UM57/ CMV 563 sound so boring, whats up?

[mattmoogus]

My CMV551 definitely runs on 120V. Its serial no 55x? - were there earlier ones than that?


Matt

 

[drpat]

...

 

[JLM Audio]

The 200v for the CMV551 does make sense. I was only going on the fact that Matts CMV551 came with a N61 power supply which is 120vdc out but that doesn't mean it is the right one of course.

Anyone know the power supply number N?? for the CMV551?

 

[hitchhiker]

cool info drpat,

The line out level explains why I love my cmv563 staight into a QE227

sans mic input xformer. Now with the better output transformer from Olly

it's even better. I could see clients not wanting to sing into anything else.

cheers,
Lance

 

[mattmoogus]

From all reports only some of the PSU units have the transistor preamp, and its sposed to be well worth bypassing. If your CMV seems to have a line level output you might want to look in the PSU to see if it has a preamp.

Have you changed the output xformer in your CMV? Did the original look the same as the one in mine (pics posted earlier)?

Matt

 

[hitchhiker]

hi Matt,

yes the output xformers in my two cmv563 mics look the same as yours.

My two n61 pwr supplies are adenyical, same sound ,voltages and no
transistors. I don't think they are really line level though, just a bit hotter than my G7.

Lance

 

[soundguy]

joe/matt-

how do you open the case for the M7 capsule?

dont want to break mine in the process of finding out...

thanks

dave

 

[mattmoogus]

Hey Dave,

Thanks for reminding me, I was going to put up instructions about opening the capsules up at some point. The first time I did it i had no idea if I was about to break the damn thing, but luckily i didnt, so heres whatcha do:

Loosen the two small grub screws that are just under where the head joins to the stalk until the heads are just past the surface of the hole.

Then hold the stalk in one hand and the head in the other and gently twist them back and forth while slowly pulling the two appart.

When they come appart there will be a thin rod on a spring that sticks down into from the head into the stalk, just make sure that doesnt catch on anything as you pull it out. Also make sure you dont loose the little piece of brass shim that will fall out.

Now youve got the head sepperated, you just need to undo the screw at the top of it. Some of them are covered with a bog, if yours is just dig it out to expose the screw. Once the screw is out, take the metal ring thats under it off.

Now you can sepperate the two halves of the head - you might have to prize them appart with a screw driver. When they come appart be careful you dont let the spring rod coming out the bottom of the head fall out as it may break the thin wire that is soldered to it inside the head.

Its pretty easy and once youve done it carefully the first time youll know what to look out for. When youre putting it back together, make sure the brass shim hasnt been bent or warped and if it has, bend it back to the right curve. Hold it on the head part (male) opposite the grub screws and then push the two together. If you try to put them together with it sitting in the 'female' part it will push up onto the spring rod and short out the capsule.

The one other thing I did to my M7 was clean the end of the rod that brings the capsule signal into the mic. It was black and so I scrubbed it clean with some steel wool.

Good luck with it, keen to hear some sounds from you (or anyone's) CMV. Ill be posting mp3s of the sounds of the different mods soon.


Matt

 

[Gus]

hitchhiker

Does the replacement transformer fit the same way the stock transformer does? Is it the same size?

 

[mattmoogus]

I really dont think the transformer is where its at if you want to improve this mic. Im basing that opinion on mine sounding pretty damn fantastic with the stock xformer and a few other repairs/mods.

Hey, if anyone has some lying around, send em to me!



M@

 

[Gus]

Matt

What other microphones did you compare it to? The reason I ask is sometimes a microphone can sound good untill you compare it to a REF microphone.

A ref microphone in this post means a good one that you "know well"

Gus

 

[hitchhiker]

Gus,

yes , the transformer is the same size and mounts directly in place.
I have to dissagree with mattmoogus.
The transformer upgrade is a great idea. I have a G7 with an M7, a U87ai, groove tubes 6TM to compare with besides two CMV563's with two m7 capsules.The two CMV's sounded identical before the transformer change in one.
One m7 sounds big ,fat and smooth from bottom to top.The other has a bit
less bottom and a bit of a boost around 8k-9k. Even though I knew this capsule was not quite right , it was my fave of the two for my voice before . The fat one sounded good on a woman's voice but on mine it was too round.
But now the upgraded CMV563 is my fave by far. I feel like I have a u47 type pressence but not quite as nasal. Punchy yet smooth.
When I tried the other M7 on the upgrade mic it was exposed for it's imperfection as a capsule. That capsule benefits from the veiled sound of the original transformer.

I would say if you hear any standout frequecy in your M7 then you might not want to upgrade.

cheers,
Lance

 

[Gus]

I just finished a p48 mod on one of my mv692s. I also changed a few caps. I used a um70 head and the microphone has a crappy transformer sound to it. It kind of has the sound of some of the china transformers less clear or detail than good lams can have.

FWIW I used the resistor voltage drop and ended at 33K for 11.8 V.

 

[jensenmann]

I was talking to a MG guy at the Frankfurt Musikmesse this year. I wanted to know if they sell M7 capsule OEMs, but they don´t. But he told me that if you own a MG/Neumann with a M7 you will always get a replacement for them.
What do you mikebuilders think about that
DIY U47 comes to my mind :wink:

From the Horch-distributor I heared that those mikes use MBHO OEM Capsules. Those mikes are really really decent. They easily blow most other mikes away. Maybe MBHO sells in small quantities...

:sam:
Jens

 

[Gus]

I have two microphones with MBHO capsules. One capsule I bought from a tt member. From the fall out of me posting about the capsule it seems that MBHO does not sell capsules to the public.

The Brauner I have has MBHO and the MBHO ck12 TYPE capsule is in the square microphone. I would like to get more of the MBHO CK12 type ones.

 

[soundguy]

does anyone know if there is an alternative transformer upgrade besides the tab transformer mentioned earlier?

dave

 

[jensenmann]

I don´t think that we are the public. There should be a way to get them. We are enough professionals who can communicate with MBHO on a bussiness level. I will lurk around for while, maybe I can find someone who has connections to them. The world is so small....
:sam:
Jens

 

[hitchhiker]

Dave,

I was given this info by Tab "ratio approx. 6 to 1 200 ohm min. load"

So I'd bet the lundhal for the g7 would work, or anything good between
5 & 7 : 1 ratio.

If I was'nt going to sell my second CMV I'd be trying out the lundhal to
compare. I'd bet the Tab to edge out others though. It's very even and natural yet still has a charactor. Very hard to describe.

Lance

 

[Gus]

Jens

If you can buy that capsule I think you will be very happy with it.

 

[soundguy]

I havent built a G7, will that lundahl fit inside of the CMV body? There isnt an incredible amount of room in there. I would be happy to have a lundahl in this circuit, its certainly not going to make it more boring, thats for sure...

dave