Pumpkin preamp - ordered by Steen , official making thread

hershann said:



Anything needed to be changed on Shunty if I use a 36v-0-36v transformer? Found a 72VCT 50VA transformer that is much smaller than the 250VA 84VCT I found earlier - but I guess 50VA might be too anemic.

I do not need that much gain planning on 5 or 7 - so a lower max voltage swing does not matter.

Still looking for suggestions for good source of EI transformers - only sinker is that I am going to need 240V primary.

her shann

for Shunty:


change one of zenners (in D1 - D5 string) for 4V7 , so - you'll have ~ 40V after Q2

set (with WR1 ) output voltage to 30V

in case that you can go so low - increase R9 to 7K5

same procedure for negative side of Shunty

you'll be fine even with 50VA , just look is it too warm .......... in case that these 50VA aren't real 😉
 
Magura said:



Magura 🙂 / whom is contemplating the option of making a new rear plate for Steens pre box.

That sounds really cool 🙂

ROVSING said:
Zen Mod said:



you two are crazy danske & dutchie

Wonder if those ALU flatbars will be replaced with something like this ?

🙂


There is a great chance for excactly that to happen😀
How did you figure that out😕

🙂
 
Magura said:

Magura 🙂 / whom is contemplating the option of making a new rear plate for Steens pre box.

Steen, you're the man! I knew it.
I still wan't to see the frontplate :smash:


Work in progress almost finished.
(Not speaking of the casing. I think I will follow Holgers suggestion on german fora : buy a ML 32S. Throw away the inside ... (Holger : ich scherze nur.
Nice INt 150 review BTW.
I like your style.)
Just waiting for some missing caps for shunty.

manu
 
steenoe said:

Dude, my shadow solders faster than me.
Me just finito the Shunthings, they operate ok(despite having half the junk soldered on the Sponge Bob side)
I had to call in the cavalry to identify the pass devices, me saving Fairchilds for better use.
(a sadist would request a blind person to sort some semis, then hand him a bunch of virtually blank IRFs)