What mods did Joly do to the MXL 990?
« on: March 23, 2019, 06:16:23 AM »
What did he replace in it? I know it has a replaced headbasket, and a K47 style capsule, but what else did he do? Did he completely replace the PCB, or just certain components in the mic?


Re: What mods did Joly do to the MXL 990?
« Reply #1 on: March 23, 2019, 10:34:34 AM »
It does feel strange that he closed up shop without doing a DOOM-style "here's the source code" dump into the DIY community. I wonder why he'd keep those mod secrets - such as they were - under lock & key? It seems like he's moved on to other pastures, so they're not doing much good just sitting in his storage closet. (Meanwhile, some of us would still love to try and "Joly mod" our Oktavas, among other mics.)

Re: What mods did Joly do to the MXL 990?
« Reply #2 on: March 24, 2019, 01:50:47 AM »
It does feel strange that he closed up shop without doing a DOOM-style "here's the source code" dump into the DIY community. I wonder why he'd keep those mod secrets - such as they were - under lock & key? It seems like he's moved on to other pastures, so they're not doing much good just sitting in his storage closet. (Meanwhile, some of us would still love to try and "Joly mod" our Oktavas, among other mics.)
You can't even find the old listings for his mics on Oktavamod either. So you can't even compare the mods to PCB kits or other mods either.

RuudNL

There is a solution for every problem!

http://www.vansteenisaudio.nl

Re: What mods did Joly do to the MXL 990?
« Reply #4 on: March 24, 2019, 07:41:34 AM »
http://web.archive.org/web/20180816223733/http://www.oktavamod.com/
Thanks. Any idea what he does to lower self noise to 10 dB A? Is it just a matter of replacing the components (capacitors, resistors, FET, etc) with quieter, more expensive parts?

Khron

Re: What mods did Joly do to the MXL 990?
« Reply #5 on: March 24, 2019, 08:11:04 AM »
I'd call that a "maybe". Pricier not necessarily always correlating with "better", though (outside of confirmation bias, that is).

But then again, one must wonder how many of his buyers actually ran any before / after (or A/B) tests or measurements... ::)

As we've noticed many times before, it's easy to "fluff up" one's marketing blurb...

[later edit]

In fact, come to think of it, one must wonder how much of the (perceived?) noise reduction came from the capsule itself (smaller ones, like the stock 990 one, usually being noisier). And/or tweaks of the capsule bias voltage, perhaps?



Thanks. Any idea what he does to lower self noise to 10 dB A? Is it just a matter of replacing the components (capacitors, resistors, FET, etc) with quieter, more expensive parts?
« Last Edit: March 24, 2019, 09:39:38 AM by Khron »
Khron's Cave - Electronics - Audio - Teardowns - Mods - Repairs - Projects - Music - Rants - Shenanigans

Gus

Re: What mods did Joly do to the MXL 990?
« Reply #6 on: March 24, 2019, 10:50:09 AM »
 I don't know what he did I have not seen inside a microphone that he worked on.
Some guesses
Most likely at a minimum changed the input jfet and adjusted the bias and the standard cap changes.

there is more you can do than that

You can find information on adjusting the Schoeps like circuit by doing a searches lots of stuff posted here and at at other places.

cyrano

Re: What mods did Joly do to the MXL 990?
« Reply #7 on: March 24, 2019, 02:56:27 PM »
Lemme guess...

He got a letter from a lawyer stating that he was misusing the lawyer's client's trademark.

They wouldn't sue him if he signed the enclosed agreement to delete all pages, stop all modding and never mention it to anyone.

I don't know, but that's what happened to me over yoghurt...
Why is it people love to believe and hate to know?

analogguru

Re: What mods did Joly do to the MXL 990?
« Reply #8 on: March 25, 2019, 12:32:43 PM »
Here you go:

http://taperssection.com/index.php?PHPSESSID=6330vjv8j27jquvacgcehjr8q2&topic=127204.0

(You have to be logged in to see the pictures.)

psycom

Re: What mods did Joly do to the MXL 990?
« Reply #9 on: August 18, 2019, 07:24:36 AM »
Changed a couple parts, added a 10$ china capsule and billed $500 for it.


Re: What mods did Joly do to the MXL 990?
« Reply #10 on: August 18, 2019, 07:39:52 PM »
Changed a couple parts, added a 10$ china capsule and billed $500 for it.
I figured it was the usual Chinese K47 capsule (sure looks like RK-47). I'm just wondering what the actual parts he changed were. Wouldn't surprise me if it was just the usual capacitor swap people do to slightly clean up the signal path and a FET upgrade.

Seeker

Re: What mods did Joly do to the MXL 990?
« Reply #11 on: August 23, 2019, 02:08:08 AM »
Its not a 990 but I own a NT1A that he modded... Got it on a trade...
Initially I was impressed, but it didn't seem to work as well in the mix as I'd like and I was busy and put it aside. 

The other day I got it out to see what was going on and I was surprised to find what looked like a silver mica cap from the capsule to fet!  It looks like the only mods he did were to replace the capsule, the 1000pf cap to the fet, and the electrolytics, he didnt even change the capsule voltage.

I ended up changing the capsule to fet capacitor, and lowered the capsule voltage from a whopping 73v to about 48v... sounds pretty sweet to me now.

Also he covered the edges of the capsule in silicone, all the way around and over the edges of the mic mount I'm guessing to seal and possible leaks?

I can post pics if anyone is interested, I think I still have the capsule to fet cap around somewhere too...

"Sometimes you have to play a long time to be able to play like yourself.” - Miles

Khron

Re: What mods did Joly do to the MXL 990?
« Reply #12 on: August 23, 2019, 04:18:25 AM »
Yes, please.

Also he covered the edges of the capsule in silicone, all the way around and over the edges of the mic mount I'm guessing to seal and possible leaks?

I can post pics if anyone is interested, I think I still have the capsule to fet cap around somewhere too...


Khron's Cave - Electronics - Audio - Teardowns - Mods - Repairs - Projects - Music - Rants - Shenanigans

Re: What mods did Joly do to the MXL 990?
« Reply #13 on: August 23, 2019, 04:48:54 AM »
Its not a 990 but I own a NT1A that he modded... Got it on a trade...
Initially I was impressed, but it didn't seem to work as well in the mix as I'd like and I was busy and put it aside. 

The other day I got it out to see what was going on and I was surprised to find what looked like a silver mica cap from the capsule to fet!  It looks like the only mods he did were to replace the capsule, the 1000pf cap to the fet, and the electrolytics, he didnt even change the capsule voltage.

I ended up changing the capsule to fet capacitor, and lowered the capsule voltage from a whopping 73v to about 48v... sounds pretty sweet to me now.

Also he covered the edges of the capsule in silicone, all the way around and over the edges of the mic mount I'm guessing to seal and possible leaks?

I can post pics if anyone is interested, I think I still have the capsule to fet cap around somewhere too...
I'm interested in seeing pictures too. A lot of mic modders are quiting, so having pictures of their work might help people who either have their mods repair them, or just get an idea for some simple mods.

Joly quit (obviously) and says he won't even answer questions about mics and mic modding anymore. John Bonnell quit. JJ Audio is still around, and Sitler is doing mods still, but he just does Oktavas.

Re: What mods did Joly do to the MXL 990?
« Reply #14 on: August 23, 2019, 12:11:06 PM »
Sealing the capsule is the last thing you want to do. Unless you want changes in mic's performance to change due to atmospheric and temperature changes.

Not sure what happens with those capsules on planes, but those pops you get in your ears during takeoff and landing might give you a clue ;)


Unsealing capsules might actually help.

Re: What mods did Joly do to the MXL 990?
« Reply #15 on: August 23, 2019, 05:43:50 PM »
I'm actually also interested in the custom capsules he made for the Rode NT5. I heard he also did mods to the Oktava MK-012 capsules, though I can't recall seeing that service listed, and I don't see why you'd want the capsules modded. My only experience with the Russian capsules are the hypercardioid pair I just got, but they sound nice.

Seeker

Re: What mods did Joly do to the MXL 990?
« Reply #16 on: August 23, 2019, 11:30:59 PM »
Here you go...
"Sometimes you have to play a long time to be able to play like yourself.” - Miles

Seeker

Re: What mods did Joly do to the MXL 990?
« Reply #17 on: August 24, 2019, 12:13:44 AM »
And one more.... 

I can’t find the cap that I replaced, but I was listening more today and still thought it wasn’t quite right, so I took a closer look at the circuit...

I had ASSumed this was the schoeps circuit with smd parts but upon further inspection it looks a bit different.  What I thought was the capsule to fet capacitor actually goes from the backplate to ground.  In this mic (part of the original design) the backplate is polarized and there is no cap in between the capsule and fet.

I ended up removing that cap (C20) completely and heard a nice improvement.  After comparing with some other mics in my locker, I’m now very pleased.






"Sometimes you have to play a long time to be able to play like yourself.” - Miles

Seeker

Re: What mods did Joly do to the MXL 990?
« Reply #18 on: August 24, 2019, 12:18:16 AM »
Here’s one of the front of the capsule...

Also the electrolytics are Hitano EXR 105deg...
« Last Edit: August 24, 2019, 12:30:44 AM by Seeker »
"Sometimes you have to play a long time to be able to play like yourself.” - Miles

Seeker

Re: What mods did Joly do to the MXL 990?
« Reply #19 on: August 24, 2019, 12:53:47 AM »
Any idea what he does to lower self noise to 10 dB A?

I have not been inside of one of his 990s however Jim Williams has discussed his design for the NT1 on gearslutz quite a bit...

My guess is Jolly essiantially copied Jim Williams...  in Jim’s discussions i believe it was a combination of raising the polarization voltage to 70 ish volts and the pnps he used that got the noise so low.... hitachis if I remember correctly.
 Sorry I can’t seem to dig up the thread at the moment.
"Sometimes you have to play a long time to be able to play like yourself.” - Miles


 

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