SP C1 Modification
- Thread starter sowhoso
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Help Support GroupDIY Audio Forum:
Easiest mod, change the capsule. The C1 has a 67 style capsule which isn't great for the C1's circuit. Replace it with any number of capsules available online.
Strangely, I actually like the RK87 capsule in the C1. I've recorded a sample with it in one off my C1 mics on the Microphone parts site.
I've heard that the RK47 is also a great option for the C1. I have a spare pair I've been looking for a home for so I might pop one in one of my C1s and post a comparison.
Strangely, I actually like the RK87 capsule in the C1. I've recorded a sample with it in one off my C1 mics on the Microphone parts site.
I've heard that the RK47 is also a great option for the C1. I have a spare pair I've been looking for a home for so I might pop one in one of my C1s and post a comparison.
Blue Jinn
Well-known member
Here is a thread you might check out:
http://www.groupdiy.com/index.php?topic=35202.0
Here is a link to a circuit trace.
http://www.twin-x.com/groupdiy/displayimage.php?pid=4434&fullsize=1
You could also change the polarization method of the capsule and eliminate C18 the coupling cap. I did this to a MXL 2006 (which as a very similar circuit) and replaced the capsule with a C12 clone. Tamed what seemed like to me a brittleness to the sound. Also, this one has a pot to adjust the bias on the FET. If you have a 'scope you can do it the right way, I don't so on another mod I just adjusted for a voltage. I don't know off hand what the optimal parameter is on this one, and I don't remember what I set the ohter one to I'll have to look up my build thread on HR.com!
http://www.groupdiy.com/index.php?topic=35202.0
Here is a link to a circuit trace.
http://www.twin-x.com/groupdiy/displayimage.php?pid=4434&fullsize=1
You could also change the polarization method of the capsule and eliminate C18 the coupling cap. I did this to a MXL 2006 (which as a very similar circuit) and replaced the capsule with a C12 clone. Tamed what seemed like to me a brittleness to the sound. Also, this one has a pot to adjust the bias on the FET. If you have a 'scope you can do it the right way, I don't so on another mod I just adjusted for a voltage. I don't know off hand what the optimal parameter is on this one, and I don't remember what I set the ohter one to I'll have to look up my build thread on HR.com!
tchgtr
Well-known member
Do you have any photos of the innards?
This is what's known as the Shoeps circuit. It's very common these days with transformer-less mics, and actually sounds pretty good. Blue Jinn has given a good link to a schematic (something you might want to include when you ask questions here, as you will likely get more help).
What kind of caps are in the place of C3 and C4? These are in the audio path, and I just recently acquired a Nady SCM 1000 that uses the same circuit. When I opened it up they had used nice caps in the circuit, except in this crucial place. Today I'll swap them out, and see if it helps what is probably a so-so capsule.
Usually you will find .22uf caps in those spots, but putting in .47 or 1uf caps will let a little more low-end pass thru the mic. The only problem is fitting the slightly larger caps in there. Try to get polypropylene, or metal-film caps. They will sound the best.
Also check C18 (and it's mate, if this is a multi-pattern mic). Most likely SP put a decent cap in here, but sometimes it's not so good, and you might ant to replace it.
If you do a little more research here, there is LOTS of info about modding the Shoeps circuit and what caps to use. If your solder skills are poor, I would practice on some other stuff first before starting with a mic. Get a good iron.
This is what's known as the Shoeps circuit. It's very common these days with transformer-less mics, and actually sounds pretty good. Blue Jinn has given a good link to a schematic (something you might want to include when you ask questions here, as you will likely get more help).
What kind of caps are in the place of C3 and C4? These are in the audio path, and I just recently acquired a Nady SCM 1000 that uses the same circuit. When I opened it up they had used nice caps in the circuit, except in this crucial place. Today I'll swap them out, and see if it helps what is probably a so-so capsule.
Usually you will find .22uf caps in those spots, but putting in .47 or 1uf caps will let a little more low-end pass thru the mic. The only problem is fitting the slightly larger caps in there. Try to get polypropylene, or metal-film caps. They will sound the best.
Also check C18 (and it's mate, if this is a multi-pattern mic). Most likely SP put a decent cap in here, but sometimes it's not so good, and you might ant to replace it.
If you do a little more research here, there is LOTS of info about modding the Shoeps circuit and what caps to use. If your solder skills are poor, I would practice on some other stuff first before starting with a mic. Get a good iron.
tchgtr
Well-known member
Here is someone being very generous with their experience and knowledge of this circuit (read the whole thread):
http://www.gearslutz.com/board/low-end-theory/691793-studio-projects-c1-mod.html
As always, take everything you read on the net with a grain of salt. What this guy likes, might not be what you are after.
http://www.gearslutz.com/board/low-end-theory/691793-studio-projects-c1-mod.html
As always, take everything you read on the net with a grain of salt. What this guy likes, might not be what you are after.
Something else to note, doesn't this all depend on which version of the C1 he has? The capsule in the 797 audio version is much better (as far as I know from reading on the net) than the newer version. I could be wrong though so don't take that as gospel.
tchgtr
Well-known member
I have one of the older B1s, and the 797 capsule on that sounds good. The mic itself is very scooped, but good on some things, so I've left it alone. Don't know much about the newer stuff.
To the OP, if you can dismantle it, and post some photos, there are a lot of folks here who have worked on similar mics. Can you get a good shot of the capsule thru the mesh? If so, we might be able to confirm if it's a 797 capsule.
And Gus, I love my old 2003, which also has the 797 capsule in it. I squeezed some 1ufs in there, and replaced the capsule to gate cap, and it sounds good, especially for my own voice.
Are you talking about adding a cap to the C1 for a LPF?
To the OP, if you can dismantle it, and post some photos, there are a lot of folks here who have worked on similar mics. Can you get a good shot of the capsule thru the mesh? If so, we might be able to confirm if it's a 797 capsule.
And Gus, I love my old 2003, which also has the 797 capsule in it. I squeezed some 1ufs in there, and replaced the capsule to gate cap, and it sounds good, especially for my own voice.
Are you talking about adding a cap to the C1 for a LPF?
hey y'all
i've been checking out the links provided and watching some videos (Tube Tests on youtube) . thx!
i came here after hearing this podcast: Show 184 – DIY microphones and more in which changing the capsule is discussed
i bought my mic about 4-5 yrs ago and have since learned there are other versions of the C1. i will post some pictures this weekend
(what's with the required questions to make a post. really annoying. and i never get the letter right the 1st time. Oi!)
i've been checking out the links provided and watching some videos (Tube Tests on youtube) . thx!
i came here after hearing this podcast: Show 184 – DIY microphones and more in which changing the capsule is discussed
i bought my mic about 4-5 yrs ago and have since learned there are other versions of the C1. i will post some pictures this weekend
(what's with the required questions to make a post. really annoying. and i never get the letter right the 1st time. Oi!)
tchgtr
Well-known member
I wouldn't do much of anything to that mic. Says right there that it's a 797 mic, and it looks to me like all the caps that one would normally change in the Shoeps circuit are already polypro or similar.
You could spend $200-400 on a capsule, but the one in there is not too bad. If you don't like the sound of it, it's just not the mic for you.
If you need to do some soldering and want to learn, I understand that, but get a used MXL or something and learn with that. You'll hear a bigger difference in the changes you make. The MXL 2003 that Gus mentioned has this same capsule and circuit, but the components are not as nice, and it sounds good with an upgrade. You can get an older one used for not much, and the mods are easy. When you are done, you will have something very similar to this mic.
I just modded a Nady SCM 1000 that has a Shoeps circuit. They did a pretty good job of putting better components in it, but sure enough, two of the caps in the signal path were tantalum. I changed those to polyester (.68uf instead of the original .22uf ) and the two in the capsule to gate position (it's multi-pattern) to 1500pf polypro, and now the mic sounds much better, even with the original capsule. I even made some recordings of Ac. Gtr. to prove to myself that I wasn't imagining the changes.
Thanks for taking the time to put up photos...that's my 2 cents.
You could spend $200-400 on a capsule, but the one in there is not too bad. If you don't like the sound of it, it's just not the mic for you.
If you need to do some soldering and want to learn, I understand that, but get a used MXL or something and learn with that. You'll hear a bigger difference in the changes you make. The MXL 2003 that Gus mentioned has this same capsule and circuit, but the components are not as nice, and it sounds good with an upgrade. You can get an older one used for not much, and the mods are easy. When you are done, you will have something very similar to this mic.
I just modded a Nady SCM 1000 that has a Shoeps circuit. They did a pretty good job of putting better components in it, but sure enough, two of the caps in the signal path were tantalum. I changed those to polyester (.68uf instead of the original .22uf ) and the two in the capsule to gate position (it's multi-pattern) to 1500pf polypro, and now the mic sounds much better, even with the original capsule. I even made some recordings of Ac. Gtr. to prove to myself that I wasn't imagining the changes.
Thanks for taking the time to put up photos...that's my 2 cents.
i have no other condenser microphone to compare mine to (nor access to). i just thought there might be room for improvement in this mic. i certainly don't want to do anything for the sake of doing it. if it ain't broke...
so it's the case that this capsule is indeed good for a flat response circuit?
thx!
so it's the case that this capsule is indeed good for a flat response circuit?
thx!
tchgtr
Well-known member
If I were you I'd look toward more low-budget choices for my mic collection. If you're able to shop for used stuff, I'd look into MXL, Nady Apex, Oktava, Shure, EV, etc....
You've got a decent LDC mic, so pick up a small-diaphragm condenser, or a dynamic mic like a Shure SM57. I just found a SM54 in a thrift store for $10 that just needed a wire soldered. Sounds great and different from the 57/58 line. More like an EV RE20.
If you want to do some modding, get one of the standard platforms like the Alctron HST-11/Apex 460 or similar. That's a tube mic with multi-patterns and you can pick one up now in the white market for decent price. It sounds OK right away and you can switch the capsule if you want.
Oktava MK319s are sometimes inexpensive used. You can mod them or use them as is. I like 'em both ways for different sources.
Very few mics sound great on everything, so the more you have the better your recordings will sound. A lot has changed with recording music over the last few decades, but putting the right mic on a good sounding source is an art that hasn't changed too much.
You've got a decent LDC mic, so pick up a small-diaphragm condenser, or a dynamic mic like a Shure SM57. I just found a SM54 in a thrift store for $10 that just needed a wire soldered. Sounds great and different from the 57/58 line. More like an EV RE20.
If you want to do some modding, get one of the standard platforms like the Alctron HST-11/Apex 460 or similar. That's a tube mic with multi-patterns and you can pick one up now in the white market for decent price. It sounds OK right away and you can switch the capsule if you want.
Oktava MK319s are sometimes inexpensive used. You can mod them or use them as is. I like 'em both ways for different sources.
Very few mics sound great on everything, so the more you have the better your recordings will sound. A lot has changed with recording music over the last few decades, but putting the right mic on a good sounding source is an art that hasn't changed too much.
I recently picked up a pair of MXL 2001s on eBay for $125 which made for a very fun project. Just keep your eyes on the usual sites e.g. Gumtree, eBay etc... eventually some used mics turn up very cheap that nobody wants.
HellfireStudios
Well-known member
sowhoso said:
Re-read post #3.
-James-
You can try putting a 6n8 capacitor (or thereabout) in parallel to R6 (the 2k2 drain resistor). I did that to my C1 (also a 797 version) and it helped tremendously taming the high-end. You can experiment with different values of the capacitor for more (higher) or less (lower) roll-off. If you don't like any of it, just remove the capacitor....
