[nutcracker]

Hi folks,
From what I understand, the higher the impedance of the can, the harder it is to drive, thus requiring a suitable amp. I guess senn hd650 fits in the category. I recently purchased the AudioTechnica AD2000 in Japan (58,000yen, or $520), which is a low impedance can (70ohm). How will my amp selection be affected by its low impedance???? I am considering MF xcan. I apologize if my thread overlaps with a previous thread about senn hd595, but I do appreciate any suggestion for an amplifier. THANKS

 

[adhoc]

actually, both 'high' and 'low' impedance cans are 'difficult' to drive.

high - because you require more voltage (ie gain) to overcome the high resistance. this is however easily accomplished by most amps.

low - because being low impedance, the can would have a tendency to draw more current, requiring an amp with a high(er) current capability, which is more rare.

afaik, the xcan can power both low and high impedance cans satisfactorily. i do not consider 70ohms to be 'low impedance' - the usual 'benchmark' for low impedance around here is <50ohms.

fwiw, around here the general opinion is that there are better amps for the money rather than the xcan.

 

[nutcracker]

my bad, the impedance for ad2000 is 48 ohms.

So, the impedance of the can doesn't really matter when selecting an amp???? Or do low impedance can generally don't improve much with any amp, as compared to high impedance senn hd650 (which improves dramatically - to my knowledge). thanks

 

[adhoc]

Quote:

Originally Posted by nutcracker my bad, the impedance for ad2000 is 48 ohms. So, the impedance of the can doesn't really matter when selecting an amp???? Or do low impedance can generally don't improve much with any amp, as compared to high impedance senn hd650 (which improves dramatically - to my knowledge). thanks

it does actually.

a high-impedance can would imply that you need an amp with more gain (ask the manufacturer about this). afaik this (having enough gain) is very rarely a problem.

a low-impedance can would imply that you need either: 1. a ss amp with stacked buffers so that you can provide the juice (current) your can needs when things get busy [this is not always implemented, so do ask the manufacturer] or 2. a tube amp with either A. a low output impedance (so as to avoid impedance mismatching) or B. an output transformer (ie NOT an OTL-design). having the latter (a transformer-coupled tube amp) would certainly take care of the former (low output impedance). the problem is that the amp manufacturer now has to choose a 'good sounding' transformer - one with a wide bandwidth, fast response time and naturally, a bearable price. afaik ss amps all have ridiculously low output impedances.

in general - a hig-impedance can is difficult to drive to louder volumes and a low-impedance can, while easily driven to louder volumes, is likely to clip when things get loud and quick.

hope that helps!

 

[Jazper]

Quote:

Originally Posted by adhoc it does actually. a low-impedance can would imply that you need either: 1. a ss amp with stacked buffers so that you can provide the juice (current) your can needs when things get busy [this is not always implemented, so do ask the manufacturer] or 2. a tube amp with either A. a low output impedance (so as to avoid impedance mismatching) or B. an output transformer (ie NOT an OTL-design). having the latter (a transformer-coupled tube amp) would certainly take care of the former (low output impedance). the problem is that the amp manufacturer now has to choose a 'good sounding' transformer - one with a wide bandwidth, fast response time and naturally, a bearable price. afaik ss amps all have ridiculously low output impedances.

or 1.5 a big beefy mosfet driver stage..

 

[nutcracker]

from the review of the raptor in 6moons website, the reviewer stressed that while senn hd650's performance improved significantly when hooked on the raptor, the audio technica woodie had no improvement at all. is this got to do with the difference in the impedance of these two cans (one very high, one very low)??? or is senn hd650 just so good it livens up on any good amp????

i appreciate your advices on the kinds of amps I should look for, but I seriously have no idea about brands/models and their reputation. I will appreciate if anyone could recommend me an amp suitable for low impedance can in the pricerange of $1000 or so. how bout benchmark dac???
THANKS