Studio Projects C1 circuit mods ONLY (keep original capsule)?

[Gus]

From my expérience with sp mics capsule is too bright, your sounds improve over exchanging parts.

I disagree about changing the parts
http://www.groupdiy.com/index.php?topic=52526.0

All you need to do is tame the high end a little.  The stock parts are OK in a C1 changing them is more a waste of time.

I did the same type adjustment to an older MXL2003 of mine

 

[Paul678]

From my expérience with sp mics capsule is too bright, your sounds improve over exchanging parts.

I disagree about changing the parts
http://www.groupdiy.com/index.php?topic=52526.0

All you need to do is tame the high end a little.  The stock parts are OK in a C1 changing them is more a waste of time.

I did the same type adjustment to an older MXL2003 of mine

Gus, you mentioned in the other thread:

    "The best adjustment was when I added a cap from source to drain some time ago. I have not posted about this until I saw other people figure this simple adjustment out."

This was on Q3, right?  What value cap did you use?

 

[Paul678]

Ok, update:

      I finally got "She sells seashells by the seashore" to not sound too sibilant with my voice
on this mic.  It sounds very smooth at the high end, but still very clear enunciation and detail,
and not too harsh.

      Unfortunately, it was this very same harshness that made the stock C1 mic my best acoustic guitar
mic for my signal chain and room.  With steel string guitar, I feel the need for some high end "bite", to
get the fast transients of pick noise and high end "shimmer".  With the new tuning I have done, that
shimmer is gone.

      So this is a reminder to me that there is really no such thing as a Do-All microphone, and that one
should have different flavors in the locker.

      I was a bit disappointed at first, but I'm not really bitter, because I've learned quite a bit, and it's nice to know I have some control over the tone of my mics.  And it would be super easy to go back to stock:  I only soldered the caps in to the
back on the PCB, and did not remove any of the original components. 

      Perhaps I should keep this modded mic to use as a vocal mic, and get another stock C1 just for
acoustic guitar?  Or perhaps a pair of Shure KSM141s, or Studio Projects C4s?

      The KSM414s will be a bit pricey for me....

 

[micaddict]

Good thread.

I was a bit disappointed at first, but I'm not really bitter

It sounds very smooth at the high end, but still very clear enunciation and detail,
and not too harsh.

That is quite an achievement! Be happy, man. 

Acoustic guitar mics a-plenty. Look at pencils first.

 

[Paul678]

Good thread.

I was a bit disappointed at first, but I'm not really bitter

It sounds very smooth at the high end, but still very clear enunciation and detail,
and not too harsh.

That is quite an achievement! Be happy, man. 

Acoustic guitar mics a-plenty. Look at pencils first.

    Well yes, it's a hell of a lot of work to tune a microphone specifically
for one voice:  many, many iterations.....I'm sure you know about this.

    I'm happy that I have more control over the tone of my mics than the
average Joe who accepts them from the factory as-is.  But my search
for a good acoustic steel-string guitar mic is still on-going.

      What model pencil mics would you recommend?  Specific models?
     

 

[micaddict]

Well yes, it's a hell of a lot of work to tune a microphone specifically
for one voice:  many, many iterations.....I'm sure you know about this.

Yep, and you've become a richer man.
Not money-wise, although I'm sure it will pay off in the future.

I'm happy that I have more control over the tone of my mics than the
average Joe who accepts them from the factory as-is.

Now we're talking. 

What model pencil mics would you recommend?  Specific models?

There are too many to mention, in every price category. For acoustic guitar, pencils tend (!) to work a little better, especially in stereo. Easier to position, too. But of course the big ones can do a great job, as well.

BTW there are harsh mics a-plenty, too. It's a plague. But fortunately you've found a cure.
Interestingly, harsh and bright mics (not necessarily the same) often impress at first, especially to less "trained" ears (no offense intended). But it's kinda like trying a couch. The ones that immediately feel comfy are usually the worst.

 

[Paul678]

Well yes, it's a hell of a lot of work to tune a microphone specifically
for one voice:  many, many iterations.....I'm sure you know about this.

Yep, and you've become a richer man.
Not money-wise, although I'm sure it will pay off in the future.

I'm happy that I have more control over the tone of my mics than the
average Joe who accepts them from the factory as-is.

Now we're talking. 

What model pencil mics would you recommend?  Specific models?

There are too many to mention, in every price category. For acoustic guitar, pencils tend (!) to work a little better, especially in stereo. Easier to position, too. But of course the big ones can do a great job, as well.

BTW there are harsh mics a-plenty, too. It's a plague. But fortunately you've found a cure.
Interestingly, harsh and bright mics (not necessarily the same) often impress at first, especially to less "trained" ears (no offense intended). But it's kinda like trying a couch. The ones that immediately feel comfy are usually the worst.

    Wait a minute!  Stop the presses! 

    I was simply too close to the sound hole and the guitar, so I had too much proximity effect!

    So I backed off another 4 inches or so, and pointed to the 12th fret, instead of the 14th fret, and....

    Voila!  Decreasing the too-boomy bass has the same effect as increasing the treble end.  And in
fact, now that I have listened to the stock mic recording more carefully, I can hear how the guitar recording
was over-hyped the same as the vocals were.  You are correct that a too-bright capsule can impress
at first, but upon more careful listening, on quality monitors, you can hear that it becomes a form of
distortion.

    That was just from one recording I just did, so I have even more experimenting to do!  This is why they
say mic positioning is critical...it's very hair-trigger. 

    I don't have a U87 myself, but I've heard many recordings done with the U87, and it wouldn't surprise me
if the mic I have now would hold it's own against one.  Maybe what I have now is a slightly brighter version
of the U87.  I read one guy complaining that he had two C1s, and one was brighter than the other.  I believe some people got lucky, and got good, non-hyped capsules, and this is why they compared this mic to the U87.

    And speaking of paying off in the future:  Now I know why Michael Joly and other mic modders usually
refuse to give their secrets away......it takes them too long to find the perfect combination of mods!  I mean,
I may want to charge money for this one day!      But it's a hell of a lot of work, and although you can
come up with a general solution, I think to do this properly, you really have to tune EACH capsule.  The
good news is, if you experiment with ONE circuit, you learn which caps have the greatest effect, and
so tuning each mic will become quite easy.

    Ok, so now I think my C1 is my best vocal AND acoustic guitar mic!  **** yeah!  It's probably going
to be a great drum overhead mic as well, etc, etc......

    I'm still going to look for a SDC, just to pair up with this mic, to give me even more tonal control
over acoustic guitars. 

    THANKS EVERYONE!!  ;D

 

[RuudNL]

And speaking of paying off in the future:  Now I know why Michael Joly and other mic modders usually
refuse to give their secrets away......it takes them too long to find the perfect combination of mods!  I mean,
I may want to charge money for this one day!

So you are not going to reveal to all helpers on this forum what you exactly changed? 

 

[micaddict]

Well, I should hope he doesn't take my words that literally. 

 

[Paul678]

LOL!  You dudes are funny! 

10nF paralleled across R6 (2.2k drain resistor).

10nF from the base of Q1 to the base of Q2.

8.2nF paralleled across C20 and C21.

All these are soldered to the back of the PCB, which makes returning
to the stock circuit very easy, because none of the original parts are
removed.

And since each capsule is different, and since we all like different
tones, you have to experiment with these values to find what is
right for YOU and YOUR mic.  Please keep in mind that only a
capsule swap can make a really big change in the sound.  This mod
is rather subtle, and is only noticeable with good monitors, but if
your capsule is bright like mine is, you'll notice a difference. 

I'd like to see if anyone else here has good results with this particular mod "recipe".

Enjoy, and thanks everyone.    ;D

 

[RuudNL]

Mmmm... good solution. I always like the or/or situation, don't make changes that can't be easily undone.
Personally I don't like the C across R6, because this will cause a (level) unbalance between the two output pins at high frequencies. (Q4 becomes a source follower at higher frequencies.)
I think I would prefer to increase the value of 10 nF between the bases of the transistors to get the same result. (In fact: between drain an source for AC.) In that case the level on both outputs will remain equal at all frequencies.

The situation can even be simpified further: two capacitors of 8.2 nF in parallel with C20 and C21 is the same as one capacitor of 4,1 nF between the bases of the transistors. So IMHO a capacitor of ~15 nF (14.1 nF) between the bases (=10 + 4.1 nF) would give a similar result.

But I am glad to hear this modification works for you!

 

[Paul678]

Mmmm... good solution. I always like the or/or situation, don't make changes that can't be easily undone.
Personally I don't like the C across R6, because this will cause a (level) unbalance between the two output pins at high frequencies. (Q4 becomes a source follower at higher frequencies.)
I think I would prefer to increase the value of 10 nF between the bases of the transistors to get the same result. (In fact: between drain an source for AC.) In that case the level on both outputs will remain equal at all frequencies.

The situation can even be simpified further: two capacitors of 8.2 nF in parallel with C20 and C21 is the same as one capacitor of 4,1 nF between the bases of the transistors. So IMHO a capacitor of ~15 nF (14.1 nF) between the bases (=10 + 4.1 nF) would give a similar result.

But I am glad to hear this modification works for you!

    You are right, the two 8.2nF are essentially in series, so it's equivalent to a 4.1nF.  So I might try
simplifying it with one cap as you said.

      The C across R6:  what would the level unbalance sound like?  It definitely seemed to help
tame the high end.....

 

[RuudNL]

The C across R6:  what would the level unbalance sound like?  It definitely seemed to help
tame the high end.....

Well, you don't hear it! But technically it simply does not feel right...
In a balanced circuit both 'legs' should carry the same (AC) voltage (independent of frequency) , only in opposite phase.
The maximum attenuation you can get with a capacitor over R6 is 6 dB.
(That is the difference bewteen the full drain signal and no drain signal.)
I think you can get the same result by increasing the capacity between drain and source.

 

[Paul678]

The C across R6:  what would the level unbalance sound like?  It definitely seemed to help
tame the high end.....

Well, you don't hear it! But technically it simply does not feel right...
In a balanced circuit both 'legs' should carry the same (AC) voltage (independent of frequency) , only in opposite phase.
The maximum attenuation you can get with a capacitor over R6 is 6 dB.
(That is the difference bewteen the full drain signal and no drain signal.)
I think you can get the same result by increasing the capacity between drain and source.

    It doesn't matter if a modification is technically "correct" or not.  The only
thing that matters is if the mic sounds better, and doesn't damage the preamp, etc,
and this cap across R6 has definitely helped my microphone sound better.

    But thanks for your feedback, and thanks to everyone here!