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post #46 of 111
Thread Starter 

Right I finally got around to testing it. The first version has a glitch, and the left side works but the right was monumentally messed up.

 

So to test the concept I created a franken-circuit, excuse the crappy photos.

IMG_20120506_112958.jpg

 

I used (per channel) 2x 47ohm 0.75w resisters in parallel since I couldn't find any 24ohm resisters that could carry the current

and 1x 4.7ohm 0.6w resister

 

And wow it really does waste power, I haveto put the STX on extra high but at 40% max.

I am running 2x AD797BR opamps, which nullifies the crappy bass of the JRC, but retains the sharpness (which I dont like, but it helps identify differences) and increases clarity.

 

Overall I notice the highs are back to normal, which is still bright in the D2000, but thankfully not painful, it actually makes the aggressive sound of the AD797 bearable.

I dont know if its affecting the SQ, I have a feeling it is but it could very well be my franked adapter, It should improve when I solder it in place, or its just that the AKG K242HD has some serious synergy with the AD797.

Bass is still as hard hitting as ever, but its definately clearer and not there when not needed.

 

whether its worth the effort.... I wouldn't say it isn't, but I wouldnt say it is.

 

 

 

Since I have some spare power to play with, can I bump up/down the resistor values to get a stronger effect (lower output resistance) ?

 

EDIT: I would say I have exactly 50% more power then I am using now to waste before I put stress on the STX components (keeping volume lower then 76)


Edited by WiR3D - 5/6/12 at 3:40am
post #47 of 111
Quote:
Originally Posted by WiR3D View Post

Right I finally got around to testing it. The first version has a glitch, and the left side works but the right was monumentally messed up.

 

So to test the concept I created a franken-circuit, excuse the crappy photos.

IMG_20120506_112958.jpg

 

I used (per channel) 2x 47ohm 0.75w resisters in parallel since I couldn't find any 24ohm resisters that could carry the current

and 1x 4.7ohm 0.6w resister

 

And wow it really does waste power, I haveto put the STX on extra high but at 40% max.

I am running 2x AD797BR opamps, which nullifies the crappy bass of the JRC, but retains the sharpness (which I dont like, but it helps identify differences) and increases clarity.

 

Overall I notice the highs are back to normal, which is still bright in the D2000, but thankfully not painful, it actually makes the aggressive sound of the AD797 bearable.

I dont know if its affecting the SQ, I have a feeling it is but it could very well be my franked adapter, It should improve when I solder it in place, or its just that the AKG K242HD has some serious synergy with the AD797.

Bass is still as hard hitting as ever, but its definately clearer and not there when not needed.

 

whether its worth the effort.... I wouldn't say it isn't, but I wouldnt say it is.

 

 

 

Since I have some spare power to play with, can I bump up/down the resistor values to get a stronger effect (lower output resistance) ?

 

EDIT: I would say I have exactly 50% more power then I am using now to waste before I put stress on the STX components (keeping volume lower then 76)

 

Sure,  trying increasing or decreasing the 4.7 ohm resistor.

The value will not be the same for both headphones.

You can probably just delete "Franken-circuit" with the AKGs.

 

BTW what does the STX and either 'phone sound like without "Franken-circuit"?

 Just want to get some impressions of the AD797............

 

I've noticed that some of the AKG Q701 guys like the STX but you should be warned that some people think the Q701 is a bright 'phone!

post #48 of 111
Thread Starter 
Quote:
Originally Posted by Chris J View Post

 

Sure,  trying increasing or decreasing the 4.7 ohm resistor.

The value will not be the same for both headphones.

You can probably just delete "Franken-circuit" with the AKGs.

 

BTW what does the STX and either 'phone sound like without "Franken-circuit"?

 Just want to get some impressions of the AD797............

 

I've noticed that some of the AKG Q701 guys like the STX but you should be warned that some people think the Q701 is a bright 'phone!


No I am not using the K242 with the franken-circuit, I really do think it has an affinity, clarity wise, with the AD797, its harsh but it seems my brain compensates after a while, it has insane imaging and a big soundstage, it is warm with the K242, and intimate, and has an intoxicating heroin-like effect with its clarity when matched with the K242, but I do think the highs are a bit much, but that could be due to the treble spike in the FR of the K242. On a side note the THS4032 is 90% the AD797 but with a smooth sound signature.

 

The k242 already eats way too much power anyway so I doubt I will get enough power to it, I will try later though.

I'm going to play with the math now now aswell and see what numbers I get :P

post #49 of 111

Hey guys!

 

I'm stuck with an issue I figured might be relevant to this whole debate.

 

I'm currently using PC --> Foobar / (WASAPI) --> Coax cable --> Yulong D100 --> JH16 / Heir Audio 8.A. It sounds great, but I'm having trouble adjusting the volume. If I leave Foobar at it's max (which is the standard), my CIEMs are so loud I cannot listen to them even at the lowest ticks on the volume knob of the D100. I assume this is because both of my custom IEMs are relatively sensitive (26 ohm impedance iirc)

 

Obviously dampening the volume in Foobar solves this, and with around -18dB in Foobar I'm able to go up a few ticks on the D100 (nowhere near 1/4 of the potential though). I keep thinking that dampening the digital signal might be a bad idea for the SQ and ideally I'd have Foobar's volume at it's maxed standard and my D100 much less brutal to my CIEMs meaning I could adjust volume to my specific needs rather than settling for "a bit too quiet" or "way too high".

 

Would an impedance adapter from say Apuresound fix this, or do I need to go a different route?

 

Thanks in advance.

post #50 of 111
Thread Starter 

So just to catch everyone else up Staal, I'm going to repeat myself.

 

A normal output increasing adapter should do the job, but i keep hearing reports that it affects the sound, which makes sense since it pretty much introduces an impedance mismatch.

 

Chris J I was busy thinking that the same type of parallel circuit i am using will do a good job at wasting power, but will it actually work in this application? it may make them more sensative to noise...

post #51 of 111
Quote:
Originally Posted by Staal View Post

Hey guys!

 

I'm stuck with an issue I figured might be relevant to this whole debate.

 

I'm currently using PC --> Foobar / (WASAPI) --> Coax cable --> Yulong D100 --> JH16 / Heir Audio 8.A. It sounds great, but I'm having trouble adjusting the volume. If I leave Foobar at it's max (which is the standard), my CIEMs are so loud I cannot listen to them even at the lowest ticks on the volume knob of the D100. I assume this is because both of my custom IEMs are relatively sensitive (26 ohm impedance iirc)

 

Obviously dampening the volume in Foobar solves this, and with around -18dB in Foobar I'm able to go up a few ticks on the D100 (nowhere near 1/4 of the potential though). I keep thinking that dampening the digital signal might be a bad idea for the SQ and ideally I'd have Foobar's volume at it's maxed standard and my D100 much less brutal to my CIEMs meaning I could adjust volume to my specific needs rather than settling for "a bit too quiet" or "way too high".

 

Would an impedance adapter from say Apuresound fix this, or do I need to go a different route?

 

Thanks in advance.

 

Do you have any idea how much gain the Yulong has?

I really don't know much about the Yulong but I will guess that it has approx. 20 dB of gain.   Does it have adjustable gain?

I am no expert on IEMs but I do have a pair of Shure SE210 IEMs (they sound rather crappy............the bass is AWOL).

I plugged them into my Matrix M Stage, the M Stage can be set to a gain of 0, 10 18 or 20 dB.

At 20 dB I had the problem you describe, very little control over the volume and the control is at approx. 8 o'clock.

There is also a fair amount of hiss coming from the amp.    frown.gif

At 0 dB gain I have some control over the volume and have usable range from approx. to 12 o'clock.

 

Quote:
Originally Posted by WiR3D View Post

A normal output increasing adapter should do the job, but i keep hearing reports that it affects the sound, which makes sense since it pretty much introduces an impedance mismatch.

 

Chris J I was busy thinking that the same type of parallel circuit i am using will do a good job at wasting power, but will it actually work in this application? it may make them more sensative to noise...

 

I've heard some people say that an in-line resistor is a good idea and I've heard other people say that you get too much hiss from some amps................YMMV!

post #52 of 111
Thread Starter 

OOOOOO wait I just had a crazy idea. How about both?

 

An inline resister to increase the noise floor with the sideffect of introducing an impedance mismatch, and then the faux impedance decreasing adapter, that will waste power and counteract the negative effects of the impedance mismatch. In theory anyway

post #53 of 111
Quote:
Originally Posted by WiR3D View Post

OOOOOO wait I just had a crazy idea. How about both?

 

An inline resister to increase the noise floor with the sideffect of introducing an impedance mismatch, and then the faux impedance decreasing adapter, that will waste power and counteract the negative effects of the impedance mismatch. In theory anyway

 

I think the problem is usually too much hisssssssss.very_evil_smiley.gif

Adding another resistor will not reduce the nassssssssty hissssss.frown.gif

That's my theory, anyway.

 

I've heard a lot of guys say they don't like the sound of "digital damping".

Staaal, what does it say in the Yulong manual about reducing the Analog gain of the headphone amp in the Yulong?

post #54 of 111
Quote:
Originally Posted by Chris J View Post

 

I've heard a lot of guys say they don't like the sound of "digital damping".

Staaal, what does it say in the Yulong manual about reducing the Analog gain of the headphone amp in the Yulong?

 

It doesn't really mention anything regarding the issue.

post #55 of 111
Quote:
Originally Posted by WiR3D View Post

OOOOOO wait I just had a crazy idea. How about both?

 

An inline resister to increase the noise floor with the sideffect of introducing an impedance mismatch, and then the faux impedance decreasing adapter, that will waste power and counteract the negative effects of the impedance mismatch. In theory anyway

 

Come to think of it,

any attentuator (in line resistor) that attenuates the signal will also attenuate the hiss.

 

I don't think I would bother adding a resistor in parallel with the headphone.

Apparently most IEMs are very simple loads and don't need the resistor in parallel.

But you can try it out..................you never know.

post #56 of 111
Thread Starter 

well the whole point of the inline resisters (output impedance INCREASING adapters) is too raise the noise floor for IEMs, which it should do.

 

But it introduces an impedance mismatch. But Staal just buy one, it will do what you want, just be warned the side effect is colouration and possible loss of clarity.

post #57 of 111
Thread Starter 

Right I just did the Math.

 

If I drop the parallel resistor to 2.21ohms then the following results:

 

 

Amp load: 38~39 ohms (this will never really change)

Output impedance(from headphone perspective): 2.07ohms

Maximum output Vrms: 0.37

Maximum output Arms: 0.182

SPL:105dB

 

so I will have more then enough power in my opinion anyway. and then this pushes the impedance balance over the 10/1 barrier.

 

I'm doing it :p

post #58 of 111
Quote:
Originally Posted by WiR3D View Post

well the whole point of the inline resisters (output impedance INCREASING adapters) is too raise the noise floor for IEMs, which it should do.

 

But it introduces an impedance mismatch. But Staal just buy one, it will do what you want, just be warned the side effect is colouration and possible loss of clarity.

 

I think you mean drop the noise floor, lower the noise floor, reduce the level of the noise?????????

post #59 of 111
Thread Starter 
Quote:
Originally Posted by Chris J View Post

 

I think you mean drop the noise floor, lower the noise floor, reduce the level of the noise?????????

yes that 

post #60 of 111
Etymotic ER4P -> ER4S adapter $50 75 Cabled

 

I have this one.

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