DIY Modding for MXL 2003/603s HELP

M

M'appy

New member
So I've gone through a number of threads regarding this topic, and I hope I am not exhausting it, but I could really use some specific advice.. (1st post by the way. Hello all)

These two mics are the only ones I own, and I don't have much to drop on any more. I COULD afford something in the $100- $150 range, though it seems another mic wouldn't really be worth while. Considering my step father is an electric engineer and willing to help me, I figure we can mod these. Is it worth while?

First off, I was wondering if someone could confirm which caps are worth replacing for both mics. And anything else perhaps..?

More specifically, I am wondering if it is worth replacing the capsule. I understand Michael Joly and others can mod this capsule, but again my budget doesn't really permit. Does anyone know anything about the RK-47 Capsule? Good option?

I am a multi-instrumentalist and singer. I plan on recording EVERYTHING with these two mics. Primarily acoustic guitar and vocals, but also everything from strings to winds, brass and percussion. I also plan on doing quite a bit of traveling with these and will likely record in a large variety of spaces..

Any advice helps, and thank you.
 
The coupling cap has the biggest impact on the sound (the tiny capacitor that sits between the capsule and the FET). By the time you get down to the power-filtering electrolytic caps, you might as well not bother. Everything between those two extremes is debatable.

No opinion on the capsule.
 
The mod that I do for for these mics involves replacing all of the electrolytic capacitors, replacing C90 and C40 with Wima film caps: 1uf in the 2003 and .47 in the 603. I change C30 to 1000pf Polystyrene. C60 and C80 to Cog Np0 ceramics.

I change the two resistors R60 and R70 to hand selected 2.2k matched resistors. I also change R30 and R40 to matched 100k resistors.

On the 603 I add two polystyrene capacitors, 470pf to 1000pf in parallel with resistors R30 and R40 . In the 2003 they are 1000pf ceramic these are also replaced with polystyrene or polypropylene.

The results are cumulative. Dgatwood is right about the capsule to Fet capacitor. It makes the most impact., however all of these changes as a whole is much more dramatic. The quality of parts matter. The mic is much smoother more detailed and has a better overall tone.

There are other things I do to custom tune these mics for clients.

Schematic: @ (Copy and paste) sdiy.org/oid/mics/MXL-603S.gif

Happy Modding!!!

:):)​
 
Thank you both very much. I'm sure I may have more inquiries as the process progresses, but this is very helpful.

Jim, do you have any input on the capsule?
 
The capsule in the 2003 is not bad. This Schoeps circuit in the 603/2003 is flat and does not have any NFB to tune the circuit. Thus these mics will be bright. The nice thing about the mod is that it becomes much smoother and less harsh.

The quality of microphone capsules coming from China continues to get better and using them in a properly implemented circuit will bring out their strengths. It becomes a matter of taste. That is why we have many mics in our mic locker. I would not want all of my mics to have K67 type capsules or all K47 type capsules. That would be boring.

Bright mics have their place just as mid forward and dark mics. For instance the AKG 451 is very bright. It is brighter than the MXL 603 and yet it sounds better and has more depth and detail. The C12 and the C800g are also bright however the quality of the mics bring out the detail.

The MXL 2003 is a bright mic. Changing the capsule to a K47 style will give it a different character. Not necessarily better. If you are on a budget and looking for a darker mic, buy something like a V67g that has the K67 capsule that has the NFB and is darker. Then you will have 2 mics to choose between different sources. It will cost less than a capsule change.

There are some very good capsules that are available. The ADK Hamburg is tuned with less high end bump than the 2003 capsule. If you have deeper pockets the ADK custom shop has a great variety of capsules both single and dual membrane. The RK47 from microphone parts(dot)com is a good economic choice. Also Dave Thomas has some nice capsules at a good price.

It sounds like on your budget you can mod this mic and buy a second mic and mod that one also!!


:):)​




M'appy said:
Thank you both very much. I'm sure I may have more inquiries as the process progresses, but this is very helpful.

Jim, do you have any input on the capsule?
Click to expand...
 
M'appy said:
So 3 yrs later I'm unable to find this information... Can anyone help? I'm interested in any specific mod recommendations..
Click to expand...

...have you looked thru the original DIY threads?:
...MXL 603
MXL 603s... crappy capsule?
MXL 603s mod
MXL 603S vs 991

...Other MXL or similar Chinese Mics
What were those MXL mics that people liked to modify?
Old Mod, New(ish) Mic?
What's the best condenser mic to mod in your opinion ?
Apex 460 as body/grill/PSU for G7 or other DIY mic
Small Diaphragm Mics - DIY
MXL 990 mic mod...

...or the entire META Mic archives:
META - Microphones
 
Hazmatstrat said:
The capsule in the 2003 is not bad. This Schoeps circuit in the 603/2003 is flat and does not have any NFB to tune the circuit. Thus these mics will be bright. The nice thing about the mod is that it becomes much smoother and less harsh.

The quality of microphone capsules coming from China continues to get better and using them in a properly implemented circuit will bring out their strengths. It becomes a matter of taste. That is why we have many mics in our mic locker. I would not want all of my mics to have K67 type capsules or all K47 type capsules. That would be boring.

Bright mics have their place just as mid forward and dark mics. For instance the AKG 451 is very bright. It is brighter than the MXL 603 and yet it sounds better and has more depth and detail. The C12 and the C800g are also bright however the quality of the mics bring out the detail.

The MXL 2003 is a bright mic. Changing the capsule to a K47 style will give it a different character. Not necessarily better. If you are on a budget and looking for a darker mic, buy something like a V67g that has the K67 capsule that has the NFB and is darker. Then you will have 2 mics to choose between different sources. It will cost less than a capsule change.

There are some very good capsules that are available. The ADK Hamburg is tuned with less high end bump than the 2003 capsule. If you have deeper pockets the ADK custom shop has a great variety of capsules both single and dual membrane. The RK47 from microphone parts(dot)com is a good economic choice. Also Dave Thomas has some nice capsules at a good price.

It sounds like on your budget you can mod this mic and buy a second mic and mod that one also!!


:):)​
Click to expand...

Thank you much. This has been very helpful. We have replaced some of the electrolytics with good results I think. Of course my ears are still very amateur in this regard and I am still learning to hear these subtle differences.
Now we are trying to diagnose and repair another problem in the 2003. The mic fades out and back in periodically, and having tested numerous preamps and cables I've confirmed it is the mic itself. We are going to try changing out the transistors one by one and see if that works. If not, could it be the capsule? I have no idea.
Regarding your comments on the capsule: I am not sure if "darker" is what I want. Again, I am still learning to hear the differences between highs and lows, but I guess I figured a K47 would bring out the "mids" more based off of what I've read. Considering I am trying to create a pretty universal mic I thought that might be a worthy mod, but maybe not.
Also, I have read alot about this "Schoeps circuit" not fitting well with this capsule, but i don't quite understand the concept. What does NFB stand for?

kidvybes said:
...have you looked thru the original DIY threads?:
...MXL 603
MXL 603s... crappy capsule?
MXL 603s mod
MXL 603S vs 991

...Other MXL or similar Chinese Mics
What were those MXL mics that people liked to modify?
Old Mod, New(ish) Mic?
What's the best condenser mic to mod in your opinion ?
Apex 460 as body/grill/PSU for G7 or other DIY mic
Small Diaphragm Mics - DIY
MXL 990 mic mod...

...or the entire META Mic archives:
META - Microphones
Click to expand...

SUPER helpful kiddyvibes. That's exactly what i was lookin for. Good lookin out.
 
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