[BobSaysHi]

Hi all!
 
I've been lurking around the forums for a while, however I have a couple questions on choosing an amp to build.
 
This is going to be my first build and I don't have a large budget (less than 100, preferably less than 50) and while I currently own sr80s I am planning to upgrade to sr225s or sr325s as soon as I find the money.
 
I looked at threads recommending building a RA-1 clone, however the threads are years old. Would there be a better (newer) option for an amp, or is the RA-1 still recommended? Where could I find a schematic to build it?
 
Thanks a lot for helping a newbie out

 

[Yoga Flame]

RA-1 clone is basically the same thing as a CMoy. See http://tangentsoft.net/audio/cmoy-tutorial/ for more info on the CMoy. You can also find CMoy printed circuit boards from a few places, such as JDSLabs. Order the other parts from Digi-key or Mouser.
 
Other (newer) DIY amps to consider are:
PIMETA - http://tangentsoft.net/audio/pimeta2/
Mini^3 - http://www.amb.org/audio/mini3/
 
 
 
 
[edit: added "on the CMoy" for clarity]

 

[fortney]

There is nothing wrong with a CMoy. I use the OPA2227 and like the sound (apparently some others don't). The input capacitors are important if there is any risk of the music  source having or developing high DC offset which will be amplified by the CMoy and damage your headphones. I replaced the input caps with 1K resistors and the audio improved. Do that at your own risk of course.
 
F

 

[Xan7hos]

pm sent

 

[nikongod]

 
Quote:

RA-1 clone is basically the same thing as a CMoy.

Except that it uses a very specific op amp and gain, and has a strong track record for its sound with Grados. So yes, the RA-1 is a cmoy, but a cmoy isnt an RA-1.
 
Cary on.

 

[Netdewt]

Is there a tutorial/PCB out there for an RA-1 clone (or which opamps, etc does the RA-1 use)?

 

[BobSaysHi]

Quote:

Is there a tutorial/PCB out there for an RA-1 clone (or which opamps, etc does the RA-1 use)?

YAY! You just bumped my 1st or 2nd post. High Five!
 
Anyway, talking about cloning amps isn't allowed on these forums. Read the rules.

 

[ESCS]

Heres something about the differences between Grado RA1 & CMOY.

 

[Netdewt]

Quote:

Quote:

Is there a tutorial/PCB out there for an RA-1 clone (or which opamps, etc does the RA-1 use)?

YAY! You just bumped my 1st or 2nd post. High Five!
 
Anyway, talking about cloning amps isn't allowed on these forums. Read the rules.

 
I wasn't the first to bring up clones in this thread. I couldn't possibly read all the rules for every forum I visit, but thank you for the friendly nudge.
 
Thank you ESCS.