[Anathallo]

Two opamp choices available - one for higher impedance cans, one for lower (JDS states the one suited for higher impedance cans emphasizes bass over transparancy).  It doesn't look like they can be rolled.
 
http://blog.jdslabs.com/?p=179
 
 
According to the blog entry, only 95 amps will be available (at most) for preorder.  Who's taking the dive?

 

[i_djoel2000]

looks like an arrow 4g killer..

 

[ClieOS]

Nice, the spec looks very promising and it even has my favorite opamp for portable amp, AD8620.

 

[Hi-fi Wigwammer]

I ordered my C421 yesterday, based upon positive impressions of my JDS cMOY V2.03. I'm really excited about the C421 - great price ($169), great spec and hopefully a good upgrade on his terrific cMOY.
Judging by his cMOY John appears to share my personal sonic preferences. I think the C421 could be a real winner.

 

[i_djoel2000]

Quote:

(JDS states the one suited for higher impedance cans emphasizes bass over transparancy).  It doesn't look like they can be rolled.

and i wonder why is that? usually higher impedance cans are more source revealing, they should emphasizes transparency more over bass IMO
 

 

[Josef]

I've ordered mine just after the rss-feed shouted at me
 
I'm looking forward to listen to it after loving the CMOY.

 

[Hi-fi Wigwammer]

Indeed, I think the JDS cMOY is very underrated - a smoother, cleaner listen than the FiiO E11 to my ears.

 

[Jonasklam]

Quote:

Nice, the spec looks very promising and it even has my favorite opamp for portable amp, AD8620.

Btw, was thinking, have you heard the other opamp option they offer?
 
 
 

 

[kyoshiro]

anyone know how this compares to the GoVibe Magnum 

 

[Hi-fi Wigwammer]

I doubt anyone can answer that question. It hasn't been released yet. John Seaber has taken a pre-production prototype to the Rocky Mountain Audio show today. Maybe an attending Headfier will get to listen to it?
Regardless it looks like a very promising amp for $169.

 

[kyoshiro]

Quote:

I doubt anyone can answer that question. It hasn't been released yet. John Seaber has taken a pre-production prototype to the Rocky Mountain Audio show today. Maybe an attending Headfier will get to listen to it?
Regardless it looks like a very promising amp for $169.

 
true true, quite a damn steal for 169 (plus looks great)  for what is listed  my magnum was 300~ tho I do love it
I wonder if the high impedence version will drive AKG K702 fine, looking into buying a pair soon (tm)

 

[ClieOS]

Quote:

Btw, was thinking, have you heard the other opamp option they offer?
 

You mean AD8066? I have both in my cmoyBB. AD8066 sounds pretty good as well, but generally I'll go for AD8620 if given the choice as AD8620 sounds more refined. I think the reason for John to recommend AD8066 for high impedance headphone is because AD8066 can do rail-to-rail, which means it will give a higher output voltage over AD8620 and that is more important for high impedance headphone (to achieve higher output volume).
 
 

 

[Anathallo]

I could be 100% wrong, but I think it's because the higher impedance cans require more push in the lower end of the spectrum to even things out, so the amp has to emphasize the bass to normalize the tonal balance.
 
Check out the Impedance vs. Frequency graph of the HD650.
 
http://www.innerfidelity.com/images/SennheiserHD650.pdf
 
It'd be interesting to hear from someone who actually knows something about sound science, though.
 
Quote:

and i wonder why is that? usually higher impedance cans are more source revealing, they should emphasizes transparency more over bass IMO
 

 
 
EDIT: and as I wrote that, ClieOS gives a much better response!
 
 

 

[Jonasklam]

Quote:

You mean AD8066? I have both in my cmoyBB. AD8066 sounds pretty good as well, but generally I'll go for AD8620 if given the choice as AD8620 sounds more refined. I think the reason for John to recommend AD8066 for high impedance headphone is because AD8066 can do rail-to-rail, which means it will give a higher output voltage over AD8620 and that is more important for high impedance headphone (to achieve higher output volume). 
 

 
Yep, i meant the AD8066.
Great man! Exactly what i wanted to hear actually .) - and thanks for clearing things up, you just explained the differences pretty much as precise as possible - so that even a noob like me understand it

 

[F900EX]

Tempting ....  But will be interested to see how it compares to the E11 and UHA-4 and of course there cheaper Amp.