saxmonster
Well-known member
- Joined
- Jan 3, 2012
- Messages
- 534
My new project will be a build of the Telefunken ELA M 251 out of my Apex 460. I would like all of the components to be as close to the factory specs as can be. I know it will not be an actual 251 but clones are a lot of fun make and understand.
I want this to be an all in one resource to all the links I have found online and the schematics.
From looking and reading on this forum and on the net i have compiled a list of what I need to swap and change so far. Please make suggestions as to what i might be doing wrong or any concerns you might have.
My Apex 460 Swap for an Elam 251
Capsule Chinese Tim's CT-12 or Peluso CEK12 or PK47
TUBE 12AX7B GE 6072A 5 star NOS or Ecc801s
Transf Stock Transf BV11
PSU Original Zener diodes Change Z5 to a 61v Zener from a 72 volt zener
Circuit Cathode Follower Cathode Follower CCDA (constant current draw amplifier)
R2 2w 100k 3w 100k
R3 1/2w 270k 1/2w 500k
R4 1/2w 270k 1/2w 500k
R6 200M 7w 200M
R7 1/2w 2.7K 1/2w 1.8k
R9 51M 1w 250M Use Ohmite
R10 1KM / 1G 1w 250M Use Ohmite
C1 1uf/450v Don't have to swap already Electrolytic
C2 1uf/450v Don't have to swap already Electrolytic
C4 1000p/630v 1000pf/160v Polystyrene
C5 .022uf/400v 4700pf/160v Polystyrene
C6 100uf/25v Remove
C7 0.1uf/63v Remove
C8 1uf/450v electrolytic 1uf/250v Metal Film (solen Fast)
C9 0.1uf/63v Remove
C10 0.1uf/63v Remove
C11 NONE 100pf/500v Mica Silver
Links That I am finding the info from,
http://www.groupdiy.com/index.php?topic=47764.0
http://www.groupdiy.com/index.php?topic=48211.0
http://recordinghacks.com/microphones/Telefunken/ElaM-251
http://www.groupdiy.com/index.php?topic=31837.0
http://www.treblebooster.com/m251e/telefunken_ela_m251e_circuit.htm
http://recordinghacks.com/2010/02/14/the-advanced-audio-cm12-mod/
http://www.saturn-sound.com/Curio's/elam_microphones.htm
http://www.gearslutz.com/board/low-end-theory/599895-help-w-diy-telefunken-ela-m-250-251-a.html
http://www.coutant.org/akgc12/index.html
http://www.foxaudioresearch.ca/TheM251.htm
http://www.foxaudioresearch.ca/The460secret.htm
http://homerecording.com/bbs/equipment-forums/microphones/apex-460-a-180723/
http://messageboard.tapeop.com/viewtopic.php?p=536568
http://messageboard.tapeop.com/viewtopic.php?p=536568
http://www.soundonsound.com/sos/may10/articles/peluso22251.htm
http://www.morphproductions.com/apex460transformermod.htm
Schematics
http://www.groupdiy.com/index.php?action=dlattach;topic=47764.0;attach=11980;image
http://www.coutant.org/akgc12/elam250_2.jpg
http://www.treblebooster.com/m251e/m251e.pdf
http://www.coutant.org/akgc12/c12schem.gif
http://www.coutant.org/akgc12/akg-c12.pdf
http://www.gearslutz.com/board/attachments/geekslutz-forum/111879d1235602544-apex-460-mod-u47-apex-460-mods.pdf
Capsule
http://www.timcampbell.dk/index2b.htm
http://www.pelusomicrophonelab.com/parts/Capsules.html
Transformer
http://www.tab-funkenwerk.com/id76.html
http://cinemag.biz/mic_output/mic_output.html
Am I missing anything else? Pictures will follow for each swap I do, caps, resistors, etc.
Thanks so much
-Scott
I want this to be an all in one resource to all the links I have found online and the schematics.
From looking and reading on this forum and on the net i have compiled a list of what I need to swap and change so far. Please make suggestions as to what i might be doing wrong or any concerns you might have.
My Apex 460 Swap for an Elam 251
Capsule Chinese Tim's CT-12 or Peluso CEK12 or PK47
TUBE 12AX7B GE 6072A 5 star NOS or Ecc801s
Transf Stock Transf BV11
PSU Original Zener diodes Change Z5 to a 61v Zener from a 72 volt zener
Circuit Cathode Follower Cathode Follower CCDA (constant current draw amplifier)
R2 2w 100k 3w 100k
R3 1/2w 270k 1/2w 500k
R4 1/2w 270k 1/2w 500k
R6 200M 7w 200M
R7 1/2w 2.7K 1/2w 1.8k
R9 51M 1w 250M Use Ohmite
R10 1KM / 1G 1w 250M Use Ohmite
C1 1uf/450v Don't have to swap already Electrolytic
C2 1uf/450v Don't have to swap already Electrolytic
C4 1000p/630v 1000pf/160v Polystyrene
C5 .022uf/400v 4700pf/160v Polystyrene
C6 100uf/25v Remove
C7 0.1uf/63v Remove
C8 1uf/450v electrolytic 1uf/250v Metal Film (solen Fast)
C9 0.1uf/63v Remove
C10 0.1uf/63v Remove
C11 NONE 100pf/500v Mica Silver
Links That I am finding the info from,
http://www.groupdiy.com/index.php?topic=47764.0
http://www.groupdiy.com/index.php?topic=48211.0
http://recordinghacks.com/microphones/Telefunken/ElaM-251
http://www.groupdiy.com/index.php?topic=31837.0
http://www.treblebooster.com/m251e/telefunken_ela_m251e_circuit.htm
http://recordinghacks.com/2010/02/14/the-advanced-audio-cm12-mod/
http://www.saturn-sound.com/Curio's/elam_microphones.htm
http://www.gearslutz.com/board/low-end-theory/599895-help-w-diy-telefunken-ela-m-250-251-a.html
http://www.coutant.org/akgc12/index.html
http://www.foxaudioresearch.ca/TheM251.htm
http://www.foxaudioresearch.ca/The460secret.htm
http://homerecording.com/bbs/equipment-forums/microphones/apex-460-a-180723/
http://messageboard.tapeop.com/viewtopic.php?p=536568
http://messageboard.tapeop.com/viewtopic.php?p=536568
http://www.soundonsound.com/sos/may10/articles/peluso22251.htm
http://www.morphproductions.com/apex460transformermod.htm
Schematics
http://www.groupdiy.com/index.php?action=dlattach;topic=47764.0;attach=11980;image
http://www.coutant.org/akgc12/elam250_2.jpg
http://www.treblebooster.com/m251e/m251e.pdf
http://www.coutant.org/akgc12/c12schem.gif
http://www.coutant.org/akgc12/akg-c12.pdf
http://www.gearslutz.com/board/attachments/geekslutz-forum/111879d1235602544-apex-460-mod-u47-apex-460-mods.pdf
Capsule
http://www.timcampbell.dk/index2b.htm
http://www.pelusomicrophonelab.com/parts/Capsules.html
Transformer
http://www.tab-funkenwerk.com/id76.html
http://cinemag.biz/mic_output/mic_output.html
Am I missing anything else? Pictures will follow for each swap I do, caps, resistors, etc.
Thanks so much
-Scott