else that would do a tube mod..please reply.

-Jim
 
Probably not until they start putting tubes in the 012, but then again, that's just my hunch... ;)
 
Oktava makes many different mics, and some of them are tube mics. But the MC-012 is not a tube mic. Perhaps the tube mods you are discovering relate to other Oktava mics.
 
ChoobieWoobie said:
I also found a place called oktavamod.com...the guy mentions using tubes, but i dont think he offers them yet.
Click to expand...
Michael Joly states on oktavamod.com (which is a pretty established site/biz) that he's assessing interest in this according to how many people email him (in order to determine whether or not it would be cost effective to offer this). he makes the point that the building of the tube power supply is generally so costly, that it would probably only be worth it if that got outsourced. If you email him and let him know you're interested maybe he can tell you where he's at with this.
i've seen tube power supplies on hamptone.com starting (i believe) at like $350, but by the time you get everything you need, unless you're just using a "starved tube" kind of design, then you might just as well get something like the chameleon labs tube sd mic that's coming out ($500 i believe), or the mic that another poster here mshilarious makes (a 1/10th of that!) that seems to be drawing rave reviews. i think groove tubes might make a sd tube condenser too.

edit: disclaimed added: i may be talking completely out of my arse.
 
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Yikes. Charging $350 for a power supply!?! What's it made of? Titanium!?! That's nuts!

Depending on the tube circuit and tubes chosen, you can build a cheap tube power supply with about $30 worth of parts (at retail prices). Been there, done that. It's not particularly hard, either.

I found a wonderful supply schematic that does a bit of a dirty trick: It steps 110V down to 12V and then back up to 220V using a second transformer wired in reverse. When you rectify that through a full wave bridge and throw some giant electrolytics at it, you end up with something like a dual ended 250VDC supply or so. I forget the details, but....

Really? $350 for a power supply!?!?!?! No, really. People can't really charge that much for something that brain-dead simple, can they? Seriously?

:eek:
 
MK-102 Tube Mod

Dave Royer published an article in Tape Op about modifying a small diaphragm SDK mic with a 5840 tube run in cathode-follower mode. This powersupply and signal circuit will work with the '012. I've built a couple for myself but am so swamped with my regular mods and the retailing of new, modded mics that I don't see offering a commercial version of my '012 tube mod anytime soon.

re: the $350 power supply - somewhere I saw a post by Dan Kennedy about the cost difference between a homebrew preamp made from $20 of parts and a boutique pre. The latter, if it has an internal transformer, has to be UL approved and will also have finishing touches like attractive graphics and silkcreening. In other words, a true professional product. Not that DIY'ers can't make really nice looking and fine performing stuff. But if they charged what their time is worth the item would be back up in the boutique price range.
 
MichaelJoly said:
re: the $350 power supply - somewhere I saw a post by Dan Kennedy about the cost difference between a homebrew preamp made from $20 of parts and a boutique pre. The latter, if it has an internal transformer, has to be UL approved and will also have finishing touches like attractive graphics and silkcreening. In other words, a true professional product. Not that DIY'ers can't make really nice looking and fine performing stuff. But if they charged what their time is worth the item would be back up in the boutique price range.
Click to expand...

Two stock transformers, a FWB, a couple of connectors, and a couple of capacitors or three. I counted, and it's 15 solder joints and took all of five minutes to build for someone of only average soldering ability (me).

The reasons I can build one so cheap are:

A. The dual-ended design instead of single-ended results in lower maximum voltage (+/- 150V instead of +300V) requirements.

B. Because the voltage requirements are lower, you can use common, off-the-shelf transformers instead of highly specialized parts.

The tube power supplies I see for $350+ all have variable output voltage, etc. The ones designed for a specific application don't cost anywhere near that, typically, even from commercial sources. Marshall has a tube mic for $200 new that comes complete with a power supply.
 
kojdogg said:
Michael Joly states on oktavamod.com (which is a pretty established site/biz) that he's assessing interest in this according to how many people email him (in order to determine whether or not it would be cost effective to offer this). he makes the point that the building of the tube power supply is generally so costly, that it would probably only be worth it if that got outsourced. If you email him and let him know you're interested maybe he can tell you where he's at with this.
i've seen tube power supplies on hamptone.com starting (i believe) at like $350, but by the time you get everything you need, unless you're just using a "starved tube" kind of design, then you might just as well get something like the chameleon labs tube sd mic that's coming out ($500 i believe), or the mic that another poster here mshilarious makes (a 1/10th of that!) that seems to be drawing rave reviews. i think groove tubes might make a sd tube condenser too.

edit: disclaimed added: i may be talking completely out of my arse.
Click to expand...

GT makes a medium diameter tube condenser -- what was the AM-40 under the Alesis deal and was then renamed the GT-44 under the M-Audio deal. I believe they still make a version of it (I'm too lazy to look right now). GC blew them out a couple years ago for $200. Really good mic (really!) with interchangeable capsules. Well worth picking up and still pretty commonly available used for @$250. I've got a couple.
 
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