hi everyone!
last weekend i finished my first cornet 2, i'll describe the final steps of the building:
- AC is 222 VAC so i decided to connect 370BX transformer to 220V, correct?
- transformer is not connected to ground PCB or binding post
- i installed a slo-blow fuse 0'5A
- i used metal standoffs not connected to ground binding post
- Earth from IEC connected to ground binding post
- PCB Earth quick release terminal connected to ground binding post
- RCA in&out ground (not the tip, the ring) connected to ground binding post
I switched ON, no smoke, no burning, RED LED turned GREEN in 5-8 seconds then:
-12AX7 (both are Sovtek) and 5Y3GT (TAD) started glowing, very nice
-12AU7 did not glow as much as other tubes, only a few
i measured voltages on PCB and i found the next image
http://www.audiocircle.com/index.php?action=gallerylastup&cat=0&pos=0i found it strange (values marked as 1) so i change the position of the 12AX7, the first stage tube put it on the second one and viceversa and i measured voltages (values marked as 2)
sorry because my english is not very charming, so if you don't understand something i'll explain it again
Can anybody tell me what's wrong?
may be 12AU7, may be some cap or resistor?
i double checked my work but i'll do it again to be sure is not my mistake
Thanks everyone!!!