Sorry guys
I've been very busy ... a lot of work. These vintage tube are a passion..a hobby for me..a fantastic hobby. Since June my scott 99c is standing on the bench.
So. Last night I decided restart work on it.
Remembering.
The problem Started like this.
I was listening to My Scott 99C, 70% of the total power.
At one point, I heard a small winch and the amplifier was muted.
The amplifier remained on, with the filaments lit.
I power off immediately. I felt a faint smell of burning ...
Thanks Century and Cademann for the latest posts.
The R54 is separated. There are 3 individual resistors. I checked all 3 (on circuit), and all are OK. It still replaces the R54C for testing. I tested R46too, and it is fine.
R46 and R47 should both be present? When i am looking for a diagram, there is something like a cut on circuit....
link to scheme here:
http://www.acousticpsychos.com/Files/H. H. Scott/Scott_99c.jpg
The situation now is this. I'm afraid to power on direct on the wall (117VAC). So, i removed all tubes, and connected it a Dim Bulb Test (60W).
Result. Without rectifier tube, VAC voltages from power transformer are OK.
After, i installed a rectifier tube, and stills using a Dim bulb test. The B + now is just 13VDC before the R54C (5U4 8 pin rectifier tube). After R54C the B + voltage is 12.0VDC
I did not try power on direct on the wall.
Can you help me to find where is the problem?
Regards, and thank you