[iamthecheese]

Switchbox parts

Purpose – switch RCA outputs from my DAC between minimax and future desktop monitors. Might as well build a section thats a ¼in splitter/selector into the front.

Other thoughts – small simple preamp for speaker out section?

Parts needed
wire – how much TBD
maybe some breadboard or similar to
3x ¼ jacks
2 on or off switches that control L/R. Would I be fine just running the ground right to the jack?

3x pairs of RCA jacks
1x selector switch
Chassis – 5.5x6 or larger but smaller than 9x8


text diagram?


^ ^ \/\/ ^^
RCA out ***** rca in******RCA out
|************ \ ************|
|************ | ***********|
____________ Switch---[preamp]--




|----------[]---------|-------[]-------|
1/4 OUT**switch***1/4 IN **switch***1/4 OUT
| |***** \ *****| ^ |***** \ ***** | |


I guess my big questions are:
Is this even possible?
Does a small preamp exist?
Where is the best place to get parts/chassis for this?
Am I even making sense(not sure of this one myself...)?

 

[xxbaker]

I don't really understand your diagram, but your idea makes sense. What might make more sense is to add preamp outs to your minimax. Otherwise a switchbox with a preamp on one of the outputs would work too.

 

[iamthecheese]

Does this diagram make more sense?

 

[Marcus_C]

Correct me if i've misunderstood this but unless your input is from vinyl a pre-amp is just a switch. Any changeover/Rotary Switch would work in that case. The idea looks solid though.

 

[grawk]

That's basically how every preamp with multiple source options is designed. Or you can get something like a twisted pair darwin or manley skipjack, among others.

 

[xxbaker]

Quote:

Originally Posted by Marcus_C /img/forum/go_quote.gif Correct me if i've misunderstood this but unless your input is from vinyl a pre-amp is just a switch. Any changeover/Rotary Switch would work in that case. The idea looks solid though.

While a regular switchbox would make sense in most cases, he wants a volume control in the switchbox for controlling the [future] active monitors. He could go with a passive preamp, or he might opt for an active preamp. Either way they'll be some sort of "preamp" in the box.

Edit: Also your new diagram makes much more sense. It's what I had envisioned based on your description.

 

[grawk]

if you have enough gain to control your options so far, you could just get an autoformer or external stepper to put in the loop, as well. Lots of options, really.

 

[iamthecheese]

Quote:

Originally Posted by Marcus_C /img/forum/go_quote.gif Correct me if i've misunderstood this but unless your input is from vinyl a pre-amp is just a switch. Any changeover/Rotary Switch would work in that case. The idea looks solid though.

Vinyl is unlikely right now due to space constraints right now, but I saw this small kit and I figure for a small cost a little tube flavor in the sound of some active monitors would be welcomed. But your correct in that a preamp isn't necessary unless with a vinyl source. A convenient volume control would be nice too.

-------------------------------------------
Quote:

That's basically how every preamp with multiple source options is designed. Or you can get something like a twisted pair darwin or manley skipjack, among others.

I was adding the 1/4 in section as kinda a headphone splitter for when I have friends over listening, or from A/Bing headphones without unplugging them. Also I just like building things

-------------------------------------------

Quote:

While a regular switchbox would make sense in most cases, he wants a volume control in the switchbox for controlling the [future] active monitors. He could go with a passive preamp, or he might opt for an active preamp. Either way they'll be some sort of "preamp" in the box. Edit: Also your new diagram makes much more sense. It's what I had envisioned based on your description.

That's pretty much my thoughts, glad the new diagram was clearer.
I figure if I add a volume pot and a small PSU to that small tube preamp i linked to earlier. (Raytheon JAN6418 Valve (Tube) Preamplifier / Headphone Amp Kit)
------------------------------------------

Quote:

if you have enough gain to control your options so far, you could just get an autoformer or external stepper to put in the loop, as well. Lots of options, really.

I'm open to alot of options right now, I figure if I'm gunna build this I may as well do a decent job and give myself alot of options.


Andrew

 

[FraGGleR]

If you are going single source to two amps, why not just split the signal with an RCA adapter? Or are you going to have your active monitors on all the time?

I just built a 3 source 2 out switch box that feeds some active speakers and my headphone amp. Each out has its own rotary switch to choose from the 3 sources. Would something like that work for your purposes? http://www.head-fi.org/forums/f6/pos...ml#post6527336