Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: gheorge77 on September 17, 2019, 02:09:52 pm
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So I've been searching for this simple question and I can't find anything. On this build: https://el34world.com/Hoffman/files/Hoffman_AB763_2.pdf
The second wire from the primary side of the PT....how does it connect to the white wire from the 3 prong power cable? This seems obvious when building with an IEC. Do I just add a terminal strip?
Similar hookup question (which I can't find a specific answer to), when wiring the primary speaker output, do I just not wire the 4 and 16 ohm wires (since I'm wiring a single 8 ohm speaker and my OT has 4/8/16 secondary outputs). Thanks!
-Ian
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The second wire from the primary side of the PT....how does it connect to the white wire from the 3 prong power cable? This seems obvious when building with an IEC. Do I just add a terminal strip?
That's one way. Or you could use a single chassis mount standoff turret. Or you could just twist together with a wire nut (ugh!), or use a crimp butt splice, or neatly solder the two wires together and slip some on heat shrink tubing (one of my favs). Just be secure and safe.
Similar hookup question (which I can't find a specific answer to), when wiring the primary speaker output, do I just not wire the 4 and 16 ohm wires (since I'm wiring a single 8 ohm speaker and my OT has 4/8/16 secondary outputs). Thanks!
If 8Ω is all you will ever use just tape the ends of the unused leads and tuck them out of the way, not near any sensitive preamp or reverb tubes though.
Many people like the option of being able to chose different output impedances. Hoffman sells a simple, heavy duty rotary switch that is ideal for this.
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The second wire from the primary side of the PT....how does it connect to the white wire from the 3 prong power cable? This seems obvious when building with an IEC. Do I just add a terminal strip?
That's one way. Or you could use a single chassis mount standoff turret. Or you could just twist together with a wire nut (ugh!), or use a crimp butt splice, or neatly solder the two wires together and slip some on heat shrink tubing (one of my favs). Just be secure and safe.
Similar hookup question (which I can't find a specific answer to), when wiring the primary speaker output, do I just not wire the 4 and 16 ohm wires (since I'm wiring a single 8 ohm speaker and my OT has 4/8/16 secondary outputs). Thanks!
If 8Ω is all you will ever use just tape the ends of the unused leads and tuck them out of the way, not near any sensitive preamp or reverb tubes though.
Many people like the option of being able to chose different output impedances. Hoffman sells a simple, heavy duty rotary switch that is ideal for this.
Thanks! I realized the simple solution of soldering the 2 wires together but I thought there may be a better way. This is my first non-kit build (built a BYOC Classic Brit 50, which works great and came with great instructions) but still not as hard as a true scratch build, which is where I'm going next. I wanted to build a Matamp GT120/Orange OR120 as a scratch build but proved too difficult to design. I'm going to actually work off of the 1 Channel Hoffman AB763 to design that circuit hopefully.