MXL 603s... crappy capsule?

[Rossi]

[quote author="Flatpicker"]Hi Sleeper,
I?m betting the ?stock? one marked 1000 that Kelly refers to is 1000pF, and I agree 100% that polystyrene rules here between the capsule and the FET.[/quote]

Better than polyprop? I wanna mod a t.bone SC950 (very similar to SE Electronics SE-1A), and I have a polyprop cap that would fit. Can't get polysterene from local dealers, but I can order them of course. Would it be worth the wait?

 

[Flatpicker]

[quote author="Rossi"]Better than polyprop?[/quote]Don't know about that - I've tried just about every other cap in that position, but not a polyprop. Gus probably has though. I'm betting it'd sound better than a ceramic.

 

[Sleeper]

well, the 1ufs didn't fit, also realized I was looking to mod the wrong caps
I guess I need to try reading.
Anyhow, kind of glad those didn't fit...

I did find some subminiature caps at mouser, sure the .47 will fit. I'm also going to order a sm 1uf cap and try to record some thunderstorms if I can sort a way to mount it.

Thanks again for the info.
Later
Sleeper

 

[Bear]

Anyone (probably being Marik) know if the capsule in the MXL 991 is the same one as in the 603s, the 6 micron job?

Bear

 

[bradzatitagain]

[quote author="Bear"]Anyone (probably being Marik) know if the capsule in the MXL 991 is the same one as in the 603s, the 6 micron job?

Bear[/quote]

It's the claim that the 603 and 991 are identical, pics posted here confirm and I believe someone confirmed in 3D having both mics in hand; same capsule is also side address mounted in the 990 using the same (or very very much the same) circuit as the 603 & 991. Makes the 990/991 pair at GC for $99 a very good deal indeed especially if you resell the 990.

 

[Bear]

[quote author="bradzatitagain"]
It's the claim that the 603 and 991 are identical, pics posted here confirm and I believe someone confirmed in 3D having both mics in hand; same capsule is also side address mounted in the 990 using the same (or very very much the same) circuit as the 603 & 991. Makes the 990/991 pair at GC for $99 a very good deal indeed especially if you resell the 990.[/quote]

Well, yeah, but then you don't have as much space to put in a tube and iron. If it's the same capsule, I'd actually be more intent on keeping both pieces so I could mod both.

Bear

 

[bradzatitagain]

[quote author="Bear"][quote author="bradzatitagain"]
It's the claim that the 603 and 991 are identical, pics posted here confirm and I believe someone confirmed in 3D having both mics in hand; same capsule is also side address mounted in the 990 using the same (or very very much the same) circuit as the 603 & 991. Makes the 990/991 pair at GC for $99 a very good deal indeed especially if you resell the 990.[/quote]

Well, yeah, but then you don't have as much space to put in a tube and iron. If it's the same capsule, I'd actually be more intent on keeping both pieces so I could mod both.

Bear[/quote]

I think I missed the first part of this argument...

 

[Marik]

[quote author="Bear"]Anyone (probably being Marik) know if the capsule in the MXL 991 is the same one as in the 603s, the 6 micron job?

Bear[/quote]

Yes,

I took both apart, and they are identical. Please note though, the first 603s had slightly different backplate construction, as well as different thread for center terminal. Also, 603 had slightly different PC board, where FET and 0.22MF caps were connected with wires. In 991 they changed it for conductors on PCB. Later 603s also switched to this PCB.

Re: 0.22MF caps. As I have already wrote a few times here, I was able to find flat 3MF film caps, which would fit here. They seem to noticably extend low frequencies. Keep looking in your local electronic or surpluse stores for something similar.

A Royer mod works quite well here and is very easy to build on perf board.

 

[cprieb]

... Also, 603 had slightly different PC board, where FET and 0.22MF caps were connected with wires. In 991 they changed it for conductors on PCB. Later 603s also switched to this PCB.

Both of my 603S (SPR pack) have the FET and 220nF capacitors connected through PCB traces.
Maybe these lack that "sonic integrity" provided by the "world-renowned" Mogami wires... :roll:
César

 

[Guest]

I got some 990s and 991s in the other day... had a listen to them stock. They really are pretty decent... I wonder if the 603 i made a fuss about was not a great one. Oh well, at least I learnt sumthin. Now, time to mod! :twisted: after i finish up a few other things....

 

[fum]

Here's a fun piece of info =).

I was modding a 603, and the replacement caps on the under side of the board are a tight squeeze. In taking the board back out of the mic, I managed to blow up the white connector thing that connects to the capsule.

I said "****", took it off, and ditched it. Soldered a wire to the capsule end, and put it back together. The mic now sounds like total garbage. I thought maybe I hosed something else, went back over it, and it was all good.

Thought about it a bit, and then cut a piece of foam, and inserted it where the hard plastic piece was. Boom, I'm back in good sound. The mic sounds different than with the hard plastic piece, tho. So now I'm running around the shop looking for other "stuff" I can use in this spot.

So note, you can totally change the sound of this microphone, merely by changing what material is sitting behind the capsule.

Regards

ju

 

[Gus]

That piece of plastic is a BIG part of the capsule body system as you found ou The taper helps cut down standing waves because of its shape. Remember that capsule is cardiod and has rear ports.

 

[fum]

I'm pretty sure I chucked it, but will have a look in my junk box ( where all the bits and pieces go), to see if I was smart enough to save it.

Regards

ju

 

[Flatpicker]

[quote author="fum"]I'm pretty sure I chucked it...[/quote]Oh no! :shock:
Check with MXL. They might just send you a new one.

 

[fum]

[quote author="Flatpicker"][quote author="fum"]I'm pretty sure I chucked it...[/quote]Oh no! :shock:
Check with MXL. They might just send you a new one.[/quote]

Well, I did chuck it. =) Not to worry tho, I've got it sounding pretty good with just a piece of packing foam. It's got a little more high end than the unmodded 603( read a little too bright), but it took me 30 seconds to make. I'll come across something that's a little less porous that should fit the bill.

And if not, I've only got like $50 into it. It's worth it just for the learning experience :grin:

Regards

ju

 

[Marik]

[quote author="fum"][quote author="Flatpicker"][quote author="fum"]I'm pretty sure I chucked it...[/quote]Oh no! :shock:
Check with MXL. They might just send you a new one.[/quote]

Well, I did chuck it. =) Not to worry tho, I've got it sounding pretty good with just a piece of packing foam. It's got a little more high end than the unmodded 603( read a little too bright), but it took me 30 seconds to make. I'll come across something that's a little less porous that should fit the bill. [/quote]

Anything different from original will result in different sound, esp. if you are using material with completely different sound absorbtion (foam). If you have the mic with caps I sent you, the sound of the mic should be more balanced than stock, with nicer low end.

 

[fum]

[quote author="Marik"]
Anything different from original will result in different sound, esp. if you are using material with completely different sound absorbtion (foam). If you have the mic with caps I sent you, the sound of the mic should be more balanced than stock, with nicer low end.[/quote]

Yes, I would assume it would sound different. Remember when I mailed you a while back, saying it was darker( that was on the bench, which is in the process of upgrade, so as a monitoring environment, leaves things to be desired at present, it pretty much just lets me know whether something squawks or not). Well, once I got it into a critical listening environment, it wasn't darker, it was hosed ( this was without anything behind the capsule). Putting the foam there was a test to see if that was the problem, which took the microphone from being completely crap, back to being usable.

I've got a couple of these mics, so I'm comparing to a stock mic, and can model a new piece once I find a more solid material ( won't be foam, some kind of plastic maybe).

I should be able to get it back to sounding good once I get there ( again, won't sound exactly like a 603, but hell, I don't want it to sound like a 603, or I wouldn't be messin with them to begin with :grin: ).

Thanks for keepin me straight guys. Once the modded mic sounds good, I'll mod the stock mic =).

Regards

ju

 

[Guest]

Hey guys, quick question about the dc to dc converter... is there a difference between actually disconnecting the dc to dc converter and varying the voltage on the capsule by adjusting R12? Thanks.

 

[Brent Casey]

[quote author="fum"]Here's a fun piece of info =).

So now I'm running around the shop looking for other "stuff" I can use in this spot.

ju[/quote]

I have some of those at my bench. If you run out of options, or MXL doesn't want to deal with it, let me know.

Brent Casey

 

[micro1_de]

Hi,

does anybody have the schematics for the MXL mics?