Babelfish M25, SissySIT - general building tips and tricks

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Joined 2003
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100R
4K7
5K6
1N4148
6N139
10uF/16V (even 6V3 is enough)

all resistors can be even 1/16W

Will your M25/Sissysit boards eventually be offered with these modifications on the board?

If so, or maybe even if not I am inclined to build M25, (proven stable without mods) which is what my kit was for initially. I would buy transformers and power supplies as if building mono blocks, reserving transformer and one supply for eventual Sissysit build.

At that time, buy additional chassis, use reserved transformer and power supply and convert them to half M25, haif Sissysit with switch to shift power supply to one board (M25) or the other (Sissysit) like another member did with his M2 and Aleph J.

Many advantages (mono block configuration) and only one disadvantage I can think of, not being able to use both different amps in two different systems. Heaven knows I have a spare amp or two.

But, before I buy another set of boards, will they be available with these mods on boards, or will this always be add on? If always as add on, will build Sissysit first.

Thanks,

Russellc
 
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Joined 2003
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One other question, at risk of once again demonstrating the depth of my not understanding.....

I have two matched sets of the required sits from Prass. Does this amp function with 2 sits on each side, rather than sit/mosfet mix, or (as I assume) the magic in the mismatch? (not to mention the special tidbits and opto workings)

Why I would do this I have no idea, just popped into mind when Zenmod was discussing nature of mismatch (between mosfet and sit) causing bias drift upwards, and how M25 didnt do this.

Ouch,
Russellc
 
Last edited:
One other question, at risk of once again demonstrating the depth of my not understanding.....

I have two matched sets of the required sits from Prass. Does this amp function with 2 sits on each side, rather than sit/mosfet mix, or (as I assume) the magic in the mismatch? (not to mention the special tidbits and opto workings)

Why I would do this I have no idea, just popped into mind when Zenmod was discussing nature of mismatch (between mosfet and sit) causing bias drift upwards, and how M25 didnt do this.

Ouch,
Russellc

The SissySIT needs opposite sex devices, so does M2 (M25). The F6 uses same sex devices. So that may work if you can figure out the bias, etc.

Rush
 
Official Court Jester
Joined 2003
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so , you've got your answers .......

this one as completing one :clown:

from now on , pcbs for Babelfish M25 and SissySIT will not be the same one
 

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Official Court Jester
Joined 2003
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everything stays the same for existing pcbs , and little pic tutorial is going to be posted in few days , taking care of existing parts nomenclature

schmtc from post #1500 is a guide , and if one is confused with it , simply ignore it

regarding SIT gate resistor - in general - if wires are short between SIT gate and pcb , gate resistor (100R) can be placed on pcb

if wires are of liberal length , use 0R in place of pcb gate resistor and add fluying gate resistor , soldered at SIT gate and heatshrinked with wire

one can use both , in praxis , without too much thinking ........ and problem could arise only in case of leaky SIT gate ........ when problems are there , anyway
 
Official Court Jester
Joined 2003
Paid Member
which means - you have lousy mains

remember that SIT is not nicely behaved part when rail is going up or down :clown:

sole solution is - regulated rails .......... :rofl:

and I don't like that ...... besides - resulted DC offset drift is small enough for me not to worry

change phase for your FiFI gadgets ...... try to find one free of Cousine