[WNBC]

Ha! Now I want to try speakers tap again 

.  I need to stop reading head-fi.  Right out of the headphone output of the 737 sounds fantastic.  Can it get better?  Only one way to find out.
 
Quote:

I haven't come across a headphone out that has been able to duplicate the sonic quality of the HE-500 via speaker taps. The best I have heard it is via the speaker taps of a 25WPC solid state amp (5.3 watts @ 38 ohms). We are into flower-bed territory so any descriptions of the sound would fail. The only thing to do is to at least try it out to see what the sonic differences may be and whether it's worth the effort.

 

[Llloyd]

Yeah many people have reported amazing differences with the HE-500 via taps.  I wish I had the money to try myself.  I'll doubtfully be spending a whole lot more on audio equipment though.  Maybe a pair of more efficient speakers.  Maybe.

 

[Terja]

One reason I'm digging vintage audio right now is because most of the amps are in the 20 to 50 watts per channel range, unlike modern audio amps with their 100 to 200 watt boasts. Vintage audio is just about right power-wise to match up with orthodynamics. Also aesthetically some of this stuff is miles ahead of most of the stuff produced post 1980. Prices and availability are still good too, so the getting is still good. It's an unusual but beautiful match-up -- vintage amplifiers paired with state of the art headphone development.
 

 

[CJG888]

If I connect my HE-500s to the 8 Ohm speaker taps of my 18W 300B single-ended amp, do I risk damaging the output transformers? Would I need a resistor in parallel? Is it worth purchasing HiFiman's connection box?

 

[plin]

Quote:

If I connect my HE-500s to the 8 Ohm speaker taps of my 18W 300B single-ended amp, do I risk damaging the output transformers? Would I need a resistor in parallel? Is it worth purchasing HiFiman's connection box?

No, higher impedance means lower current load and better transformer operation. You do not need a resistor in parallel.
 
Only some digital amplifiers, that need a low pass filter in their output, may work best with lower impedance loads. Some of them may also require balance operation, because they short circuit their outputs in single ended connections like the normal headphone jack.
 
18W in 8 Ohms translates to 3.8W in the nominal impedance of HE-500 (38 Ohm). So, there is really no need to protect it with a resistor divider like the HifiMan's protection box.
 
BTW, impedance of HE-500 varies considerably with possible detrimental effects in sound quality. Have you measured your's HE-500 resistance?

 

[Calypso]

Quote:

If I connect my HE-500s to the 8 Ohm speaker taps of my 18W 300B single-ended amp, do I risk damaging the output transformers? 

Well, It has actually been claimed by some people here on heaf-fi.org. Apparently running a high impedance/resistance headphone on a tube amplifier intended for 4-8 ohm speakers will damage the output transformers 

. I can´t personally see why or how, so I would define this as B...S... 

.

 

[Calypso]

Quote:

BTW, impedance of HE-500 varies considerably with possible detrimental effects in sound quality.

As long as the left and right speakers have the same impedance, you should be all right 

. My HE-500 (1 month old) measures 50.4 ohm on both left and right.

 

[plin]

Quote:

As long as the left and right speakers have the same impedance, you should be all right 

. My HE-500 (1 month old) measures 50.4 ohm on both left and right.

 
How can you say so? Have you tested your HE-500 side-by-side with one with different resistance and verified that there is no difference in sound quality? Do you know that, according to this, Fang himself, the man who designed HE-500, seems to accept +-25% resistance variations only? 
 
I have compared my HE-500 (48 Ohm) with a fellow head-fier’s HE-500 which had almost half the impedance (25 Ohm) and the difference in sound quality was easily apparent by both of us.  
 
It seems that a lot of HE-500’s have higher impedance than nominal (even the HE-500 measured by Tyll had 47 Ohms). I do not know if this is a good or bad thing sonic-wise, but, between the two HE-500’s that I have compared, the one with higher impedance had better SQ.
 
Of course, I fully agree with you that impedance matching between the left and right channel is the first thing to check. Any significant difference there will be clearly audible as channel imbalance.

 

[plin]

Quote:

Well, It has actually been claimed by some people here on heaf-fi.org. Apparently running a high impedance/resistance headphone on a tube amplifier intended for 4-8 ohm speakers will damage the output transformers 

. I can´t personally see why or how, so I would define this as B...S... 

.

Very odd! Do these amplifiers warn against open (with no output load) operation? Is it normal for an amp to be destroyed when working with no load?
 
Maybe you are right, this is nonsense. 

 

[Loevhagen]

Just out of curiosity; did you detect any difference in sound signature prior to measure the impedance - and therefore decided to meeasure them. Or, vice versa?
Quote:

I have compared my HE-500 (48 Ohm) with a fellow head-fier’s HE-500 which had almost half the impedance (25 Ohm) and the difference in sound quality was easily apparent by both of us.  

 

[plin]

Quote:

Just out of curiosity; did you detect any difference in sound signature prior to measure the impedance - and therefore decided to meeasure them. Or, vice versa?

The 1st thing we noticed was serious difference in apparent sound volume. Then I measured the resistance and after we level match them, we compared them and then we noticed the sonic quality difference. 

 

[CJG888]

No, higher impedance means lower current load and better transformer operation. You do not need a resistor in parallel.

Only some digital amplifiers, that need a low pass filter in their output, may work best with lower impedance loads. Some of them may also require balance operation, because they short circuit their outputs in single ended connections like the normal headphone jack.

18W in 8 Ohms translates to 3.8W in the nominal impedance of HE-500 (38 Ohm). So, there is really no need to protect it with a resistor divider like the HifiMan's protection box.

BTW, impedance of HE-500 varies considerably with possible detrimental effects in sound quality. Have you measured your's HE-500 resistance?

Does this mean that I don't actually need a balanced cable, and can wire speaker leads up to a TRS socket?

 

[Ultrainferno]

So it is safe to use my 2 x 80W (8Ohm) Kenwood amp with the HE-500? My He-500 measures 38Ohm
 

 

[Loevhagen]

This might help: http://www.head-fi.org/t/570590/he-500-on-speaker-amps-via-he-adapter#post_7805800

 

[captouch]

Does this mean that I don't actually need a balanced cable, and can wire speaker leads up to a TRS socket?

Most everybody I've heard use speaker taps uses a 4-pin XLR female speaker tap and has their cans equipped with a cord that terminates in a 4-pin male XLR.

I'd say if you're going for the best sound by exploring the higher power, why not go balanced as well? Likely any speaker tap you buy will be 4-pin XLR female and it's not that big a deal to reterminate a TRS cord to XLR male - just did a retermination for the first time yesterday and it went smoothly. The XLR male connector is only like $5, but of course you'd need soldering iron, solder, etc to complete the job. Of course you can always buy an aftermarket cord that comes this way, but that may not be cheap.