Mike Mod Errata
Scott Dorsey
There are some big problems with the parts numbers on the schematic in the
Making Mikes Better article, and a worse problem with the board layout.
First of all, the parts list IS correct and has the correct parts names
and numbers.
The layout has a small problem; there are two C6es listed on it. The C6
on the top of the layout in the center between the FET and the input pin
really is C6, the 820 pF cap. The C6 on the bottom left which is across
the zener is really C4, the 10 uF tantalum cap.
The schematic has two caps marked C4, 10 uF tantalum. The one across
the zener really is C4. The cap between the base of Q2 and the source
of the FET is really C3, the 1 uF film cap. (Remember, C2 and C3 have
to be the same type and value so the circuit can be symmetric).
But, the REAL problem, and I want to thank a reader for finding this
one, is that the PC board layout is incorrect. On the schematic, the
330 ohm resistor R3 is tied to the lower side of R6 (the 6.8k resistor)
which is held at 12V with the zener, but on the layout, it's tied to
the top side of R6 which is pulled to 30V. This means there is 30V
across C1 (which is bad) and too high a voltage across the FET (which
is actually fine).
To fix this, remove the 330 ohm resistor completely, and take one of
the spare 330 ohm resistors and use that as a replacement. Put one
side of the resistor into the top hole of the original resistor, the
one that goes to C1. Then take the other lead of the resistor and
snake it across the board a bit, then tack-solder it to the bottom
side of the 6.8K resistor, the side that connects to the zener.
If you use the published layouts to make your own board, or you got
the original board from me, you will have to do this. This is only
the case for the first 50 boards made, however. If your board says
"REVISION II" in big letters in the lower lefthand corner, you have
one of the newer boards which have had this change made on them and
you can ignore this.
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
Mitchell Benson
Thanks for the update! I sure am glad I saw this post!
I just got the mag tonite, but haven't had much time to look at it.
Thanks again...........Mitch
Ulysses
One other think I noticed which is rather nitpicky but could cause some
difficulty for your young disciples. The CW9100 deflux pen on your parts
list is intended for use with no-wash solder, according to Digikey's web
site. The CW9200 is for use with rosin-core solder which most hobbyists
are much more likely to be using. A lot of folks might not realize this,
and not know the flux hadn't come off, and not know why their mics are
noisy...right?
Also, the 1G resistors are backordered at DigiKey and the next best thing,
a 1/2W resistor of the same type, comes with a minimum order of 10 units,
which tacks about $30 onto the price tag unless you're doing 5 mics.
I went down to Mars today and actually bought something (shudder). I
picked up four Marshall MXL V57M's for $79 apiece. That's pretty damn
cheap. I knew the girl at the counter so while chattin' her up I managed
to pull the case off of a V57 and a V63 ($99). They were both identical
except for color, as far as I can tell, and shaped right for
Dorsey-fying. But interestingly, it looks like they already have
something vaguely resmbling the Schoeps design. I haven't drawn it out
yet but I have it here in front of me and I see a FET at the front end
that has a K170 on it, between a pair of 1G resistors. the output
transistor are 2N5401, and there's a 2nd circuit board that looks like it
could possibly be an inverter circuit for generating a higher polarizing
voltage. I guess somebody in China figured out that a handful of
components in somebody else's circuit design costs less than a crappy
transformer. I haven't listened to it yet, and I'm actually kind of
bummed I didn't find one of the ultra-crappy transformer models (though
who knows, this circuit could be worse) because I wanted to see just how
bad they really are. If I'm lucky, this design here will really suck and
I can be awed at the transformation that occurs.
--
Justin Ulysses Morse
Roll Music Studios
Minneapolis, MN
www.rollmusic.com War is terror.
Ulysses
it's at http://www.rollmusic.com/projects/images/MXLV57M.JPG. I didn't
draw the DC-DC converter board out, but I think I've got the rest of it
right. I'm curious to know what's good and bad about this design as
compared to Scott's. It's similar, but not entirely.
Mitchell Benson
> picked up four Marshall MXL V57M's for $79 apiece. That's pretty damn
> cheap. I knew the girl at the counter so while chattin' her up I managed
> to pull the case off of a V57 and a V63 ($99).
Hey Justin & Scott,
It has been a few weeks since I have been to Mars, but every time I
have been in there, I fail to see any of the low-end LDCs(they do have
the lower priced ATs). The only time I have ever seen any Marshall on
display, was when I picked up my first two over a year ago. Are the
Marshalls and other mics on display at your Mars, or are these
something you have to specifically ask for?
Come to think of it, the only lowend LDCs I see at GCenter are the
Oktavas and the ATs.
Are these guys ashamed of them? I find that very hard to believe,
considering that the lower priced gear is probably the bulk of their
sales!
Mike Rivers
> It has been a few weeks since I have been to Mars, but every time I
> have been in there, I fail to see any of the low-end LDCs(they do have
> the lower priced ATs).
If LDC means Large Diaphragm Condenser (see, I'm learning), what's a
lower priced AT? Audio Transformer? Analog Tube? Asshole Tweaker?
Or does AT stand for Audio Technica, and you really meant that they
had some lower priced Audio Technica small diaphragm condenser mics,
and the SDC was implied? Is that it? Have I decoded your message
even without the secret decoder ring?
Please, people, don't assume everyone knows what your shorthand stands
for.
--
I'm really Mike Rivers (mri...@d-and-d.com)
Brian Allen
Thanks.
Brian
>
Ulysses
"Brian Allen" <ro...@earthlink.net> wrote:
> What are you using to draw your schematics?
A ballpoint pen.
Oh, then photoshop. It's what I'm fastest with.
Mitchell Benson
> If LDC means Large Diaphragm Condenser (see, I'm learning), what's a
> lower priced AT? Audio Transformer? Analog Tube? Asshole Tweaker?
I don't know about the asshole tweaker, I don't go that way!%-}
> Or does AT stand for Audio Technica, and you really meant that they
> had some lower priced Audio Technica small diaphragm condenser mics,
> and the SDC was implied? Is that it? Have I decoded your message
> even without the secret decoder ring?
No, I was refering to the large diaphram condensor ATs. Like the 3035
or the 3525. I think the 3035 was about $200, and the 3525 was $300 or
$350. While this is not a 75 or 100 buck MXL, I and probably most
everyone here would consider them "lower end" mics.
> Please, people, don't assume everyone knows what your shorthand stands
> for.
I will try to be more specific in the future. I have seen the
abbreviation AT in several posts, and just assumed that most knew what
it meant, especially since we are posting about mics.
Scott Dorsey
>One other think I noticed which is rather nitpicky but could cause some
>difficulty for your young disciples. The CW9100 deflux pen on your parts
>list is intended for use with no-wash solder, according to Digikey's web
>site. The CW9200 is for use with rosin-core solder which most hobbyists
>are much more likely to be using. A lot of folks might not realize this,
>and not know the flux hadn't come off, and not know why their mics are
>noisy...right?
Yeah, but Digi-Key won't ship the CW9200. The honest truth is that the
stuff in the spray cans works a hell of a lot better than any of the
pens. And I now find that MCM Electronics will ship the spray stuff by
Airborne.
>Also, the 1G resistors are backordered at DigiKey and the next best thing,
>a 1/2W resistor of the same type, comes with a minimum order of 10 units,
>which tacks about $30 onto the price tag unless you're doing 5 mics.
Welcome to Just in Time purchasing. Did Digi-Key give you any time
estimate on the 1G resistors? I won't even talk about how they kept me
waiting for nine months for op-amps....
>I went down to Mars today and actually bought something (shudder). I
>picked up four Marshall MXL V57M's for $79 apiece. That's pretty damn
>cheap. I knew the girl at the counter so while chattin' her up I managed
>to pull the case off of a V57 and a V63 ($99). They were both identical
>except for color, as far as I can tell, and shaped right for
>Dorsey-fying. But interestingly, it looks like they already have
>something vaguely resmbling the Schoeps design. I haven't drawn it out
>yet but I have it here in front of me and I see a FET at the front end
>that has a K170 on it, between a pair of 1G resistors. the output
>transistor are 2N5401, and there's a 2nd circuit board that looks like it
>could possibly be an inverter circuit for generating a higher polarizing
>voltage. I guess somebody in China figured out that a handful of
>components in somebody else's circuit design costs less than a crappy
>transformer. I haven't listened to it yet, and I'm actually kind of
>bummed I didn't find one of the ultra-crappy transformer models (though
>who knows, this circuit could be worse) because I wanted to see just how
>bad they really are. If I'm lucky, this design here will really suck and
>I can be awed at the transformation that occurs.
Send me the schematic... I'd love to look at it. Is the FET a metal
can? You sure there is no transformer in the base?
--scott
Scott Dorsey
>What are you using to draw your schematics?
A Rapidograph and a straightedge. I'll go over it first with an architect's
pencil and then ink it in.
--scott
Robert Angst
Schematics welcome ;)
Robert
Ulysses
Dorsey) wrote:
> Welcome to Just in Time purchasing. Did Digi-Key give you any time
> estimate on the 1G resistors? I won't even talk about how they kept me
> waiting for nine months for op-amps....
We (myself and two cohorts) bought 4 mics between us, so we can use the
minimum order of 10 pieces of the 1/2w package. However, I think I'll
just use the 1G resistors that are already in these mics instead.
> Send me the schematic... I'd love to look at it. Is the FET a metal
> can? You sure there is no transformer in the base?
http://www.rollmusic.com/projects/images/MXLV57M.JPG
I'll try to throw some pictures up. The FET is a normal black plastic
2SK170 and it's definitely transformerless. I'll try and find time to
draw out the dc-dc board soon. It's pretty basic (I think...what do I
know about those circuits?) with one transistor, two inductors, and a
couple of diodes.
Scott Dorsey
>In article <a1ao56$b16$1...@panix2.panix.com>, klu...@panix.com (Scott
>Dorsey) wrote:
>
>> Welcome to Just in Time purchasing. Did Digi-Key give you any time
>> estimate on the 1G resistors? I won't even talk about how they kept me
>> waiting for nine months for op-amps....
>
>We (myself and two cohorts) bought 4 mics between us, so we can use the
>minimum order of 10 pieces of the 1/2w package. However, I think I'll
>just use the 1G resistors that are already in these mics instead.
The ones in the mikes I took apart were not consistent at all. If these
are the brown flag-shaped ones. Let me know if you do use them and how
they compare with the half-watters.
>> Send me the schematic... I'd love to look at it. Is the FET a metal
>> can? You sure there is no transformer in the base?
>
>http://www.rollmusic.com/projects/images/MXLV57M.JPG
>
>I'll try to throw some pictures up. The FET is a normal black plastic
>2SK170 and it's definitely transformerless. I'll try and find time to
>draw out the dc-dc board soon. It's pretty basic (I think...what do I
>know about those circuits?) with one transistor, two inductors, and a
>couple of diodes.
This is not Chinese production... this is definitely something added
in the US or at least designed in the US. And yes, it's a Schoeps-style
circuit, and a very fine one too.
Kato Jenkina
with electronics that match that schematic), you would recommend that
he *not* perform the Dorsification, I assume?
Kate
Nice article by the way - I rarely buy H&SR but I picked it up just
for this article.
klu...@panix.com (Scott Dorsey) wrote in message
Scott Dorsey
>So in Justin's case (or in the case of someone who bought a Marshall
>with electronics that match that schematic), you would recommend that
>he *not* perform the Dorsification, I assume?
Maybe. I haven't actually listened to it, but I suspect I wouldn't recommend
it. Same with the CR3A and some of the other mikes out there that have
already replaced the electronics.
>Nice article by the way - I rarely buy H&SR but I picked it up just
>for this article.
Many thanks! It has been a lot of fun.
Ulysses
dongr...@innocent.com (Kato Jenkina) wrote:
> So in Justin's case (or in the case of someone who bought a Marshall
> with electronics that match that schematic), you would recommend that
> he *not* perform the Dorsification, I assume?
I haven't actually listened to these mics yet, outside of spitting into a
demo unit at the store. So I don't have an opinion as of yet. It does
look pretty good in theory. And the funny thing is, they probably went
with these electronics to save the cost of the transformer. I would think
even a crappy transformer would cost more than a "borrowed" discrete
circuit like this one. There's not much to it. I'll probably fool around
with replacing components on these mics, and maybe try Scott's board out
for comparison. Heck, maybe I could figure out a way to use Scott's board
in conjunction with this inverter board to keep the high polarizing
voltage. (at least I assume it's a high voltage...how exactly do you
measure the voltage of a circuit with 1000M impedance?)
I don't like the idea of these cheap mics being fine just how they are.
Hopefully they'll sound bad and I won't have to revise my world view. I'm
probably going to have to buy another mic, one of the crappy transformer
models, just to see how much worse those are.
Homer Jackson
I just got my 2nd Nady SCM 900 from Musician's Friend today.
Well, well well. This one is different. The first had a transformer
and two transistors. This one, like the mic that Justin had,
has no transformer, but it has four transistors.
It even has two- 220uf 25V caps, one - 47uf 50v electrolytic cap
and two diodes. Both boards in the new one are smaller in
size and the leads from the capsule are bare.
I'm a total rookie and plan to mod this bad boy anyway, but how
can a company have consistent product quality using such vastly
different setups for the very same product?
Homer Jackson
uly...@rollmusic.com (Ulysses) wrote in message news:<ulysses-0901...@x134-84-254-198.dialup.umn.edu>...
Kato Jenkina
know that's probably the case.
When I read Scott's article, I thought to myself "under mass
production it wouldn't cost more than $1-2 per mic to use these
electronics and probably no more than the components that are in their
original design anyway." So why don't they use a similar design?
Then you discovered that *now* they do. It seems a freakish
coincidence. Perhaps Scott and someone at Marshall simultaneously
stumbled upon the same circuit design somewhere.
I'd like to think Marshall employs an idealistic, enthusiastic design
engineer who's always coming up with new ideas to make their mics
sound better. In reality, they probably do, but as soon as he presents
it with the information that implementing it will raise the
manufacturing cost by 20 cents it's rejected! That's my little
imaginary scenario.
How much do you suppose it costs to build a complete MXL V57? Five
bucks?
Kate
uly...@rollmusic.com (Ulysses) wrote in message news:<ulysses-0901...@x134-84-254-198.dialup.umn.edu>...
Scott Dorsey
>Hey Scott and Justin!
>I just got my 2nd Nady SCM 900 from Musician's Friend today.
>Well, well well. This one is different. The first had a transformer
>and two transistors. This one, like the mic that Justin had,
>has no transformer, but it has four transistors.
>It even has two- 220uf 25V caps, one - 47uf 50v electrolytic cap
>and two diodes. Both boards in the new one are smaller in
>size and the leads from the capsule are bare.
That is interesting. Send me the board if you pull it out.
>I'm a total rookie and plan to mod this bad boy anyway, but how
>can a company have consistent product quality using such vastly
>different setups for the very same product?
NADY is just getting them by the containerload from the factory in China
and putting them in boxes. The factory is just putting whatever they
have on hand into boxes. Or maybe NADY is upgrading them. Be interesting
to see.
I have opened hundreds of these mikes and have not seen this transformerless
board, so this is something new.
--scott
Scott Dorsey
>
>Then you discovered that *now* they do. It seems a freakish
>coincidence. Perhaps Scott and someone at Marshall simultaneously
>stumbled upon the same circuit design somewhere.
Probably. It's an extremely common design, used in thousands of mikes
in the past thirty years.
>I'd like to think Marshall employs an idealistic, enthusiastic design
>engineer who's always coming up with new ideas to make their mics
>sound better. In reality, they probably do, but as soon as he presents
>it with the information that implementing it will raise the
>manufacturing cost by 20 cents it's rejected! That's my little
>imaginary scenario.
Brent Casey is a good guy, and he knows his stuff, and I do know he works
to try and get their quality up as much as possible given the production
limitations.
>How much do you suppose it costs to build a complete MXL V57? Five
>bucks?
Dunno. The Shanghai mikes were selling for $90 new, FOB Shanghai port
three years back before the flood. Most the cost of the mike itself
is in the capsule machining and in the case. Since they are now selling
for way less than $90 retail in the US now, the price from the factory
has to be a lot lower.
--scott
Mitchell Benson
> demo unit at the store.
Remind me to never ask if they will sell me the demo model!!
Ulysses
First the box. I was just noticing the following:
-The photo on the box shows a different color mic with NO markings or
label on it.
-The V57M model number is just a sticker on the box.
-There's another sticker sealing the box that says, "Not Returnable if
Seal is Broken or Removed"
-The description printed on the box says, "The output is transformer
balanced and this microphone is perfect for both vocal and instrumental
recording." (two lies in one sentence!)
-The "features" indicated on the box include:
"Balanced Transformer Coupling
Allows long cable runs without signal loss"
BUT
that part has a sticker over it that says:
"Transformerless Balanced Output
Allows long cable runs without signal loss"
I think this new model is REALLY new. Scott, did you tell anybody at
Marshall about your article before it was published? I think the seal
sticker is a pre-emptive strike against people returning botched mod
jobs. When I bought my mics at Mars, I had told the sales clerk what I
was planning on doing with the mics and he stamped my receipt,
"Non-returnable item."
More importantly, I listened to these things tonight. First thing I did
was put a pair of them up behind the drummer's head. Good place for a
drum mic, but not such a good place for a coincident or near-coincident
pair for XY stereo. Ran them through the Great River MP-2NV. I wasn't
thrilled with the sound I got there, especially compared with some vastly
differen mics on other positions, but it did seem that both mics had about
the same output level and same basic sound. The output level seemed
fairly high. Overall there was nothing seriously lacking with the sound
but nothing impressive either. Mundane, maybe a bit muddy and undefined.
Next I swapped one of the mics for a Neumann U89 and repositioned them so
they were both facing the snare and were very close together. My partner
and I were not aware at this point which mic was plugged into which
channel of the Great River. We compared the two for quite a while,
listening to individual drums and cymbals. Then I swapped the physical
position of the two mics to be sure the differences we heard were not due
to placement. We took turns playing while the other listened, so we did
not discuss our opinions til we were done. Be both heard dramatic
differences between the two mics of course. But at first we disagreed as
to which channel was better. I said channel one had much better high-end
detail. I started to get frustrated because it seemed like every time I
switched which mic I was listening to, Johnny would switch and play a
different cymbal. It turns out it only sounded like a different cymbal
because the mics were so different. But Johnny said channel one sounded
thin and papery, whereas channel two had a much more detailed bottom and
the drums sounded more like real drums. So we went in and listened again.
When we were done a 2nd time we agreed that mic #2 (which of course turned
out to be the U89) did have much better bottom and a much fuller sound.
Mic #1 (the MXL) simply had a lot more top end, a large presence peak.
Toms on mic #1 sounded thin and harsh. I think they could be very nice on
some sources IF the damn things had some meaningful low end. I think the
U89s started to seem dull and muddy to me, but only because I was
comparing them to something so top-heavy. I've always been very pleased
with the way the U89s sound on a drumset.
So I guess I'll probably be replacing some capacitors in the MXLs.
Scott Dorsey
>
>I think this new model is REALLY new. Scott, did you tell anybody at
>Marshall about your article before it was published? I think the seal
>sticker is a pre-emptive strike against people returning botched mod
>jobs. When I bought my mics at Mars, I had told the sales clerk what I
>was planning on doing with the mics and he stamped my receipt,
>"Non-returnable item."
Yes, I told Brent about it, but I told him about it almost two years ago.
I have looked inside one of those mikes, and what I saw did not look like
what you saw at all, so my assumption is that there have been a lot of
recent changes.
Jim Gilliland
>
> Some more interesting tidbits about the MXL V57M.
>
>
> I think this new model is REALLY new.
>
> Toms on mic #1 sounded thin and harsh. I think they could be very nice on
> some sources IF the damn things had some meaningful low end.
>
So what do you think is the likelihood that you'll be able to get better
sound from these mics by changing capacitors or other circuit elements,
or even the entire board? Scott assures me that all of the mics from
the Shanghai factory (V57s, V67s, and countless others) use exactly the
same capsule - that the only difference is the grill/case, circuit, and
logo.
Yet this circuit is similar to Scott's. Is the problem that it's just
not a very good capsule? Or is the circuit just different enough to
cause the problems you're hearing? Or both? <g>
In the last paragraph of his article, Scott acknowledges the presence
peak that you noted, but he also says that his mod fixes "a lot" of the
problems in the low end. Maybe even this new V57 will benefit
substantially from Scott's mod.
Scott Dorsey
>Ulysses wrote:
>>
>> Some more interesting tidbits about the MXL V57M.
>>
>> "Transformerless Balanced Output"
>>
>> I think this new model is REALLY new.
>>
>> More importantly, I listened to these things tonight.
>> Mic #1 (the MXL) simply had a lot more top end, a large presence peak.
>> Toms on mic #1 sounded thin and harsh. I think they could be very nice on
>> some sources IF the damn things had some meaningful low end.
>>
>> So I guess I'll probably be replacing some capacitors in the MXLs.
>
>So what do you think is the likelihood that you'll be able to get better
>sound from these mics by changing capacitors or other circuit elements,
>or even the entire board? Scott assures me that all of the mics from
>the Shanghai factory (V57s, V67s, and countless others) use exactly the
>same capsule - that the only difference is the grill/case, circuit, and
>logo.
In the past this has always been the case. And I looked inside an older
V57M and found a board identical to the normal Shanghai board. This is
most definitely different.
>Yet this circuit is similar to Scott's. Is the problem that it's just
>not a very good capsule? Or is the circuit just different enough to
>cause the problems you're hearing? Or both? <g>
The capsules have some problems. But those coupling caps are also a big
deal. Also, making sure the supply voltages are really stiff and well
decoupled makes a huge difference in the low end. But the circuit is simple
and clean and dozens of manufacturers have been using it for thirty years now,
so it's no huge secret.
>In the last paragraph of his article, Scott acknowledges the presence
>peak that you noted, but he also says that his mod fixes "a lot" of the
>problems in the low end. Maybe even this new V57 will benefit
>substantially from Scott's mod.
The peak around 6K is from the capsule, and it's different on every capsule.
I considered trying to EQ it out on the board, but I couldn't do this without
having to hand-tweak the EQ network for every capsule. So if you like the
peak, it's there, and if you don't like it, you should use a different mike
for the job.
Jim Gilliland
>
> Jim Gilliland <usemyl...@altavista.net> wrote:
> >Ulysses wrote:
> >>
> >> Some more interesting tidbits about the MXL V57M.
> >>
> >> "Transformerless Balanced Output"
> >>
> >> I think this new model is REALLY new.
> >>
> >> More importantly, I listened to these things tonight.
> >> Mic #1 (the MXL) simply had a lot more top end, a large presence peak.
> >> Toms on mic #1 sounded thin and harsh. I think they could be very nice on
> >> some sources IF the damn things had some meaningful low end.
> >>
> >> So I guess I'll probably be replacing some capacitors in the MXLs.
> >
> >So what do you think is the likelihood that you'll be able to get better
> >sound from these mics by changing capacitors or other circuit elements,
> >or even the entire board? Scott assures me that all of the mics from
> >the Shanghai factory (V57s, V67s, and countless others) use exactly the
> >same capsule - that the only difference is the grill/case, circuit, and
> >logo.
>
> In the past this has always been the case. And I looked inside an older
> V57M and found a board identical to the normal Shanghai board. This is
> most definitely different.
Looking over the MXL website, I note that the MXL 1006 has a physical
appearance that is identical to the V57, and it claims to have a
transformerless balanced output. It doesn't mention an FET though, just
"the latest in balanced transistor output for maximum frequency
response".
Analogeezer
Hmmmm this is all very encouraging.
So if you buy one of these MXL mics, with the thought of going back
and getting a 2nd one a while later, chances are it's gonna be a
different mic altogether?
Let's forget for a while that the chances of buying two cheap LDC's at
random and getting a matched pair would be like the proverbial
"infinite number of monkeys typing on an infinite number of
typewriters will write War and Peace" ...
Let's just say one would "Hope" they are in the same ballpark
soundwise.
So you buy one at one store visit and it's got transformers and some
parts, and the next time it's altogether different?
That is just whacky, it sounds like these things are not "designed",
they are just "built" with whatever parts are around...
"Hey Cheng, we're all out of transformers, what do we do?"
"It's ok Chang, we'll just make this batch transformerless, that way
we can put on the side of the box that they push long cable runs
without any problems, everybody buying these things are always hooking
up 300 feet of mic cable to them"
Stuff like this is beginning to make things like the AT 4033 seem like
a great value (which it is). With a mic from a "real mic" company, at
least you don't have to worry about the mic being a totally different
design two months later, and if they do change the design they at
least change the model number...
I thought that MXL was doing "extra QC" stateside...geez might as well
just buy the $69 Nady.
Analogeezer
Jim Gilliland
>
> Ulysses <uly...@rollmusic.com> wrote:
> >One other think I noticed which is rather nitpicky but could cause some
> >difficulty for your young disciples.
Hey, who are you calling young? <g>
> >The CW9100 deflux pen on your parts
> >list is intended for use with no-wash solder, according to Digikey's web
> >site. The CW9200 is for use with rosin-core solder which most hobbyists
> >are much more likely to be using. A lot of folks might not realize this,
> >and not know the flux hadn't come off, and not know why their mics are
> >noisy...right?
>
> Yeah, but Digi-Key won't ship the CW9200. The honest truth is that the
> stuff in the spray cans works a hell of a lot better than any of the
> pens. And I now find that MCM Electronics will ship the spray stuff by
> Airborne.
The website seems perfectly willing to accept an order for the CW9200.
I don't know if they'll ship or not, but there's nothing to indicate
that they won't.
> >Also, the 1G resistors are backordered at DigiKey and the next best thing,
> >a 1/2W resistor of the same type, comes with a minimum order of 10 units,
> >which tacks about $30 onto the price tag unless you're doing 5 mics.
>
> Welcome to Just in Time purchasing. Did Digi-Key give you any time
> estimate on the 1G resistors? I won't even talk about how they kept me
> waiting for nine months for op-amps....
The website gives an estimate of February 3rd.
Ulysses
Dorsey) wrote:
> Ulysses <uly...@rollmusic.com> wrote:
> >
> >I think this new model is REALLY new. Scott, did you tell anybody at
> >Marshall about your article before it was published? I think the seal
> >sticker is a pre-emptive strike against people returning botched mod
> >jobs. When I bought my mics at Mars, I had told the sales clerk what I
> >was planning on doing with the mics and he stamped my receipt,
> >"Non-returnable item."
>
> Yes, I told Brent about it, but I told him about it almost two years ago.
Well, I knew they couldn't have read your article and then implemented the
changes and had mics in stores already. Maybe this Brent fella took your
ideas to heart, and presented them to the company as a cost reduction.
Nobody has anything to complain about there!
> I have looked inside one of those mikes, and what I saw did not look like
> what you saw at all, so my assumption is that there have been a lot of
> recent changes.
Yeah, the "transformerless" sticker over the "tranformer balanced" line
tells you it's a new change. I guess they just needed to use up all the
old boxes they had.
Ulysses
<usemyl...@altavista.net> wrote:
> So what do you think is the likelihood that you'll be able to get better
> sound from these mics by changing capacitors or other circuit elements,
> or even the entire board? Scott assures me that all of the mics from
> the Shanghai factory (V57s, V67s, and countless others) use exactly the
> same capsule - that the only difference is the grill/case, circuit, and
> logo.
>
> Yet this circuit is similar to Scott's. Is the problem that it's just
> not a very good capsule? Or is the circuit just different enough to
> cause the problems you're hearing? Or both? <g>
>
> In the last paragraph of his article, Scott acknowledges the presence
> peak that you noted, but he also says that his mod fixes "a lot" of the
> problems in the low end. Maybe even this new V57 will benefit
> substantially from Scott's mod.
The circuit that's in these mics is similar but not identical to Scott's
boards. One advantage the stock circuit has that Scott left out of his
design (probably for simplicity, since it's a project for hobbyists) is
the higher capsule polarizing voltage supply. With these mics, I'm sure I
could use Scott's board along with this DC-Dc converter circuit (which is
on its own 2nd circuti board) but I'm guessing that the crummy performance
of this mic's low end has more to do with component selection than with
circuit topology. For example, Scott specifies 1湩 film caps between the
FET and the output transistors, whereas this mic uses tiny ceramic caps.
And when I'm installing parts myself, I can hand select them to match
pairs of resistors, transistors, and caps. Then again, I can also botch
the soldering and make a mess.
I think what I'll end up doing is swapping components on one mic, putting
the Dorsey mod in another mic, and comparing them to stock. My problem is
I'm much better about performing mods than about critcially comparing the
results. It's tough to find time outside of a session to put up two
nearly-identical mics on the same source and compare them closely. And
you just can't do it during a session at all.
Ulysses
Dorsey) wrote:
> The peak around 6K is from the capsule, and it's different on every capsule.
> I considered trying to EQ it out on the board, but I couldn't do this without
> having to hand-tweak the EQ network for every capsule. So if you like the
> peak, it's there, and if you don't like it, you should use a different mike
> for the job.
While I'm confident the electronics can be made to sound good and the
capsules themselves can sound good (I kind of like the presence peak...it
gives a sense of detail to things like cymbals), my primary concern about
this little project is that I won't be able to find a reasonably matched
pair of capsules out of the four I've got. And the deal is we're supposed
to find two pair!
Mike Rivers
> Some more interesting tidbits about the MXL V57M.
Egad! Maybe you got a Chinese knock-off of a Marshall mic. <g>
--
I'm really Mike Rivers (mri...@d-and-d.com)
Paul Winkler
> Looking over the MXL website, I note that the MXL 1006 has a physical
> appearance that is identical to the V57, and it claims to have a
> transformerless balanced output. It doesn't mention an FET though, just
> "the latest in balanced transistor output for maximum frequency
> response".
I called Marshall on Tuesday to ask them about the 57, since there
was no info about it on their website.
The guy who answered the phone said (paraphrased):
The MXL-V57M was designed as an OEM product to be sold only via
Mars. They have recently re-released it to other markets with a new
name: MXL 1006. He says it's "virtually the same mic".
I asked what's the diff, and he said:
Externally, there are some slight cosmetic differences.
Internally, he wasn't sure, he thinks there is some slight
difference like maybe a different brand of wire.
I didn't press for further details.
I also asked what was the correct shockmount for this mic, since their
website didn't list one. He said to use the MXL57 shockmount (the same
one used for the V67G). He said DON'T use the MXL56 shockmount (the one
used for the 2001P and others); "you might get it in there once and
only once."
- Paul Winkler
Jim Gilliland
>
> > I have looked inside one of those mikes, and what I saw did not look like
> > what you saw at all, so my assumption is that there have been a lot of
> > recent changes.
>
> Yeah, the "transformerless" sticker over the "tranformer balanced" line
> tells you it's a new change. I guess they just needed to use up all the
> old boxes they had.
I traded emails with Brent Casey on this subject today, and here's some
of what he had to say:
"The MXL V57 has an FET impedance conversion on the input of the
circuit. The output of the V57 is transistorized rather transformer
based.
"To answer your question, the V57 is not available with a
transformer-based output circuit. The reason for the "transformerless
output" sticker on the damn box is because the box designers didn't have
the copy proof-read properly before five zillion of the boxes were
already made. The "transformer balanced for long cable runs" is a copy
error. The sticker is a correction, albeit a last-minute one.
"Maybe you should just let some more theories stack up before mentioning
this to anyone on R.A.P, since the theories themselves are a lot more
fun to read about than the reality of the situation. <g>"
If I'm interpreting him correctly, it appears to be his contention that
there has never been a V57 with an output transformer. Scott, might you
be thinking of a different mic? I know you've seen several dozen of
these Shanghai mics, so it wouldn't be too surprising. The V57 and V63
mics are new enough that they don't even show up on the MXL website, so
it seems unlikely that they'd have already gone through a major
revision.
Anyway, I'm just reporting what I learned - I've never seen either of
these mics in person, so I can't comment further.
Jim Gilliland
>
> klu...@panix.com (Scott Dorsey) wrote in message news:<a1kc5h$rq5$1...@panix2.panix.com>...
> > Ulysses <uly...@rollmusic.com> wrote:
> > >
> > >I think this new model is REALLY new.
> >
> > what you saw at all, so my assumption is that there have been a lot of
> > recent changes.
> > --scott
>
> Hmmmm this is all very encouraging.
>
> So if you buy one of these MXL mics, with the thought of going back
> and getting a 2nd one a while later, chances are it's gonna be a
> different mic altogether?
See my note from last night (in this thread) regarding the MXL mics.
Scott Dorsey
>
>That is just whacky, it sounds like these things are not "designed",
>they are just "built" with whatever parts are around...
>
>"Hey Cheng, we're all out of transformers, what do we do?"
>
>"It's ok Chang, we'll just make this batch transformerless, that way
>we can put on the side of the box that they push long cable runs
>without any problems, everybody buying these things are always hooking
>up 300 feet of mic cable to them"
Yes. This happens more often than you want to think about. It happens
all the time with Russian production too; I have seen a lot of Oktavas
where they ran out of the 680M polarization resistors and just used the
highest value they had at hand.
>Stuff like this is beginning to make things like the AT 4033 seem like
>a great value (which it is). With a mic from a "real mic" company, at
>least you don't have to worry about the mic being a totally different
>design two months later, and if they do change the design they at
>least change the model number...
Even on quality gear you will find subsitutions now and then. Last year
when tantalum caps were backordered six months due to the demand from the
cellphone people, I was seeing a lot of legitimate manufacturers doing
all kinds of weird things to replace them.
>I thought that MXL was doing "extra QC" stateside...geez might as well
>just buy the $69 Nady.
They are. MXL is actually doing a very impressive job of extra QC locally.
Ulysses
nitr...@us.inter.net (Mitchell Benson) wrote:
My solution is to simply never buy anything from Mars, though I did break
that rule last week when we got these MXLs. Mars is good for two things:
Comparing prices and testing demo gear for durability. You're lucky to
find a display model microphone that still works, so it shold go without
saying that they shouldn't be purchased. Besides, I'd rather give my
money to a good old ma & pa establishment such as Guitar Center.
Ulysses
homer...@yahoo.com (Homer Jackson) wrote:
> Hey Scott and Justin!
> I just got my 2nd Nady SCM 900 from Musician's Friend today.
> Well, well well. This one is different. The first had a transformer
> and two transistors. This one, like the mic that Justin had,
> has no transformer, but it has four transistors.
> It even has two- 220uf 25V caps, one - 47uf 50v electrolytic cap
> and two diodes. Both boards in the new one are smaller in
> size and the leads from the capsule are bare.
>
> I'm a total rookie and plan to mod this bad boy anyway, but how
> can a company have consistent product quality using such vastly
> different setups for the very same product?
>
Well, for the record I finally got around to comparing our 4 MXL V57Ms and
as far as I can tell, they all sound the same. This test involved putting
up all 4 mics in a line pointing at a drumset, running them through 4
channels of SX202, and listening to the drums. Tonal quality didn't seem
to change noticeably between mics (more than I can say for 4 random SM57s)
and their output levels were consistent. So there's hope in that regard.
Now if I can only get them to sound _good_, and make them look like a
different mic.
Scott Dorsey
Okay, I have now seen inside one of these. It's actually not a bad
design.
They do use a voltage multiplier to crank the capsule up to around 50V
or so, close to the voltage that the capsule they knocked off was designed
at. Running these capsules with the higher polarization voltage tends to
emphasize differences between them, so I am assuming that they are also
being more careful about selecting capsules for these.
These boards are definitely being made at same place that made the other
Shanghai mike boards, but they aren't laid out by the same person. And
they are most definitely not designed by the same person.
Paul Winkler
> Okay, I have now seen inside one of these. It's actually not a bad
> design.
>
> They do use a voltage multiplier to crank the capsule up to around 50V
> or so, close to the voltage that the capsule they knocked off was designed
> at. Running these capsules with the higher polarization voltage tends to
> emphasize differences between them, so I am assuming that they are also
> being more careful about selecting capsules for these.
>
> These boards are definitely being made at same place that made the other
> Shanghai mike boards, but they aren't laid out by the same person. And
> they are most definitely not designed by the same person.
> --scott
This is interesting...
What's it sound like? Have you compared it to a mic with your mod?
--Paul Winkler
Scott Dorsey
Paul Winkler <ba...@slinkp.com> wrote:
>klu...@panix.com (Scott Dorsey) wrote in message news:<a21mgq$fnm$1...@panix2.panix.com>...
>> Okay, I have now seen inside one of these. It's actually not a bad
>> design.
>>
>> They do use a voltage multiplier to crank the capsule up to around 50V
>> or so, close to the voltage that the capsule they knocked off was designed
>> at. Running these capsules with the higher polarization voltage tends to
>> emphasize differences between them, so I am assuming that they are also
>> being more careful about selecting capsules for these.
>>
>> These boards are definitely being made at same place that made the other
>> Shanghai mike boards, but they aren't laid out by the same person. And
>> they are most definitely not designed by the same person.
>
>
>What's it sound like? Have you compared it to a mic with your mod?
The one I have here sounds okay, but since the capsules are so
different between mikes, I won't generalize.