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Old 19th June 2013, 11:59 AM   #691
AmpUtator is offline AmpUtator  United States
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Love all the pics. Looking forward to getting started on a B1 build.
Glad I joined
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Old 24th February 2014, 07:17 PM   #692
nikosokey is offline nikosokey  Greece
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Default B1 BUFFER

this is my B1 Buffer .
Pcb its from gerber fille .
2sk 170 matched to 7.8 ma at 640 mv vgs
10mf-1mf Audiophiller
JLH Shunt Reg at 22V
LM 317 at 22.10 V
Two separate pots 25kΩ
Attached Images
File Type: jpg IMGP2401.jpg (980.8 KB, 429 views)
File Type: jpg IMGP2385.jpg (1,000.5 KB, 417 views)
File Type: jpg IMGP2235-1.jpg (5.9 KB, 433 views)
File Type: jpg IMGP2236-1.jpg (5.5 KB, 432 views)
File Type: jpg IMGP2239-1.jpg (5.5 KB, 430 views)
File Type: jpg IMGP2241-1.jpg (5.5 KB, 433 views)

Last edited by nikosokey; 24th February 2014 at 07:38 PM.
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Old 25th February 2014, 01:35 PM   #693
thomasnadeau is offline thomasnadeau
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Do you have a reference/BOM for the chassis? That looks fantastic.
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Old 25th February 2014, 05:50 PM   #694
generg is offline generg  Germany
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B1 builders thread
Originally Posted by Earthloop View Post
Hi all,
I’ve recently built a B1 using a Pass DIY PCB and have been listening and experimenting with different capacitors. I have tried some audio grade MKP types from Maplin on their own and with low value (100nF) bypass caps and also some Mundorf aluminium – oil types from Hifi Collective wih and without the bypass capacitors. All combinations sound different with the ally – oil types on their own sounding nicest.
The B1 is powered using a simple linear regulator circuit with a John Linsley Hood shunt regulator across it giving about 18.6 volts. I am quite a fan of these shunt regulators and have been using a pair on the supply to a Linsley Hood discrete component shunt feedback phono stage for nearly 20 years and they made an impressive improvement to the sound (using a low output moving coil cartridge) when I added them.
Anyhow, I have to agree with KatieandDad’s opinion that the sound lacks excitement. It’s as if the “attack” and dynamic impact of the music is diminished. Also the stereo soundstage has somehow shrunk. I had a long listen last Sunday afternoon and eventually re-connected my 26 year old (it’s older than I was when I bought it!) Audiolab 8000C preamp and WOW excitement, dynamics and attack have returned and the stereo soundstage is now huge, 3 dimensional and well out of the speakers again. I’m using 2 Pass A40 monoblocks which I finished earlier this year. I was wondering if anyone may be able to shed any light on this or if KatieandDad managed to cure their B1 and make it sound as good as it should? I have included a photo with the Mundorfs fitted.
I had the same impression…..

and I decided to look at Nelsons commercial product well reviewed.

That means the classic circuit but the caps Nelson recommends in the B1 pdf himself

- the Vishay metallized polyester 1uF caps for the input

- the Axon 10uF for the output

This combination was the only one that had magic to my ears.
They but the B1 a bit on the dark side, blow up the stage….so if your system is already on the dark side this might be too much, if not highly recommended.

for me the most convincing example that caps form sometimes a better sound.

and these caps are cheap!
and the First Wtt is......a really First Class PSS Idea

Last edited by generg; 25th February 2014 at 05:54 PM.
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Old 25th February 2014, 06:29 PM   #695
nikosokey is offline nikosokey  Greece
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Υes is half cut metal drawer. I'm serious.
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Old 14th July 2014, 12:11 PM   #696
alfred wan is offline alfred wan  Malaysia
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Generg. Nice looking caps!!
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Old 14th July 2014, 12:57 PM   #697
jameshillj is offline jameshillj  Australia
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Earthloop, have you tried lifting the voltage, above 20 volts?

And those Mundorf caps take ages to start sounding good - well over 100 hours of signal use - sound quite dull and lifeless for first 50 odd hours.

The B1 is so simple that anything/everything connected has some effect on it's sound quality - the supply, the resistors, those caps, even the connecting wires, the interconnects - everything - a great opportunity to 'tweak' it any way you want.
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Old 27th April 2015, 03:03 PM   #698
vdi_nenna is offline vdi_nenna  United States
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B1 builders thread Send a message via Yahoo to vdi_nenna

Does anyone know how to add additional inputs to the original B1 board?
Saw photos a long while ago that used jumpers on the board and a rotary switch for more inputs. I can't find the photo.


I build, therefore I am.
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Old 27th April 2015, 04:02 PM   #699
1108 is offline 1108  United States
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Here's what Jim (6L6) did for me. Worked great.
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Old 27th April 2015, 04:46 PM   #700
6L6 is offline 6L6  United States
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B1 builders thread
The photos in my build show it reasonably well.

B1 preamp build thread

PKI's photo is great -

Click the image to open in full size.
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