DIY RIP: The MCA SP1 goes SMT
Tuesday, March 19th, 2013 | by matthew mcglynn
The best mic mod platform in history just died. RIP.
The 
MCA SP1 is a $50 condenser mic based on MXL’s version of the Schoeps transformerless circuit. The circuit design is capable of greatness; it is very well understood, and easy to improve. Numerous technicians have offered commercial modifications to this mic over the years, and today you can buy a mod kit for the SP-1 — a set of handpicked replacement components that transforms the mic into an exceptional studio tool. [Full disclosure: the kit was my idea.]
But the days of modding new SP1s are over. Marshall Electronics has apparently swapped the venerable “V57” circuit board set for a single surface-mount PCB. While it is technically possible to modify an SMT board, it is not worth the effort and risk of drilling out all the components you’d want to swap. For example, the mod kit referenced above changes 21 different components.
For years, I have been recommending that would-be DIYers buy the ~$50 SP1 for modding. But now there is a distinct risk of getting an SMT mic that you’d have to return. I can’t recommend buying SP1s new any longer. Instead, pick up an older SP1 on Ebay. Consider the following mics equally desirable, for they all use the V57 PCB set: MXL 2006, MXL V63M, MXL V250. But ask the seller to send a photo of the circuit board first, just to be sure.
See the original V57 PCBs at right. This is what you want to see in your SP1 if your intention is to modify it.
If the Ebay route doesn’t work, I recommend buying an 
MXL 990 instead. The MXL 990 uses the same circuit and capsule as the SP1, and is actually easier to modify. (And yes, there is a mod kit for this one too.)
Update! May, 2014
We have introduced PCB replacement kits for the MXL 990, MCA SP-1, MXL 2006, MXL 550, MXL 910, MXL V63M, and many more. Visit our DIY store: https://microphone-parts.com/pages/mic-mods#mxl
[SMT SP1 PCB photo credit: David Hamon]
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Posted in DIY, Microphones | 15 Comments »
Dave
March 20th, 2013 at 5:58 am
Have you thought about just getting a custom PCB made for the mic? You could even have it include a small prototyping area if you wanted to.
For small runs, the cheapest custom PCB manufacturers I’ve found is batchPCB (they are owned by SparkFun). But there’s loads of custom PCB manufacturers around on the internet.
Dewald V
March 20th, 2013 at 11:00 pm
Why not simply DIY a circuit-board for through-hole components and keep on diy-ing?
DC Patterson
March 21st, 2013 at 11:16 pm
I love the idea of a circuit board replacement that you can swap out parts on easily
Paul Babiak
March 28th, 2013 at 4:19 pm
Hi Matt,
Well. Upon your recommendation, I just purchased 2 MXL 990’s, with the intent of modding them. Turns out, they have gone SMT too!! I tried to take some photos, didn’t turn out well, I’ll forward them if you want.
They will be going back…..
Paul.
Andrew
April 8th, 2013 at 5:34 am
Surface mount boards aren’t all that difficult to work with, depending on what mods you have in mind. Surface mount components can be removed from the board quite easily. Putting new components in their place can be a bit tricky, but not impossible, and the board doesn’t have to drilled. You can put new surface mount components onto the pads (but they are very fiddly to work with by hand), or you can solder conventional through-hole components onto the pads without drilling holes by bending the leads to sit on the pads.
I wouldn’t do this with large components because the weight could put too much strain on the pads and pull them off the board, but it’s ok with small ones.
DaveB
May 7th, 2013 at 1:24 pm
As others have said, this is in no way a show stopper. The circuits used in these mics are simple enough that a person could create their own PCB. Yes, you could do a run of boards too, but in the meantime, just measure out where the mounting holes need to be and create the thing in Eagle.
Compared to the modding skills you’ve already acquired, PCB etching is small potatoes.
Matt Hankins
May 8th, 2013 at 3:34 am
In some ways this could eventually be liberating but with a time of stepping backwards before a good platform for mods gets even better. Here’s what I mean: if indeed new PCBs are made for the mic modding community regarding the SP1, 990, etc, then I suspect folks will start exploring even more options for these microphones. A switch for cardioid operation AND omni? Adding a pad or high pass circuit to a mic that does not have one?
Anyway, it could be a good thing to start with just an affordable microphone body and consider all the electronics inside stuff for the garbage can.
Herman
May 12th, 2013 at 3:05 am
Give it a few years. You’ll be able to 3D-print your own PCBs on a whim.
http://www.wired.com/design/2012/11/conductive-plastic/
Chris
January 4th, 2016 at 6:04 pm
Has anyone drawn out the PCB for the 990 in Eagle yet? I got Eagle with doing it in mind, but I’m not that familiar with it yet..
matthew mcglynn
January 4th, 2016 at 8:20 pm
@chris, we do have a replacement circuit kit for the 990.
Eagle is a bit of a nightmare. Good luck!
Andrei
April 22nd, 2016 at 12:54 pm
Besides the switch to SMT, is it still the same circuit?
Drusca
May 9th, 2016 at 6:10 am
Is the single surface-mount PCB version still an implementation of the Schoeps-type circuit?
matthew mcglynn
May 9th, 2016 at 8:25 am
@Andrei, @Drusca – as far as I know, the surface-mount MCA SP1 and MXL 990 are still using a Schoeps-like circuit.
Donald McCallum
April 9th, 2017 at 6:53 pm
If you are buying an MXL 990, etc, how do you know if is through hole or SMT …by date? Photo of PCB?
Donald
matthew mcglynn
August 10th, 2017 at 6:23 pm
@donald – if you can see the circuit board, it will be obvious whether it is through-hole or SMT. Just compare to the photos in this article.
Note that if your question is intended to identify suitable DIY upgrade candidates: #1, replacing the capsule is the biggest bang-for-the-buck mod f for this mic, and any new true condenser capsule will work fine with the stock circuit (even the surface-mount one), and #2, if you decide to go farther, micparts.com has a circuit board replacement for the 990 that brings the mic into TLM49 territory. (The TLM49 costs $1700.)