ELAM 251 build for beginners :)

[magnusp71]

Hi all

I am in the first steps of beginning a ELAM 251 DIY build. I have done a few 500 Series DIY so I am not a complete novice in terms of building, soldering etc., however, I have almost zero circuit knowledge.


In my first research, I have stumbled upon a few questions, I would like to ask.

1. I am really hooked on the BeesNeez body with their CK12 capsule. Do you guys know of any PCB (including BOM) that fit into this body. Could the kits from micparts or mod&mic work? This would be very helpful in terms of getting as simple and well-dokumenter build as possible.
2. Can I use any PSU for the build (ex the one from BeezNees) or must it be designed specifically for that PCB I end up using?
3. If I end up using a kit from micmod og micparts - what other parts would you recommend sourcing individually and changing (transformers, tube etc.)?

Thank you all in advance. Cant wait to get started

 

[pasarski]

1. Ela M 251 circuit fits in almost any body. Easy to do point to point. And much more fun.

2. Almost any PSU with 6.3v heater voltage will do. B+ maybe need to be modified. Also what kind of polar pattern control you want? You have to decide.

3. If you use a 251 kit I don't think you have to source anything. But there's a caveat, the capsule. If you really want to make a good 251 clone you need a good CK12 capsule. A good edge terminated k67 will get you close but note quite there. That's by far the most important component. And also most expensive.

Lots of information here if you do the search. Must be the one most discussed and studied microphone besides U47. And be careful, high voltages are dangerous, and have fun

 

[KrIVIUM2323]

Hi,
1)You don't really need a pcb: most of those classic mic were build point to point. I know it's not the answer you were looking for but it had to be said. Pcb are nice when you plan to build a number of circuit. If it's for one or two then i find ptp to be faster. Some turret board or turret and acrylic plate (as board) and it can be adapted to any body you plan to use. The real issue in mic built (imho) is relative to the high impedance part of the circuit ( everything before tube grid) which need special care: don't touch parts or cables with bare hands ( it'll leave greasy finger print which will make the circuit lacking bass as outcome), clean everything with 99,9% isopropyl alcool ( except polystirene capacitors if used) and use special turret as they must be high insulation.
2) No you can't use any psu to power any circuit. With mic b+ is used to bias circuit but capsule too and if you want multipattern you might have issue, so it have to be taylored to the circuit, heater voltage can vary too as there is 6,3V and 12,6v .
3) you are on your own about this: only someone which have done the same kit AND decided to change things might give you advice but it would be subject to preference and level of circuit understanding of the one giving advice.

Edit: Pasarski was faster than me!

 

[pasarski]

Hi,
1)You don't really need a pcb: most of those classic mic were build point to point. I know it's not the answer you were looking for but it had to be said. Pcb are nice when you plan to build a number of circuit. If it's for one or two then i find ptp to be faster. Some turret board or turret and acrylic plate (as board) and it can be adapted to any body you plan to use. The real issue in mic built (imho) is relative to the high impedance part of the circuit ( everything before tube grid) which need special care: don't touch parts or cables with bare hands ( it'll leave greasy finger print which will make the circuit lacking bass as outcome), clean everything with 99,9% isopropyl alcool ( except polystirene capacitors if used) and use special turret as they must be high insulation.
2) No you can't use any psu to power any circuit. With mic b+ is used to bias circuit but capsule too and if you want multipattern you might have issue, so it have to be taylored to the circuit, heater voltage can vary too as there is 6,3V and 12,6v .
3) you are on your own about this: only someone which have done the same kit AND decided to change things might give you advice but it would be subject to preference and level of circuit understanding of the one giving advice.

Edit: Pasarski was faster than me!

Great minds etc...