Babelfish M25, SissySIT - general building tips and tricks

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Official Court Jester
Joined 2003
Paid Member
well , I can give you short explanation , pointing on some things I already wrote here and there ( in related threads)

or I can give you longer explanation .......

or , as maximally enjoyable variant for you , I can recommend - read first post of this very thread looking for linked related threads .... then read them all

:rofl:

let me know what you prefer ......

:)
 
SissySIT is a special DEFISIT where transistors are paired with Hall chips and opto-couplers .

As i know no single amplifier in the world has Hall current sense chips for a bias sense .

So.... the SIT 3 and DEFISIT may have nothing to do with this topic (except by SIT in the name) ....even sound ... because they say Sissy sound differently from SIT 3. :D
 
Official Court Jester
Joined 2003
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don't be nervous ...... if you're going to trust me :)

it's on par with my DEFiSIT

I have no original SIT-3 , nor my test iteration of same had Papa's Golden Touch , but I'm finding DEFiSIT better sounding ( sweeter , more agile) than (mine) SIT-3 , when driving speakers where 8W is enough

where more is needed , well ..... SissySIT is having 18W :)

so , if you take SIT-3 as some kind of goal , this is best thing instead

there are aso several other possibilities , mainly thinking of varying input stage topologies , sans or with overall NFB ...... but I really like this approach with xformer and all

tried driving same OS with ubermambojumbononeTHD FE , but magic is not entirely gone , but of lesser amount for sure
 
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Joined 2007
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don't be nervous ...... if you're going to trust me :)

it's on par with my DEFiSIT

I have no original SIT-3 , nor my test iteration of same had Papa's Golden Touch , but I'm finding DEFiSIT better sounding ( sweeter , more agile) than (mine) SIT-3 , when driving speakers where 8W is enough

where more is needed , well ..... SissySIT is having 18W :)

so , if you take SIT-3 as some kind of goal , this is best thing instead

there are aso several other possibilities , mainly thinking of varying input stage topologies , sans or with overall NFB ...... but I really like this approach with xformer and all

tried driving same OS with ubermambojumbononeTHD FE , but magic is not entirely gone , but of lesser amount for sure

That's very reassuring ZM
 
Hi,

I am making the SissySIT and would like to ask some questions:

1. What is the initial setting value for P2 (OFFSET), zero or max?

2. What is the value of C5? It is marked 10uF in schematic but you gave 22uF in your kit.

3. All zeners are 7V5-9V1 in schematic. What exact value should I use?

Thank you.
 
Slow progress on my part , I took a little time over the holidays to try and get some of the case work done as this requires the most hours and noise

a few steps along the way








Assembled an AMBLABS e24 to use as a trigger for powering up the transformers






getting it all wired up





and finally completed a little more of the wiring so that I can test the power supplies - discovered that I have plenty of fuses but no spare fuse holder , so now I have a good excuse to continue soldering the boards.






And little Mu hats for the cinemags in case they hum like the M2X




..dB
 
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I am using a F4 bought (on here) completed for my Sissy Sit. I am in the process of converting to dual mono. I didn't consider my new psu boards and connector blocks would fail to line up with the holes in the Modushop tray. It's a pain and messy having to drill in between the pre-drilled holes of the base. About time the whole world went metric if you ask me.