[normalife]

Hi guys

I know some about soldering but not confidence enough to build the b22,
I am thinking about buying the parts and send to China and get it done. ( Cheap labour cost there! )
Besides Epslion 22, Sigma 22 and Beta 22 kit x4 from glassjar audio,
What other things do I need? (Power supply/input output jack?)
And where should I order the case..? Front pannel express? I remember the O2 amp has a template for FPE, does B22 also have one?
Thanks!
 

 

[normalife]

Um...I think 4 channel doesnt need the Epslion 22...?
http://www.amb.org/audio/beta22/audio4.png
For the XLR input/output, does it matter if I use male/female? 

 

[bcg27]

No beta 22 'needs' the epsilon 22. It is simply for convenience and clean wiring, but you are correct it does not support a 4 channel build. You probably want to use female sockets as plugs are usually male. Aside from the glassjar kits, you will need audio input connectors, headphone/speaker output connects, a switch to change between multiple inputs if applicable, a mains connector, a switch for mains power, wire, and maybe some other assorted odds and ends. If you do a two case build you will also need an umbilical to carry power from the power supply case to the amp case. There are various B22 FPE templates floating around, but you will have to dig around for them. The group build template is probably a good place to start for a balanced build. Many people, including myself, use the par-metal 20 series cases and replace the panels with custom milled FPE ones.
 
If you are comfortable soldering I would recommend trying to do this yourself. The documentation at amb's site and support on amb's forum are top notch and should help you through any difficulties.

 

[normalife]

Thanks for advise,
Should I use single or dual sigma22 for the 4 channel?
Should I get 80 or 100 VA?
and For the Beta 22 gain, GJA has 2x 5x 8x 11x and active ,
Should I get 11x for 4 channel?
And what model should I get for the PSU?
Thanks!

 

[nikongod]

Why not buy an amp prebuilt from an experienced builder who can canswer your questions and save lots of trouoble with sourcing parts? YMB Audio builds B22s. check his site out.

 

[normalife]

Can't afford the $2550

 

[bcg27]

I suggest you read through the beta22 and sigma22 websites at amb.org. Most of your questions are answered there. Regarding the gain, 11x for a balanced build would be massively too much. Because both sides of the signal are amplified you end up with double the effective gain, meaning you would have a gain of 22! I have a gain of 5 on my single ended B22 and find it quite adequate for everything I have listened to on it. I would suggest a gain of 2 to be good for pretty much every headphone except maybe HE-6 and k1000. Although gain is of course somewhat dependent on the output voltage of your source. 

 

[nikongod]

Buy one off of the FS boards.
 
It is a bit more cash, but it saves tons of headaches. B22s are not particularly forgiving amps.