[DarthVader92]

Lovely! Now you own two high impedance headphones. Look into (?) a high output impedance SS headphone amplifier - such as Beyerdynamic A20 [100 ohms]. Aeolus, 6XX, and your ears will thank you .

So sell my topping a90d?

 

[jonathan c]

So sell my topping a90d?

Topping A-90D is a powerful amp but into low impedance loads. A 300-ohm headphone (Aeolus, 6XX) needs a h/p/a with high voltage delivery and high voltage swing capability to 'come alive'. A-90D does not 'fit the bill' here; A-90D likely fares better with low/linear impedance planar-magnetic headphones.

 

[DarthVader92]

Topping A-90D is a powerful amp but into low impedance loads. A 300-ohm headphone (Aeolus, 6XX) needs a h/p/a with high voltage delivery and high voltage swing capability to 'come alive'. A-90D does not 'fit the bill' here; A-90D likely fares better with low/linear impedance planar-magnetic headphones.

Thank you a bunch!! I will definitely be looking into this. Great advice much appreciated

 

[drbusner]

Topping A-90D is a powerful amp but into low impedance loads. A 300-ohm headphone (Aeolus, 6XX) needs a h/p/a with high voltage delivery and high voltage swing capability to 'come alive'. A-90D does not 'fit the bill' here; A-90D likely fares better with low/linear impedance planar-magnetic headphones.

Can you say more about an amp's "voltage swing" capability and how that is measured? My understanding is that high output impedence of an amp can restrict its capacity to drive high impedance headphones, but maybe I've misunderstood. I'm getting this here: https://sites.google.com/view/quipa/faq-hub/output-impedance

 

[jonathan c]

Can you say more about an amp's "voltage swing" capability and how that is measured? My understanding is that high output impedence of an amp can restrict its capacity to drive high impedance headphones, but maybe I've misunderstood. I'm getting this here: https://sites.google.com/view/quipa/faq-hub/output-impedance

Not all h/p/a makers discuss voltage swing capability. Violectric does. From the HPA V222 owner's manual:

All else equal, higher output impedance restricts delivery of power. High impedance headphones need voltage. Note how V222 voltage delivery increases with the load (headphone) impedance. [One reason why Violectric HPA V281 is my favourite SS headphone amplifier - particulary for Senn, ZMF headphones.]

 

[drbusner]

Interesting, thanks. The spec/promo sheet describes it as having "the lowest output impedance" and indicates output impedance at .5 ohms, so I'm not sure if it is high impedance that distinguishes this amp. Maybe it's the "damping factor?"

 

[DarthVader92]

Topping A-90D is a powerful amp but into low impedance loads. A 300-ohm headphone (Aeolus, 6XX) needs a h/p/a with high voltage delivery and high voltage swing capability to 'come alive'. A-90D does not 'fit the bill' here; A-90D likely fares better with low/linear impedance planar-magnetic headphones.

So I'm a little confused but just trying to fully understand and learn here. On the specs and description for the Topping a90d, it mentions "thanks to it's high output voltage, high output current, and low impedance" which is what you were saying I needed to really make these headphones come alive. I'm in high gain to help drive my full size cans using a balanced xlr cable. And from what I've read, the a90d has no problem pushing 300ohm headphones planar or dynamic cans. Am I missing something here? Can you help me out understand a bit better?

 

[DarthVader92]

Can you say more about an amp's "voltage swing" capability and how that is measured? My understanding is that high output impedence of an amp can restrict its capacity to drive high impedance headphones, but maybe I've misunderstood. I'm getting this here: https://sites.google.com/view/quipa/faq-hub/output-impedance

That's what I've read too, that it's better to have low output impedance for high impedance headphones like ZMF's, Senn's, etc

 

[haasaaroni]

So I'm a little confused but just trying to fully understand and learn here. On the specs and description for the Topping a90d, it mentions "thanks to it's high output voltage, high output current, and low impedance" which is what you were saying I needed to really make these headphones come alive. I'm in high gain to help drive my full size cans using a balanced xlr cable. And from what I've read, the a90d has no problem pushing 300ohm headphones planar or dynamic cans. Am I missing something here? Can you help me out understand a bit better?

It's not about the high power, it's actually a high impedance (note that the A90D has a very low outputn impedance) that makes the headphones really wake up. At least in my own experience. I'm not an engineer and can't even pretend to talk out of my a$$...but when you increase the output impedance of an amp, these 300 ohm headphones really come alive. Darkvoice, A20, Bottlehead Crack, etc.

My understanding is that it's about the damping factor. With too low of an output impedance, the damping factor is incredibly high with 300 ohms, but the higher the output impedance, the lower that number gets, and the less "dampened" these dynamic drivers sound. It's something I recommend trying out rather than just theorizing over. It'll also change the frequency response of the headphones, mostly in the bass but also in the upper mids. Definitely worth experiencing when you have headphones like these!

Maybe someone with more technical expertise can explain this more eloquently than whatever I'm doing here lol

 

[jonathan c]

That's what I've read too, that it's better to have low output impedance for high impedance headphones like ZMF's, Senn's, etc

That gives you a high 'damping factor' (load impedance source impedance). This is a measure of amplifier control over a transducer (headphone, loudspeaker). To some listeners (including me) a moderate DF permits fine sound; a very high DF (50x ?) robs the sound of 'blossoming', of airy expansion. In the end, preference will rule.

 

[DarthVader92]

It's not about the high power, it's actually a high impedance (note that the A90D has a very low outputn impedance) that makes the headphones really wake up. At least in my own experience. I'm not an engineer and can't even pretend to talk out of my a$$...but when you increase the output impedance of an amp, these 300 ohm headphones really come alive. Darkvoice, A20, Bottlehead Crack, etc.

My understanding is that it's about the damping factor. With too low of an output impedance, the damping factor is incredibly high with 300 ohms, but the higher the output impedance, the lower that number gets, and the less "dampened" these dynamic drivers sound. It's something I recommend trying out rather than just theorizing over. It'll also change the frequency response of the headphones, mostly in the bass but also in the upper mids. Definitely worth experiencing when you have headphones like these!

Maybe someone with more technical expertise can explain this more eloquently than whatever I'm doing here lol

I am for sure going to try it out, no worries there. Just confirming what you guys are saying, so I can understand a bit better.

I think you're explaining just fine haha

 

[haasaaroni]

I am for sure going to try it out, no worries there. Just confirming what you guys are saying, so I can understand a bit better.

I think you're explaining just fine haha

Thanks! I just always worry when I use words I don't know the meaning for

Anyway...high output impedance is what ti look for. Usually it means an OTL amp (the Bottlehead Crack has about a 120 ohm output impedance for example), which has a high IO out of necessity, but occasionally it'll happen in a solid state amp as well, by design.

 

[DarthVader92]

Thanks! I just always worry when I use words I don't know the meaning for

Anyway...high output impedance is what ti look for. Usually it means an OTL amp (the Bottlehead Crack has about a 120 ohm output impedance for example), which has a high IO out of necessity, but occasionally it'll happen in a solid state amp as well, by design.

No worries, it really did make sense, I just had to process it all and read a bit more, which I will have to read a lot more up and learn, but I'm here for it! I'll be looking into a few amps you mentioned above as well.

 

[DarthVader92]

That gives you a high 'damping factor' (load impedance source impedance). This is a measure of amplifier control over a transducer (headphone, loudspeaker). To some listeners (including me) a moderate DF permits fine sound; a very high DF (50x ?) robs the sound of 'blossoming', of airy expansion. In the end, preference will rule.

True, preference does rule, but it doesn't matter in the case I haven't had the chance to really experience one yet. So I'm excited! I'm curious now what I'm "missing out on"

 

[cats4cans]

I am for sure going to try it out, no worries there. Just confirming what you guys are saying, so I can understand a bit better.

I think you're explaining just fine haha

Like most things generalizations only get you so far. Just remember that a transducer works both ways. If you feed it electricity, it will move. And if it’s moving, it’s generating electricity. Sound can make it move. The diaphragm being stretched from its resting position acts like a spring to pull it back. The interaction between amplifier and speaker goes both ways. Sealed or open enclosures and their sizes and restrictions to air movement also can change things. It can get complicated, but listening is more important than figuring out all the equations of motion.
As long as the amp impedance is a few multiples smaller it’ll probably be ok. Having the amp impedance larger than the transducer sounds wonky. Small SET amps with efficient speakers, low impedance IEMs, and some high impedance headphones might get by with 3:1. I enjoy 6 ohm IEMs and 300 ohm ZMFs from a Nitsch PMax with a 1.5 ohm output impedance. From the 100 ohm A20 only one of those sounds good.
Personal preference comes into play. And expectations. Try everything. Try some of it more than once at different times. Your mood or the type of music may call for a high damping factor. Under other conditions you might want it to be looser.
Just become an amp hoarder. If you leave them all connected, it’s probably quicker and much less hassle than changing pads.