Hi All
I KNOW this is not an audio forum, but can I toot my horn for an old friend???
I have had this Bogen J330 amp for a looong time. 6L6 finals. Audio quality was ok. Tone controls were broad and didn't mean much, but I was happy with it.
It was time to look into the broad adjustment of the bass and treble controls and do a capacitor change-out. Crackling sounds every now and then..
Replaced the usual coupling caps and power supply caps. The cathode resistors for the 6L6's were way out in left field.
Replaced the 6L6's and dug into a really crappy design of the tone control. Got scheezo from ePay.
So I looks on the google for tone controls for tube circuits and saw many flavors.
I picked the Baxandall...............
http://amps.zugster.net/articles/tone-stacksand copied that circuit into the Bogen.
And I did a Timtron and changed a really high value cap in a pre-amp cathode (6SF6) from .033mf to a 50mf electrolytic.
MY GAWD!!!!!!! I have never heard this amplifier/P.A. reproduce low end or high end like this!!!!!!! It was like being 'born again'.....Typical wonderful tube sound.
I use this amp as the monitor amp for anything that is called radio. The Flex, R390A diode load, etc etc. It drives a Radio Shack bookshelf speaker with a 12 inch woofer and midrange. The tweeter died a long time ago.
Fred