Multi-effect pedalboard and amp all-in-one

Started by earthtonesaudio, June 29, 2008, 02:45:09 PM

Previous topic - Next topic

earthtonesaudio

I have some decently sized enclosures (actually 1U rack enclosures) that I want to put some effects in and a 20-30W solid state amp.  I just like the idea of having guitar and power cords going in, and a speaker cord coming out.  And so that I could have everything right there, under foot, making amp channel switching so simple. 

I was thinking of using a TDA2050 based amp, and the preamp stuff would probably be boost/fuzz face, a couple paralleled and mixed distortions, a buffered FX loop, and a simple delay right before the power amp (rehoused and modded Fab Echo).

I don't think I've ever seen a multi-effects AND an amp in one enclosure with footswitches on top, so I am looking for input and ideas. 

My goals are:
Simplicity and ease of setup (plug in power and guitar, and speaker and that's it)
Portability (everything enclosed in a 1U rack enclosure, can be rackmounted for transport possibly)
Flexibility (FX loop should take care of this)

My concerns are:
Shielding and keeping noise reasonable
Powering everything in some logical way
fitting everything in a 1U-tall space (I suppose power transformers can be on top)


...Thanks, and please let me know if anyone's done something like this before.

-Alex

earthtonesaudio

Any input on the effects-plus-amp-in-a-box idea?


Pushtone


Might as well add a cab sim to the lot.

Did you see the Weber footswitch enclosure I posted the other day?

It might work for ya on this one.

It's time to buy a gun. That's what I've been thinking.
Maybe I can afford one, if I do a little less drinking. - Fred Eaglesmith

earthtonesaudio

Thanks Dave for the suggestions.  Having a cab sim and direct out wouldn't be a bad thing at all.  My initial plan is to use a couple separate Tonemenders (runoffgroove preamp) as pre-amp channels, so maybe just an output from there would work.

As for the enclosure, I already have a suitable one in-hand, which is sort of what inspired this craziness in the first place.  (A tool without a use is a recipe for trouble!)

cheeb

It would be cool if you could do modules like Randall so the effects and order were switchable.

http://www.randallamplifiers.com/products/amplifiers/mts/modules.asp

frank_p


Hi Alex,
Something like the Gigrig for switching between effects placements (effect loops) ?

http://www.thegigrig.com/acatalog/TheGigRig_Pro-14_BLack.html

?

earthtonesaudio

Thanks guys for the input.  I thought about all the things I could want (and could fit) in this large-ish enclosure, and decided that a couple preamp channels, a couple distortions, a splitter/mixer, and a delay were about the max in terms of real estate.

But, I knew I'd want to be able to switch things in/out later, so I decided a buffered FX loop near the end of the signal chain would be about right.  After the distortions, but before the delay, preamps, and mixer.

Not the most flexible system in the world, but a good compromise.

frank_p

I think that with the Gigrig you can decide where to put X effect before Y effect just by switching those mini slide switches (without rewiring all the stuff or changing the "place" of the "physical boxes" like in that Randall system.  So you could tap an effect loop anywhere in the signal chain and move it around just with switches.

earthtonesaudio

I'm now leaning toward a Class D power amp section with full bridged output for single-supply operation without the need for large coupling capacitors.

Anyone know of any designs like this that will put out about 50W from 12V, or will I have to boost the voltage going to the power MOSFETs?


Also if anyone has info on DIY versions of the other efficient amplifier classes (E, G, H, etc), I haven't committed to Class D so I can still be swayed in another direction.   :D

earthtonesaudio

I haven't started any part of this project yet, but I have a new dilemma: the power supply.

The main choice is this: one voltage or many voltages?

One high-current switching supply (like an in-line laptop supply) would be simple, replaceable, and relatively cheap (I think I have a few just lying around).  A single voltage output of 12 or 16V would be easy to tap off of for the stompbox power, but it's about the lower limit for power amp voltage levels.

On the other hand, running one supply for the stompboxes and a separate supply for the power amp will allow more flexibility of power amp choice, but will be more complicated, expensive, and probably take up more space.

axg20202

You could consider increasing the available voltage by using a transformer with a centre tap e.g. 18V with a 9V centre tap, or a 24V transformer with a 12 volt tap......