Cmoy request/questions

[einolu]

Hey, I was wondering if any builders out there could do a sort of special request cmoy for me. I want a basic CMOY, except I dont need battery power, just plug in power. It also dont need to be in a tin, just any sort of housing. The reason for this is that dont have enough money for a normal amp for home use, and just want something that I can listen to when Im doing work at my desk. Help would be welcome . This is just sort of a interest check, not sure if I actually need one yet.

~EO

 

[Earwax]

That should be pretty straightforward to do. OR, you could even build it yourself
http://tangentsoft.net/audio/

(trying to get another one hooked on DIY)

 

[theBishop]

How do cmoy or other DIY amps compare to the ones that cost $150+? Is it of similar sound quality.

 

[jnewman]

Quote:

Originally Posted by theBishop How do cmoy or other DIY amps compare to the ones that cost $150+? Is it of similar sound quality.

You can make something closely resembling a Grado RA-1, a $350ish headphone amp, for something like $30-40 in parts, although I understand it's not terribly well suited to most headphones - and also, I understand, a CMoy with the same op-amp as the RA-1 gets about 90% of its sound - not bad for around a tenth the price in parts. That said, there are lots of people who don't like the sound of the RA-1, so that may not be for you even if it DOES sound like an expensive amp.

 

[einolu]

any links for the RA1 amp? Im not terrible at building things, but I dont think I have all lthe tools I need (just an "iron" and a pretty bad one at that, and some random other ****).

~EO

 

[jnewman]

http://www.geocities.com/rubin_jpk/rubin/page_4.html

It's one of the simplest designs that exists - one volume pot, six resistors, four capacitors, and an opamp. It is my understanding that it is NOT copyrighted or patented as it is not actually an original circuit - if this is wrong, someone please correct me and I will remove all info I've posted.

The one thing that it might take you some searching to figure out is that it uses the Japan Radio NJM4556AD High Current Dual Opamp - that's also the one you can put in a CMoy to get something resembling the right sound.

You'll also need all the standard things like a case, a powerswitch, a knob for the volume pot, rca jacks for input and a headphone jack for output, batteries and battery clips or a power supply and power supply connector, and ~22gauge hookup wire (just about standard for headphone amp work... there are people who use bigger and smaller).