the NEW MXL Royer mod thread...

[???????]

Figured the old one was getting cluttered and I'm pretty pumped to start this project so I figured it would be good to start a new thread to talk about possible transformer group buys(?), part selections/BOM, troubleshooting, etc. It will be nice to have it in one place.

Copied from the other threads, here is b3groover's BOM:

Posted: Tue Nov 06, 2007 5:20 pm Post subject: Re: Royer MXL 2001 mod circuit boards
And here's the MXL 2001 mod with Mouser part numbers in parenthesis.

Royer MXL 2001 Mod BOM

Mic circuit
C1 - 0.1uf 250v (1429-2104)
C2 - 1uf 250v (1429-2105)
R1 - 750 ohm (299-750-RC)
R2 - 22M 1/4watt (291-22M-RC)
R3 - 3M (293-3M-RC)
R4 - 2M (293-2M-RC)
R5 - 100k (291-100K-RC)
J1 ? 5 pin XLR male
T1 ? Jensen DB-E uncased or Cinemag CM-2480
V1 ? 5840 subminiature tube

Power Supply Circuit
F1 ? ? amp fuse
D1, D2, D3 ? 400x diode (512-1N4004)
C1, C2, C3 ? 2200uf 35v electrolytic (140-XRL35V2200-RC)
C4, C5 ? 33uf, 100v electrolytic (140-XRL100V33-RC)
C6, C7 ? 33uf, 160v electrolytic (140-XRL160V33-RC)
R1 ? 100ohm, 5W (280-CR5-100-RC)
R2 ? 82ohm, 5W (280-CR5-82-RC)
R3, R4 ? 4.7k, ? W (293-4.7K-RC)
T2 ? 24VAC, 1 amp (XR-2450LED)

This one you could use a regular 24vac, non-wall wart transformer because the audio transformer is in the mic itself. Mouser doesn't really have a good supply of power transformers, though. For that I'd probably go with an Amveco torroid from Digikey.

However, another benefit of that wall-wart above is that it is 2.0amps, which is enough to power two tubes mics. You could build a "stereo box" for both mics if you wanted.

Here are other items needed:

Lamp holder
Lamp (on the schematic it's on the 120V side of the power transformer, I wonder if you could use a 24V lamp on the secondary side instead without any problems?)
Lamp jewel
On/Off Switch (carling or similar)
Hammond 1590E or similar enclosure
Standoffs (4)
3pin XLR Male panel mount
Fuse holder
IEC power connector
Power cord
5 pin XLR male jack insert, probably robbed from the inside of a panel-mount jack
5 pin XLR female panel mount
rubber feet

There are plenty of 24V power transformers on eBay. Rat Shack also sells an appropriate 25.2V power transformer for about 10 bucks, not an exact value but probably close enough. I got my 24V 40VA power transformer from eBay from 5.99 + about 6 bucks shipping. All you need to do is make sure it's a 120V primary and a 24V secondary and is rated for at least 1A. Most will be unless they specify less. I accidentally bought a stancor rated at 400mA without reading the auction completely before I bought the right one. Oops. Oh well, only a few bucks. I guess when it gets here I'll just put it back on ebay or put it down in the basement.

Speaking of transformers, here are quantity prices on the audio xformers from Phantom Power:

Posted: Wed Nov 07, 2007 6:07 pm Post subject: Re: Royer MXL 2001 mod circuit boards
Hey guys,

Food for thought:
I just called Jensen and Cinemag for price break info and this is what I got.

Jensen DB-E (u)

1=$65.52ea.
4-11=$59.57ea.
12-23=$55.41ea.

Cinemag CM2480

1=(I forgot to write this one down, but it's like $42)
11-49=$36.20ea.

So, anyway, I don't actually have the time right now to put a group buy together, but in case someone else wants to, I thought I'd give a little nudge.

For 5-pin XLRs that fit into the mic body, here is some info:

The best prices on 5pin panel mounts and cable ends I could find came from a kind soul at the GroupDIY forum. Check it out:

http://www.audiogear.com/Switchcraft-5P ... ctors.html

If you are having trouble finding 5-pin XLRs, Jameco carries them. I havent gotten mine yet, but I didn't get a message that they were backordered or anything, so I assume they are on the way.

Switchcraft 5-pin XLR male (Jameco Part# 281615)
Switchcraft 5-pin XLR female (Jameco Part# 281607)

There are other brands of 5-pin XLR plugs, and they are probably cheaper, but from what I read in the other thread, Switchcrafts are the only ones that fit into the mic body properly.

Here is the link to the article and schematics:

http://www.prosoundweb.com/recording/ta ... 25_1.shtml

Alright! Now tell us about your progress, ideas, mods to the mod, show pictures, part sources, whatever.

Here's my progress:

• Got my circuit boards in the mail today, they look great!
• Bought a "donor MXL" from eBay for $28. It's an MXL 2001. Should arrive tomorrow.
• Bought a rare NOS British Mullard 5840 tube from eBay. Was a little more than the regular Raytheon, but when you're talking fives and tens of dollars, why not get the best? Shipping was a little less too. There are 3 left if anyone wants to pop for one. http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0188279648 they are about $21 shipped, and the Raytheons are about $14 shipped, IIRC.

So that's where I am right now. Might look at the BOM and order some other parts later. Whoop!

I'm definitely planning on testing it out "as-is," and then most likely springing for a Peluso capsule. I figure then I would quite likely have a very nice tube mic for well under 5 bills. Can't beat that.

[???????]

Does anyone know if this mod is the same as the Mojave MA-200? From the description it sure sounds similar...

http://mojaveaudio.com/MA-200.html

[Nate Dort]

Does anyone know if this mod is the same as the Mojave MA-200? From the description it sure sounds similar...

http://mojaveaudio.com/MA-200.html

I wondered the same thing when the MA-200 first came out. I believe Dave Royer started Mojave due to the requests for his mod kit. I'm sure the capsules are better than the MXL2001. I'd be curious to see the guts of an MA-200 and compare them.

[???????]

on the Mojave website it says that the MA-200 has a 3-micron capsule.

Does anyone know if the Peluso caps are 3 micron or 6 micron?

Also, why does this matter?

[phantom power]

Good idea!

I've been watching the hum thread and the buy/sell thread daily. Hopefully, everyone will jump on here so we can consolidate.

I think i might grab one of those mullards, thanks for the heads-up.


My progress thus far:
-fully populated the the PCBs except the tube
-gutted the mic and installed the mic PCB
-found a good deal on some Jensen DBEs (they're not the "uncased" version that the mod calls for, but I'm gonna try to make one work)


So, here's what's next:
-I'm trying to find a good deal on 5-pin cable-mount and panel-mount xlrs, PSU case, and cabling
-I need a good suggestion for a power transformer (I hear toroidal is the way to go?).
-I want to clean the capsule if someone could give me some tips. It's filthy.
-This is one of those stupid things I should know, that I never had the guts to ask. How do I mount the PCB in the PSU case? I realize that I have to drill a couple holes, but then what? Are there stand-offs that I can buy?

Thanks (can't figure out how to type your screen name) for getting this started.

-AE

[???????]

It's alt-o on a mac I dont know how to type it on a PC.


So how do you go about getting an "uncased" DB/E? I don't see that listed on Jensen's site. Hm. Maybe I'll have to e-mail them.

To mount the PCB you will want to get some standoffs. You can get them pretty much anywhere. Rat shack sells 'em.

These would probably work:

Http://www.smallbearelec.com/Detail.bok?no=75

[???????]

If we can get 12 people on board I was considering spearheading the Jensen group buy. But then I got to thinking, is ti really worth it to save 10 bucks, you know? Not much of an incentive really. Besides, knowing me, I'd end up losing money somehow on shipping or something. But I'd be in if someone else wanted to do it out of the goodness of their heart. Maybe the person who spearheads it can get an extra 2 bucks from each person, then they would at least get their xformer for half-price in return.

[phantom power]

Then Brad it is...thanks.

Yeah, I called jensen. Just ask for the DBE (u) and tell them it's the uncased version of the DBE. They'll know what you're talking about.

-AE

[???????]

haha wait wait... I haven't officially volunteered yet!

[KilledByAlbany]

I had the same feelings on the group buy thing. I was kind of pumped on it until it occured to me that I spent more on lunch today than I would be saving by trying to round up 11 other people to hopefully coordiante a group buy in a timely manner.

Anyhow
-Parts ordered from Mouser, except for one component that was on backorder (Don't remember which off the top of my head, I am on my work computer.) I most likely have many spares in my workshop though.

-Still looking for a spot to buy the 5840 tube that doesn't have a minimum on web orders. Does this strike anybody else as weird? Where did you guys get them from?

-PCBs came today and they look fantastic!

Comparing the modded 2001 to the MA-200 just got me feeling a little frisky... The MA-200 is by far my favorite LDC I've ever used, and if this mod even comes close I might legitimately do a backflip.

[???????]

look up "5480 tube" on ebay.

You can get Raytheons for $5.99 + shipping or Mullards for $14 plus shipping.

[???????]

does anyone have any insight into how much leeway there is in the power transformer? Like would 25.2V on the secondary be too far off? What about if it was only rated at 700mA instead of 1A?

Asking because I have some leads on some ultra cheap parts but they're not exact.

[Nate Dort]

-Still looking for a spot to buy the 5840 tube that doesn't have a minimum on web orders. Does this strike anybody else as weird? Where did you guys get them from?

I got mine from tubedepot.com. They cost a little more, but I got them in 2 days. Then again, they're only a 5 hour drive from me.

FWIW, I ended up using a 6205 in mine after reading this: http://homerecording.com/bbs/showthread.php?t=165191

[runrunrun]

does anyone have any insight into how much leeway there is in the power transformer? Like would 25.2V on the secondary be too far off? What about if it was only rated at 700mA instead of 1A?

Asking because I have some leads on some ultra cheap parts but they're not exact.

im sure the 25.2v would be fine...royers article show the B+ as 93-100v and 5-6v for heaters...yer fine.

about the lower amperage, i dunno. it might be fine, it probably will run a little hotter. if i was gonna go to all the trouble to build a mic i wouldn't skip on the PSU. you can save a few bucks by using an old computer PSU as the case, already has the switch and IEC jack, and enough room for all the parts.

Killed By Albany, id like to hear what you think of comparing this with teh MA-200. id also like to see whats going on inside the ma-200...

[???????]

HOT TIP!

I got my "donor MXL" in the mail today. I got it in "untested" condition for 28 bucks and it works perfectly! How often does that happen? I guess "untested" really meant "untested" in this case and not "broken."

Anyway, I have a tip that doesn't matter but is cool anyway. I decided to remove the "MXL" logos in that cheesy gold font from the mic body. A little #0000 steel wool and they came off easy as pie, and it didn't even upset the black finish below. So now I have a nice, sleek, anonymous microphone body. I left the cardioid symbol obviously.

So there you have it.

I went ahead and found a 24V secondary 40VA transformer. A little large but it will fit in the case. It was only 6 bucks.