MXL 603S Schematics?

[Guest]

Archived from groups: rec.audio.pro (More info?)

Could well be a result of miking technique. I have the list of numbers for
the pianos, but they were all B models (291, 265 and a couple of others but
those two stand out in my memory). I could see a possible problem with my
normal positioning on a 9' D model, but I can't see that they wouldn't do
the job (maybe backed up with a large condenser 4' out from the curve,
depending on what else is playing). Hopefully what you're expressing isn't
an indication of MXL's loss of quality control after Brent Casey left,
although that's been maybe 3 or so years ago now.

--


Roger W. Norman
SirMusic Studio
http/blogs.salon.com/0004478/
"Chris Cavell" <chriscavell@cavellstudios.com> wrote in message
news:1117244087.426234.197760@g14g2000cwa.googlegroups.com...
> I've had the issue (on all my 603's and 991's...at first I thought it
> was a problem with a single mic so I swapped them about) on three
> different steinways (9 foot new york D, 7 foot new york B, and a 7.5
> foot Hamburg C). Perhaps the differences in what we've noticed has
> more to do with mic techniques with these particular mics. In all the
> instances where I noticed an issue I was micing very very closely
> (within a foot of the strings, just inside the crook of the piano).
>
> Roger W. Norman wrote:
> > I don't have a clue as to what you're talking about. My 603s have been
on
> > maybe 100 Steinway recordings without a single honk. Now Mike Rivers
did
> > seem to sense some noise at one point on a different setup, but I
believe it
> > was the Soundcraft, for certainly nothing has been untoward on my Crest,
and
> > like I said, 100 recordings don't lie.
> >
> > But I guess some people just HAVE to change things. Until I get proof
that
> > these mics need something different, I'll just keep using them as I have
and
> > enjoy the results. I do have examples.
> >
> > --
> >
> >
> > Roger W. Norman
> > SirMusic Studio
> > http/blogs.salon.com/0004478/
> > "Chris Cavell" <chriscavell@cavellstudios.com> wrote in message
> > news:1117237355.304415.196030@g43g2000cwa.googlegroups.com...
> > > They have a bit of a "honk" to them that can make tonal full range
> > > instruments, like piano, really ugly on specific notes. Swapping out
> > > several of the caps (all ceramic) to film or styrene tends to cure
this
> > > for the most part. BTW, the 990 and 991 are identical...the 990 just
> > > has a rather nifty mounting scheme for the small di capsule to make it
> > > side adress (and appear like a large di to anyone who doesn't look
> > > carefully). The circuits are identical and use the exact same
> > > componentry, but the number designations on the circuit boards change
> > > from one model to the next.
> > >
> > > Unofficial means that he basically doesn't want to catch any "gruff"
if
> > > their are errors...it's basically the standard schoeps circuit.
> > >
>

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

That's why you had my 603s on the piano at the jazz festival in 2004 -
because I was using the 990s on the Steinway! <g> It's also why I use the
990s on acoustic guitars. A tad bright if they get too close, but move them
back to about 18" or more and they do a really good job.

But you're right. On the MXL page they have the 990s as a Large 20mm
diaphragm, and on the 991s, it's just a 20mm diaphragm. Maybe I'll have to
pick up a couple of 991s and see if there's a major difference.

--


Roger W. Norman
SirMusic Studio
http/blogs.salon.com/0004478/
"Mike Rivers" <mrivers@d-and-d.com> wrote in message
news:znr1117282564k@trad...
>
> In article <1117237355.304415.196030@g43g2000cwa.googlegroups.com>
chriscavell@cavellstudios.com writes:
>
> > BTW, the 990 and 991 are identical...the 990 just
> > has a rather nifty mounting scheme for the small di capsule to make it
> > side adress (and appear like a large di to anyone who doesn't look
> > carefully).
>
> I suspected as much, but the ad copy says "large diaphragm." Perhaps
> that's really meant to be two words and not a phrase. "Large" as in
> it's bigger than the small one, and "diaphragm" as in every mic has
> one. Where's Obviousman when we need him?
>
> According to the poop sheet, the pattern (or maybe it was the
> frequency response curve - I don't remember now) looked better for the
> 991, something (both, actually) that I would expect for having less
> grill around the capsule.
>
> --
> I'm really Mike Rivers (mrivers@d-and-d.com)
> However, until the spam goes away or Hell freezes over,
> lots of IP addresses are blocked from this system. If
> you e-mail me and it bounces, use your secret decoder ring
> and reach me here: double-m-eleven-double-zero at yahoo

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

And by the polar pattern diagram, the 991s are so wide of a cardioid that
they are virtually omni, while the 990s have a decided lobe at 180, making
them more supercardioids. The 603s are a very wide cardioid with a virtual
negative response from behind. Probably all the exact same capsule as is
the 993, which looks the best of the bunch on paper if you don't mind the 12
kHz bump.

--


Roger W. Norman
SirMusic Studio
http/blogs.salon.com/0004478/
"Mike Rivers" <mrivers@d-and-d.com> wrote in message
news:znr1117282564k@trad...
>
> In article <1117237355.304415.196030@g43g2000cwa.googlegroups.com>
chriscavell@cavellstudios.com writes:
>
> > BTW, the 990 and 991 are identical...the 990 just
> > has a rather nifty mounting scheme for the small di capsule to make it
> > side adress (and appear like a large di to anyone who doesn't look
> > carefully).
>
> I suspected as much, but the ad copy says "large diaphragm." Perhaps
> that's really meant to be two words and not a phrase. "Large" as in
> it's bigger than the small one, and "diaphragm" as in every mic has
> one. Where's Obviousman when we need him?
>
> According to the poop sheet, the pattern (or maybe it was the
> frequency response curve - I don't remember now) looked better for the
> 991, something (both, actually) that I would expect for having less
> grill around the capsule.
>
> --
> I'm really Mike Rivers (mrivers@d-and-d.com)
> However, until the spam goes away or Hell freezes over,
> lots of IP addresses are blocked from this system. If
> you e-mail me and it bounces, use your secret decoder ring
> and reach me here: double-m-eleven-double-zero at yahoo

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

In article <e9udnUIzdqq2CwXfRVn-2g@rcn.net> rnorman@starpower.net writes:

> On the MXL page they have the 990s as a Large 20mm
> diaphragm, and on the 991s, it's just a 20mm diaphragm. Maybe I'll have to
> pick up a couple of 991s and see if there's a major difference.

I was curious about that. 20mm is a little smaller than "large" but
kind of big to be "small." I don't know where they measure that
dimension on a microphone capsule or if there's even a standard way of
measuring it, but since the outside diameter of the 991 case at the
business end is only 22.4 mm, that hardly leaves room to suspend a
20 mm capsule with much vibration isolation even if they measure it at
the outer diameter of clamp ring and backplate (with actual diaphragm
being perhaps 4 or 5 mm less in diameter.



--
I'm really Mike Rivers (mrivers@d-and-d.com)
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

Chris Cavell wrote:
> They have a bit of a "honk" to them that can make tonal full range
> instruments, like piano, really ugly on specific notes. Swapping out
> several of the caps (all ceramic) to film or styrene tends to cure this
> for the most part.

FWIW, I just recorded a small ensemble of autoharp, tamborine, and
electric bass. I used coincident-pair 603s (unmodded except for the
xstrs so far), through a VMP-2. I did get a bump in the 8k region that
made the tamb sound shrill, but my placement and my room proabably were
not ideal. EQ mostly cured the problem, but I hope to hear some
improvement after the cap mods. Thanks again, Chris, for the helpful
info and links.

Regards,
Joe

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

"Joe Kramer" <musetrap@earthlink.net> wrote in message
news:Ns7me.1525$s64.423@newsread1.news.pas.earthlink.net...
> Chris Cavell wrote:
>> They have a bit of a "honk" to them that can make tonal full range
>> instruments, like piano, really ugly on specific notes. Swapping out
>> several of the caps (all ceramic) to film or styrene tends to cure this
>> for the most part.
>
> FWIW, I just recorded a small ensemble of autoharp, tamborine, and
> electric bass. I used coincident-pair 603s (unmodded except for the xstrs
> so far), through a VMP-2. I did get a bump in the 8k region that made the
> tamb sound shrill, but my placement and my room proabably were not ideal.
> EQ mostly cured the problem, but I hope to hear some improvement after the
> cap mods. Thanks again, Chris, for the helpful info and links.
>
> Regards,
> Joe

I'm surprised with all the modding boards I've been looking at (like for the
603S or the much-vaunted 3630 mod) there's not a single before/after clip to
be found anywhere. Are the gains so minimal that documenting them (at least
in MP3) would be useless?

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

Ricky Hunt wrote:

> I'm surprised with all the modding boards I've been looking at (like for the
> 603S or the much-vaunted 3630 mod) there's not a single before/after clip to
> be found anywhere. Are the gains so minimal that documenting them (at least
> in MP3) would be useless?

Hi Ricky,

Don't know if the lack of audio samples is due to minimal gains since I
haven't done the full mod to hear for myself. After doing a crude A/B
comparison for my own satisfaction, I'd be happy to email MP3s to
anybody who wants them (don't have any webspace to post), but I have a
hunch the data compression might skew the results somewhat.

Regards,
Joe

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

Replace the 2SK170 with either a Linear Systems LSK170 or a Siliconix
J305. Replace the output transistors with Hitachi 2SA1083's. Replace
the .22 uf output caps with Wima MKS-2 or fit a Mono ceramic 1 uf with
a .01 polyprop film bypass to extend the low end. replace the 680 pf
input cap with a Wima FKP-2 1k v or a MIT PPMFX 1000 pf. Replace the
2.2 k resistors with Dale RN55. Replace the 150 k resistors with 100k
Dale RN55. Replace the 1N4148 diodes with 1N4394's. This will increase
the polarization voltage to the capsule.

That ought to get ya all started, could make this sound pretty good.

BTW, this is another variation of the Schoeps CMC mic circuit.

Jim Williams
Audio Upgrades

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

jwilliams3@audioupgrades.com writes:

> Replace the 2SK170 with either a Linear Systems LSK170 or a Siliconix
> J305. Replace the output transistors with Hitachi 2SA1083's. Replace
> the .22 uf output caps with Wima MKS-2 or fit a Mono ceramic 1 uf with
> a .01 polyprop film bypass to extend the low end. replace the 680 pf
> input cap with a Wima FKP-2 1k v or a MIT PPMFX 1000 pf. Replace the
> 2.2 k resistors with Dale RN55. Replace the 150 k resistors with 100k
> Dale RN55. Replace the 1N4148 diodes with 1N4394's. This will increase
> the polarization voltage to the capsule.
>
> That ought to get ya all started, could make this sound pretty good.
>
> BTW, this is another variation of the Schoeps CMC mic circuit.
>
> Jim Williams
> Audio Upgrades

Thanks for the info. This is great!

I'm wondering (I think I asked before...) about the quality/consistency of the
*capsules* themselves. I mean no amount of electronics hacking is going to
fix a bad capsule. So, does anyone know the consistency/quality? I'm looking
at both MXL603s and other clone/unlabelled versions, like Apex 180, and I'm
sure there are many others. These are *identical* in appearance to the MXL,
and a lot cheaper. The Apex 180 also comes with interchangeable omni/card
caps.

Thanks again,
Richard

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

Hey Jim,

Thanks for the very specific parts rundown--this is a great help! I was
fretting mostly over those .22 caps becuase there's not much room
inside. Digikey doesn't have the Wima MKS-2, so I was thinking of
paralleling two .22 Panasonic "V" series, one on each side of the board.
I don't suppose there any "one-stop" place that has all these parts?
Thanks again.

Regards,
Joe



jwilliams3@audioupgrades.com wrote:
> Replace the 2SK170 with either a Linear Systems LSK170 or a Siliconix
> J305. Replace the output transistors with Hitachi 2SA1083's. Replace
> the .22 uf output caps with Wima MKS-2 or fit a Mono ceramic 1 uf with
> a .01 polyprop film bypass to extend the low end. replace the 680 pf
> input cap with a Wima FKP-2 1k v or a MIT PPMFX 1000 pf. Replace the
> 2.2 k resistors with Dale RN55. Replace the 150 k resistors with 100k
> Dale RN55. Replace the 1N4148 diodes with 1N4394's. This will increase
> the polarization voltage to the capsule.
>
> That ought to get ya all started, could make this sound pretty good.
>
> BTW, this is another variation of the Schoeps CMC mic circuit.
>
> Jim Williams
> Audio Upgrades
>

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

On 29 May 2005 18:52:05 -0400, Mannr@uwaterloo.ca wrote:

>...

>I'm wondering (I think I asked before...) about the quality/consistency of the
>*capsules* themselves. I mean no amount of electronics hacking is going to
>fix a bad capsule. So, does anyone know the consistency/quality? I'm looking
>at both MXL603s and other clone/unlabelled versions, like Apex 180, and I'm
>sure there are many others. These are *identical* in appearance to the MXL,
>and a lot cheaper.

Not having seen this before, I googled, and it's hugely cheaper:
http/www.dynamicmusic.com.au/Public_ProductDetails.asp?ISBN=ACY059
Okay, $1.00 is apparently a mistake (anyone want to try ordering a
few at that price?), as others show $69. OTOH, an Australian dollar
may be worth more, and then there's shipping...


> The Apex 180 also comes with interchangeable omni/card
>caps.
>
>Thanks again,
> Richard

-----
http/mindspring.com/~benbradley

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

Good point. Only time will tell, since small tolerances will show up in
problems if it's not a quality build.

So far, the 603s are still working fine, even with your notice of noise
since it didn't present itself in subsequent testing, and the 990s are still
functioning correctly.


--


Roger W. Norman
SirMusic Studio
http/blogs.salon.com/0004478/
"Mike Rivers" <mrivers@d-and-d.com> wrote in message
news:znr1117300578k@trad...
>
> In article <e9udnUIzdqq2CwXfRVn-2g@rcn.net> rnorman@starpower.net writes:
>
> > On the MXL page they have the 990s as a Large 20mm
> > diaphragm, and on the 991s, it's just a 20mm diaphragm. Maybe I'll have
to
> > pick up a couple of 991s and see if there's a major difference.
>
> I was curious about that. 20mm is a little smaller than "large" but
> kind of big to be "small." I don't know where they measure that
> dimension on a microphone capsule or if there's even a standard way of
> measuring it, but since the outside diameter of the 991 case at the
> business end is only 22.4 mm, that hardly leaves room to suspend a
> 20 mm capsule with much vibration isolation even if they measure it at
> the outer diameter of clamp ring and backplate (with actual diaphragm
> being perhaps 4 or 5 mm less in diameter.
>
>
>
> --
> I'm really Mike Rivers (mrivers@d-and-d.com)
> However, until the spam goes away or Hell freezes over,
> lots of IP addresses are blocked from this system. If
> you e-mail me and it bounces, use your secret decoder ring
> and reach me here: double-m-eleven-double-zero at yahoo

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

I like your choices, I just don't have any of them! <g>

--


Roger W. Norman
SirMusic Studio
http/blogs.salon.com/0004478/
"Chris Cavell" <chriscavell@cavellstudios.com> wrote in message
news:1117301584.821286.305280@z14g2000cwz.googlegroups.com...
> Roger,
>
> Yeah, I don't trust their published pattern sheets at all...the 991's
> and 603's made within the last year or two are completely
> identical...all the way down to the mesh lining the vents.
>
> All in all I consider the 603/991 to be the best sub-hundred buck mic
> on the market.
>
> They just had this sort of ring with my particular favored micing
> technique (serving as spots augmenting a more distant C426 in blumlein)
> that disappeared with other small di's, but was present regardless of
> the which of the 3 steinway's I had available in the room at the time.
> It tended to make them unusable for me (for piano) in the jazz combos I
> record regularly with all the upper three octave comping and soloing
> going on. For those I often wound up replacing the mxl's with the c426
> in the same position, or a pzm with a figure 8 head on a SE300B body
> taped to it for an MS setup.
>
> Cheers,
> Chris
>