Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Diverted on October 09, 2019, 02:25:05 pm
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Hi all,
I want to build a single channel AA964 Vibrolux Reverb, and I plan to put it in a Princeton Reverb chassis which is a few inches shorter than the correct chassis.
My question is about running the leads out of the output transformer. I am trying to keep the size down and will put the speaker (single 12) roughly in the middle of the cabinet. So my thought was to put the power transformer transformer in the usual spot, put the choke next to it and the reverb transformer in the normal spot. That leaves the output transformer, which I thought I would put all the way over on the opposite side of the chassis to make some room/clearance in the middle for the speaker.
The transformer has leads that terminate on the bottom, not the sides. So it's designed to run them through a hole into the inside of the chassis. I am wondering if I will have issues snaking these wires from one side to the other of the chassis, directly under the circuit board.
Would I be better off putting the output transformer on small spacers to elevate it above the chassis half an inch or so, and then snake the wires on top of the chassis to their final destination?
Thanks!
Ted
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Running OT plate wires through all the low-level stages is really begging for trouble, incurable squeal.
Find another plan.
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I can attest to what PRR says. I had volume cutting out when maxed and squealing when i routed my OT wires near V1 and under the board there.
I did get the wires routed between the PI tube and the power tubes because there ample space there, and no more troubles. ( sorry i cant find a picture of mine at the moment)
Maybe search pictures of some other amp builds to see how other did there chassis layouts for inspiration?
good luck
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Move the speaker mounting hole in the baffle down and away from the PT. The speaker doesn't have to be centered on the baffle.
And/or make the cab a little bigger.
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Thanks, that's pretty much what I figured. Spacing'll be tight so I'll shuffle it over as much as I can.
If worse comes to worst I'll raise up the OPT 1/4" or so with brackets so I can run the wires above the chassis. I would imagine the thick steel chassis itself will serve as a good shield for them.
Thanks!
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I would stick to good layout practices and offset the speaker.
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I had just that tissue in a conversion Crate cab to Sluckey's single channel deluxe. I ran the OT wires under the bd. at first, big problems, no chop sticking helped. Cab was so small I had no other place to locate the OT, luckily my OT wires came off the OT's side, sent them through a grommet and ran them outside the chassis, worked great, no issues. I'd elevate the OT and use a grommet if you can't find another home for the OT. The OT doesn't have to be mounted on the chassis, but you have high voltages to deal with outside the amp. I used the plastic case from household 14# gauge wire, just pull the 14# copper wires out and I had a nice case to protect those high voltages, I did twist them. Worked out great. I even use clips to hold cased OT wires to underside of chassis.
The secondaries are biggest problem too, never run them from one side to the next unshielded.
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...I want to build a single channel AA964 Vibrolux Reverb, and I plan to put it in a Princeton Reverb chassis which is a few inches shorter than the correct chassis...
So does this thread mean that further responses to your previous thread http://el34world.com/Forum/index.php?topic=25146.0 are pointless?