B1 preamp build thread

The B1 is pretty forgiving with its PSU.

I run mine from a 30VA 9-0-9V into a stock 1A bridge then CRC with 2 x 4700uF LCR caps with 2R2 between them. Reg is a straightforward LM317.

Its actually better than a DCB1 that I am trial building at the moment. I did use Obbligato 10uF Caps though.

The little PCB on the top left is just a Mains Filter that I pinched straight out of a VCR.

The PCB is Home-Brew. Although it is Double Sided there are no tracks on the Upper Surface, just the Ground Plane.
Ever so easy to make at home.

My B1 has evolved with a Salas Shunt Reg.
 

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If you wonder where the Salas Shunt Reg PCB came from, it's Home Brew. After talking to Salas he graciously let me use the original artwork for the Mesmorise which I cut off the B1 portion. For some reason my H.B. DCB1 wasn't at all reliable, probably down to a track shorting somewhere. I eventually kept the PSU part and reverted back to my H.B. Pass B1 with the huge Obligattos. Result is pure Nirvana.
 

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PKI

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I've changed 10uf capacitors in my B1: ClarityCap ESA --> WIMA MKP4 250v. I can tell that they are quite good. Very neutral, very! They really sound good! They are cheap (can be found at $15 pair shipped) and fits perfectly, leading spacing exactly as on the PCB. So, if you do not to spend much on Audio caps -- these are highly recommended.
 
Thanks for the build process 6L6. I have a couple of questions thou

I have the same switch as rabaird, a 6-way 2-pole from HifiCollective.

As I understand it the B1 has 2 inputs. I need to use all 6 on the switch. Do I wire all the inputs to the switch and use only one of the B1 boards inputs to receive the 6 switched inputs?

Also is it possible to have get 2 outputs from the B1 by wiring to both the boards inputs? Would help with bi-amping

Many thanks
 
PSU

Audio circuit schematic is in this article - http://passdiy.com/pdf/B1 Buffer Preamp.pdf

Audio board for sale here -- DIY Order Form

PSU circuit board - Universal Power supply PCB from Peter Daniel DIY Chip Amplifier Kits, PCB's, Components and Information. This product is not on his website, but email him and he takes care of it quickly. Lots more info on this board here - http://www.diyaudio.com/forums/audio-sector/149672-universal-power-supply-pcb.html

PSU regulator Schematic - http://cache.national.com/ds/LM/LM117.pdf

Hello guys.
I´m thinking built the B1 too.
Is this the PSU? I can´t open the file.
Have it enough filtering?
Best regards
Jose
 

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I think you mean wiring to the outputs. Just run the output from the B1 pcb to 2 output jacks.

I think you should maybe also have double output series cap/resistor

Tnx 6L6. So I wire 2x pair of phono sockets for the output. Does it matter if I do that series or parallel?

Hi tinitus - does that mean double up some of the parts from the B1 circuit or a little set on the output jack terminals?

I was thinking I could run 2x pair of wires from the input selector and run both sections of the B1 at the same time giving me 2x identical outputs. I think I'd need to do something fancy with the volume wiring thou. Was that dumb?