do I need vintage preamp?

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I have a t-amp (power amp) that I like to use but has only one RCA input. I want to use it for my PC (music files) and my desktop CD player and want to add volume/input selector.

I can see 3 major possibilities.

1. is there a "radioshack" like product, with volume/RCA selector for cheap?
2. is there a DIY product (I can solder but can't read schematics etc)
3. Possibiy a vintage preamp on craiglist.

thanks in advance, will appreciate input.

gychang
 
For $50 you can build a nice passive attenuator with input selection. An Alps pot, three sets of RCAs and a toggle switch [...]

you could also consider this thread (if you want to go fancy and maybe have remote control) - note that his is also passive unless you decide to build an active buffer...

otherwise, amt's correct. for very little money and just a few parts you can build a decent selector and passive volume.

A "vintage" preamp is also OK if it's more to your taste, or you decide you want more features. But where's the fun in that ;-)
 
For $50 you can build a nice passive attenuator with input selection. An Alps pot, three sets of RCAs and a toggle switch should sound much better than a beat up old preamp and be far more compact.

amt

any chance on the website that has the correct parts for the items u mentioned?, I have several RCAs, but no toggle switch, and do have a Alps pot laying around.

gychang
 
Heres a quick wiring diagram. The best toggle around is the Tocos sold by Percy Audio and the worst are the ones sold at Ratshack.

Keep the wiring as short as possible and make sure the RCAs are isolated from the chassis (if its metal).

amt
 

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Heres a quick wiring diagram. The best toggle around is the Tocos sold by Percy Audio and the worst are the ones sold at Ratshack.

Keep the wiring as short as possible and make sure the RCAs are isolated from the chassis (if its metal).

amt

thanks so much!, even I can follow this diagram, will order the DPDT (on/on, NOT on/off/on, right?) as u suggested. It will be in a small wooden case, the grounds on the RCA has to be soldered together? Thanks, again, I will do this. gychang
 
Heres a quick wiring diagram. The best toggle around is the Tocos sold by Percy Audio and the worst are the ones sold at Ratshack.

Keep the wiring as short as possible and make sure the RCAs are isolated from the chassis (if its metal).

amt

It works!!, I managed to follow your diagram, and soldered the RShack cheapie and Alps pot and it is dead silent in the background and music is glorious!!, thanks. Now I want to try 3RCA input, can u recommend a part?, seems like RShack and Partsexpress don't carry and I would like some recommendation, I will try some good ones this time for hopefully for my reference build. My soldering skills have improved and I am starting to get hang of this.

Thanks again amt. I will put up my pictures may be tomorrow night, just pure music without any hum, it is dead silent during music pause...

gychang
 
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I have a t-amp (power amp) that I like to use but has only one RCA input. I want to use it for my PC (music files) and my desktop CD player and want to add volume/input selector.

I can see 3 major possibilities.

1. is there a "radioshack" like product, with volume/RCA selector for cheap?
2. is there a DIY product (I can solder but can't read schematics etc)
3. Possibiy a vintage preamp on craiglist.

thanks in advance, will appreciate input.

gychang

Among the cheapest and least liked preamps that will fulfill your requirements is the Dynaco PAT-4. For your purposes it will do just fine. Find one in good condition that works. The only drawback is that the bass controls are very touchy so either adjust them carefully or there are easy ways to defeat their function. Someone familiar with it can tell you which wires to cut or bridge. It wouldn't surprise me if you find one for about $20 or $30.
 
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