#1
Hey guys - thinking of an amp build based on the ampmaker kit. I have experience soldering and the instructions with the kit are apparently quite comprehensive, so I'm not worried about being able to build it 'as it comes'

however, I have a couple of ideas (just come into my head, havent looked into practicality as yet - thats what I'm asking you lot for)

okay, so I'm thinking of adding some extras to the standard volume / tone setup for a little tonal variety, but if possible I'd want to make these completely switch-out-able from the circuit for when I'm not using them

1. old orange style FAC control. I seem to remember reading that this switches different capacitors to ground early on in the circuit or something. please correct this as I'm pretty sure it can't be this simple

2 vox style cut knob. Again, my understanding of this is limited to what i have subconsciously gleaned from forums. In my mind I picture this as a kind of low pass filter after/just before the output stage. Again, please correct my ignorance :p

3. I understand that the 18watt does not use negative feedback. I thought that I could quite easily add in a switchable negative feedback loop, perhaps with a kind of presence control. I imagine this as kind of like a 'clean-ish' switch ^^

4 I'd also like switchable valve / diode rectification, ideally - but I can imagine that adding a valve is quite a significant design alteration, kind of beyond the scope of what I'm looking at doing. A switchable passive sag circuit would be a realistic alternative, i suppose.

So thats like a pre-alpha plan that I'm just putting out there for input from the many people who know a hell of a lot more than me.

Hopefully you see what I have in mind - a low - mid gain amp without a conventional tone stack that uses more unusual methods for a nice variety of sounds that are actually different on a more fundamental level than your standard eq.

I know it seems ambitious for a first amp build, but I'm really not keen on building something that I didn't have at least some input in on a design level.


tl/dr; building 18 watter with various gimmicks :p
#2
1: Great website, learn to love it: http://schematicheaven.com/newamps/orange_graphic_mkii_or120.pdf

2: Not sure which amp it's on. Look around: http://schematicheaven.com/vox.htm

3:Can't help you there

4: Not really. If you use a 5AR4 aka GZ34, you don't need to run heater voltage to these. Use a 3PDT switch. Run two outside poles to either the two anodes of either your diode rectifier or your tube rectifier. Transformer voltage will be the common. The third pole will have the center as common, and the two outside poles for the incoming current. You may want to add a choke after the tube rectifier.

Looking forward to it.
Last edited by end_citizen at Jan 14, 2009,
#3
looks quite..... comprehensive. I suggest making the 18 watt first THEN modifying it. especially for your 1st build. Most electronics builds go over poorly unless your really good with them. I even had an electronics mentor help me with the fabrication and my amp still SUCKED. Plus it went through like 10 rev's
#4
thanks guys.

End citizen - I go on schematic heaven suite a lot but it's always frustrated me that the vox schematics are so damned hard to read. If only they could all be as clear as that orange one.

Thanks for the advice about the rectifier tube too, I didnt realise that.

Your amp build looks damn good, i'll be following it. Mainly to see how the FAC turns out :p


and to espshredder , I think that's what I'll probably do. get it working first; at least with it not being a pcb itll be simple(r) to change things afterwards.