[ClieOS]

Can't wait to read your impressions on C421 with low output Z, ClieOS.

I got mine changed by JDS Labs directly, and the impact on sound quality is immediately felt. My C421 sounds a lot like a more spacious O2 now.

My current impression of the updated C421 remains largely the same as the original C421, which is neither a good or bad thing, as I like i just as much.

 

[Makiah S]

Quote:

My current impression of the updated C421 remains largely the same as the original C421, which is neither a good or bad thing, as I like i just as much.

What differeance does the new ferrite have on Higher Impedance cans? like 250+ 

 

[ClieOS]

What differeance does the new ferrite have on Higher Impedance cans? like 250+ 

In theory, it shouldn't be any difference.

 

[Makiah S]

Quote:

In theory, it shouldn't be any difference.

well lets hope I get work soon so I cna find out :3

 

[Bill-P]

Quote:

My current impression of the updated C421 remains largely the same as the original C421, which is neither a good or bad thing, as I like i just as much.

 
Yeah, I just realized your ER4S would have no impedance problems... save for some high frequencies, but it wouldn't be that big a deal anyway.
 
It's a noticeable improvement to my ATH-ES10. It gives the headphone a more spacious sound, and more polite bass.

 

[Evshrug]

To do basic output impedance measurement, you will need
(1) A digital multimeter that can measure AC in mV.
(2) A fixed load that you can plug into the amp. I soldered a pair of matched 47ohm resistor to a Neutrik jack for this.
(3) An interconnecting cable. This is for you to measure the unload volatge easily straight from the plug
(4) A tone generator. Any decent USB DAC or sound card with Audacity on the PC will do.
(5) Some math calculation.
You can find the detail here, and it is basically the same thing NwAvGuy has described in his article about output impedance. He uses 100Hz mostly but I choose 1000Hz since it is more widely used. Note that many amp have higher output impedance on the top treble (15kHz~20kHz) so you don't want to measure in those area. Given what need to have, I don't think most typical shops will have the needed fixed load around for output impedance measurement unless they are also doing repair work and has some spare resistors around to play with.
Anyway, 1/8th is the minimum rule most are following. Some even go for the tougher 1/10th rule. The impedance adapter on ER4S (100ohm, 4P is 27ohm) is mainly to reshaped the FR curve to match the Etymotic 'ideal' curve and has less to do with dampening or the 1/8th rule. But in a way, you can say 4P is the colored sounding version of the 4S - it is just a matter of how you interpret words.

Ok... So it's a lot to swallow, should take a while to digest all this info. Thanks for it, though.

 

[Makiah S]

Quote:

Ok... So it's a lot to swallow, should take a while to digest all this info. Thanks for it, though.

Not really that made decent sense to me, I'd be happy to listen to the electrical explination of how sound is colored by electronics... that would be interesting! I think it has something to do with how the Harmonics are produced... I dunno
 
Still anything that's less colored sounds good to me :3

 

[QQSB]

Thank you very helpful information.

 

[Kaffeemann]

Will an amp actually improve the sound quality of headphone/IEM?
 
After reading NwAvGuy´s site it seems an amp sould do two things:
 
1. Make things louder <=> less volume needed from the source
2. Prevent clipping.
 
Thats it???
 
My HD 650 sound just fine straight out of my Sansa Clip Zip (RB). Still worth getting a O2?
 

 

[ClieOS]

Let's put it backward - if amp is only supposed to make things louder and prevent clipping, which neither seems to be an issue for your clip Zip driving HD650, why do you think NwAvGuy design the O2 in the first place as he also own both HD650 and Zip?
 
I think the answer is simple: because sometime 'enough' is good enough, but it isn't the best it can be. Then you need to realize that 'best' can be as subjective as it is objective.

 

[Kaffeemann]

The O2 was not made for any headphone or source in particular, AFAIK.
The O2 is your reference amp. So in your book it's the best amp in the sub-200$ range. The difference in sound quality with and without the O2 should be very obvious then, right?
 
Quote:

Then you need to realize that 'best' can be as subjective as it is objective.

I don't get this

 
EDIT: I found some data.
 
Clip Zip: maximum output = 489 mV
 
Sennheiser HD 650: 300 ohm impedance and 103 db/mW
 
So the Clip has about 0.8 mW of power into 300 ohm headphones. So there will be clipping for anything that is louder than (103 db/mW) * (0.8 mW) = 82.5 db.
 
Seems like you are right

 

[HamilcarBarca]

Quote:

The O2 was not made for any headphone or source in particular, AFAIK.

 
+1
 
It was designed for 98% of the headphones out there. It's probably inadequate for mega-buck electrostatics, but it's more than adequate for just about everything else.
 
Is it suitable for everyone? No, not if someone's looking for a "warm-sounding" amp, one with switchable inputs, an internal power supply or transformer, etc.
 
It was my second choice, but I ended up preferring it to my first choice. I wouldn't hesitate to buy another.

 

[Harito408]

What about the leckerton slim?

 

[Armaegis]

Quote:

Is it suitable for everyone? No, not if someone's looking for a "warm-sounding" amp, one with switchable inputs, an internal power supply or transformer, etc.

Or actually portable...

 

[HamilcarBarca]

Quote:

Quote:

Is it suitable for everyone? No, not if someone's looking for a "warm-sounding" amp, one with switchable inputs, an internal power supply or transformer, etc.

Or actually portable...

 
When I was in school, I would have transported it in my backpack. But you're right. It's in no way a lightweight, pocket-sized amp.