hi all, i have buit a B1 buffer P2P with ZM mod ( balanced supply and no signal Cap) i understand the 4x 240 ohm for the input and output oscillation but what is for the 1M output to ground ? can i leave them too ?🙂
An externally hosted image should be here but it was not working when we last tested it.
hi ZM it is yours and it works fine !! ( PASS B1 ZM mod) but with 2 regulator and without output cap has my sit have one at the input. so my question is as i have no caps do i keep the 1M output resistor ? 🙂
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keep it , just in case
buffer output doesn't care for it , but it's handy in case that succeeding stage (whatever it is ) have some residual DC
buffer output doesn't care for it , but it's handy in case that succeeding stage (whatever it is ) have some residual DC
thanks ZM and thanks mr PASS the silence of this preamp is just incredible with just a 15000uf C filter and a pair of 15V regulator .. brillant as usual ! 
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as always , I'm here to serve
...... and protect
(even if I must confess - B1 is so boring that I'm raaaaaarely reading da thread)
(me likee more SLCF type things - funnier to make)
...... and protect
(even if I must confess - B1 is so boring that I'm raaaaaarely reading da thread)
(me likee more SLCF type things - funnier to make)
sorry to hear that, for me building this in one afternoon is as exciting as my first date with the baker daughter 😀
I confess - it was same for me first time when I made it ........
(even if I didn't had date with exactly her )
........ 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
(even if I didn't had date with exactly her
)........ 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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nope ............. and many
visit us these dayz in da pub and remind me to draw it
I'm having PITA lately drawing schm , because my trusty scanner is refusing to work under 7-th Schweindoze
visit us these dayz in da pub and remind me to draw it
I'm having PITA lately drawing schm , because my trusty scanner is refusing to work under 7-th Schweindoze
i have some lundhal cascode CCS here , best is to use it in place of the 15V reg on the upper jfet or down in place of the -15 reg ??
gime some works for tomorrow ,,, 🙂
gime some works for tomorrow ,,, 🙂
some of these CCS
( DN2540N5 and IXYS IXTP01N100D depletion mode MOSFET)
is it good for the upper JFEt after or in place of the Regulator?
An externally hosted image should be here but it was not working when we last tested it.
( DN2540N5 and IXYS IXTP01N100D depletion mode MOSFET)
is it good for the upper JFEt after or in place of the Regulator?
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
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!) 😀
i keep the 240 kiwame input ( for the moment!) 😀
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.
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.
Attachments
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B1 with 240 ohm???
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??😕
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
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??😕
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