MXL 603 -> KM84 Replacement PCB

[GraemeWoller]

Educational fun is an awesome thing to aspire to!

 

[joulupukki]

Looks like I dragged my feet deciding whether to do the project or not and the MXL bodies I had been eyeing are no longer available. But, the Takstar CM-60 bodies via AliExpress look like they would work. But, in other posts here on the site, a lot of people are saying the 3U 0.5mm capsule is the right size for those. But, I’m also seeing other reports that the 3U 3mm capsule is the right size with the PCB from @GraemeWoller … can someone confirm what the right size is for the CM60 + Graeme PCB?

 

[Chrisfromthepast]

good question. The mxl bodies vary in quality, and the threads can be damaged easily. The 6 takstars I’ve tried have had better threads. 3 mm for the takstars.
The takstar pcb is a tad longer, and the hole in the body is just asking for a pad switch, its not an exact match to the pcb from this thread (center). The pcb being longer and the nosecone being shorter make me a little worried about the fit. I used Graeme’s pcb in a mxl840 in this photo.

 

[joulupukki]

good question. The mxl bodies vary in quality, and the threads can be damaged easily. The 6 takstars I’ve tried have had better threads. 3 mm for the takstars.View attachment 121253
The takstar pcb is a tad longer, and the hole in the body is just asking for a pad switch, its not an exact match to the pcb from this thread (center). The pcb being longer and the nosecone being shorter make me a little worried about the fit. I used Graeme’s pcb in a mxl840 in this photo.

Excellent! Thank you for answering definitively. What's the purpose of the yellow tape above the components on the PCB 2nd from the top?

 

[Chrisfromthepast]

Lol, Im the messiest . I never post my builds because they are hideous.
Harvested 1G resistors needed to be upside down it looks like. I don’t really remember.
The foam was for handling noise. Much more elegant solutions to both problems are available.

 

[joulupukki]

Lol, Im the messiest . I never post my builds because they are hideous.
Harvested 1G resistors needed to be upside down it looks like. I don’t really remember.
The foam was for handling noise. Much more elegant solutions to both problems are available.
View attachment 121254

Hah. Looks good to me. If it sounds great, that's all that matters!

 

[Chrisfromthepast]

I hope Graeme still has the pcbs from the banzai body, because that is what you really need for the takstar.
This picture is takstar cm60 left, banzai center, and mxl 603s on the right. The pcb is shorter in the mxl and the outline is slightly different.

 

[joulupukki]

View attachment 121255
I hope Graeme still has the pcbs from the banzai body, because that is what you really need for the takstar.
This picture is takstar cm60 left, banzai center, and mxl 603s on the right. The pcb is shorter in the mxl and the outline is slightly different.

Yeah, I dunno. I ordered some PCBs from him to fit into the CM60. I've got 3U capsules and transformers on order as well. I'm interested how they'll stack up against the MP SDC-84 pair I've got. I'm sure it'll be a few weeks or a month before all the parts arrive.

 

[Silas]

EDIT: seen takstar info re thread above also so may try that…!
Hey guys,
Interested in putting something like this together - was looking for same donor body as MXL but different branded
Reckon this SYC 90 is the same? Anyone used one?
Looks identical. I will ask for some dimensions…
https://www.alibaba.com/product-det...054190594cf684cbc5b5bf80f610y.png_200x200.png

 

[MicMaven]

Looks identical. I will ask for some dimensions…

Um ... er ... They do not look identical to me. Closely examine the structure of the side vents below the capsule threads - they are similar, but not the same. This underscores the importance of obtaining the actual dimensions you seek. Do let us know what you find out. JHR

 

[Chrisfromthepast]

That looks alot like the nady cm90, I am not aware of the pin depth or pcb dimensions. 22mm capsule most likely

 

[Silas]

That looks alot like the nady cm90, I am not aware of the pin depth or pcb dimensions. 22mm capsule most likely

Ahh yes that’s true

 

[Silas]

Um ... er ... They do not look identical to me. Closely examine the structure of the side vents below the capsule threads - they are similar, but not the same. This underscores the importance of obtaining the actual dimensions you seek. Do let us know what you find out. JHR

Oh yeah you’re right, missed that.

Not heard back about any dimensions yet, will update once I have

 

[jp8]

I'd like to try several transformer based circuits in the CM-60 an CM-63 mics. But there's only 26mm between the low cut switch and XLR terminals in the CM-60. See picture. With a length of 25mm for the transformers, it may only be just possible to shoehorn the trannie in between the switch and the XLR. I think I'd better start with the CM-63 PCBs.

I'm still working on my FR measurement setup. I do not yet fully trust its results, so I'm not confident enough to share FR measurements them right now. Will share other measurement data later next week.

Jan

 

[GraemeWoller]

Really good info about the Takstar, thanks. I don't have any, and there aren't any photos of the internals online that I've been able to find.

From what I can see in these images it's the same mounting as the Banzai kit we did. They directly solder the XLR contacts to the PCB pads for both electrical connection AND mechanical support. It's not the same in the MXL style, that's clamped with screws and the connections are made with wire. My PCB is 80mmx19mm and is for the MXL mounting style.

That's the hardest bit about trying to ascertain the internals based on the external photos.

No, I don't have any of PCBs in stock that I designed for the Banzai kit sorry.

 

[MicMaven]

d there aren't any photos of the internals online that I've been able to find.

Would you like high resolution detailed photos of the Takstar CM-60, like so you could read part IDS and values? I could make some in my ersatz product photo "studio". James

 

[joulupukki]

So it sounds like I may have jumped the gun on ordering a couple Takstar CM-60 for donors on these PCBs that are meant for the MXL. I haven't received the Takstars yet, but think there's any chance I could retrofit Graeme's MXL board for the CM60 and make it work?

 

[Migs 31]

So it sounds like I may have jumped the gun on ordering a couple Takstar CM-60 for donors on these PCBs that are meant for the MXL. I haven't received the Takstars yet, but think there's any chance I could retrofit Graeme's MXL board for the CM60 and make it work?

Theres’s Allways a Way.
I had to slightly file my boards to make them fit into a Non-MXL body.

This is DIY. I’m sure you can do it.
M

 

[jp8]

So it sounds like I may have jumped the gun on ordering a couple Takstar CM-60 for donors on these PCBs that are meant for the MXL. I haven't received the Takstars yet, but think there's any chance I could retrofit Graeme's MXL board for the CM60 and make it work?

The MXL nose cone will not slip into the CM-60 body. So you'll have to remove it from the CM-60 PCBA and transplant it to Graeme's board. But you would probably do that anyway. The CM-60 board is slightly longer than the MXL board. I think the bottom edge of the MXL board will just reach the XLR pins in the CM-60 body, so the PCB will not be held between the XLR pins, as in the CM-60 . It should be possible to get them in. Good luck!

Jan

 

[Chrisfromthepast]

I'd like to try several transformer based circuits in the CM-60 an CM-63 mics. But there's only 26mm between the low cut switch and XLR terminals in the CM-60. See picture. With a length of 25mm for the transformers, it may only be just possible to shoehorn the trannie in between the switch and the XLR. I think I'd better start with the CM-63 PCBs.

This is getting to be very far off topic, but Im excited to hear about what you can do with the CM-63.
The placement of the switches is better.
Km84 is a fun circuit for 2nd harmonics and due to the high degree of interaction between parts, but the much less popular AKG 451eb is the next on my list. I can actually afford to A/B 451 clones against originals.
What are your plans for the LL1968?