B1 Buffer Preamp

Official Court Jester
Joined 2003
Paid Member
I confess - it was same for me first time when I made it ........

(even if I didn't had date with exactly her :rofl: )

........ yrs ago - trying buffers of JLH , Curl , Borbely etc.

in any case , revelation was when I tried Allen Wright's SLCF - most vivid thingie I tried

vividness is following that approach with whatever you make it - sand or glass or mixed
anyway - what differentiate B1 from SL Follower is just one (bjt) cascode on top of upper Jfet...... and better CCS down
 
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Official Court Jester
Joined 2003
Paid Member
naah

that's hi-voltage thingie ...... no need for that

whatever - you need somewhat elevated B+ (say 20-25V) ,BC546 as cascode above upper jfer placed at 12-15V ;

you can leave lower Jfet as is , or replace it with Widlar CCS , with multipot for setting

I told ya - I'm lazy for puter drawing , and I need new scanner

whatever - main obstacle is that I have some things to finish tonight and tomorrow ..... going to see my Yoda (Manu) early morning Friday
 
take your time l'ami ! today i just put a 40ohm R before the 15000uf Cap to make a RC filter no change , then swapp the output series Kiwame 240ohm Resistor what makes a big change , better bass , dynamics , everything pops.. ( no oscillation with a 20K / 40K square wave)

i keep the 240 kiwame input ( for the moment!) :D
 
Fitting Obligattos to B1

I have been asked how I fitted the Obligatto 10uFs into the B1.

I used a clone of the full Pass B1 build, which uses a huge PCB when compared to the Salas B1 and DCB1 boards.

The PCB is big enough to accomodate the huge Obligattos with the leads looped under the board and connected underneath the board on the copper track side. I also fitted two cap clips to hold the big caps in place.


If you want to do this mod. to the smaller Salas boards you will need to short out the output caps on-board and fit the SODA CANS away from the board.
 

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B1 with 240 ohm???

take your time l'ami ! today i just put a 40ohm R before the 15000uf Cap to make a RC filter no change , then swapp the output series Kiwame 240ohm Resistor what makes a big change , better bass , dynamics , everything pops.. ( no oscillation with a 20K / 40K square wave)

i keep the 240 kiwame input ( for the moment!) :D

Hi Juanitox!!:)

This turn on the B1 seems interresting... but after my schematic and the one I see on Passdiy.com there are no 240 ohm resistor neither on the output or on the input??:confused:
I wonder if you mean the R204 that is 1Kohm - that is the one you are changing with the Kiwave-resistor?

Now I have moved my BIG Obligato10uf to the SIT so there are no output cap and maybe a new Kiwave on the input AND output of the B1 can keep the sound even more touchable?

Is the sound you get worth a try Juanitox???

Best from a guy out in the open NorthSea

Olav