Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Misc Schematics and Layouts => Topic started by: druz15 on April 25, 2013, 05:12:29 pm
-
Hi everyone new to the board.
Apologies if this is in the wrong place, but it seemed like the best.
I am planning a DR103 build and have started on a layout using DIYLC. So far I am at the end of the preamp and just wanted to check a few things before I progressed any further.
I am working with the schems on my iPad so I can highlight each section when I've placed it on the board, and have double checked everything so far so I fairly certain it's right but I just wanted to get some opinions on it, have I done anything that's a no-no in layouts, or perhaps made a simple, easily overlooked mistake?
I am working from this schematic http://www.el34world.com/charts/Schematics/files/hiwatt/hiwatt_100w_dr103.pdf (http://www.el34world.com/charts/Schematics/files/hiwatt/hiwatt_100w_dr103.pdf) but also the 203 (as I was initially planning a 203 build).
The first plan was for a 203, but as I am using a Dual Showman Red Knob That I Pulled apart for chassis and some parts, I discovered I could use the iron from the Showman for a 103 build, thus saving a bit of hassle and coin.
I have made some slight modifications (mostly adding grid stop resistors on the board for V1 inputs, as well as a channel bridging switch) and as such some of the components are a little different. I am going for a Hiwatt/Orange hybrid kind of feel so the brilliant channel is basic DR103 spec, but I modified the normal channel slightly to be a bit closer to the input of the OR120.
Couple of questions:
1) is the channel bride switch effective (ie to me that should work but there may be something I'm missing)
2) have I even wired the jacks up right? Do I need to use four pronged switching jacks for a circuit like this, and if so how do these need to be wired?
3) I'm thinking about putting in the OR120s F.A.C control as well, where in the circuit would this best be suited? I'm thinking pre phase inverter, perhaps directly after the Master Volume, but perhaps pre tonestack would be better?
Here is the layout so far (and thanks in advance)
-
Why not copy some original Hiwatt layouts, as drawn by Mark Huss? (http://hiwatt.org/tech2.html)
If the input jacks are on the wrong side, just mirror-image everything.
-
Cheers for the reply yeah I have looked at a few of those layouts but as I'm making a few modifications I thought I'd do my own (also the jack and control layouts will be different as I'm building it in a Dual Showman headcab + Chassis and therefore need to fit it to the holes drilled for that particular amp)
I think I need to do four lug jacks for this arrangement to work or one of the jacks will be ungrounded when not plugged in and buzz. May steal the linked jack wiring from that site instead of making it switchable.