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JFET BoZ (Bride of Zen by Nelson Pass)
http://diyaudioprojects.com/Forum/viewtopic.php?f=10&t=2740
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Author:  mwhouston [ 28 Nov 2010, 01:43 ]
Post subject:  Re: JFET BoZ (Bride of Zen by Nelson Pass)

I have to strain the brain back a bit but I would say much better. OPAMPs, like so many other devices, have a certain sound. And though often it may be very pure it is not always that musical. BoZ is very musical.

With BoZ it was probably the first time I could actually imagine the singer in front of me and not just hear him or her. I can't remember ever feeling that before. I may have a spare one soon.

Author:  KrammeAcoustics [ 29 Nov 2010, 15:38 ]
Post subject:  Re: JFET BoZ (Bride of Zen by Nelson Pass)

Hi Mark

Will the BoZ be a good match for the ZCA? Maybe this is the way, you already are using it ?

I think it was the combination ziggy, were showing here

Author:  mwhouston [ 29 Nov 2010, 15:42 ]
Post subject:  Re: JFET BoZ (Bride of Zen by Nelson Pass)

I have only used BoZ with my SET amp. Not sure if I will get a chance to try it with the ZCA. Very pleased, as you can tell, with BoZ's performance.

I critical listener is coming over today so I will see what he thinks. Others from the club like it a lot. Build one. I can help with the PS.

Author:  mwhouston [ 01 Dec 2010, 15:55 ]
Post subject:  Re: JFET BoZ (Bride of Zen by Nelson Pass)

It was suggested on other forums that you run BoZ on less than the Pass recomended 35V. I have been running mine on 18->19V from batteries. Of course when the batteries are new they are a little over volts but soon settle to 19V. I use four 9V lithiums in parrallel and series

What happens though when the voltage falls to around 18V, which can happen in a week of use, BoZ gets distorted. It is very easy to hear and it happens pretty quickly. What may be better is to say run BoZ on 27V. So three 9V in series with three in parrallel. You know what I mean.

Of course building a mains PS is the best answer. I have done this with two others BoZi working them on 30V with good effect. I may post the mains PS soon. Better still build myself a mains PS.

Author:  dtsup1 [ 01 Dec 2010, 22:28 ]
Post subject:  Re: JFET BoZ (Bride of Zen by Nelson Pass)

Mark,

I am going to build the simple BoZ with the 1uF and 10uF caps as suggested. Can you please post the PS schematic in CAD form. Your CAD diagrams are very clear - as used for ZCA/chipamp schematics.

I'm still waiting for some parts - a 10K and 50K ALPS blue velvet ordered from Germany. 11 Euros !
I can still use the BoZ without the volume control on my Mede8er player.

The combo will be BoZ + aussie amps and Boz + Symasym amp.
Will be superb!! hahahaha

Author:  mwhouston [ 02 Dec 2010, 01:01 ]
Post subject:  Re: JFET BoZ (Bride of Zen by Nelson Pass)

It may take a few days to knock-up. I'm still fixing a PS in a tube amp I sold years ago.

Author:  dtsup1 [ 02 Dec 2010, 02:26 ]
Post subject:  Re: JFET BoZ (Bride of Zen by Nelson Pass)

Thanks! In the meantime I'll get the parts for the simple BoZ. A short trip to the store should suffice.

Author:  mwhouston [ 10 Dec 2010, 01:34 ]
Post subject:  Re: JFET BoZ (Bride of Zen by Nelson Pass)

I promised a schematic of my remote (external) PS for my BoZSE. This is the same PS as I have used with the non-SEs. There will follow a much upgraded PS but this one works, is dead easy to make and keeps the naughty AC power away from the preamp active bits.
Attachment:
BoZPSss.jpg

This PS is remote with about a meter of a medium weight cable between it and the preamp. I also placed a small ferrite choke on the power lead at the preamp end. The PS produces about 30V.

Author:  mach1 [ 12 Dec 2010, 19:50 ]
Post subject:  Re: JFET BoZ (Bride of Zen by Nelson Pass)

I find the small (10mm x 10 mm) cheap green pots from Jaycar to sound better than ALPS blue. Perfect for this application. :thumbsup:

Author:  mwhouston [ 13 Dec 2010, 02:17 ]
Post subject:  Re: JFET BoZ (Bride of Zen by Nelson Pass)

mach1 wrote:
I find the small (10mm x 10 mm) cheap green pots from Jaycar to sound better than ALPS blue. Perfect for this application. :thumbsup:

I know the ones you are talking and have used them before. I think they are Ok but I bought a number of Apls so I'm sticking with them.

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