[amb]

Quote:

Originally Posted by wolf18t /img/forum/go_quote.gif Oh boy, even if I don't really need it, this makes me want to build another B22 this time in two box and balanced. I would even buy the panels if there are eventually made available to a group buy. I suppose the chassis were sourced from Par Metal?

The chassis is Par-Metal 20 series 12x12x3 in clear anodize. I specified two front panels per case rather than a front and a rear, so that I get the same support piece for the rear panel as the fronts. The cases are not too expensive but be prepared to pay a lot for the FPE panels.

 

[lisnalee]

Fantastic work guys, that is going to one very sweet amp when its finished.

Keep the pics coming..

 

[Afrikane]

Quote:

Originally Posted by amb /img/forum/go_quote.gif amphead, rockcod and I convened at my place yesterday to continue the build effort. Jrossel also joined us in the afternoon. We're in the most time-consuming phase of the build. Prior to the get-together, I pre-mounted all the panel components, marked the mounting locations of the boards and other parts, and prepared wiring diagrams for everyone to work with to help move things along. We drilled the needed holes on the chassis bottom plate and proceeded to start wiring everything together. We made some progress on the β22 amp, but were far from being able to finish it before we had to quit for the night. When we finish the β22 amp I will post pictures of it. Meanwhile, we were able to complete the σ22 power supply. It tested perfectly and is looking very nice. Here are some pics for your viewing pleasure.

Quoted purely for awesomeness

 

[digger945]

uuuuuuh......uuuuuuummmmh......oooooooh......(gulp )

 

[krmathis]

Weekly bump!

 

[amb]

Ask and ye shall receive!

I just finished building the β22. It is working and sounding beautifully. I will be bringing this β22/σ22 duo, my β24 amp, and several other amps to the Burning Amp festival this coming weekend. I'm looking forward to meet Nelson Pass, John Curl, and several other big names in audio. It should be fun.

After that, I'll do a bit more testing, and then I will reconfigure the σ22 for 230V 50Hz mains power. Amphead is making a companion plaque to commemorate this very special group-build edition β22 and σ22. When he is done we will ship everything to krmathis.

 

[amb]

More photos of the β22 innards:

Boards are mounted, wiring up the stepped attenuator (enclosed in a box for additional shielding). It is located at the rear, immediately next to the input jacks for the shortest possible wiring. The volume knob is connected via a shaft extender and panel bearing.

The volume knob "ring illumination" is done with a sanded circular acrylic piece, fitted in a front panel cavity, secured to the front panel by the panel bearing, and lit from behind by four blue LEDs.

A view of the back side of the front panel, showing the Molex connectors that plug into the illumination LEDs.

Everything is all wired up and working. The front panel has a pair of Neutrik combo jacks for balanced headphones with dual 3-pin XLR male plugs or two pairs of unbalanced headphones with standard 1/4" TRS plugs. There is also a 4-pin XLR jack for balanced headphones such as the AKG K1000.

Another front panel shot.

 

[rhys h]

Brilliant job and a big well done to everyone that worked on and designed this amp.

AMB, can i ask where you got those speaker terminals?

 

[amb]

rhys h, the speaker binding posts were donated by MrMajestic2. I believe he bought them from THL Audio (see the "Plugs and sockets" section, item TCBPs-E).

 

[MASantos]

Awesome! Looks great! Any chance of a pitstop in Portugal for a listening session?

oh, and where does one order these???

Great work everyone that contributed and even more so to the builders!

 

[Ferrari]

It's a feast for the eyes. I'm impressed, really!

 

[krmathis]

Thats sick, just sick!

Really like the component layout, chassis design, blue light, and of course the craftsmanship. This is going to be a nice christmas gift (pr pre-christmas I guess).
Enjoy the Burning Amp festival as well.


Hmmm.. I began to wonder about the 4-pin XLR though. The K1000 have a 4-pin XLR like shown in this picture at APureSound:
http://apuresound.com/images/cables/...on4pxlr/05.JPG
Is that one a female plug, hooking straight into the male jack on the B22? Sorry, but I have these whole "male/female" mixed up...

I am sure you have full control, but like to clear up my mind.

 

[amb]

Hmm. Maybe I got the connector gender wrong. Is that a stock K1000 plug? If so I'd have to replace the jack with a female one.

 

[krmathis]

I have that plug on my K1000, and I really believe its the stock one.
Any other K1000 owner around here to verify? Guys...

 

[amb]

I just looked at steinchen's build in the β22 website gallery and sure enough he has a female jack for the K1000. I should've looked there first. Lol. OK, time to order a replacement jack...