idiot

Help! cheap MXL 990 sounds like garbage. Any modifications?
« on: August 26, 2006, 04:31:13 PM »
I hate this mic,but I cant afford to buy a better one.I have two orange drops (1000pf) and five .47uf metal film. how can I upgrade?


Marik

Re: Help! cheap MXL 990 sounds like garbage. Any modificatio
« Reply #1 on: August 26, 2006, 08:54:38 PM »
Quote from: "idiot"
I hate this mic,but I cant afford to buy a better one.I have two orange drops (1000pf) and five .47uf metal film. how can I upgrade?


Make a search here for MXL603 mods. There is a loooong thread on that. It is the same mic. Since it has much larger body instead of 0.22uf use 1um or higher for better bass response.
Samar Audio & Microphone Design

www.samaraudiodesign.com

The Art of Ribbon Microphones

Flatpicker

Re: Help! cheap MXL 990 sounds like garbage. Any modificatio
« Reply #2 on: August 26, 2006, 10:00:40 PM »
Quote
I hate this mic,but I cant afford to buy a better one.I have two orange drops (1000pf) and five .47uf metal film. how can I upgrade?

If that's all you have to work with, I'd just replace the ceramic between the capsule and the FET with one of the 1000pF orange-drops. They sound fairly one-dimensional to me, but still better than the ceramic. You'd be better off using a WIMA polypropylene or some type of polystyrene, though. You could also swap out the .22s with .47s, but I wouldn't expect much difference. Certainly not a night and day difference with either part.

Bottom line, if you hate it now, the mods won't make much difference IMHO, but hey, try it and see. In the mean time, I'd start saving up for a good used AT or something.

idiot

thx guys
« Reply #3 on: August 26, 2006, 10:07:29 PM »
thx guys, the orange drop & the .47s did a nice job.

mhelin

Help! cheap MXL 990 sounds like garbage. Any modifications?
« Reply #4 on: August 27, 2006, 04:40:43 AM »
I guess some of these capsules would like to see a bigger bias voltage, at least that would improve the SNR a bit. Cheap mic's don't have a DC/DC converter at all so you should rebuild the electronics.

bigugly

Help! cheap MXL 990 sounds like garbage. Any modifications?
« Reply #5 on: August 27, 2006, 05:07:22 AM »
I've modded those with the Royer circuit before. It gets pretty cramped but it does fit. I also changed the capsule and removed the inner most layer of grill mesh, so I guess you could say it wasn't an MXL 990 anymore.
"...the land of the free*, and the home of the brave"
*some restrictions may apply, see Congress for details

Flatpicker

Help! cheap MXL 990 sounds like garbage. Any modifications?
« Reply #6 on: August 27, 2006, 09:18:31 PM »
Quote from: "mhelin"
Cheap mic's don't have a DC/DC converter...

This one does, actually, but it doesn't boost it very much.

CJ

Help! cheap MXL 990 sounds like garbage. Any modifications?
« Reply #7 on: August 27, 2006, 09:24:59 PM »
send the mic to gus, then dale, then stephen paul labs and what is up with the sp did it ever come out, over?
hi stephen, we know you up there!
[/i]
If I can't fix it, I can fix it so nobody else can!
Frank's Tube Page: www.mif.pg.gda.pl/homepages/frank/vs.html
Guitar Amps: http://bmamps.com/Tech_sch.html

pucho812

Help! cheap MXL 990 sounds like garbage. Any modifications?
« Reply #8 on: August 27, 2006, 10:37:28 PM »
I was just @ sp labs they recently moved into hollywood away from their old location in the SFV. Anyway the mic is surley comming and tony is working on it in between the usual mic repairs and mods they have been doing.
You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is.

CJ

Help! cheap MXL 990 sounds like garbage. Any modifications?
« Reply #9 on: August 27, 2006, 10:48:12 PM »
well that is certainly cool news and thaks for the update!
If I can't fix it, I can fix it so nobody else can!
Frank's Tube Page: www.mif.pg.gda.pl/homepages/frank/vs.html
Guitar Amps: http://bmamps.com/Tech_sch.html


pucho812

Help! cheap MXL 990 sounds like garbage. Any modifications?
« Reply #10 on: August 28, 2006, 10:30:09 AM »
NO prob CJ. My friend Mike took his new purchased from evilbay mic their for a checkup which is how I know as I went down with him to say Hi.
You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is.

Gus

Help! cheap MXL 990 sounds like garbage. Any modifications?
« Reply #11 on: August 28, 2006, 12:07:12 PM »
What does garbage sound like?

pucho812

Help! cheap MXL 990 sounds like garbage. Any modifications?
« Reply #12 on: August 28, 2006, 01:02:06 PM »
Quote from: "Gus"
What does garbage sound like?


sounds like rock music with lots of loops/samples and a female singer :green:
You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is.

kpeek

Help! cheap MXL 990 sounds like garbage. Any modifications?
« Reply #13 on: August 28, 2006, 07:41:53 PM »
If its got a MXL603 style circuit, then there are some mods for it beyond changing the caps.

Any MXL603 type capsule can use the 603's circuit with the following mods ala Jim Williams:

FROM RAP--

"I had a chance to go through one the other day. It's the same capsule
as that $49 MCA SP-1. It's the same "Schoeps" style circuit.

I replaced the jfet, bipolar transistors to Hitachi 2sa1084's. I
increased the coupling caps to allow deeper response in the bass. I
used MIT MultiCaps off the capsule. I replaced certain resistors with
Dale RN55's. I replaced the DC converter diodes with fast recovery
rectifiers. This increased the polarization voltage to the capsule from
42 to 53 volts. The mic has more sensitivity and reach. Much more top
end details and presence. The hard edge of the ceramic signal
capacitors is now gone. 20k air is very open. I still get better
results out of the wide body SP-1's as there is much room in there for
larger film caps. "

This obviously is some of what he does to the MCA SP-1 mics that he has stated will often be chosen over Neumanns.  There are some other mods he has talked about for this type of capsule and circuit. I have them somewhere. I have a pair of the MCA SP-1 that I am going to mod per his suggestions and see what I get.

More Jim Williams RAP--

"I'm enjoying the MCA SP-1's. They go for as little as $40. They are
Shanghai cardiode mics with a 3/4 " capsule, sized like the U-89. They
have a very flat midrange with a smooth shelf lift of about 3 db above
7k hz. They don't have that hard ass gravel tone of the 1" chinese
capsules. Low end is thin but can be fixed up with a couple of good
caps. The circuit is a Schoeps knock-off that also can be improved. A
customer that does location film/video exclusivly with Schoeps
couldn't tell a difference, I could, about $1500."

Gus

Help! cheap MXL 990 sounds like garbage. Any modifications?
« Reply #14 on: August 28, 2006, 08:13:58 PM »
I have a mca SP1 with mods I did to it.

first raising the voltage might not be a good thing.

There is a easier way to raise the capsule voltage.

Diodes don't matter much in the DC to DC

The output section of a circuit like that is two EFs.  EFs. tend to minimize any "sound" of a BJT IMO.

The only side address baffle ring around a SD microphones I have heard that sound good are some of the ATs.

Now when you put some of what is consided the best parts sometimes things cheap microphones do well go away.  I normally don't like ceramics however.....................

I had some early 603s that I modded some time ago I lent them to a friend and never got them back.  This same person had the modded MCA and they did not like it at all (same mods) capsules don't sound the same to me.

Rossi

Help! cheap MXL 990 sounds like garbage. Any modifications?
« Reply #15 on: August 29, 2006, 07:25:43 AM »
Speaking of capsule to FET caps: I recently decided to mod my Studio Projects C4 mics. In one I replaced the ceramic cap with polysterene (I also upgraded some other signal caps). The change to the unmodded C4 was perceptable but not really dramatic. That said, I must say that they sound fine stock. But there was still a slightly nasal quality. Then I modded the second C4 using a small BC components polyprop cap for capsule to FET. That was more like it IMO. It sounds much brighter and open than the polysterene one, let alone the stock ceramic one. Now, I don't know if there are various qualities of polysterene caps, but so far I've been happier with the BC polyprops than with the polysterene caps. Well, maybe for a mic that's supposed to sound vintage, I might use polysterene again. But for fast tranisent response/modern/clean/open I'm sold on polyprop. One problem, though: even those small size BC components polyprops are bigger than polysterene caps. It was a very tight fit in those small C4 mics.
"I am not a number, I'm a free man!"
"Hahahahaaaaaa!!!!!"

Flatpicker

Help! cheap MXL 990 sounds like garbage. Any modifications?
« Reply #16 on: August 29, 2006, 03:30:37 PM »
Recently I?ve been going through several polystyrenes before finding one I like. I don?t know if I?m just now noticing differences or somehow got an inconsistent batch. Also, it could be that the heat from soldering them is changing the sound. Another thing that may or may not be coincidental is that the last batch I got are the radial kind instead of the axial versions. Could it be that the radial ones are more susceptible to heat?

One thing I?ve noticed as far as differences between  polystyrenes and polypropylenes before the FET is that it seems to shift the frequency peak somehow ? like if you were using a parametric eq and just turned the frequency knob to a higher setting. That?s the way it sounds to me, anyway.

But yeah, sometimes I like polystyrenes and sometimes I like polypropylenes. Depends on the mic and the application.

Rossi

Help! cheap MXL 990 sounds like garbage. Any modifications?
« Reply #17 on: August 29, 2006, 05:13:16 PM »
The polysterenes I used wer axial parts. I got them pretty cheap at www.reichelt.de for 33 Euro cents apiece, I think. I don't think I fried any of the ones I used, but maybe there are better quality polysterenes. The BC components polyprops are consistent.

I always test with strummed accoustic guitar. That's good test material, I think. Wide band, lots of transients and sharp attacks. Plus you're very familiar with the sound of the source.

Which do you think sounds "higher" or "brighter" polyprop or polysterene?

I tried to visualize the effect using the RMAA in acoustic mode. But the effect of different capsule to FET caps does not seem to make a difference in the frequency domain. I think must it be distortion and/or transient response.
"I am not a number, I'm a free man!"
"Hahahahaaaaaa!!!!!"

Flatpicker

Help! cheap MXL 990 sounds like garbage. Any modifications?
« Reply #18 on: August 29, 2006, 05:25:26 PM »
Quote
The BC components polyprops are consistent.

Yeah, I  like them too.

Quote
I always test with strummed acoustic guitar. That's good test material, I think. Wide band, lots of transients and sharp attacks. Plus you're very familiar with the sound of the source.

My opinion exactly!

Quote
Which do you think sounds "higher" or "brighter" polyprop or polystyrene?

Polyprop. However, I meant to mention that my experience comes mostly from modifying Oktava MC012s, although I did modified 3 of the 603s 1-2 years ago. From my (limited) experience with the 603s, the polystyrenes seemed to kill the acoustic guitar's upper frequency dynamics. The polyprops were a better choice for those, IIRC.

Rossi

Help! cheap MXL 990 sounds like garbage. Any modifications?
« Reply #19 on: August 29, 2006, 05:48:20 PM »
I modded an Oktava MK-101, using a polysterene cap, but I could hardly tell a difference to the stock ceramic. But I don't think I would have liked a polyprop in there. My Oktava is pretty well made, btw, got it from Oktava-Online.

I used a polyprop cap in a Studio Projects B1, and it was a very noticeable improvement. It seemed to complement the bright sound of the mic and clean it up at the same time.
"I am not a number, I'm a free man!"
"Hahahahaaaaaa!!!!!"


 

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