U47 type microphone and multipattern

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Hi,

I just finished U47 type of the microphone with BV8 transformer from AMI,
Telefunken EF14, capsule and body from John Peluso. PSU is modified Nady TCM1050 PSU with 120V output. Does someone know how to convert U47 schematic to work with multipattern characteristic ? I look into M49, TCM1050 and G7 schematic. I found that the difference is how is connected central plate of the capsule. Otherwise I compare sound with U87 and I was really dissapointed. There was lack of the bass and the highs are bright and unpleasent compared to U87. I know that with cheap components I can't build a real thing but even my two Royer mods sounds better ... Does someone build this type of the microphone and what was your expirience with it ?

Regards.
 
Hi Lampas,
could You please share the schematic, as i am interested in building one for me, but with the EF14 like You did, instead of a VF14. Thanks,
Tom
 
could be the grill or capsule.

What I would do

Wire the capsule you have as a U47 circuit not multipattern.

Change the capsule to one from your Royer modded microphone

Use the capsule from the u47 in one of the Royers

This will help to find out if it is the capsule

Yes this is no fun but it is a good way to find out about a capsule.

I will try a new capsule in a known good microphone build as a test.

After this we can work with the pattern control part.
 
[quote author="Gus"]could be the grill or capsule.
I will try a new capsule in a known good microphone build as a test.
After this we can work with the pattern control part.[/quote]

Before I did your suggestions I checked the schematic and I found that I mixed heater wire F1 and F2, so cathode stiff was on minus side of the heater . The sonic test compared with headphones and U87 is now really different. I also found that measurement on the anode was wrong, because something was also wrong with tube. (With wrong wiring it was 32.2V). When I correct mistakes I found that tube now measure 42V so I replace with different one and the sound was now open and full compared to U87. The measure is 33.7V which is good. I will do sonic test afternoon on my friend studio and I will compare it to the rest of the my microphone arsenal. I will post some samples if I will found some time to do that.
THe only thing which must be done now is pattern control.
 
These photos were taken by my phone camera and they are not the best. I'll post better photos when I get my digital camera back.




u47-1.jpg

u47-2.jpg

u47-3.jpg

u47-4.jpg
 
Can you post your schematic and/or board layout? I'm very interested in this one. I bought an MXL 960 mic and I'm thinking about rebuilding the electronics with an EF14 and Cinemag output transformer. Even if I completely gut the electronics, the 960 seems like a good deal for the case, capsule, power supply, jacks, Mogami cables and shockmount. Especially at the price I paid for it. ;)

http://www.mxlmics.com/condenser_mic/900_Series/MXL960/mxl960.htm
http://www.jefflaity.com/gallery/mxl960
 
[quote author="BR"]Wow...
that looks great...
did the grill come with the body???
Gil[/quote]

Yes it comes complete: housing, transformer, shock mount and capsule. I bought it from John Peluso, because it was big enough to put EF14 + transformer in there. I just replace transformer with BV8 from Oliver Archut.
 
[quote author="synthetic"]Can you post your schematic and/or board layout? I
[/quote]

Unfortunatelly I can't at this time, because schematic is property of the Oliver Archut. But hey, I'll ask him if it is OK for him and if he agree I'll post it here OK ? Of course with board, but you must consider that it is done by hand (with ink pen). Anyway pattern control still doesn't work. It was designed from NADY TCM 1050 schematic.
 
[quote author="lampas"][quote author="synthetic"]Can you post your schematic and/or board layout? I
[/quote]

Unfortunatelly I can't at this time, because schematic is property of the Oliver Archut. But hey, I'll ask him if it is OK for him and if he agree I'll post it here OK ? [/quote]

I got mail from Oliver and he agree to post schematic here.

u47-ef14.gif
 
Thanks for posting that. I see that the Gyraf G7 is similar to the U47 circuit, only with an EF86 tube instead of a VF14. Is an EF14 closer in sound to a VF14 than EF86? I assume that Gyraf considered this tube when designing the G7, but doesn't the EF14 run at a lower voltage than the EF86? Maybe I should just break down and buy a VF14 tube.

:shock: :wink:

Perhaps Groove Tubes will shock us all in a few weeks when they announce a new VF14 tube at AES. I'm not counting on it... but I'll hold of on buying a tube until after the show. We have Dale's M7 capsule and Cinemag's CM-2461NiCo output transformer, all we need is the VF14 for the ultimate U47 clone. C'mon, Aspen...
[/url]
 
That's very nice Oliver gave his ok!
Btw, lampas, you mentioned the BV8 from Oliver, how much did you pay for it, they don't show prices on the web? (If i may ask that?)
BTW: GREAT thread, thank you very much for that!

@synthetic:
The VF14 is nearly the same like the EF14, BUT it has excellent choices of material for low noise and so is a special version...however they should come close anyway...
From all i read the VF14 costs around 1500 Euros nowadays...(if you can find one, it's probably the most searched for tube generally...)
On the Telefunk*en-U*S*A website look at the price difference for u47m with nuvista, ef14, VF14 or without tube...horrible!
Perhaps Groove Tubes will shock us all in a few weeks when they announce a new VF14 tube at AES. I'm not counting on it...
:shock:
They will be quite expensive i'll bet...
I think i'm going the cheaper way of buying some EF14 trying to find a spec matching one... Oliver mentioned over at PSW, that you have to choose from around 10 TFK type or nearly 20 RFT type EF14 to get one(!) appropriate tube for u47 replacement.
So lampas is a very lucky guy if the second one was good enough for great sound!

Thanks again and happy DIY :thumb:
I hope you can solve the multipattern problem soon...

Kind regards
Martin
 
Lampas,

The schematics looks allright. I don't think the grill would influence that much the LF region. So here are the suspects left:
1) Double and triple check if you have wired everything right.
2) Capacitor between tube and trafo (would be my first suspect)--measure if it is ACTUALLY 0.5MF (or higher), or put the one which works you know for sure.
3) Check polarizing voltage (before 100M resistor).
4) As Gus has already mention--the capsule--swap for a known good working one.

if all of these were OK, then the problem might be either in impedance mismatch with your pre, faulty tube, or faulty transformer.
 
Lampas,
you got a special deal with John Peluso (body&grille)? :shock:
Im very interested how much this would cost, i saw the U47 mechanics set from Gunther Wagner...you nearly can buy a whole peluso mic for it (1150Euros if i remember it right :? )

Kind regards

Martin
 
Congrats Vili :thumb:
Easiest way to make all of three patern is to combine U47 and U48.
u48.gif

U48 have lower voltage on capsule (half od 105V). To got 52,5V you must exchange 2M on voltage divider with 3M. Drive back side of capsule with 105V throught two 100M and one 10n connected to ground. You must have one three pole switch to choose between cardiod (when work only front) omni where back side have same voltage like front and eight when back side capluse have double voltage (105V)
Duka
 
I Martin,
from the pictures it seems to me that this mechanical parts from Peluso's mic are comming from a well known chinese manufacturer. I'm not really sure but this mechanical parts looks like the ones from SE Electronics microphones i have around.

I don't like thoses mics because they sound crappy to me and they're overpriced(!!) but the body, grill and internal layout is simple. It is a good one for modification! ( not a lot of tinny parts as in Rodes or Behringers which i don't like!!).

It could be interristing checking out the cost J.Peluso sell them (...if he did!) because i found a very low cost range of mic sharing the same mechanical and i suppose the same capsules... which could not be bad with a good electronic: se electronics are manufactured by 797 Audio, as Studio Projects and Behringer (i'm not sure with this one).

Maybe this Range of mics cost less than buying only mechanical parts from Peluso and you've got a capsule en plus!
If the capsule is crappy it's still interesting to try the mods explained in the C800 threat!
Remi G.
 
@martthie_08:
I found a posting at dan alexanders forum where someone stated his two U47W from gunther would use the EF12 :shock: :?: with a slightly modified psu...
But i don't know if this is right...can someone confirm this? :?
 
[quote author="smallbutfine"]@martthie_08:
I found a posting at dan alexanders forum where someone stated his two U47W from gunther would use the EF12 :shock: :?: with a slightly modified psu...
But i don't know if this is right...can someone confirm this? :?[/quote]

Yes this is right. He use them in his version of U47 clone. I also did try them in my tester (U47 typej schematic with two sockets one for EF14 and other with EF12 wiring old MXL2001 capsule and transformer from old NADY tube mic), and only useful were EF12k and EF12spez. Other tubes don't match specification (anode 34V). I didn't try them in in real mic because I am waiting for other mechanical parts from Mr. Peluso. His explanation was, that EF14 tube is using too much power (400mA) against EF12 (200mA) and produce too much heat ...
 

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