Babelfish M25, SissySIT - general building tips and tricks

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#106
noelectrix said:
today it´s not really about amp, its about bad source/cable.

I went to Conrad today to buy the 39R's to be able to trim the frontend right. Worked great btw! Aditionally i bought a minijack to cinch-cable (a extremly cheap one!) to replace the one in studio i stole frome home.

then, after rebiasing more subtle and istalling the cinch sockets i left out in the hurry, i went to the listening. stage, magic, was gone..i rechecked everything, thought i damaged something. i really was puzzled, but in the end had the stupid not so stupid idea to change back the cable to the first, better one, and magic was there again. It's still just laptop-cinchcable-amp, so not a good set, and never have been a cable fanatic, but todays lesson was clear : ) (being honest, i still can't believe it in that explicitness..)
just to share 🙂
Click to expand...


speaking about interconnect cable ?
 
#109
100 feet : ), i´m open, but that's a little too much.
For IP SE i bought some predrilled black/neutal ultrathin copperwire, and i still trust in quality of laquered thin copperwire. I like that colorcoding, but now unshure if quality is good there either. Bought from Hobby store to connect LEDs in miniature Railway thingie.. : )
 
#113
PSU

my habit - custom made Donut - always asking for decreased flux in core , which means more turns per volt than usual jobbie

300VA , separate 18Vac secondaries , one per channel

static shield , magnetic screen

filter - CRC , made of 33mF-0R1/WW/5W-33mF , per rail

yup, one Graetz bridge per secondary , so two per PSU

meaning that - when case is common , you'll have just IEC and switch shared between channels , after that NTC (CL-60 or equivalent) in series with primary and one fuse per primary

then 10-15R NTC from audio GND to chassis , safety GND of chassis is mandatory

as illustration - Papa's drawing from F6 article

EDIT: Member requested an edit to 'is mandatory'
 

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#117
dear ZM with the last update to post # 1 you finally answered my incessant question "Bias procedures .... bias procedures ... BP .... beep" . now you have finally turned off the alarm that had been lit for quite some time.
Now the picture is complete .....
really .... thanks for your great work:cheers::worship:


PS=another little question .......
why not use a "soft start" instead of NTC?
 
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#118
of course you can use soft start instead of NTC ;

but - as I'm always saying - to get really soft soft start - replace all fixed series** resistors with NTCs .... no more than 30R in sum value

**some are making soft start with paralleled resistors , which is recipe for .... not exactly disaster , but certainly non-functional soft start

edit: your avatar - Giger ?
 
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