Telefunken ELA M 251 Clone Tube Microphone Build Thread (D-Ela M 251E)

[magnusp71]

Tim, I've ordered about a dozen EH6072s over the last year from various sources in France and Germany... and the quality is pretty good and consistent. And there hasn't been a tube more noisy or even bad as the noise level of a good GE6072A or Siemens Halske ECC801S that I've ever bought. But I've also never found an EH with that ultra elegant, cutting midrange presence, with those perfectly balanced sibilances, highs and lows that the GE delivers. Not a little bit or at least with a homeopathic dose of GE. Would be intersting how much FLEA test to find a fitting one and how do they really sound compared to GE...

Hi Herbert and others
I am buying a 6072 for my build and are asked what tube generation I prefer.
- the brighter 60's and 70's era GEs
- full, rich low-mids in the 1950s and early 60's versions

Anyone who have used the CT12 capsule and have find a GE’s that matches it nicely?

 

[Accelerator]

@magnusp71​

Hi Herbert and others
I am buying a 6072 for my build and are asked what tube generation I prefer.
- the brighter 60's and 70's era GEs
- full, rich low-mids in the 1950s and early 60's versions

Hi magnusp71 and greetings from Greece.

If you are ready to “bite the bullet” and “pull the trigger” for a high priced G.E. 6072A 5***** tube it will be wise for you to prefer the 1950s and early 60's versions, because back in the 1950's and early 60's days the G.E. GL-6072A 5***** tube was a J.A.N. tube and the Q.C. was much more “tighter”, than the 60's and 70's era GEs when the 6072 tubes were just commercial products…

Anyone who have used the CT12 capsule and have find a GE’s that matches it nicely?

I haven’t used the CT-12 capsule with G.E. GL-6072A tube, but if I have to be “fair” to all the other brands (included the new production E.H. – Sovtek & JJ Electronic tubes) I have to say that a high priced G.E. GL-6072A 5***** tube maybe or maybe not been an “overkill” for just a PCB board microphone, so it will be much more wiser for you to keep the CT-12 capsule for this project, then put the rest of your money to a Moby T14/1 (C12, ELA M 251) output transformer and passive components that you will need and then after all of these to look around to see if you prefer the “timbre” that you get with an 6072/12AY7 or the “timbre” of an ECC81/12AT7 or even the “timbre” of an ECC82/12AU7 tube…

 

[magnusp71]

@magnusp71​

a high priced G.E. GL-6072A 5***** tube maybe or maybe not been an “overkill” for just a PCB board microphone,

Is this also true if I do the point-to-point build from vintagemics?

Personally, I know nothing about tube quality, and I have just seen everyone recommend the GE6072. I want the best possible mic and Im ready to pay the Price for it. However; what other tubes could be preferred?
I am gonna use a OPR Capsule instead as Tims seem to be a ghost

 

[Accelerator]

Is this also true if I do the point-to-point build from vintagemics?

Personally, I know nothing about tube quality, and I have just seen everyone recommend the GE6072. I want the best possible mic and Im ready to pay the Price for it. However; what other tubes could be preferred?
I am gonna use a OPR Capsule instead as Tims seem to be a ghost

Usually the P2P (point-to-point) builds have a more “organic” sound than a PCB board build construction, which gives you more “accuracy” in the reproduction of a circuit but these “fine details” of a “better tube” get lost…

If you have any link about the vintagemics and their point-to-point build microphones I like you to post a link here to have a view at them.

There are many European N.O.S. ECC81 – 12AT7 tubes that will make “a better fit” in a ELA-M 251E circuit than the overpriced & overrated G.E. GL-6072A 5***** tube like the Siemens ECC801 or the Philips ECC81 etc., just remember to replace the 1k8 Cathode Resistor with a 2k7 Cathode Resistor and you will be ready to go.

For the capsule the Australian OPR CK-12 sound to me “good” on their OPR P2P Microphones, but the –also Australian- BeesNeez Microphone Capsule sounds to me a little bit more “dark” and ‘50’s CK-12 flat-shallow dish, so I preferred as a "better option" over the OPR CK-12…

Here is a Mic Shootout of the OPR P-2-P microphones with their OPR CK-12 capsule just to have a “reference point” if you like a C-12 or a ELA-M 251E circuit.

OPR Tube Mic Shootout (introduction) - C12 Ultralux vs. OPR 251 Ultralux, Part 1


OPR Tube Mic Shootout - C12 Ultralux vs. OPR 251 Ultralux, Part 2


Tube Mic Shootout - Telefunken U48, Neumann U67, OPR 251 Ultralux , OPR C12 Ultralux, Part 3

 

[magnusp71]

Usually the P2P (point-to-point) builds have a more “organic” sound than a PCB board build construction, which gives you more “accuracy” in the reproduction of a circuit but these “fine details” of a “better tube” get lost…

If you have any link about the vintagemics and their point-to-point build microphones I like you to post a link here to have a view at them.

There are many European N.O.S. ECC81 – 12AT7 tubes that will make “a better fit” in a ELA-M 251E circuit than the overpriced & overrated G.E. GL-6072A 5***** tube like the Siemens ECC801 or the Philips ECC81 etc., just remember to replace the 1k8 Cathode Resistor with a 2k7 Cathode Resistor and you will be ready to go.

Thank you so much for the input.
I often prefer a more bright tone as seen in most modern pop vocals today. So I have ordered the OPR capsule.

This is the circuit I referred to:
https://vintagemicrophonepcbkit.com/D-251.html

 

[magnusp71]

Here is a Mic Shootout of the OPR P-2-P microphones with their OPR CK-12 capsule just to have a “reference point” if you like a C-12 or a ELA-M 251E circuit

Tube Mic Shootout - Telefunken U48, Neumann U67, OPR 251 Ultralux , OPR C12 Ultralux, Part 3

Definately prefer the 251 on vocals in this clip

 

[Accelerator]

magnusp71​

This is the circuit I referred to:
https://vintagemicrophonepcbkit.com/D-251.html

Well, since we are talking about the Danny’s D-251 Tube Microphone and not for something P2P “boutique exotic” like the Flea12 mechanical kit you can use for it any 6072A – 12AY7 tube or even any ECC81 – 12AT7 tube or even if you like any ECC82 – 12AU7 tube without the “need” for buying the overpriced and maybe overrated G.E. GL-6072A 5*****, as (IMHO) I think it is more important the impedance “matching” of your chosen T14/1 Output transformer with the Output Coupling Capacitor and the Internal Resistance of your chosen tube and the proper and correct biasing of your chosen tube, rather than the brand of your tube…

It will be –more- wiser for you to investment your money to the components that “quality counts & stays” like the Output transformer, the value & the type of your Output Coupling Capacitor, the whole package of your passive components (resistors, capacitors) for your microphone & don’t forget in any way the quality and the value of the filter resistors & the filter capacitors of you PSU…

Just for an exable:

Here are some videos of the Handbuilt in Switzerland P2P “boutique exotic” BSA ELAM 250 Microphone and as you can see it has Haun CK12 capsule, Haufe T14/1 transformer, NOS ECC81 vacuum tube…

Goodbye Yellow Brick Road


Fast Car, Tracy Chapman, Cover by Joe And The Reluctant Prophets


Thunder Road, Bruce Springsteen cover by Joe and the Reluctant Prophets


Hallelujah Cover by Joe and The Reluctant Prophets Enjoying the joy of the new BSA M250 Microphone


BSA "Blackspade Acoustics" M250 Microphone Review and test song, Summertime From Porgy and Bess.

 

[magnusp71]

magnusp71​

Well, since we are talking about the Danny’s D-251 Tube Microphone and not for something P2P “boutique exotic” like the Flea12 mechanical kit you can use for it any 6072A – 12AY7 tube or even any ECC81 – 12AT7 tube or even if you like any ECC82 – 12AU7 tube without the “need” for buying the overpriced and maybe overrated G.E. GL-6072A 5*****, as (IMHO) I think it is more important the impedance “matching” of your chosen T14/1 Output transformer with the Output Coupling Capacitor and the Internal Resistance of your chosen tube and the proper and correct biasing of your chosen tube, rather than the brand of your tube…

It will be –more- wiser for you to investment your money to the components that “quality counts & stays” like the Output transformer, the value & the type of your Output Coupling Capacitor, the whole package of your passive components (resistors, capacitors) for your microphone & don’t forget in any way the quality and the value of the filter resistors & the filter capacitors of you PSU…

Once again, thank you for the thorough reply. That create a whole new set of questions from me

1. I see now that Dannys circuit is actually half PCB/half PTP. My feeling was, that it was the best accessible DIY circuit out there. Do you agree?
I am, however, also curious to know more about PTP. Having only ever done PCB builds, I am unsure if this might be a bit over my skill level. Do you know of a place where I can order the boards for PTP and find build guides? (Are they included in the FLEA kits?) If not, I might have to go for the PCB solution this time around if I am to succeed.

Thanks again

 

[egroys]

Edit: Bad RCA 12AT7 I had in solely for testing! How annoying. Everything is sounding great so far!


I just finished my build and the signal is extremely high passed and the pattern switch isn't doing anything.
I am using pin 3 for omni and pin 6 for fig8 and everything is consistent and giving me solid continuity beeps. I have a Beesneez capsule.
H+ is 6.0V, B+ is 118V measured at the mic.
I am going to go over all of my connections but upon visual inspection, everything appears to be connected correctly.

Can anyone direct me as to where I should focus my sleuthing efforts?

Thank you!

 

[magnusp71]

Anyone with a updated BOM for the build? Specifically, what parts can I use to replace the obsolete relays and capacitors? Also, if any parts could be replaced with some of better quality to improve the build I am eager to learn about it

 

[egroys]

Anyone with a updated BOM for the build? Specifically, what parts can I use to replace the obsolete relays and capacitors? Also, if any parts could be replaced with some of better quality to improve the build I am eager to learn about it

View attachment 138998

View attachment 138997

You can start with eBay for the relays. This gentleman is willing to sell more or less than the listed batch of 5.

 

[magnusp71]

You can start with eBay for the relays. This gentleman is willing to sell more or less than the listed batch of 5.

Thanks man. And is this because the suggested alternative from Mauser - 769-TX2-6V is not as good or a direct substitute?

 

[Accelerator]

@magnusp71​

Once again, thank you for the thorough reply. That create a whole new set of questions from me

1. I see now that Dannys circuit is actually half PCB/half PTP. My feeling was, that it was the best accessible DIY circuit out there. Do you agree?
I am, however, also curious to know more about PTP. Having only ever done PCB builds, I am unsure if this might be a bit over my skill level. Do you know of a place where I can order the boards for PTP and find build guides? (Are they included in the FLEA kits?) If not, I might have to go for the PCB solution this time around if I am to succeed.

Thanks again

You welcome!...

1. As an alternative option for a PCB Board ELA- 251E circuit with ready PCB Board, schematic and build instructions you can take a look also at Matador’s ELA M251 Inspired Microphone - Build Thread which having some more advancing options like the typical C-12’s 9-position polar pattern over the 3-position polar pattern only Danny’s D-251 Tube Microphone and it is without relays.

2. The C-12 Epoxy Glass eyelet disc boards are included with the Flea12 mechanical kit, in other words with the Flea12 mechanical kit you will receive something very similar with the Telefunken Elecroakoustik USA C-12 microphone body, but you have to do all the “hard work” to build it up with the resistors, the capacitors, the tube, the capsule, the transformer, the power supply or the cable that you like…

 

[Accelerator]

@egroys​

I attached the Vintage Microphone PCB Kit D-251 ‘’Walter White’’ schematic and the Vintage Microphone PCB Kit D-251 ‘’Walter White’’_PSU schematic for you to have a reference point for re-checking if everything is been connected correctly.

 

[egroys]

@egroys​

I attached the Vintage Microphone PCB Kit D-251 ‘’Walter White’’ schematic and the Vintage Microphone PCB Kit D-251 ‘’Walter White’’_PSU schematic for you to have a reference point for re-checking if everything is been connected correctly.

Turns out it was simply a bad test tube! I tested with a different test tube and everything is gorgeous! Now I put in my 1961 GE 6072 from @Bowie and it's ALIVE! I'm going to let it warm up for a while before I test more, but so far, so good! Thank you!

 

[egroys]

I am noticing, although I wired my Moby T/14 transformer as suggested, that the leading waveform on my voice in cardioid is negative and it sounds "correct" in my headphones while monitoring when I flip the polarity.

What's would be the correct way to remedy this?

 

[TLRT]

I am noticing, although I wired my Moby T/14 transformer as suggested, that the leading waveform on my voice in cardioid is negative and it sounds "correct" in my headphones while monitoring when I flip the polarity.

What's would be the correct way to remedy this?

swap the secondary cables anywhere(in the mic or in the PSU output XLR)

 

[egroys]

swap the secondary cables anywhere(in the mic or in the PSU output XLR)

I figured but wanted to make sure.

Am I doing something wrong along the way? I just want to prevent this from happening. Comparing to my SM7b, the leading waveform is positive on my voice.

 

[egroys]

Thanks man. And is this because the suggested alternative from Mauser - 769-TX2-6V is not as good or a direct substitute?

Not sure. I’ve read about various woes here IIRC so I didn’t want to deal with it once I found the originals.

About the big 3.3uf cap: I, and many others, use a 1uf cap instead. I have a Beesneez capsule and Ben was kind enough to include a handful of options including a custom one he had made for his ELA M clone.

 

[magnusp71]

Not sure. I’ve read about various woes here IIRC so I didn’t want to deal with it once I found the originals.

About the big 3.3uf cap: I, and many others, use a 1uf cap instead. I have a Beesneez capsule and Ben was kind enough to include a handful of options including a custom one he had made for his ELA M clone.

Alright. What difference will the 1uf make? Can you possible link to a Mouser material number that could work?
I’ve read somewhere that I should go for Polystyrene & Tantalum capacitors.