thanks guys for the answer, i finally got confirmed whit what i always had in my mind.
well for the blowing up part, it was a faulty diode in my bridge rectifier, which allowed to destroy more.. i think... havent tested much further in the circuit.
the project is a experiment from, yes china! as i have a variable bench supply (really old one) i wanted to test how bad is this DIY China stuff might be... (not bad actually 1% resistors came with the kit, quality through hole PCB, and if you replace the dodgy looking components (like the transistors and pots) for quality ones you end up with a not the best but semi good project!)
Specs:
input: 24Vac 3A
Output: 0-30Vdc 2mAh-3A
if you guys want more and help give me a heads up so i can provide more data
!
for now i'm going in with the old multimeter and gut feeling! (as i still lack a scope!)
List of Components:
R1=2.2K 1W C4=0.1uF(104)
R2=82R C5=0.22uF(224)
R3=220R C6=100P (101)
R4=4.7K C7=10uF/50V R5?R6?R13?R20?
R21=10K
C8=330P (331)
R7=0.47R 5W C9=100P (101) R8?R11=27K D1,D2,D3,D4=1N5408 R9?R19=2.2K D5,D6=1N4148
R10=270K D7,D8=5.1V ZD R12?R18=56K D9,D10=1N4148
R14=1.5K D11=1N4004
R15,R16=1K Q1=9014
R17=33R Q2=2SD882
R22=3.9K Q3=9015
RV1=100K 3296W Q4=2SD1047
P1,P2=10K B U1,U2,U3=TL081
C1=3300uF/50V D12=LED
C2,C3=47uF/50V