Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Steve S. on January 15, 2012, 05:25:45 pm
-
Hello
I am working on a Silvertone1484 which belongs to a friend of mine. The amp has been sitting unused for quite a few years. I replaced the filter and bypass caps, put in new tubes, jacks and a few other odds and ends. The amp works well now except for the reverb, the tank appears to have a bad transducer.
The problem is with the tremelo unit. It works well but when it is turned all the way off you can still hear a faint tremelo effect which is as though the speed is up all the way. Turning the speed control while this is happening has no effect one way or the other.
Grounding the footswitch has no effect. The control pots test good as far as resistance goes. If you remove the tremelo tube the effect stops and there is a noticeable rise in volume.
One by one I tried disconnecting connections on the tremelo tube to try and isolate where the effect was coming from. The only thing that stops it is to disconnect the plate on the second half of the tube, the one that connects to the oscillator. Also , disconnecting the cathode stops it. I currently have a switch wired to the cathode which works but I'd really like to figure out the problem and not just put a "bandaid" on it.
I own a 1484 in really good shape, so I've been able to compare voltages and other readings between the two. Everything seems to be within normal range on the problem amp.
Thanks for your help.
Steve
-
Someone who I can't remember had a 1484 vibrato problem recently and they solved their problem by re-arranging lead dress or seperating wires that were too close together. So if you haven't tried it all ready you might get a chop stick and seperate some tremolo related wiring to give them their own space so to speak and see if that helps. Platefire
-
Someone who I can't remember had a 1484 vibrato problem recently and they solved their problem by re-arranging lead dress or seperating wires that were too close together.
It was Loose Change. Look in here.
http://www.el34world.com/Forum/index.php?topic=12807.0 (http://www.el34world.com/Forum/index.php?topic=12807.0)
Brad :icon_biggrin:
-
Thanks for responding
I had already read that post and tried the lead dress approach, no effect on the problem.
Steve