Babelfish M25, SissySIT - general building tips and tricks

[Zen Mod]

What's wrong with simple kiss , boy?

I hope you're going to have general PSU for that drek ....... take two wires and one resistor from there

spoiled Greedy Boyz are wanting even LED on PCB ......

 

[noelectrix]

knew it´s chicken question, but I am chicken 🙂, wasnt brave nor smart enough to simply put it between +/gnd with few k Resistor,
tnx
st.

 

[Zen Mod]

thumb of rule :

(rule of thumb is so boring )

1K for each DC volt

then , with nowadays hysteric LEDs , if too bright - ad 50%

if it's Dodo , polarize it the other way

🙂

and yes, plain 600mW MF resistor is going to be cool , with LED as load

 

[noelectrix]

can i hang A0 Poster from this post in my Studio?
Maybe i´m too amateur for M2 circuit Poster 🙂

best and tnx!
st.

 

[Zen Mod]

well , nice that you remind me ...

must check/make M2 and Babelfish M25 and SissySIT files for posters

though , Mr. MR's are those I saw and got idea (even if he's using some sissy circuits from Treshold era ..... )

 

[sontero]

Hi ZM
the sink visible in the photos: what is it? physical dimensions.
also the inner baseplate: physical dimensions?

 

[Zen Mod]

local to you - Modushop

their Swiss Knife case for FW format amps - 4U/400 , with inner base for 400 deep cases

works as charm , more than decent quality , and hard to beat money/quality ratio

Wakoo 'Talians



pic (even if I think this one is for 5U/400, but you'll catch it) :

An externally hosted image should be here but it was not working when we last tested it.

 

[sontero]

yes ...of course Modushop is my target 🙂

heatsink 5U = height 210 mm
heatsink 4U = height 165 mm

I would say that 5U is adequate for the right dissipation

 

[Zen Mod]

4U/400 is enough for targeted dissipation , whatever you set - 70-90W per side

though , with hot summers ........ I believe nice Babysitter is making more difference than going from 4U to 5U

4U/500 would be real gem ..... but there is no 500 , without resorting to 5U

 

[noelectrix]

Grg, I have a problem, i set the pots as said in schematic. R6 max value , what measures about 23 Ohm across pot. R7 set at 0 Ohm.
Than i powered it up, Multimeter across R8, set for 200mV DC, and it instantly gave me the Diode-Test tone for ecceeding the measurement limit. Powered off instantly, dunno, i got to recheck everything tomorrow.
@ ZM: Potsetting schematic is right? Du you think buffer went dodo now?

srry for trouble

 

[noelectrix]

could it be normal, going from up to down? lookin at the voltage divider (pot/R8) as i understand it, it could be...
lets hope!!

 

[Zen Mod]

gimme pictures please

if you mount everything as intended , 200mV is way too much , of course

check your JFets (both groups ) with resistance/diode check , and let me know what's readout

I'm going to type some things tonight, to edit first post ...

 

[noelectrix]

damned, having had some hope,

will post pics tomorrow, amp is not at home.

tnx,
st.

 

[noelectrix]

Didn´t realize that 2SK 2145 Bl has 2Gates and 2Drains,
Could you give me Diode/Resistance test advise?

tnx!

 

[Zen Mod]

with everything powered off and JP not closed, measure resistances as shown

you can set ohmmeter either on 200R or higher , or on diode test position

 

[noelectrix]

sorry , had to go out for an opening.
1000 tnx, will do humble research tomrrw...

 

[mikorist]

myths and legends

AHA, xformers myths and legends BY Hans Christian

 

[noelectrix]

I just hooked up (messed up) left channel, so here are the testpoint figures
Input shorted!


figures on right channel are 11Ω and 12 Ω

 

[Zen Mod]

give me few hours, chill in a meantime

 

[noelectrix]

i give you days also, don´t expect you sitting on helpdesk all day : )

meanwhile i try to get cable for camera, me stupid forgot it. And then going examine solderpoints on bottom side.

tnx!