[pdiddypdler]

So from what I gather from all the ad8620 vs opa2227 talk is that 
 
opa2227 is warmer sounding with more bass and mid range emphasis and a more forward signature
ad8620 seems to be slightly better technically with slightly better soundstage, detail and a brighter signature. This seems to be similar to the o2 sound signature if I'm reading correctly.
 
Obviously the differences will be relatively small and both will sound great most likely.
 
Am I correct with these assumptions?
I think I'm leaning towards the opa2227 variant as I've read it would be a safer bet if unless I've heard the ad8620 before.
 
Should what opamp i chose depend on what type of headphones I'm using with the amp?
I'll probably mostly be using IEM's on the go but maybe occasionally my pro900 at home.
 
 
 

 

[ClieOS]

Yes, I'll say your assumption is closely mimic my experience with both version of C421. AD8620 version is indeed closer sounding to O2 than OPA2227 version. If you are using IEM mostly (which I am), I would think AD8620 is most likely the better pairing of the two. OPA2227 version would be a better pairing for full size headphone IMO.

 

[pdiddypdler]

Thanks for the advice ClieOS
 
So the AD8620 would be more neutral and clean and doesn't add its own flavour to the sound but just makes everything better whereas the OPA2227 does change the sound more so.
 
Yes?
 
Maybe the AD8620 is what I want but I'm not sure a neutral/bright amp would pair well with my pro900's (that is my second priority anyway because I have my E10 for them).

 

[ClieOS]

I think the most important point why I recommend AD8620 over OPA2227 is the fact that AD8620 gives much better imaging and soundstage to IEM (which is something IEM always seems lacking when compared to full size). OPA2227 on the other like to put thing upfront - it might seems wider on the side, but the true is you are not getting as much depth as you can. With IEM, where depth is generally a weak spot, the AD8620 offers something OPA2227 doesn't have. As for brightness - I won't say AD8620 is very obviously bright compared to OPA2227. AD8620 just handle the detail more delicately, and makes the listener listen to the detail more plainly. But the true is I can hear just as much detail in OPA2227 as well, but they are generally hidden behind ./ obscured by the richness of the tone and you'll have to pay more attention to find them out.

 

[syphen606]

I can't compare C421's, but I have 2 CmoyBB's... one with an OPA2227 and one with a AD8620. I find the 2227 pairs well with my brighter headphones like my Senn HD558's as it warms them up a little.  My 8620 model pairs better with my mid-centric cans like my HD650's as it fleshes out the sound.
 
I think its a personal choice based on what you have for cans or iems already.

 

[placebo-fi]

So, the ODAC (an USB-powered 24/96 DAC with probably more measurements than you can dream of) is coming next month in the same enclosure as the c421. http://blog.jdslabs.com/?p=309. The CLAS + ALO Rx Mk2 combo finally found its long lost brother! At one forth the price and unrelated whatsoever to Apple!
 
Which other c421 users will be attaching the ODAC to their c421? I certainly will. Seems like a strong competitor to the Pico, UHA-6S.mk2, Cruise, D12, DacPort, etc

 

[pdiddypdler]

But the ODAC doesn't take the digital out of an ipod like a clas though right?

 

[ClieOS]

The ODAC in the C421 enclosure looks great. Won't mind getting one myself in later time.

 

[placebo-fi]

I was just talking about the form factor. Hence "unrelated whatsoever to Apple"
 
Quote:

But the ODAC doesn't take the digital out of an ipod like a clas though right?

 
 

 

[pdiddypdler]

Ah ok, I wish it was though.

 

[bluishgreen]

Quote:

So, the ODAC (an USB-powered 24/96 DAC with probably more measurements than you can dream of) is coming next month in the same enclosure as the c421. http://blog.jdslabs.com/?p=309. The CLAS + ALO Rx Mk2 combo finally found its long lost brother! At one forth the price and unrelated whatsoever to Apple!
 
Which other c421 users will be attaching the ODAC to their c421? I certainly will. Seems like a strong competitor to the Pico, UHA-6S.mk2, Cruise, D12, DacPort, etc

I'm definitely interested in the standalone version.  I've always looked at getting an O2, and the idea of an integrated O2/ODAC sounds really cool, but since the way I work and listen to music requires not being tied to a wall power source (even with my computer) the non-battery-O2 option wouldn't work for me.  But a USB-powered, standalone version in a C421 enclosure sounds even more practical anyway.
 
One thought after looking at the prototype images--since both the USB and output are on the same side of the device, and usually people want the more bulky USB/power source cables facing the "back" to avoid cable clutter around the front amp controls, this means that (when paired with the C421) the ODAC output and the C421 input would be on separate sides, being too long a distance for most people's stock short 3.5-3.5 interconnects.  Not a big deal for those making custom cables, but it may be a good idea to either include or offer separately a good interconnect at a length specific for pairing with the C421.
 

 

[syphen606]

I'll be pre-ordering the standalone ODAC in C421 case when available. I can hook it up to my C421 or my O2 then!!  Very excited for it.

 

[Mutnat]

I know it's probably a pipe-dream, but I'd love to see JDS make an affordable, great-sounding, battery-powered & USB charged, CLASS competitor in the C421 case.  I'd be all over that, as a competitor to the CLAS + Rx stack.  For now, I'll make do with the DAC in my iPod feeding my C421/2227 via an LOD but it would sure rock to have a JDS iPod DAC in the middle instead! 

 

[pdiddypdler]

Quote:

I know it's probably a pipe-dream, but I'd love to see JDS make an affordable, great-sounding, battery-powered & USB charged, CLASS competitor in the C421 case.  I'd be all over that, as a competitor to the CLAS + Rx stack. 

+ a million

 

[Ultrainferno]

That would be nice indeed!