Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: mresistor on February 03, 2015, 09:57:26 am
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Hello all. I've been embarked on a Single Channel AB763 DR build and reached the point of laying out the iron orientation and all the holes for pots, tubes etc. I took a pic of where I think the iron could be placed and want to hear your opinions. It's a 17 x 8 x 2 aluminum chassis so it's going to be a little different than any I have built before. It's my first attempt using an undrilled bare alum chassis. The t-board was a dual channel that I had in the closet for a few years that has had the norm channel hacked off. Of course due to this it has a couple of extra unused turrets and corrections. The t-board is 13.25 inches long, so I think turning the OT this direction is better to mount it and not interfere with the board mounting. Anyway here is the pic of my idea of where to place the iron. Its all Classic Tone DR stuff except for the Hammond reverb trans that isn't in the picture. It will be near the right side behind the driver.
(http://i122.photobucket.com/albums/o250/privateacct/SCDR%20AB763%20build/IMG_3340_zps9af1a9eb.jpg)
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Here's the turret board (the sheet of the layout is a little larger than 1:1)
(http://i122.photobucket.com/albums/o250/privateacct/SCDR%20AB763%20build/dad4310c-4ea2-4e86-a5b3-fa782e933273_zpsa457db81.jpg)
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the small bottles are 1.25" apart and the octals are 1.5" apart.
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I'd move the OT to the right in the picture away from the PT so you can run the secondary wires to the speaker jacks in between the PI tube and the 1st power tube.
Otherwise you might have trouble running them under the turret board/circuitry.
And your small bottle tubes, preamp, reverb, ....., are kinda close together. See how their spread out further apart in the layout diagram you have?
Brad :icon_biggrin:
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Ok I changed it up and lengthened the spaces. The PI will now be directly across from the leads coming off the board.
Which one of these two look better?
(http://i122.photobucket.com/albums/o250/privateacct/SCDR%20AB763%20build/IMG_3346_zpsfd86bcff.jpg)
(http://i122.photobucket.com/albums/o250/privateacct/SCDR%20AB763%20build/IMG_3345_zps2297e05f.jpg)
the turret board will be on 1/2 spacers so I should be able to run the OT wires fairly easily but still could end up moving the OT over some and fit the choke inbetween.
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but still could end up moving the OT over some and fit the choke inbetween.
Yes. Yes. Yes.
May I suggest wiring the OT to the tube sockets and speaker jacks before putting the board in? Plan to be wrong with the NFB phase. IOW, leave the OT plate leads full length and only trim to fit AFTER you are sure the NFB look is properly phased.
Also, mounting your big tubes on 1.75" (or more) centers is a good idea.
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Definitely Sluckey, I learned that one the hard way already :-) Thanks.
And I just realized that my layout on the chassis is backwards. The DR is meant to be in a Fender chassis, and this one will be in a chassis with the bottles up. So tomorrow I'll get it reversed. The input will be on the right side and the power switch will be on the left. The pots will be going from right to left.
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The input will be on the right side and the power switch will be on the left.
Be careful. That's how it's s'posed to be!
(http://home.comcast.net/~seluckey/amps/6v6plexi/P-6V6_07.jpg)
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Thanks for posting that Sluckey. Looks nice. Mines going to have chicken head knobs, neon lamp, and off-stby-on switch. Think I'll call it a DRR.
Deluxe Reverb Reverse.