Quote:

kozmo said:

All this talk about using speaker amps got me to thinking about utilizing some of my existing equipment. All of my gear is tube based, so after looking at the HiFiMAN HE-Adapter I thought I could build a nicer unit for the same kind of $ and I came up with this:
 

 
Internally it is almost identical to the HiFiMAN unit with the exception of having both XLR & mini XLR outputs, using a 10ohm parallel resistor with the 27ohm resistor in series, which will be adjusted later if needed:
 

 
Congratulations on your fine looking adapter box! I hope it brings you much enjoyment with your headphones.

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Mambosenior, I'm encouraged by your results with the Threshold 400A and the HE-5LE. I hadn't considered using an amp with that much power before.
 
Is there any noise or hiss with no source playing?
 
You're using this without any series resistance, is that correct? Any issues with sensitivity?
 
Have you tried it without the parallel resistors in place?
 
I'm hoping to have a SIMA W2002 available for testing shortly.

Quote:

kozmo said:

All this talk about using speaker amps got me to thinking about utilizing some of my existing equipment. All of my gear is tube based, so after looking at the HiFiMAN HE-Adapter I thought I could build a nicer unit for the same kind of $ and I came up with this:
 

 
Internally it is almost identical to the HiFiMAN unit with the exception of having both XLR & mini XLR outputs, using a 10ohm parallel resistor with the 27ohm resistor in series, which will be adjusted later if needed:
 

 
I had planned to use this with the Golden Tube Audio SE-40 pictured on the lower right, but the level of the noise floor was high enough to be heard with no source input, the sound was very good but probably with too much gain, maybe I'll need to increase the value of the series resistor? Though this would eliminate any damping factor, but if Operakid's conclusions are correct, this may not be a problem. Surprisingly, the sound through the 300B monoblocks was very impressive and dead quiet, though this was only my initial impressions and I will need to spend more time with it to develop an honest opinion.
 

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Nice job.  Looks great.

I'm listening to a balanced K702 An. Ed. on the Rotels and they sound killer. I've not compared a/b to the DAC hp amp or the SP but I don't think I've heard them so dynamic with this much impact and bass. I've not put the Senns on these yet but I bet they do great on here. Since I've got to have access to a fellow head fier's stable of gear, I've been able to run T-1, HE-4, 400, 500 on them and prefer the more defined soundstage and bigger bass they offer compared to the headphone amps I've used.

Quote:

kozmo said:

Mambosenior, I'm encouraged by your results with the Threshold 400A and the HE-5LE. I hadn't considered using an amp with that much power before.
 
Is there any noise or hiss with no source playing?
 
You're using this without any series resistance, is that correct? Any issues with sensitivity?
 
Have you tried it without the parallel resistors in place?
 
I'm hoping to have a SIMA W2002 available for testing shortly.

Click to expand...

 
I have had zero, zilch, nada, NO noise problems driving either the HE5-LE or HD-800 with the speaker amp. I started using the 10ohm/10watt resistors in parallel only after reading a recommendation by Operakid. Previously, I had not used any resistors with the 5-LE and experienced nothing but great sound. Now I also get the same from the HD-800.

I'm now running LCD-3 off the powerful speaker amp with a true voltage divider network which has a parallel resistor at the amp, next a series resistor, next a parallel resistor, and finally another series.  This is the way to keep impedance in the amps happy zone, introduce quite a bit of attenuation so the volume control is in the middle, and have the headphone look back into a low impedance.  The results are great.  Interesting, the rolled off highs and lack of neutrality that many report from this headphone just are not present running them this way.  Very clear, very neutral sounding.  Certainly there is less HF energy than with HD800, but I don't know that this means soft or rolled off.  The highs are really the same level that some speakers I own, often used in the recording industry as studio moniitors, display.  I am really becoming convinced that some of the characteristics attributed to certain headphones are due to interactions between low powered headphone amps and the headphones.  Certainly this will to some degree always be the case with amps and transducers, but I'm wondering if is more prevalent with headphone amps.
 
In any case, I think it is a real advantage to be able to manipulate the impedance the amps sees and that the headphones see to look for a sound that you like best.  If you have power to throw away, which is more the case when you use speaker amps with a lot of power and low output impedance, this is more easily accomplished.  
 
If you want a portable system or one that fits on a little desk then this is not such a good solution.       

Operakid,
 
Could you please elaborate on the voltage divider network you're using?
 
Did you use the network already described earlier in this thread?
 
This?> http://www.ilgazeboaudiofilo.com/t2938-partitore-resistivo-per-cuffie

Yes, that's the setup.  R1, R2, R4 = 10 ohms, R3 = 5.6 ohm.  They are all 5 watts or so, Dale wire wound non-inductive.
 
I run the headphones balanced.  My values might change if I used them with a common ground, i.e, headphone jack, as the connections to the network.  Left and right channels "talk to each other"  through the minimum resistance in this circuit between the 2 positive leads, all made possible by the common ground.  I'm not spending any time looking at that as I'm not running them through a headphone jack and have no plans to.

Quote:

mambosenior said:

 
I have had zero, zilch, nada, NO noise problems driving either the HE5-LE or HD-800 with the speaker amp. I started using the 10ohm/10watt resistors in parallel only after reading a recommendation by Operakid. Previously, I had not used any resistors with the 5-LE and experienced nothing but great sound. Now I also get the same from the HD-800.

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Did adding the 10 Ohm resistors actually do anything? And, if so, was it positive?
I guess I'm just a sceptic.

I think this question may be best answered here. I want to listen to two HE-6s on one amp. One will be recabled and the other stock. If I run the two in parallel, the amp would see half resistance? The amp will be SS so no need for further RLC influences.

Chris,
I was not using anything when it was recommended to use the parallel resistor for all amps over 80 watts. I used the 10 ohm parallel resistor for a year and then removed it. I felt the dynamics suffered with it slightly. By themselves, the 6s were more alive.

Yes, the amp will see half the impedance, but it will be way up at 25 ohms so no matter, the ss amp will deliver twice the power at 25 ohms anyway.      

Excuse my electricity ignorance, but I'm getting a tube amp soon to use with the He-6.
 
If I want the amp to see the He-6 as a ~8 Ohm load without building/using the He adapter (the duelund resitor won't fit in the box anyway), can I just tied a 10 Ohm resistor between the + - of each binding post?
 
Edit: something similar to this?
 

yes sir, that's how I used mine

Hmm do I need to solder the resistor to the binding post or just wrap/tie the wire around them?
 
Must the banana plugs of the He-6 not touch the wire of the resistor? Or it doesn't matter at all?

Quote:

khaine1711 said:

Hmm do I need to solder the resistor to the binding post or just wrap/tie the wire around them?
 
Must the banana plugs of the He-6 not touch the wire of the resistor? Or it doesn't matter at all?

Click to expand...

 
It doesn't matter.