[Rossliew]

I prefer tube speaker amp over solid state listening to HE-6. My favorite tubes are the old US made GE Electronic 6550A and the old Tung-Sol 6550. I don't like the sound of the reissues from Russia or China. And they are not as reliable too.

If GE and/or Tung-Sol (US) could make KT120s today I bet they would sound awesome.

Do you use any resistors across your tube amp when connecting the HE6 directly to the speaker taps? I've read in Stereophile where a contributor, Herb Reichert drove his Susvaras directly off a Cary tube integrated amp's speaker taps. I was always under the impression that for transformer coupled tube amps, a resistor across the speaker taps is a must. Or am i mistaken?

 

[wuwhere]

Do you use any resistors across your tube amp when connecting the HE6 directly to the speaker taps? I've read in Stereophile where a contributor, Herb Reichert drove his Susvaras directly off a Cary tube integrated amp's speaker taps. I was always under the impression that for transformer coupled tube amps, a resistor across the speaker taps is a must. Or am i mistaken?

I use resistors, my output transformers are not designed for 50ohms. I use the 4ohm tap.

You don't need the resistors to match impedance if the output transformers are designed for higher impedance.

 

[Rossliew]

I use resistors, my output transformers are not designed for 50ohms. I use the 4ohm tap.

You don't need the resistors to match impedance if the output transformers are designed for higher impedance.

OK thanks for the advice

 

[gonzalo1004es]

I've put up for sale a custom power amp they made for me, in case someone is interested. I used to use it with my HE6, but I don't have it anymore
https://www.head-fi.org/threads/custom-power-headphone-amp.896762/

 

[Thenewguy007]

I use resistors, my output transformers are not designed for 50ohms. I use the 4ohm tap.

You don't need the resistors to match impedance if the output transformers are designed for higher impedance.

So if the amp has 16 ohms speaker taps, no resistor would be needed?

 

[jerick70]

So if the amp has 16 ohms speaker taps, no resistor would be needed?

You'll still need to take precautions. Power amps are totally different beasts and are not made for headphones. Depending on the power amp you are using you can fry a set of headphones in a instant. Especially with low impedance headphones.

 

[wuwhere]

So if the amp has 16 ohms speaker taps, no resistor would be needed?

50 ohms is still too high for the 16 ohms tap.

 

[Thenewguy007]

50 ohms is still too high for the 16 ohms tap.

What amps are there that have a output for higher impedance then? The highest I've seen is 16 & usually always either 4 or 8.

 

[wuwhere]

What amps are there that have a output for higher impedance then? The highest I've seen is 16 & usually always either 4 or 8.

I don't know if there are.

 

[SilverEars]

It's fine to run 16 ohms ouput taps to 50 ohms. The rule in speaker world is you don't run speakers of lower ohms than the amp's (internal) impedance due to overheating the amp from it's greater internal impedance relative to the load or the speaker's.

You need a preamp (as volume control) to lower (attenuate) the DAC's output signal to the amp, so the amp doesn't output too much power to the headphone to blow out the headphones. Start with lowest volume or max attenuation, and raise it slowly to desired volume. Because amp's output is the gain of the DAC's signal, and when you reduce DAC's signal, you lower the overall amp'd output due to smaller signal being gained.

I just don't see the purpose of the hifiman box as all it's doing is adding another current path to dissipate power, so HE6 doesn't get as much current. You can just attenuate the DAC's signal to the amp with a pre-amp instead. I guess it's for amps with too much power that small change in volume knob increases the output significantly.

I know a buddy that has the ribbon headphones that's .2ohms, and that's a load that an amp rated 4ohm internal impedance will overheat all the wattage in the amp. That's when you require impedance adaption to raise what impedance the amp sees of the headphone so the amp doesn't get burnt out.

 

[astrostar59]

It's fine to run 16 ohms ouput taps to 50 ohms. The rule in speaker world is you don't run speakers of lower ohms than the amp's (internal) impedance due to overheating the amp from it's greater internal impedance relative to the load or the speaker's.

You need a preamp (as volume control) to lower (attenuate) the DAC's output signal to the amp, so the amp doesn't output too much power to the headphone to blow out the headphones. Start with lowest volume or max attenuation, and raise it slowly to desired volume. Because amp's output is the gain of the DAC's signal, and when you reduce DAC's signal, you lower the overall amp'd output due to smaller signal being gained.

I just don't see the purpose of the hifiman box as all it's doing is adding another current path to dissipate power, so HE6 doesn't get as much current. You can just attenuate the DAC's signal to the amp with a pre-amp instead. I guess it's for amps with too much power that small change in volume knob increases the output significantly.

I know a buddy that has the ribbon headphones that's .2ohms, and that's a load that an amp rated 4ohm internal impedance will overheat all the wattage in the amp. That's when you require impedance adaption to raise what impedance the amp sees of the headphone so the amp doesn't get burnt out.

I would say be very careful. A 100 watt amp powering headphones is risky to say the least. And you will have a high noise floor. So, yes, the HE-6 box has it's function IMO.

Also remember permanent hearing damage can be caused if there was ever an issue, such as power thump caused by a fridge. Or worse, the mains going off and back on as it can do in a power cut. I have had the mains go of and back on within 3 seconds a few times as the electric board try to reconnect the service.

 

[jerick70]

Here's an article that I found that looks like pretty good advice for running headphones from speaker taps.

https://diyaudioheaven.wordpress.com/tutorials/power-amp-adapter/

 

[SilverEars]

I would say be very careful. A 100 watt amp powering headphones is risky to say the least. And you will have a high noise floor. So, yes, the HE-6 box has it's function IMO.

Also remember permanent hearing damage can be caused if there was ever an issue, such as power thump caused by a fridge. Or worse, the mains going off and back on as it can do in a power cut. I have had the mains go of and back on within 3 seconds a few times as the electric board try to reconnect the service.

Yes, we should be careful, and it's the best habit not to turn anything on until you check the volume knob is all the way at the end in the counter clock-wise, no volume position. You should only slowly raise it up.

I've run 100W to 8ohm integrated amp out of speaker taps to 4-pin XLR to HD800S with sensitivity of 102 dB/mW. Hifiman is spec'd to be 83 dB/mW, but also I've read people say it may realistically be in the 70's.

You will likely not hear noise-floor with HE-6, but with the HD800S I did with the 100W amp. I can't even say it was noise-floor I heard even. I heard some sort of minute mechanical noise in the amp itself, when nothing was playing. It was not hiss.

I did have it at the lowest of the two gain setting, and volume at the lowest and slowly raised it. No issue with the 300 ohm nominal and close to 700 ohm peak impedance HD800S. This is just anecdotal, not that I would recommend people to try this. Safety first.

 

[MadSounds]

So i finally acquired a Firstwatt J2 a bit over a month ago, but due to moving i wasn't able to get any time with it until this week. Its not what i expected but I'm extremely impressed. keep in mind I've been using my Audio-gd NOS 11 which has plenty of power and I've tried a large range of other amps at meets. I was expecting a touch more/deeper base and maybe a bit of added fullness as the J2 is often described as sounding 'tube like' for a solid state amp. (though i don't think that phrase is a good way to describe sound).

Instead I found the J2 makes the he-6 sound like an e-stat, incredibly crisp and airy, like a whole level of extra detail I was missing before. base be maybe a touch less pronounced with the J2 then directly from NOS11, but by such a small margin i'm not sure, definitely not deeper like i was expecting.

Im connected directly to the speaker taps using stock Hifiman cables. I had an extra 4pin to TRS adapter that i simply lopped the end off of and cleaning up the left/right split with so shrink tube. I'm using the NOS11 as DAC and preamp with volume around 30-40 out of 100 compared to the 50-60 I was using directly from the NOS11. not having any issues with volume increments being too small. If i had a conventional volume pot with the same output range i would be worried someone might bump it too high, but i really cant see that happening with a digitally controlled latch relay.

 

[Silent One]

I’ve had no issues inside my living room since 2013:
HE-6 via speaker taps to Sansui G-22000 @ a confirmed “benched” 265 wpc. BUT...I watch plug-in, turn-on, volume defeated with rigor. Silent background as well.