[MrSlim]

CF, thats a nice looking build regardless of what you spent. It's nice to see what can be done at the other end of the spectrum.

I'm a big proponent of "Bang for the Buck", and it's a credit to your ingenuity to be able to bring a B22 in for such a low price.

Congratulations

 

[SoapSeller]

cfcubed,
Very nice build.

Where did you get this case?

 

[cfcubed]

@ MrSlim - Thanks... I appreciate the comments. I think my cost came in just below $350USD, partly due to getting the 2 wallwarts for $15 shipped. Some details in this post. Note that although the Beta18 used a similar PS design, this represents a compromise compared to σ22 of course (see "High performance but modest cost" in σ22 tech highlites). Should find out @ NYC meet this weekend if the compromise is audible to me as MoodySteve will have his very nice 3-ch "full-blown" build to compare to.

@SoapSeller - Thanks... The case is the fleabay HB-350 one for $45USD shipped. Note though that it IS very cheap (very thin panels, only front one is decent thickness), but serviceable.

 

[mattcalf]

Great builds guys, a US$350 beta22 is really awesome.

And oneplustwo, your Buffalo looks amazing!

I can't wait to be able to make a real contribution to this thread (posting my Christmas DIY endeavours

)!

 

[oneplustwo]

Thanks... the build took quite a bit more time than I anticipated. The board stuffing only took a day. But the wiring, trouble shooting, case work, and wood work and even the layout planning took friggin' forever. On to the next projects!

 

[Anonanimal]

My apologies for those who have already seen this, since I have a couple pictures already in the β22 thread. I borrowed my dad's digital SLR and tried to get some better pictures so that anyone else currently building can check it out. I know looking at others' builds was one of the biggest helpers I had.

Here's a small list of what's used! It's pretty easy to see much of my inspiration came from the Krmathis group build.

3-channel β22 with σ22 power supply.
Par-Metal 20-series chassis in black anodized.
Front+Rear panels from Front Panel Express.
Neutrik jacks front and back.
Amphenol Eco-Mate connectors for the DC umbilical.
Alps 50k pot with Goldpoint knob.
Lian Li computer case feet from Performance-PC.

Thanks for looking, and many thanks to all in the community who've shared their experiences and allowed me to build such a fun project!

http://lh6.ggpht.com/_VQQAX5iIQL0/Sv...0/IMG_2496.JPG
http://lh4.ggpht.com/_VQQAX5iIQL0/Sv...0/IMG_2499.JPG
http://lh6.ggpht.com/_VQQAX5iIQL0/Sv...0/IMG_2500.JPG

 

[apatN]

^ Beautiful Beta!

 

[pila405]

WoW! Such a clean work! truly amazing.

What case/chassis is that?

 

[krmathis]

Quote:

Originally Posted by Anonanimal /img/forum/go_quote.gif My apologies for those who have already seen this, since I have a couple pictures already in the β22 thread. I borrowed my dad's digital SLR and tried to get some better pictures so that anyone else currently building can check it out. I know looking at others' builds was one of the biggest helpers I had. Here's a small list of what's used! It's pretty easy to see much of my inspiration came from the Krmathis group build.

Really great looking amplifier. Well done!

 

[Anonanimal]

Quote:

Originally Posted by pila405 /img/forum/go_quote.gif WoW! Such a clean work! truly amazing. What case/chassis is that?

They are both Par-metal 20 series cases. I think the part number was 20-12123 for this exact size. I borrowed some dimensions from amb's generously-shared files for Krmathis' group-build edition and saved money by ordering the cases from Par-metal without front/rear panels.

 

[j4cbo]

Progress:

 

[Beefy]

BAM! And Jacob slaps down a huge e-penis......

 

[j4cbo]

One at a time, ladies.

 

[Beefy]

Quote:

Originally Posted by j4cbo /img/forum/go_quote.gif One at a time, ladies.

HEH!

Got any listening in yet? And perhaps an explanation of the photo..... I bet there are a mountain of people here who don't even know the significance of what you just posted......

 

[j4cbo]

I have, in fact, done some listening. Eighteen of the boards are under construction; not pictured are the two boards that are completed and hooked up to temporary heatsinks, a σ22, and my source.

It is, to put it mildly, pretty damn good.

For the uninitiated: the above is a whole batch of DynaFET boards. These are a custom board layout that I'm in the process of building for a few people. Besides the actual amplifier, each has onboard monitoring of voltage, current, output transistor temperature, case temperature, and output offset servo position, and a relay for selecting between the two options for feedback point from the original design.

Each board has 24 BJTs, four input FETs, eight output FETs, seventeen caps (a few in the monitoring circuit and servo, one compensation, the rest power decoupling), about 60 surface mount resistors, fourteen through hole resistors, a pot, four LEDs, three ICs (microcontroller, sense opamp, servo opamp), four connectors, and... a partridge in a pear tree. The feedback loop resistors are 0.5% low-tempco thin film. The input JFETs are a matched quad, and the input stage BJTs are in matched pairs, thermally bonded into custom dual-TO-92 heatsinks.

Multiply all that by four boards per (balanced!) amp, and five amplifiers that I'm building.

And that's not even getting into the master control system...