[raisedbywolves]

i'm looking to buy my first amp, most likely a cmoy as i don't want to spend too much money. i just have some questions that hopefully those of you who have more expertise in amps and technical matters can tell me.

i'm looking at 3 different cmoys, the jds labs cmoybb 2.03, the biosciencegeek cmoys and another by a guy named ampedup77 on ebay. i plan to use it mostly with iem's. the type of sound signature i prefer is neutral and transparent if possible, but i'd rather slightly warm and smooth than cold or dark and bright if i had to make a choice. so here are my questions:

1. from a technical standpoint, which of these cmoys seem the most well-made?
2. out of the available opamp choices from these guys (opa2227 on the jds labs, jrc4556 on the ampedup77, choice of opa2227/ad712/lm4562/tle2082 from biosciencegeek), which would most fit my sought after sound signature?
3. is it worth it to get the 2 x 9v options?

thanks for any help you can give me. if you have any other suggestions for me or questions, feel free to say.

 

[raisedbywolves]

anyone?

 

[jseaber]

Quote:

i'm looking to buy my first amp, most likely a cmoy as i don't want to spend too much money. i just have some questions that hopefully those of you who have more expertise in amps and technical matters can tell me.

i'm looking at 3 different cmoys, the jds labs cmoybb 2.03, the biosciencegeek cmoys and another by a guy named ampedup77 on ebay. i plan to use it mostly with iem's. the type of sound signature i prefer is neutral and transparent if possible, but i'd rather slightly warm and smooth than cold or dark and bright if i had to make a choice. so here are my questions:

1. from a technical standpoint, which of these cmoys seem the most well-made?
2. out of the available opamp choices from these guys (opa2227 on the jds labs, jrc4556 on the ampedup77, choice of opa2227/ad712/lm4562/tle2082 from biosciencegeek), which would most fit my sought after sound signature?
3. is it worth it to get the 2 x 9v options?

thanks for any help you can give me. if you have any other suggestions for me or questions, feel free to say.

 
I'm surprised no one has responded...
 
2) You can swap opamps in any of these amps since they all use sockets. We've found OPA2227 to be most popular. JRC4556 is also a great chip (lower cost, excellent performance--used in the Objective2). 
 
3) There's no need to go for 2x9V unless you're driving high impedance headphones, typically 64+ ohms. A single 9V is plenty for most headphones. 

 

[raisedbywolves]

thanks for your response. i've been talking a bit to bsg and he told me didn't consider two rail splitters necessary for low impedance use like for iem's, but i noticed in one of the reviews of your product that you include two rail splitters for your low impedance cmoybb. any reason for that? 

and if i wanted to mostly use the amp for low impedance iem's for now but maybe wanted to buy high impedance headphones later on, would it be useful just to go for the 2 x 9v option so i'm more futureproof that way?

 

[jseaber]

Quote:

thanks for your response. i've been talking a bit to bsg and he told me didn't consider two rail splitters necessary for low impedance use like for iem's, but i noticed in one of the reviews of your product that you include two rail splitters for your low impedance cmoybb. any reason for that? 

and if i wanted to mostly use the amp for low impedance iem's for now but maybe wanted to buy high impedance headphones later on, would it be useful just to go for the 2 x 9v option so i'm more futureproof that way?

 
Two rail splitters increase maximum output current (and current consumption). While it's not mandatory, it provides a noticeable improvement in output power that some users demand.
 
I'd stick with 1x9V. The cMoy requires other changes for optimal performance with high impedance headphones. You're better off with something like the O2 if you're after a future-proof amp.