120ohm adapter takes the KSC35 to another level
Mar 5, 2007 at 3:12 AM Post #31 of 60
Seems like Meier Audio had Oelbach cables some time ago. Maybe a source for the impedance adapters? Didn't check the site yet.
CPW
 
Mar 5, 2007 at 4:28 AM Post #33 of 60
Quote:

Originally Posted by patrox89 /img/forum/go_quote.gif
i cant find anywhere on the meier audio cable pages these adapters.


They don't have them anymore.

The only places I can find any sort of impedance adapters available online are the Ety P-S cable (100ohm) for $40 and the one over at Moon-Audio (125ohm) for $65.
 
Mar 5, 2007 at 11:31 PM Post #34 of 60
I'm mostly curious as to why this seems to work! What is happening with the amp (or the inductance of the headphones?) that causes this cool change of sound?

I notice it works not only on my Portapros but on my current-hungry Ultrasone Proline 750's coming out of my current-deficient laptop headphone-out. I'm using the attenuator from my Shure E4c to experiment with different volume vs, resistance settings, and the laptop seems to like being driven at about 70%-80% on the Wave and Master volumes with the attenuator adjusted down to taste. Much firmer bass! And there definitely is a "sweet spot" where a perfect combination exists!

My question is: Why is this happening???

Terry
750prolinebx3.png
 
Mar 8, 2007 at 5:54 PM Post #35 of 60
Today very first time I tried my 120ohm adapter (diy) with my dt831 and ksc-75.

Source was my iriver h120 and unfortunately I don't have an amp (yet).

Kind of hi-jacking part 1, dt831's sound is completely changed with the adaptor - unbelievable. I think I liked the new sound but without an amp my iriver can barely drive them. And, compared to ksc75 there is definitely no booming; i.e. bass is there but without any boom. Desperately waiting for an amp.

When it comes to ksc75 with 120ohm adaptor I definitely didn't like the sound. Everything is tamed down and its signature bass response is reduced dramatically. IMO it's much better without an adaptor.

Kind of hi-jacking part 2, how can I reduce the bass on ksc75 - for my taste its extension is good but when I am listening anything the first thing it comes to my mind is 'how bassy this headphone' is - which I don't like at all (or i got used to 831's too much that anything booms sounds strange
smily_headphones1.gif
 
Mar 10, 2007 at 5:23 AM Post #36 of 60
well, I just made my own
but seems to have mistaken one resistor for another...
The sound is definitely more bassy, but the headphone didn't transform or anything, the bass is just a bit more apparent. Maybe later this year I will mix and match resistors to get the perfect sound from the ksc75
 
Mar 10, 2007 at 5:27 AM Post #37 of 60
Quote:

Originally Posted by poonpower /img/forum/go_quote.gif
well, I just made my own
but seems to have mistaken one resistor for another...
The sound is definitely more bassy, but the headphone didn't transform or anything, the bass is just a bit more apparent. Maybe later this year I will mix and match resistors to get the perfect sound from the ksc75



Is that it? Yow...might want to heatshrink some of that stuff up before actually soldering it all together.
 
Mar 10, 2007 at 5:34 AM Post #38 of 60
Quote:

Originally Posted by tbritton /img/forum/go_quote.gif
I'm mostly curious as to why this seems to work! What is happening with the amp (or the inductance of the headphones?) that causes this cool change of sound?

I notice it works not only on my Portapros but on my current-hungry Ultrasone Proline 750's coming out of my current-deficient laptop headphone-out. I'm using the attenuator from my Shure E4c to experiment with different volume vs, resistance settings, and the laptop seems to like being driven at about 70%-80% on the Wave and Master volumes with the attenuator adjusted down to taste. Much firmer bass! And there definitely is a "sweet spot" where a perfect combination exists!

My question is: Why is this happening???

Terry
750prolinebx3.png



I don't know anything about Ultrasones, but in most cases, the extra impedance will help a little bit with more sensitive phones - say, Grados in the 32ohm range. Since the headphones are so sensitive, they'll generally get more out of the amp, thus accentuating everything (including any sort of interference) you hear. Less sensitive amps, like Beyers and Senns, usually won't have this problem. The goal is to match the amp's output impedance with the headphones as best you can to ensure getting the best sound out of the rig.

However, you don't really want to use those inline attenuator adapters you get with Shures and UE products, they suck and you won't get quite the same effect. The more you attenuate with those things, the muddier it will sound.

Also, just a little disclaimer, any and all effects on the sound are generally less significant than you might think.
 
Mar 10, 2007 at 5:48 AM Post #39 of 60
Quote:

Originally Posted by Mrvile /img/forum/go_quote.gif

However, you don't really want to use those inline attenuator adapters you get with Shures and UE products, they suck and you won't get quite the same effect. The more you attenuate with those things, the muddier it will sound.

Also, just a little disclaimer, any and all effects on the sound are generally less significant than you might think.


Heh... well shoot, then!

I was using the variable attenuator hoping to find a nice spot and then measure the resistance once I do, but that "spot" is proving to be elusive with different types of music! Figures! And yes, they do get muddier at the higher resistances - these aren't the greatest wire-wounds - unless they are carbon composite to be worse! - and their slider bars I'm sure can't handle much current. Anyway, the final thing would be to get an amp for the bulk of my issues, but the laptop would not benefit from one much since I would be amplifying an amplifier's headphone out (no line out on this). So, this resistor workaround is ample for when I am stuck with that.

It seems to me there is more going on than mere impedance matching, though. If I recall, a fixed resistance and an inductor in series will change impedance based upon the frequency delivered - that is, impedance will not be uniform across all frequencies, so it will ultimately act as a tone control circuit of sorts. (The inductor in this instance is the voicecoil in the dynamic drivers). Anyone with more knowledge have an insight into this?

Terry
750prolinebx3.png
 
Mar 10, 2007 at 6:03 AM Post #40 of 60
Quote:

Originally Posted by tbritton /img/forum/go_quote.gif
It seems to me there is more going on than mere impedance matching, though. If I recall, a fixed resistance and an inductor in series will change impedance based upon the frequency delivered - that is, impedance will not be uniform across all frequencies, so it will ultimately act as a tone control circuit of sorts. (The inductor in this instance is the voicecoil in the dynamic drivers). Anyone with more knowledge have an insight into this?

Terry
750prolinebx3.png



Well, impedance is never going to be exactly the same across the entire frequency range...when headphone measurements are taken for specs, they usually test impedance at 1,000hz. However, different headphones will obviously have different impedance variations - Senns usually have an impedance spike at around 100hz, AKG's peak at around 20,000hz, and Grados/Beyers will tend to have a flatter graph. I would take this with a grain of salt, however, since impedance acts differently on all headphones.

The thing about the voicecoil, in-line resistance won't have any effect on the voicecoil. However, different models of headphones sometimes will. I think some examples are the different types of Beyers, as there are always several resistance versions of the headphones (80ohm, 250ohm, 600ohm, etc), and the differences are a result of, say, a thicker voicecoil which will change the sound.
 
Mar 10, 2007 at 6:10 AM Post #41 of 60
Quote:

Originally Posted by poonpower /img/forum/go_quote.gif
well, I just made my own
but seems to have mistaken one resistor for another...
The sound is definitely more bassy, but the headphone didn't transform or anything, the bass is just a bit more apparent. Maybe later this year I will mix and match resistors to get the perfect sound from the ksc75



nice work..
why not just install the resistors inside the plug?
 
Mar 10, 2007 at 6:15 AM Post #42 of 60
Quote:

Originally Posted by cantsleep /img/forum/go_quote.gif
nice work..
why not just install the resistors inside the plug?


Chances are, those resistors won't fit in a standard 1/8" plug.
 
Mar 10, 2007 at 7:01 AM Post #43 of 60
Quote:

Originally Posted by Mrvile /img/forum/go_quote.gif
Chances are, those resistors won't fit in a standard 1/8" plug.


hmm.. maybe... you're right.

they fit in canare and switchcraft plugs(barely) but not neutrik plugs. i havent tried any other brands..
 
Mar 11, 2007 at 1:14 AM Post #44 of 60
Yea, I couldn't find any readily available plugs here in toronto, so I just went to The Source(by Circuit city) to get these. They fit in there pretty well. One question: I got a reply from my other thread that I installed 2000ohm of resistance, is this true?
It sounds pretty good, and my laptop can drive it with no problem...
 
Mar 11, 2007 at 1:16 AM Post #45 of 60
Quote:

Originally Posted by poonpower /img/forum/go_quote.gif
Yea, I couldn't find any readily available plugs here in toronto, so I just went to The Source(by Circuit city) to get these. They fit in there pretty well. One question: I got a reply from my other thread that I installed 2000ohm of resistance, is this true?
It sounds pretty good, and my laptop can drive it with no problem...


Do you know what resistors you used?

I would make sure that the resistors used in both left and right channel are the same, otherwise one side will sound different from the other.
 
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