There....it is started. I am interested to know how to do this. Anyone?

BTW...

I'm not really interested in rebuilding a mic from scratch.

But I could probably replace a Tube, Transformer and a couple of Caps. Beyond that I would just buy a different Mic.

Cool. But the thread should read 460 / TCM1050 OR Chinese Mic Mods

All I can add to get this going is that there is a helluva potential market (for the end user) that is just getting tapped here.No shit, despite comments from some cats searching ( ad nauseum at times) for that perfect german mic to suit their needs, a mod'd chinese mic can more often than not fill the void, imho based on my findings and other ppl that have high end german mics....

I for one have a vintage Neumann 87i and have seen (heard) it lose out to recent A/B's against a mod'd Nady TCM 1050...While seemingly unimportant to some, these findings have been HUGE and have lead me to re-evaluate how I relate to "quality mics," ( like the bullshit that you need to spend $3K for a top shelf mic) that aren't of notable brand..I'm not just talking about Neumann and Gefell but US Tele's and Peluso's even..This CM47-LE that I've been playin with for eg is WAY less dough than a 2247LE (which I've 'heard' but not had in my possesion) and I could buy 2 CM47-LE's for the $ of a 22 47LE and still have change left over for an SM7b .. "ymmv"

I have a 1050 sitting on my bench just waiting for
a few slight mods. I recorded using the stock mic and was surprised that it sounded like it did. Eventually it will get a new capsule but probably just put a hammond transformer in that I have. At the price I got it it's a good one to mess with. Perhaps even changing the cathode follower circuit to a plate one.

quote:

Originally posted by Bazz:
This CM47-LE that I've been playin with for eg is WAY less dough than a 2247LE...

I think the key here is the capsule. Modding a 1050 or 460 without putting in a good capsule is only going to get you so far. I agree that the CM47 sounds great. The one I have has a Peluso CEK367 capsule, and I think that's the reason it sounds great.

Well guys, I can make a list of the mods I've made personally:
1. Replaced capsule with Peluso CEK12 (could have used CEK367)
2. Replaced transformer with Cinemag 2480 (removing C9 and C10, which are unnecessary with a good transformer).
3. Replaced C8 with 1uf 400V Ansar (C8 is an important signal path cap which couples the transfomer to the tube).
4. Replaced C1, C2 with 100uf 250V Black Gate
5. Remove the cathode follower (can give details if anyone's interested). Transformer upgrade makes this useless. Gets the circuit more in line with AKG C24, or ELAM250/251.
6. Replace D5 and D6 in power supply with IN4758 zener diodes to lower voltage. Be very careful when attempting this and stay away from the big capacitors nearby.
7. Removed C6 (could also remove C7).

Hope this is useful.

Craig

Guess what? The Chinese can make good capsules too. You might have to pay a couple of bucks more, but it can be done and is being done.

Yes,

Please explain more about eliminating the cathode follower. How to, and what it does.

Does it lower the gain of the mic? I'm just concerned about having too little output, with a 6072 tube already.

And concerning the p.s. mod, here is something Michael Perez-Cisneros told me. I hope he doesn't mind me posting it. He'll probably be on here soon anyway.

"Also, Lowering the value of the diodes will give you mixed results IMO. Those zener diodes provide the voltage for both part of the tube and the mic's capsule. I toyed with that mod but didn't like the result.

First, the good part: Lowering the voltage slighty to the capsule seems to change the sound in a nice way. A bit smoother more vintage-y.

The bad part: while lowering the voltage to the capsule is arguably better IMO the net result of lowering the voltage to the tube is not good."

Also, 100uF/25 volt for C1 and C2 is pretty different from the 1uF/50V caps that are in there. Why so high on the uF? Was that just what was available via Black Gate? Wait! It just occured to me that I have a couple Wima MKS-2 (really small) film caps that are 1.0/63V. Maybe I'll try those.

Yep, they can make good capsules. You probably won't find one in the Nady and Apex tube condensers though.
Peluso gets his brass work done there. When they take the time to put the bits together, I'm sure they can do as good a job as anybody.

Regarding capsules, the Apex460/Nady1150 really don't sound that good with their original capsule. I think it has to do with the cage size for the capsule. While the Nady1050, which has a much larger capsule cage, sounds much better with the same capsule. It also needs to be remembered that the original tube in all those mics, whether they say it or not, is not a 12AT7 or 6072 but a 12AX7B chinese tube. The cathode follower does not add any gain, but has the ability to drive a much smaller impedance that the standard gain circuit. Especially with the capsule change, I found the cathode follower to sound too bass heavy or lumpy. There's a long topic on the mods over at homerecording.com that has all the mods, with loads of comments.

The cathode follower I believe makes it possible to use a cheaper, lower ratio transformer. When you change the transformer to a higher ratio model, the cathode follower isn't necessary. I prefer to make a circuit as simple as possible in any audio gear. Plus, as I stated earlier, it makes the circuit closer to the ELAM 250/251 or half of the C24.
As Michael said, the mod thread at homerecording.com talks about all of these mods. I believe it's called something like "Apex 460 capacitor change".
He's also correct, in that the cathode follower affects the low end of the cicuit. I prefer the sound of the mic without it. I've tried both.

Ah, okay,

I've actually read that thread a few times now. So, removing the cathode follower WOULD be C6 and C7 part of the circuit?

I don't know enought about the circuit yet to realize what part is what.

quote:

Remove the cathode follower (can give details if anyone's interested).

Yes, yes! please do!

mud

That Ansar cap is not polarized, is it? Does that matter? The schemo indicates a polarity there.

mud

The Ansar is not polarized.

To remove the CF you need to:
1. remove R8
2. disconnect tube pins 6, 7, 8-connect them together and to a ground point
3. connect C8 to the junction of tube pin 1 and R2.

Here's the schematic to clear things up:
http://www.angelfire.com/ky3/craigorris74/a460schemCFremoved.JPG

Excellent, great job!

I'm in the mod process with my 460 now - will try this, too.

mud

Hello - I have an MXL V69 and would like to replace the tube. Can anybody tell me a few little things ... like how?

You should be able to unscrew the bottom of the mic, then slide the rest of the body off. Once inside, the tube should be in a socket. Gently wiggle the tube until it comes out. What kind of tube is in there?

I actually have a question re removing / replacing the tube.

A friend of mine kinda freaked when he saw me touch the tube on his 460 and said: DOn't touch the tube with your bare fingers!@!! You'll create a hotspot on the tube, and it might crack!!!!11

Huh? I guess in theory, but I've replace a ton of guitar amp tubes (which run hotter) and have never experienced that prob? Anyone else ever heard of this?

Craig - it's a MXL 12at7 - I've got a Mullard - gold pin to replace it with.

The tube is just REALLY tight in the socket and I was worried there might be some kind of lock.