Babelfish M25, SissySIT - general building tips and tricks

Official Court Jester
Joined 2003
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some input xformer trickery

as already mentioned - with Cinemags there is some trickery necessary , to put them on pcbs

pins 1 and 2 are closer than other ones , so you know which pin 1 is - red dot on pictures

cut pins 1 , 6 , 7 and 12 , then you can mount Cinemags on pcb ; as you can see , on both channels pin 1 is near pcb edge

also pics of Edcors , Cheapskate Champions (one of cases where article is cheaper than shipping) - they're oriented with 180deg difference between channels ; pinout orientation pretty clear and straightforward , so no biggie there
 

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Sissy does not like me :bawling:

Problem with right channel:
This time setting Iq for buffer was almost straight forward. I just didnt get offset to zero and had to increase Iq to 22mA. Trick could be to increase upper R27 to have more headroom?
Then inserted JP, but turning on Iq pot did increased (U over R0.1) from around 4mV to just 5.6 mV to the end of pot, offset increased to almost 15 Volts.
Got me a bottle of wine to the studio to celebrate stereo this night, but this must wait (stereo, not wine).
Will of course recheck da hole thing tomorrow. Its really not that i watch series while stuffing PCBs, but this time i´m troublemaker.

It´s late ZM, i´m happy for your thoughts in time : )
best
st
 
Official Court Jester
Joined 2003
Paid Member
well , troublemaker or not , I'm sure you'll find what's the culprit

it could help if you post some pictures , if you don't find it straight away in the morning or so


regarding source resistance .... I did check about dozen or so JFet groups and in all cases 27R ll 100R pot combo was adequate ..... but it seems that switch to 39R ll 100R pot will cover all possible Idss cases

I did some editing of post #1 , will proceed .....
 
Official Court Jester
Joined 2003
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i made that supernice cableends i saw in your pics, from soft wire with hard wire end, i used laquered 1,4mm, i of course sanded
them but they seem to be cold (soldered) even if solderpoint looks nice,
thats work for now : )

explain , what you mean - which cable ends I made ?

those shown in this very thread are nothing else than regular cables stripped on ends little longer , then covered with heatshrink - simply because I hate to see even slightly melting cable isolation ....... heatshrink is just even more shrinking , and still looks nice :)