[linuxworks]

Quote:

Originally Posted by JamesL /img/forum/go_quote.gif Look what just came out of the oven!

mmm, I like the smell of hot metal in the morning.

Quote:

The other two will fit nicely in with a pimeta and ppav2.

same here, more or less. one was a demo dac that I can play with and I have 2 more boards and parts sets so that I can mount them in a pimeta for portable use and some kind of ppa or something for 'home' use. yup, same here!

so, do you have pro SMD tools or is this a home oven setup you have? I built mine the hard way and I'd prefer to learn easier ways...

 

[linuxworks]

update: the entire 'output level is too low' problem was due to win-xp! ;(

even though I was running asio4all and foobar2k I was still getting very attenuated output. it really looked like it was the dac's fault.

it wasn't. I booted up to ubuntu and ran xine as a player. the volume level was about 4x compared to my windows setup (same hardware exactly since I was dualbooting). I could not believe it.

xine has access to the hardware mixer in the pcm chip (I'm pretty sure) and moving the slider did raise and lower the volume. at full volume my pimeta was way too loud and I had to back it off. GOOD!

so, things are just fine. the dac is fine. there is not a hardware problem, but somehow my xp box is in 'xp attenuation' mode (lol) and won't come out. I actually don't even care anymore and I'll fix it next time its total-reinstall-xp day

linux sound was flawless. no gaps or breakups or data loss at all; plus all the volume I wanted. and no worries about a demonic kmixer or anything like that with a linux system. all audio in linux is 'kernel streamed' so to speak.

also, I should mention (though its a bit embarassing) - freebsd audio for usb is quite broken ;( its not this device (again, this dac is just fine) but a friend and I spent some time on 2 different freebsd boxes and both had periodic static in the usb-audio (about a minute or 2 in the cycle, then it repeats) and it just seems that the usb-audio device driver stack in freebsd 6.x is kinda broken ;( I cannot recommend freebsd for this until it gets fixed (or redesigned).

but linux is just fine and quite up for the job.

fwiw.

 

[saboja]

OK - I've been reading a lot about the BantamDAC and I'm all excited about making one for myself. I have not been able to figure out where to obtain the PCB. If there is someone out there that knows where to source the borad or that has an extra board they're willing to part with please let me know the cost and how to get the part.

Thanks,
Saboja

 

[elliot42]

The boards are available here: Beezar.com
As well as some of the harder to find and upgraded capacitors and also the small case.

 

[emelius]

just a heads up, the new millett max boards are supposed to have space for a bantamdac module...if you wanted to kill two birds with one stone...

 

[tomb]

Good grief! I never saw this thread. You guys have done great work!

 

[tomb]

Quote:

Originally Posted by emelius /img/forum/go_quote.gif just a heads up, the new millett max boards are supposed to have space for a bantamdac module...if you wanted to kill two birds with one stone...

Yep - prototype pics here:

We're using relay switching with a simple SPST switch to control the choice of inputs from the BantamDAC or RCA jacks.

We should be ordering the PCB's for DIY-er's in a week or two, I hope.

 

[individual6891]

Is this v1.2 as advertised @ beezar?

 

[individual6891]

Also, is that a ground plane I see underneath the PSU to counter the ripple? like the miniMax?

 

[tomb]

Quote:

Originally Posted by individual6891 /img/forum/go_quote.gif Is this v1.2 as advertised @ beezar?

Yes.
Quote:

Also, is that a ground plane I see underneath the PSU to counter the ripple? like the miniMax?

Yes and yes - it uses the MiniMAX power supply, but it's successfully scaled up, too. That's a MOSFET-MAX running 125ma bias on the MOSFET diamond buffer. Caps are 2 x 2000uf in the power supply and the decouplers are 4 x 3300uf. The power supply measures 45uVAC noise/ripple (0.045mVAC), so as good as the MiniMAX with a much higher current capability due to the MOSFETs, larger board size, and taller heat sinks.

 

[individual6891]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif Yes and yes - it uses the MiniMAX power supply, but it's successfully scaled up, too. That's a MOSFET-MAX running 125ma bias on the MOSFET diamond buffer. Caps are 2 x 2000uf in the power supply and the decouplers are 4 x 3300uf. The power supply measures 45uVAC noise/ripple (0.045mVAC), so as good as the MiniMAX with a much higher current capability due to the MOSFETs, larger board size, and taller heat sinks.

Ahh fantastic work, very cool. Finally on par with the MiniMax then

Also, good idea to use the relay switcher. I mean you could have used a DPDT, but I suppose the leads would have picked up interference from the rest of the circuit?

That's a lot of capacitance, you recommend a 24VAC 1A, but won't such a large capacitor bank surge too much on start up?

 

[individual6891]

Oh, and will the silver miniMax cases be in stock soon?

 

[tomb]

Quote:

Originally Posted by individual6891 /img/forum/go_quote.gif Ahh fantastic work, very cool. Finally on par with the MiniMax then Also, good idea to use the relay switcher. I mean you could have used a DPDT, but I suppose the leads would have picked up interference from the rest of the circuit? That's a lot of capacitance, you recommend a 24VAC 1A, but won't such a large capacitor bank surge too much on start up?

Actually, I use a 50VA 24VAC walwart for the MOSFET-MAX. That's over 2 amps, so it doesn't have a problem.

Quote:

Oh, and will the silver miniMax cases be in stock soon?

Silver is out of the picture for the time being - just didn't sell enough of them to justify my ordering a few $thousand's worth just to get the price down to a manageable value. Maybe if the kits take off, I'll have enough to invest in the silver again.

 

[individual6891]

Oh blimey, can't find any 24VAC wall adapter that puts out over 0.4A anywhere in the UK. Anyways, thanks for the tip. Might just have to build my own 12V+12V transformer box

 

[tomb]

Quote:

Originally Posted by individual6891 /img/forum/go_quote.gif Oh blimey, can't find any 24VAC wall adapter that puts out over 0.4A anywhere in the UK. Anyways, thanks for the tip. Might just have to build my own 12V+12V transformer box

That's a shame. They're fairly common over here in the security business. 24VAC doesn't require code-certified electricians to run the wiring, so they load up as much as they can on 24VAC Class II walwarts. A 50VA version is commonly available at many places that supply such systems. They're also available at Grainger, MCM Electronics, and Beezar even sells them, but they're out-of-stock at the moment. Seemed a bit pointless to stock them lately until the MAX V1.2 PCB is released. The MiniMAX doesn't need that much power.

BTW, just to get this thread back on track - Jeff Rossel now carries the BantamDAC in kits at GlassJarAudio.