Tube Mic Royer Mod Build Thread

[tchgtr]

Will most likely leave the 2.2 in there. If that's what's called for in the Cinemag transformer notes, I'm fine with that.

Cinemag recommends a 2.2uf cap? Don't see that in the datasheet.

My mistake. I thought that was what was being implied above.

 

[sr1200]

http://pacifictv.ca/socket.htm#submin
This is the site where the tube socket i posted earlier came from he has somewhere around a dozen left if anyone is interested.

 

[Blue Jinn]

FWIW's I don't have a problem with buzz on my first build of this (grounds float and my transformers are under spec'd somehow, but don't get hot.)

Are you sure that your audio ground is not connected to the chassis? Checked with a multimeter? I ask because I tried this last weekend and it buzzed like mad.
The mic pcb will connect audio ground to the mic body unless you used insulating washers / screws.

I didn't isolate the board from the mic body. So I"ll talke a look tonight and report back.

I took a look at this last night. The outer mic body itself is painted with insulating paint. The pcb does ground to the internal frame. Therefore the frame is also connected to the common ground wire on my (5 pin) XLR and to a ground point on the PSU PCB. Pin one on the output male XLR is also connected to the other ground point on the PSU PCB. (Those connections on the PCB are pot wiper/B+/Ground/Ground/Heater.)

The cable shield wire is connected at teh PSU side only, to the frame of the 3 Pin XLR.

Note on this build I did not use the pattern select.  I wonder if that makes any difference? I'd assume that if you disconnect the pattern and go straight to ground you'd get fixed omni. It may be worth checking out.

 

[sr1200]

Im a bit confused. sorry. the schematic and bom I have are fine(I hope)  And pardon my ignorance, and maybe im reading something wrong, but i could really use a wiring diagram from the mic to the PS.  This is the way i figure it, (please correct me where im wrong)

Powersupply(connh5/j3)	MIC 7Pin Connector
5(heater)	pin 5
2(B+)	pin 4
1(pattern)	pin 6
3(gnd)	pin 1
4(gnd)	pin 7
XLR +	pin 2
XLR -	pin 3

                                                   
                                             
                                             

                                                       

 

[Blue Jinn]

Im a bit confused. sorry. the schematic and bom I have are fine(I hope)  And pardon my ignorance, and maybe im reading something wrong, but i could really use a wiring diagram from the mic to the PS.  This is the way i figure it, (please correct me where im wrong)

Powersupply(connh5/j3)	MIC 7Pin Connector
5(heater)	pin 5
2(B+)	pin 4
1(pattern)	pin 6
3(gnd)	pin 1
4(gnd)	pin 7
XLR +	pin 2
XLR -	pin 3

                                                   
   

                                       
                                             
I've not done the multipattern build yet. I haven't looked to see if there is a "standard" 7 pin configuration, you might look at the "classics" and see which pins are used in case you use your psu/mic with a different psu/mic combination. Otherwise I don't see a problem with your scheme.

                                                     

 

[Blue Jinn]

Stock Royer Mod with BigUgly's boards:

sr1200 asked me for advice on doing this. There is likely more than one way to get to this goal but here is a suggestion:

Take the Royer schematic and relabel as follows; Royer part number -- part number on board

C2 -- C4
R5 -- R7
R1 -- R6
R2 -- R3
R4 -- R4
R3 -- R5
C1 --C1 (see below though)

And use the Royer values. I haven't done the math to see if you could use either resistor values, depending on the B+ voltage used -- I stuck with the stock Royer values including C2(C4). 1uF. Depending on the transformer used, you could go with 2.2uF. This seems to be a matter of taste. I used a noname 10.5:1.

References below are to part numbers on the board, not the Royer schematic and "left/right" "Top/bottom" looking at the component side of the board oriented as it would be installed (with teh three big holes at the top):

The capsule "red" lead has to go straight to the control grid, pin 1 on the tube. You could:

1. use the middle post for this and a larger teflon post and jumper C3,
2. connect direct to the tube lead (probably the best solution), or what I did, was
3. recycle a teflon post from the 2001 and connected the capsule lead where C3 on the board connects to grid. (the "left" side of C3) -- if you connect this way, don't omit the teflon post

The white (ground) lead on the capsule, has to connect to the "left" of R3 and C1 with C1 going to ground. This is where you need to get creative. I ran R3 over to the "top" of R1 connected the "top" of C1 where it is labeled on the board the other end to an unused ground spot (top of C2), and installed a screw and nut and then soldered it in place (a post would be better) on the "left" of the three big holes, and connected the capsule lead there. 

EDIT: You could also install R3 on the solder side of the board (the coupling capacitor C4 goes on the back too) I used 1/2 watt resistors, as they were easier to obtain locally.

 

[sr1200]

thanks man, this is really helpful!

 

[tchgtr]

  I'm beginning to wonder if the noise problems aren't because of the multi-pattern wiring, since the capsules are connected to ground, and the backplate to the tube. Perhaps this is why the multi-pattern builds have needed to isolate the ground...?
  Just guessing.
I think I may have found a transformer that will allow me to wire the PSU in a similar fashion to the G7 PSU.

MCI #4-05-2016
Primary:
115/ 230Vacs
Secondary:
Series 16VCT @ 0.35A
Parallel 8V @ 0.70A
Low-profile pc mount transformer. 48 x 39 x 21mm high. PC pins. UL, CSA.

It's a volt off from the specified voltages, but I like the fact that the primaries can handle 220 or 110.
At my local surplus store they are only $7 apiece...

 

[ma_pa]

Hi,

I wanted to do the Royer Mod as described in the TapeOp article for a long time. The last thing I need is a suitable and not too expensive transformer. Royer recommends a Cinemag CM2480 or a Jensen DB-E but I don't know where to buy them here in Europe (Germany). If possible I'd like to avoide buying them in the US as I don't want to pay customs.
Are there any alternative transformers?

Thanks!
Max

 

[tchgtr]

Are there any alternative transformers?

Thanks!
Max

Write the nice folks at Lundahl http://www.lundahl.se/ and see what they recommend.
There's also Sowter in the UK http://www.sowter.co.uk/.
Tell them what you want it for,  and that the ratio should be about 10:1.

 

[Blue Jinn]

There also is this: http://www.ebay.com/itm/KCM-TUBE-CONDENSER-MICROPHONE-OUTPUT-TRANSFORMER-11-5-1-/120836615153?pt=LH_DefaultDomain_0&hash=item1c226c6bf1

I installed this in my first Royer Mod build.

Shipping to Germany is US$20.00 though. Mista Min (in Germany) had some I do not know if he bought them in the US or not. You might email and see if they can ship first class or third class rather than priority. I can check for you on monday I am close to a Post office.

I have PCB's for a dual capsule Royer Mod, which can be used for the tapeop circuit for sale on the Free Market.

 

[ma_pa]

Thanks!

Just sent Sowter an email.
The KCM transformer looks interesting especially at that price but I'm curious how it compares to more expensive ones like the Cinemags?

@ Blue Jinn:
You said "your first Royer mod". Does that mean you have used other transformers as well with this mod?
Can you describe how different models compare?

I already got a NOS RCA 5480 so I hope I find a nice transformer soon.

Max

 

[tchgtr]

I already got a NOS RCA 5480 so I hope I find a nice transformer soon.

Max

Hey Max...look in the Black Market. I see some folks have both Lundahl and Sowter trannies for sale there. I'm not sure if they would be the right ones for you, but the people selling them can probably tell you.

 

[bigugly]

Hi,

I wanted to do the Royer Mod as described in the TapeOp article for a long time. The last thing I need is a suitable and not too expensive transformer. Royer recommends a Cinemag CM2480 or a Jensen DB-E but I don't know where to buy them here in Europe (Germany). If possible I'd like to avoide buying them in the US as I don't want to pay customs.
Are there any alternative transformers?

Thanks!
Max

you should take a look at this.
http://www.neutrik.de/de-de/lichttechnik/zubehr/nte10-3

I haven't used it but I've used their NTM4 and it was really good. If you wire it up as a 10:1 step down you should be in business.

 

[sr1200]

Blue, sorry to bug ya with this, but if ya dont mind, did you use the PS that came with the dual cap board or did you build your own.  I think i may just follow royer's original PS design.

 

[Blue Jinn]

For ma_pa: Sorry I wasn't clear. I've done one build so far. I am waiting for parts for some other mods, and haven't thought about other transformers just yet for another MXL 2001 mod. I received several of the KCM transformers in trade.  I'm inclined to try Edcors or Cinemag next though. Cost is a factor for me right now, and I am budgeting for a pair of C12'sh Apex 460 mods too.

For sr1200: I used BigUgly's PCB for the PSU, just without the pattern switching part, and with orig values and an 80v transformer gets about the right voltage.

 

[tchgtr]

Blue, sorry to bug ya with this, but if ya dont mind, did you use the PS that came with the dual cap board or did you build your own.  I think i may just follow royer's original PS design.

If you are not doing a multi-pattern mic, the original Royer PS works just fine, is educational, doesn't require a lot of parts, and can easily be put together P2P. I did mine inside of an old lock box I got at a thrift store for $3. The hardest part was cutting the holes in the box for jacks, cables, etc..
I did not use a toroid transformer (the design does not call for it) and the mic is very quiet.

 

[Blue Jinn]

If you are not doing a multi-pattern mic, the original Royer PS works just fine, is educational, doesn't require a lot of parts, and can easily be put together P2P. I did mine inside of an old lock box I got at a thrift store for $3. The hardest part was cutting the holes in the box for jacks, cables, etc..
I did not use a toroid transformer (the design does not call for it) and the mic is very quiet.

I'm a bit lazy and messy, and like to avoid P2P whenever I can.  :-[  Did you use a punch for the XLR jacks or how did you drill those? That is another quandry of mine. I've been thinking of buying a punch set.

 

[tchgtr]

Lazy and messy? It's like I have a twin!
  In this case, I was lucky enough to have a good friend with a shop who cut the holes for me. He even cut a nice odd-shaped one for an IEC AC connector, and felt bad when he scuffed the paint on the box, so he gave me an ammo box, and offered to do it again. I told him it was perfect, and offered to buy the ammo box, which he gave me anyway. Nice guy.
  Now I'm pondering cutting into that for my dual-capsule throw-together, and know exactly what you are talking about. The only problem I see is the XLR jacks. Most of them seem to call for a .76" hole, which likely could be done easily with a punch. I just looked at punch prices, and decided I'd try to find a local metal shop and see what they might charge to punch two holes.
  Almost everything else, I could drill with a good AC-powered drill and some good bits. Bypass the IEC connector, and just use a good old-fashioned cable with strain relief.
  Believe me, I've also been scanning used ads for people selling Chinese tube mic PSUs with pattern switches, but so far, no luck.

 

[Blue Jinn]

Lazy and messy? It's like I have a twin!
  In this case, I was lucky enough to have a good friend with a shop who cut the holes for me. He even cut a nice odd-shaped one for an IEC AC connector, and felt bad when he scuffed the paint on the box, so he gave me an ammo box, and offered to do it again. I told him it was perfect, and offered to buy the ammo box, which he gave me anyway. Nice guy.
  Now I'm pondering cutting into that for my dual-capsule throw-together, and know exactly what you are talking about. The only problem I see is the XLR jacks. Most of them seem to call for a .76" hole, which likely could be done easily with a punch. I just looked at punch prices, and decided I'd try to find a local metal shop and see what they might charge to punch two holes.
  Almost everything else, I could drill with a good AC-powered drill and some good bits. Bypass the IEC connector, and just use a good old-fashioned cable with strain relief.
  Believe me, I've also been scanning used ads for people selling Chinese tube mic PSUs with pattern switches, but so far, no luck.

I hear you on the attached power cable, with a little rubber grommet.

Punches aren't too costly, if you go 'off brand' so to speak, but the its the variety of sizes, and getting the right set.

I've been tempted to see if there was any interest in a group buy for OEM mics to mod either tube (like the HST-11a) or FET (like the myriad U87 style). There seems to be a current interest in mic modding, so it might be a good time to organize something like that.