[avengernoonzz]

Thanks a lot guys. Also I was referring to this.

Very true. I'm sure it's a very good soundcard, but it's still a soundcard. Not only that, but the STX is like 2.5 times the cost of the USB add-on for the Bifrost, so the USB option would be much cheaper in the long run. Are you sure your computer doesn't have an optical Toslink output? Then you wouldn't need either.

So if I have a Toslink connection which I do. Does that eliminate me from having to get a Bifrost or? I'm just slightly confused by "Then you wouldn't need either".

 

[fuzzy1969]

Quote:

Do you guys know if the HD650 could be properly driven by the Apogee Duet 2 (30 Ohms output impedance)? I read somewhere that the "1/8" rule is what I should live by, but I have also read that I should try to match the source's output impedance with the headphone impedance. 

Im not a electronics engineer but as i understand it below 10 ohms is best something to do with damping the headphone drivers correctly.

 

[amandarae]

Quote:

Do you guys know if the HD650 could be properly driven by the Apogee Duet 2 (30 Ohms output impedance)? I read somewhere that the "1/8" rule is what I should live by, but I have also read that I should try to match the source's output impedance with the headphone impedance. 

It should be good to go with headphones 240 ohms and up!  I remember seeing a graph where the HD-650 impedance swing across the freq range to be about 253 to like 500 ohms or thereabouts.

 

[ac3320]

Quote:

It should be good to go with headphones 240 ohms and up!  

What led you to believe the 1/8 rule? I am trying to decide if there is an industry-wise acceptance of this as fact, or just some conjure on the interweb

 

[fuzzy1969]

Quote:

Do you guys know if the HD650 could be properly driven by the Apogee Duet 2 (30 Ohms output impedance)? I read somewhere that the "1/8" rule is what I should live by, but I have also read that I should try to match the source's output impedance with the headphone impedance. 

This might give some explanation why low impedance output is better most decent amps are below 10 ohms.
 
http://www.benchmarkmedia.com/discuss/feedback/newsletter/2011/12/2/0-ohm-headphone-amplifier-sonic-advantages-low-impedance-headphone-amp

 

[HamilcarBarca]

Quote:

Ive been considering the matrix M stage basically because its a copy if a Lehman cube linear for a fraction of the price but there's, so many other amps to consider Yulong amps do have a good reputation so i will have to add it to the list.

 
I think it's a not quite a copy because it uses cheaper parts.

 

[fuzzy1969]

Quote:

Thanks a lot guys. Also I was referring to this.
So if I have a Toslink connection which I do. Does that eliminate me from having to get a Bifrost or? I'm just slightly confused by "Then you wouldn't need either".

I think the Bifrost has optical input as standard the USB option is a extra . I havn't seen one to confirm this but someone on here should confirm this as its a popular DAC for the HD650's.

 

[HamilcarBarca]

Quote:

[...] I have also read that I should try to match the source's output impedance with the headphone impedance. 

 
That's what we learned, in school, as the means to maximize power transfer from one circuit to the other. Apparently, what's desired here is to maximize voltage transfer.

 

[fuzzy1969]

Quote:

 
I think it's a not quite a copy because it uses cheaper parts.

Most the reviews state that it sounds just like the Lehman design, the 'lovely cube' design from China is a closer clone.

 

[captouch]

Quote:

I think the Bifrost has optical input as standard the USB option is a extra . I havn't seen one to confirm this but someone on here should confirm this as its a popular DAC for the HD650's.

 
Has both optical and coax digital inputs.  USB is $100 extra I believe.  I have the base version with just optical and coax.

 

[amandarae]

Quote:

What led you to believe the 1/8 rule? I am trying to decide if there is an industry-wise acceptance of this as fact, or just some conjure on the interweb

It is not an "industrywide" standard.  It is possible that it is just an assumption base on the web as I read it there also.

 

[fuzzy1969]

The Objective 2 was designed with low output impedance i think its something like .5 ohms.

 

[Draygonn]

HD650s sound great with a Bottlehead Crack which has a 70-80Ω impedance.

 

[ac3320]

Quote:

HD650s sound great with a Bottlehead Crack which has a 70-80Ω impedance.

Aha! This is something I can sink my teeth into. Thanks for that note.

 

[ac3320]

Quote:

It is not an "industrywide" standard.  It is possible that it is just an assumption base on the web as I read it there also.

That's the only place I could find for the 1/8 thingy :/ I think it IS just an assumption, but that's okay. Some things in life are more empirical than objectively based.