Improving the ADK-51 Large Diaphragm Mic

Hey Guys,

Does anyone have any suggesting for improving the sound of a large diaphragm ADK-51, it is the one that looks very much like the MXL 2001.

I know you can do the royer mod but I was thinking about starting small by just replacing a few parts on the current PCB. Do you think it will make a sonic difference to do so? I know this has been achieved with these mics from other manufactures and I?ve gone through the Mic META but couldn?t find anything on this particular mic.

It just got me thinking because I am about to mod my guitar pedal PSU which has so many cheap knock off parts and thought I might attempt to do the same with the mic.

If it hasn?t been done would anyone be willing to look at it if I shoot some pics of the PCB inside and make suggestions? Let me know if you are up for the challenge.

Thanks

Matt

Read the meta on microphones in the meta meta. The Meta meta has lots of good stuff the Meta meta is at the top of the page.

[quote author="matta"] I?ve gone through the Mic META but couldn?t find anything on this particular mic.
[/quote]

Maybe not on that mic in particular, but there should be plenty of generic information that would help you, particularly the information about modding other condenser mics.

Stewart

http://www.groupdiy.com/index.php?topic=234

There is alot of stuff to read in the meta. That microphones transformer is not the best and the main limit on the microphone. I have tried all kinds of stuff to that stock china microphone circuit. I have 2) 2001s and maybe 10) v67s in different states of mods. The two 2001s are tubed with the stock grill I was not looking for clean/clear with the two.

The transformer is the biggest problem.

You can change the caps but without changing the transformer the difference might not be worth the effort IMO.

The capsule grill is is the tricky part. Some people like it stock some like it with just the one outside layer. Think of grills as EQs

When you look at mesh for grill it is rated in holes per inch and % open area.

If you talk in say a 55 gallon drum you get a lot of echos and EQ.

Think of a grill a container with holes in it.

FWIW the most open grills are about 49% as best I can tell.

Also the shape makes a difference

Hey Guys,

Thanks for your help. I did go thought the Meta (and continue to) and I guess my question wasn't clear.

I had seen your tube Mod Gus and actually as some point I was looking into a mod myself, in fact it was what got me tuned into DIY audio. I contacted Royer and they said the kit was $300. I was just wondering if there were any tips of just swapping out parts on the ADK like one does on the 603, which you came up with from what I gather, to improve the sound, I guess being cheap and not forking out $300 ;-)

Your last post really cleared things up for me. I had read about the various 2001 vs 2003 MXL mics and the differences in grill being a contributing factor to the way it sounds.

Out of interest did you notice a big improvement in sound quality modding out you MXL with the Royer Mod? I notice you did it without the PCB and built it on perf board instead. Was it easy enough to do and what were the costs involved?

Thanks again for all your input and help.

Cheers

Matt

are you actually looking to do the tube mod?

I have been through the meta and there seems to be a general theme of recaping these chineese mic units. This often yields to better /more pleasing sounding. I would suggest trying that first. IMO The royer kit is a good start for a first time DIY in the microphone mod if you looking to do a tube. Pretty straight foward and step by step.

for example

Change ceramic caps C3 and C4 from .22uf ceramic to .22uf Metal Film Panasonic caps

Click to expand...

another example

Change the capsule/Gate cap C13 (on back of PC board) from a .001uf (1000pf) cermaic to a 1000pf Xicon Styroflex polystyrene cap

Click to expand...

[quote author="matta"]
Out of interest did you notice a big improvement in sound quality modding out you MXL with the Royer Mod? I notice you did it without the PCB and built it on perf board instead. Was it easy enough to do and what were the costs involved?
[/quote]

Yes. IMO it is a big improvement in many ways. I've built about 4 variations on this circuit now and like them all. Remember that this also involves replacing the stock transformer which may be a big part of the sound. But it does sound obviously 'tubey' in my opinion, so it depends if you want this. Attention to grounding is very important - look carefully at the schematic.

I won't talk about costs - depends where you live, where you buy and what you can recycle from other sources!

Stewart