Deal?.......MXL 603S for $30 at MF

Erockrazor said:
Got my two mxl 603s in the mail two days ago.

One is making the sweeping ringing noise. Not loud but enough to ruin a take for me. It goes from high to low pitched... never heard that before.

Might be time to try and use the warranty ?
Click to expand...

yeah man just take it back --

it should be no problem for MF or MXL...

dont screw about ;)
 
Mods in general

antichef,
those clips are great... On my PC speaks I herd the most difference between the Stock and the .22 and what a difference! I am definitely going to give the Modding a try. The worst that could happen is I lose $30 + $ for parts and I learn something new.

Can I ask a Couple Newb questions?

1. Is most modding trial and error... and once someone finds the right Cap for improvement the word spreads? Or is it just known that Cheap caps are used in low end gear (so the manufacture can save $.50 per unit) and replacing them w/ a higher quality one will ALWAYS be best.

2. Once someone is experienced, can they pretty much look at the board and tell right away that there are sub par Caps and Resistors in there and which ones will, if replaced, make a improvement?

3. I guess I'm wondering if it's not just the quality but the # rating on the Cap like .22 to 1.0 then why doesn't MXL just put in the Cap w/ the rating that will best suit the Mic?

I'm probably not even scratching the surface and I'm not looking for a Mic Mod 101 class as I know if I really want to get into this I have a Ton of Homework to do but for the time being I'm thinking if I just use the same parts you guys use I know I can do this... and if it goes well I can move on to my ACM mics. :D

Thanks,
B.
 
Booda said:
Can I ask a Couple Newb questions?
Click to expand...
sure, but if you're asking me, you'll have to settle for newb answers :)

Booda said:
1. Is most modding trial and error... and once someone finds the right Cap for improvement the word spreads? Or is it just known that Cheap caps are used in low end gear (so the manufacture can save $.50 per unit) and replacing them w/ a higher quality one will ALWAYS be best.
Click to expand...
Left to my own devices, it would be trial and error, but we're lucky enough to have folks on the board like Marik, who have a strong background in eletro-acoutics and actually understand the circuits and the physical aspects of the microphones, so I pretty much just listen to them, and experiment in very narrow bands.

Booda said:
2. Once someone is experienced, can they pretty much look at the board and tell right away that there are sub par Caps and Resistors in there and which ones will, if replaced, make a improvement?
Click to expand...
I think so -- I'm getting to the point where I look for ceramic caps in the signal path to replace, since that's usually where the easiest improvements are. Understanding the circuit completely (which I generally don't) is key, because I've seen ceramics in the signal path that sound just fine (or at least, don't yield noticeable improvement when replaced). That's why web searching is my friend :) -- Folks with an electronics background generally make it to the finish line in this area more quickly.

Booda said:
3. I guess I'm wondering if it's not just the quality but the # rating on the Cap like .22 to 1.0 then why doesn't MXL just put in the Cap w/ the rating that will best suit the Mic?
Click to expand...
The example is over my head -- perhaps Marik saw an opportunity to improve the circuit that was overlooked by the engineers who designed the circuit, or perhaps there were other non-sound concerns (certainly including cost - .22uf caps are cheaper than 1uf caps, everything else remaining the same), etc. -- the physical size of the caps would certainly have been a concern. Also I know some other mods I've performed, such as removing inner grill baskets, have had the effect of physically weakening a mic or making it more susceptible to EM interference (neither would be the case here, I'm sure), and although the sound was [occasionally] improved, I might not want to sell them, because I don't know what situation they're going into and worry they might fail the new owner -- that kind of stuff. Additionally, with regard to mass produced electronics, once you get FCC (and other non-USA governmental) approval on a particular design, it's expensive and time consuming to change it, so you might do better to live with a suboptimal design rather than go after an improvement
 
I asked this a while back and I just want to make sure I've understood correctly. In this 603 mod the .22uF ceramics should have been replaced with a 1uF? exactly what type and voltage? Does anyone have a part number at Mouser or Digi-Key? Thanks.

Paul:D
 
Well, I tried a bunch of those other capacitors in my 991, and none of them seemed better (and the flat white one in the lower right had this weird saturation bumpy bump problem that I find with some other types I tried, making it unusable). I wound up leaving in the yellow one with the green ends, because it seemed to cut the sensitivity.

If anyone's interested, I cut a couple of tracks with one of the modified mxl603s (unchanged since the mod) and also an Oktava MC-012 (also modified with the same input capacitor as the 603, but no other changes) in as close to the same position as I could get them -- the 012 was immediately over the 603, both pointing at the 14th fret of my guitar (1972 Martin D28), and I kept the guitar pretty much at 90 degrees to the mics. It's just improvising, but one of the tracks is "rhythm" and the other "lead" (digitally boosted 3db), and I mixed them together (in all four ways), and made wav files (54 megs) and mp3 files (2.6 megs):

603rhythm 603lead wav 603rhythm 603lead mp3

012rhythm 012lead wav 012rhythm 012lead mp3

603rhythm 012lead wav 603rhythm 012lead mp3

012rhythm 603lead wav 012rhythm 603lead mp3

I mostly record acoustic guitar with these type of mics, so this is really what's important to me. I think I generally like the MC-012 better - seems fuller. But the mix with the 603 in the background and the 012 on lead is kind of nice, because it brings the lead out. That said, the 603s are awesome for $30 (+ 90 cents in mod parts), and I'm sure I'll be using them.

edit: ugh - the first set of files I posted was bounced with a -5db below 200hz eq setting (anti-boominess) that shouldn't have been there -- I'm uploading dry files now.
edit: - ok - dry files are up. Sorry about that.
 
Last edited:
Wait...there seems to be some mentioning here of this microphone semi-interchangeably with the 991. Are they similar?

Thanks for any clarification. I realized I have a 991 here I got with this combo for $49 at a Guitar Center sale a year or so ago. I got these, tested them and put them away and promptly totally forgot about them. :rolleyes:
 
bongolation said:
Wait...there seems to be some mentioning here of this microphone semi-interchangeably with the 991. Are they similar?
Click to expand...
very similar -- essentially the same. I got mine the same way - $49.99 at GC. I've done a lot of soldering practice on the 990 and the 991 :D.
 
Is there any common wisdom about what cap to use for the coupling cap on mics in general? The reason I ask is that all the Chinese condensers (both SDCs and LDCs) I've looked at all have visually indistinguishable tantalum caps, none of which have any markings that look like numbers with a uF/pF after them.

Short of removing them from the circuit and using a capacitance meter (which I do have and can do), is there any general rule that I should follow, e.g. 1 uF for SDCs, or should I just pull them and test them one at a time?
 
dgatwood said:
Is there any common wisdom about what cap to use for the coupling cap on mics in general? The reason I ask is that all the Chinese condensers (both SDCs and LDCs) I've looked at all have visually indistinguishable tantalum caps, none of which have any markings that look like numbers with a uF/pF after them.

Short of removing them from the circuit and using a capacitance meter (which I do have and can do), is there any general rule that I should follow, e.g. 1 uF for SDCs, or should I just pull them and test them one at a time?
Click to expand...
A higher value will allow more low frequencies to pass, but there is a point that it becomes indistinguishable and possibly harmful. For example allowing super low frequencies like 10Hz or even 1Hz. The caps are there to block DC voltage from leaving the output of the mic. Larger caps take longer to block the DC. A very large cap can take several seconds to block the DC and you may damage your preamp or run out of headroom in your DAW while it blocks the DC. On the flip-side a value too high will block too much low frequency and give the mic a filtered sound.
The value of an output cap can be just about anything. The value is determined by the output impedance of the mic. And that is different from mic to mic.
 
tarnationsauce2 said:
A higher value will allow more low frequencies to pass, but there is a point that it becomes indistinguishable and possibly harmful. For example allowing super low frequencies like 10Hz or even 1Hz. The caps are there to block DC voltage from leaving the output of the mic. Larger caps take longer to block the DC. A very large cap can take several seconds to block the DC and you may damage your preamp or run out of headroom in your DAW while it blocks the DC. On the flip-side a value too high will block too much low frequency and give the mic a filtered sound.
The value of an output cap can be just about anything. The value is determined by the output impedance of the mic. And that is different from mic to mic.
Click to expand...

*scratches head*

How can it be acting as a DC block when it goes between the two legs of the capsule, one of which is, AFAIK, the voltage source, the other of which is, AFAIK, the output? That voltage should already be blocked by the capacitance of the capsule, and if not, adding parallel capacitance won't do any good. Is this acting like a shunt for some feedback-based amplifier circuit where the feedback would otherwise have to pass through the capsule?
 
antichef said:
The example is over my head -- perhaps Marik saw an opportunity to improve the circuit that was overlooked by the engineers who designed the circuit, or perhaps there were other non-sound concerns (certainly including cost - .22uf caps are cheaper than 1uf caps, everything else remaining the same), etc. -- the physical size of the caps would certainly have been a concern.
Click to expand...

The 1um has a lower cutoff frequency--the reason you heard bass response improvement.

dgatwood said:
*scratches head*

How can it be acting as a DC block when it goes between the two legs of the capsule, one of which is, AFAIK, the voltage source, the other of which is, AFAIK, the output? That voltage should already be blocked by the capacitance of the capsule...
Click to expand...

One "leg" of the capsule connected to the ground and another is a "signal" side, which also receives bias voltage. The capacitor blocks this voltage.

Best, M
 
Marik said:
The 1um has a lower cutoff frequency--the reason you heard bass response improvement.
Click to expand...

Since the .22uF has a fair amount of lows already, would .47uf be suitable compared to a 1uF? I guess it's a matter of preference, isn't it?



Marik said:
One "leg" of the capsule connected to the ground and another is a "signal" side, which also receives bias voltage. The capacitor blocks this voltage.

Best, M
Click to expand...

What's the word on silver mica caps? I'm not clear as to what the quality is on these. Are they an improvement over ceramics, or just as bad in your opinion?
 
Last edited:
PhilGood said:
Since the .22uF has a fair amount of lows already, would .47uf be suitable compared to a 1uF? I guess it's a matter of preference, isn't it?
Click to expand...

It is actually questionable how fair is the amount of lows is ;). Say, the output impedance of the first stage is 6K, then with .22uf the cutoff starts ~@120Hz :eek::eek::eek:.
Think this way, .47uf cutoff is little more than octave lower than .22uf, and 1uf is already @26Hz.


What's the word on silver mica caps? I'm not clear as to what the quality is on these. Are they an improvement over ceramics, or just as bad in you opinion?
Click to expand...

Sorry, never tried those.
 
Marik said:
One "leg" of the capsule connected to the ground and another is a "signal" side, which also receives bias voltage. The capacitor blocks this voltage.
Click to expand...

But it still isn't blocking the voltage even with the output being on the + side of the capsule. If it is in parallel with the capsule, that means that one end of the capacitor sees a bias voltage and signal, the other end of the capacitor is grounded, so there should be neither a bias voltage nor a signal usable at that point.

:confused:
 
dgatwood said:
But it still isn't blocking the voltage even with the output being on the + side of the capsule. If it is in parallel with the capsule, that means that one end of the capacitor sees a bias voltage and signal, the other end of the capacitor is grounded, so there should be neither a bias voltage nor a signal usable at that point.

:confused:
Click to expand...

Could you be forgetting that since the capsule is producing sound, it is in fact a change in current?

Just a thought.
 
You must log in or register to reply here.
Back
Top