mxl v67 mic mods?

[Ntchi]

Hi!

Looks like there is a lot of good electronitian in here!

I have an SE Electronic H3500 FET microphone That I used for the past 6 years. Even though I own 5 other mics, I really loved this one once in a while. I has a certain character very similar to a TLM103 but warmer.

Now my problem is that sometime the output gain drops by 20 to 30db for a couple minute and then goes back in. Like there's a fade out of the signal for some strange reason and comes back a few minutes later.

Is this a capacitor or transistor problem? or trasformer? I'd like to repair it myself with new parts.

Thank you!

[Ntchi]

Originally Posted by Haz-Mat-Strat

The front end of this circuit is basically a copy of the U87. If you take some of the values Neumann used this may be a better option.

C2 470p Styroflex
C3 820p Styroflex
C8 1uf Film

C2 Most people us a 1000pf here however the 470pf gives you more of a vintage sound
C8 is one of the most important caps in the circuit you can use a BIG cap here. Solen, Wima, Axon, Mundorf @ 250v this will give you a great tone.

Neumann also used Tantalum capacitors in in their U87 mics. This is also part of the tone of the mic.

What change will it make to change C2, C3 and C8? What do you mean by vintage sound?

If I use the same value as in the scheme I will still have an upgraded sound right?

Guess I'll do 2 mods...

[Haz-Mat-Strat]

Originally Posted by Ntchi

Hi!

Looks like there is a lot of good electronitian in here!

I have an SE Electronic H3500 FET microphone That I used for the past 6 years. Even though I own 5 other mics, I really loved this one once in a while. I has a certain character very similar to a TLM103 but warmer.

Now my problem is that sometime the output gain drops by 20 to 30db for a couple minute and then goes back in. Like there's a fade out of the signal for some strange reason and comes back a few minutes later.

Is this a capacitor or transistor problem? or trasformer? I'd like to repair it myself with new parts.

Thank you!

You can try a "breath test" on the mic capsule. Gently breath on to the headbasket while listening to the mic. If the volume cuts out or the mic becomes noisy there may be too much dirt/debris on the capsule. You should also try to keep the mic in a case with a silica gel pac in the case to reduce moisture and humidity.


True capsule cleaning should be left to a professional, however, you can use a very soft Sable hair artist brush to GENTLY remove some of the dust that may be on a capsule. Do not anything but a dry brush to clean the capsule. The Gold sputtering on the Mylar can come off very easily and you will have to buy a new capsule.

If this persists, It may be time for a new capsule.

[Haz-Mat-Strat]

Originally Posted by Ntchi

What change will it make to change C2, C3 and C8? What do you mean by vintage sound?

If I use the same value as in the scheme I will still have an upgraded sound right?

Guess I'll do 2 mods...

You may want to find out what these mods sound like by experimenting with each value capacitor.


C1= .01uf to 047uf I use Wima film caps.
C2= 100, 220,470, 820pf Polystyrene/ Styroflex


Neumann used many different values throughout the years. Record each combination and change you make so you can find the best sound for you.



C3= 470-1500pf Polystyrene/ Styroflex/ Polypropylene



C8 Neumann used in the U87 a 1UF Tantalum electrolytic capacitor in this position. Tantalums do work here however Polypropylene capacitors have a clearer, less colored sound. Again experiment to find the capacitor that you like in that spot.

Film caps: 1uf to 3.3UF(depending on size) and 1UF to 4.7uf on the Tantalum.


You can learn a lot about the microphone by this type of experimentation an the satisfaction of doing it yourself.

Enjoy!!

Jim Jacobsen
JJ Audio

[MrSedor]

Hello,

I have 2 V67i and I want to mod them.
Is it the same mod as the V67?
Most of the components seem to be similar...

Please excuse my English, and thanks for your replies

best,

Remi

[Ntchi]

Originally Posted by Haz-Mat-Strat

You may want to find out what these mods sound like by experimenting with each value capacitor.


C1= .01uf to 047uf I use Wima film caps.
C2= 100, 220,470, 820pf Polystyrene/ Styroflex


Neumann used many different values throughout the years. Record each combination and change you make so you can find the best sound for you.



C3= 470-1500pf Polystyrene/ Styroflex/ Polypropylene



C8 Neumann used in the U87 a 1UF Tantalum electrolytic capacitor in this position. Tantalums do work here however Polypropylene capacitors have a clearer, less colored sound. Again experiment to find the capacitor that you like in that spot.

Film caps: 1uf to 3.3UF(depending on size) and 1UF to 4.7uf on the Tantalum.


You can learn a lot about the microphone by this type of experimentation an the satisfaction of doing it yourself.

Enjoy!!

Jim Jacobsen
JJ Audio

Thank you Jim!

As for the H3500 I'll try the breath test later on at the studio. Hope this is the problem. I thought it was an electronic problem. But I remember seeing spit traces on the capsule last year lol.

No alcohol to clean it? just a dry brush?

[Ntchi]

Originally Posted by Haz-Mat-Strat

C1= .01uf to 047uf I use Wima film caps.

Jim Jacobsen
JJ Audio

Is this correct or typo? 047uf??

[prontold]

Originally Posted by Wavebourn

Some time ago I took pictures while modding a pair of V67G mikes especially for this topic, but can't find them. They should be on one of SD cards, but I forgot the date when I took them.

I'm sure anybody going through this for the first time would love to have that as a resource. I know I would have been helped.


At any rate, I figured things out with some help from Andybot, and I've got to say that this mic sounds really, really good at this point (as long as you position it right, the off axis response seems pretty colored to me). Thanks a lot Wavebourne! You're directions were at times difficult for me to understand, but right on for getting a great mic out of the v67.

For anybody interested in a preview I did a little side by side comparison with an AT4050 here:

Modded v67 vs AT4050

[Haz-Mat-Strat]

Originally Posted by Ntchi

Is this correct or typo? 047uf??

.047uf

Any value between .01 to .047 will work.

Jim Jacobsen
JJ Audio

[Haz-Mat-Strat]

Originally Posted by Ntchi

Thank you Jim!

As for the H3500 I'll try the breath test later on at the studio. Hope this is the problem. I thought it was an electronic problem. But I remember seeing spit traces on the capsule last year lol.

No alcohol to clean it? just a dry brush?

Dry soft Sable hair artist brush find the softest one.

Jim Jacobsen
JJ Audio

[MrSedor]

Hi,

I started to mod my V67i today, but it seems to be different than the "original" V67.
Indeed, C1 is the same,
there's no C2, no C3, no C4,
C5 is 226 (like C4?) 22uF lytic apparently.
There is a C5A, whitch is like C6 and C8A: 334 - 0.33uf
I don't know if C7 is the same (because I don't know the "original" V67 value, I don't see it on the shematic),
C8 is same as the original,
There is no C9,
C10, C11, C12, C13, C14 are same as the original.

Are the TehGuitarist caps mod alright with this V67i (with these differences)? I think so but I don't want to destroy my mike...

Many thanks for your help,

Remi

[prontold]

Originally Posted by MrSedor

Hi,

I started to mod my V67i today, but it seems to be different than the "original" V67.
Indeed, C1 is the same,
there's no C2, no C3, no C4,
C5 is 226 (like C4?) 22uF lytic apparently.
There is a C5A, whitch is like C6 and C8A: 334 - 0.33uf
I don't know if C7 is the same (because I don't know the "original" V67 value, I don't see it on the shematic),
C8 is same as the original,
There is no C9,
C10, C11, C12, C13, C14 are same as the original.

Are the TehGuitarist caps mod alright with this V67i (with these differences)? I think so but I don't want to destroy my mike...

Many thanks for your help,

Remi

Most of the Tehguitarist mods are just putting a higher quality capacitor of the same value into the circuit. I think the value of one of them was changed, maybe c6? It's in this thread. You would have to figure out which cap corresponded to that one if you were going to change the value, but otherwise you just order some of the type of caps he was recommending for all the capacitors that might be in the signal path. I highly recommend doing the rebiasing and negative feedback mods, though.

[Wavebourn]

Here is the Mod Number One for V67, to start with: I've found that pictures finally.

www.wavebourn.com • View topic - Marshal MXL V67g microphones

[Aerophone]

wavebourn, is that a simple mod that can be done with any stock v67g?
What are the benefits and side effects?

thanks

[D_T_Music]

Hey I've been gearing up to try this mod and I'm finding that the J305 FET originally recommended is no longer available (at least not at mouser or anywhere else i've looked).

Is there a good alternative FET that people have been using?

Thanks a lot,

Dave

[PereGrinoz]

Originally Posted by D_T_Music

Hey I've been gearing up to try this mod and I'm finding that the J305 FET originally recommended is no longer available (at least not at mouser or anywhere else i've looked).

Is there a good alternative FET that people have been using?

Thanks a lot,

Dave

J309 I think.
Regards.