So I have this Bugera 1960 on the bench... When I first turned it on, it was loud as hell... I was scratching my head as to what the problem was... So I turned the amp off, then back on... BAM! it was half the volume... I turned it back off then on again, half volume... So I let it sit for a day... Came back and turned it on again and had full volume... Put the standby on, then switched the standby off and I had half volume.... It came in originally with a blown mains fuse and a bad tube... I replaced all 4 tubes with a matched quad and I've had zero problems with the power tubes... They all are on and have that nice blue glow inside... I have replaced the choke with a resistor, same thing... Full volume than half after I cycle the standby switch... Put the choke back in, same thing.... Replaced all preamp tubes with know good tubes.... Same problem.... Does it sound like maybe a cap? Coupling or otherwise? Maybe something in the phase invertor? Any replies would be most appreciated.... Thanks for looking...
Announcement
Collapse
No announcement yet.
Bugera 1960 half volume?
Collapse
X
-
Is it the infinium or not?
Have you tried it with a patch cord connecting the FX send to FX return?Originally posted by EnzoI have a sign in my shop that says, "Never think up reasons not to check something."
-
Whilst in half power fault mode, I would do some basic tests like check the bias current in each tube just see see if they are all making connection. Then I would check that each output tube grid is being driven - use a 1KHz sine wave signal generator on the input (or FX return), dummy load and scope or DVM on ACV with a 10nF 600V cap in series with one of the leads.Last edited by nickb; 01-27-2018, 10:37 PM.Experience is something you get, just after you really needed it.
Comment
Comment