[Micaiah]

I don't know how many have heard of Redgum Audio from Australia but they make some pretty good sounding speaker amps from what I've read. Just stumbled on their "add-on headphone connection" for just under $80 US dollars. Doesn't say how it works or if it has resistors in it.
 
http://redgumaudio.com/shop/index.php?route=product/product&path=60_65&product_id=115

 

[Chris J]

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?

Do NOT solder anything to the binding posts.
Just wrap the resistor wire around the binding post.
Doesn't matter if the resistor wire touches the bananas of your headphones.

What you are doing looks fine.
If the resistor gets too hot I'm sure you'll get the same effect from a 16 Ohm or 20 Ohm resistor.

 

[alan s]

Quote:

 
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.

How did the volume control attenuation compare in these configurations with the different HP's ?
 
I'm wondering if there was considerably more play (an ability to fine tune between soft and loud ) with the 5-LE and is that somewhat restricted on the set-up you have for the HD-800 ?
 
 
I'd like to hear from any of the HE-6 users as well.
 
thanks !

 

[Mambosenior]

Hello Alan,
 
With the resistors and HD-800, volume control is at 9 for rock/pop and at 10 with most classical and jazz. Without the resistors and the HE-5LE, the same. Since I have the resistors on banana plugs, it's easy to take them in and out of the chain (well, first turning off the amp and then restarting).
 

 

[alan s]

Thank you for the follow up. I'm definitely going down this route.

 

[lugnut]

When using resistors with a speaker amp, does the connection have to be balanced ? Thanks

 

[Operakid]

If the amp is bridged or dual mono then yes, the connection must be balanced.  Bringing 2 different grounds together (the grounds of the 2 amp negative output terminals), which a non-balanced cable would do, could be disastrous for the amplifier.
 
If the ground output terminals the 2 channels of a stereo amp are connected (they can be checked with a multimeter) then an unbalanced connector can be used.  However, any parallel resistors in the resistor network will cause a lot of crosstalk (unless the parallel resistor values are quite high) and you would be better off to use only one ground connection (ground from one channel only) going from the resistor network to the female headphone jack you'll be using to connect to your headphone plug.   

 

[Chris J]

If the amp is bridged or dual mono then yes, the connection must be balanced.  Bringing 2 different grounds together (the grounds of the 2 amp negative output terminals), which a non-balanced cable would do, could be disastrous for the amplifier.

If the amp has a balanced output (bridged output) then the negative terminal (usually a black binding post) is NOT ground.
It is an inverting output.

The positive output (usually a red binding post) is the non-inverting output.

 

[saowin111]

reading over this thread and the 'HE-6' thread, i'm starting to wonder why a speaker amp doesn't become the default amp for home setups - so many more choices, and most of us already have one or more speaker amps at home

 

[Operakid]

Quote:

reading over this thread and the 'HE-6' thread, i'm starting to wonder why a speaker amp doesn't become the default amp for home setups - so many more choices, and most of us already have one or more speaker amps at home

 
After hearing headphone amps, then speaker amps, I have wondered the same thing.  My answers to myself were:
 
1.  The separates I am using (preamp and speaker amp) are MUCH more expensive than any headphone amp.  
 
2. They are totally non-portable: 75 pound preamp, almost 200 pound amp. 
 
3. It is not turnkey like buying a headphone integrated amp is and just plugging in the headphone jack.  
 
4. You can damage your headphones if you don't pay attention.
 
5. The ideal impedance matching setup for each headphone will be different, so it requires fiddling, knowing something, effort, and a bit of understanding.  
 
It is so much fun, though, having this level of sound, essentially infinite power to drive any headphone, and the same amp to make headphone and speaker comparisons.  

 

[khaine1711]

Hello again,
 
I've been wondering: does the wattage of the resistor matter?
 
The Duelund cast 10 ohm is only available at 5W, while the Mills is at 12W. I've ordered both, but won't try the duelund anytime before I can confirm the safety. How does the Watt of the (paralleled) resistor interact with the power of the amp anyway?
 
Do I need a higher Watt resistor for a high output power amp? Say if the amp outputs is 350W @ 8 Ohm, do I need a higher spec resistor or the 5W Duelund will still work?

 

[Chris J]

Quote:

Hello again,
 
I've been wondering: does the wattage of the resistor matter?
 
The Duelund cast 10 ohm is only available at 5W, while the Mills is at 12W. I've ordered both, but won't try the duelund anytime before I can confirm the safety. How does the Watt of the (paralleled) resistor interact with the power of the amp anyway?
 
Do I need a higher Watt resistor for a high output power amp? Say if the amp outputs is 350W @ 8 Ohm, do I need a higher spec resistor or the 5W Duelund will still work?

 
In theory, you should require a 350 Watt resistor for a 350 Watt amp.
 
In practice, I assume you are not going to turn the volume up until the amp is clipping and the music has no dynamic range!
So a 12 Watt resistor may work.
Try it out and see how hot it gets when you are listening to music.
I have found that my average listening level is approx. 1-2 Watts when driving my loudspeakers.

 

[Operakid]

You would have to have tremendously efficient headphones to ever need more than a 10 watt resistor!  You are just looking to attenuate signal enough to be in a normal volume range, above the first few clicks.
 
You don't need to be able to bury the volume control, any more than you need to when using speakers.  Most systems will blow drivers if turned ALL the way up, headphones would simply be in the same range.  

 

[khaine1711]

Quote:

You would have to have tremendously efficient headphones to ever need more than a 10 watt resistor!  You are just looking to attenuate signal enough to be in a normal volume range, above the first few clicks.
 
You don't need to be able to bury the volume control, any more than you need to when using speakers.  Most systems will blow drivers if turned ALL the way up, headphones would simply be in the same range.  

You mean inefficient 

.
 
I'm pretty sure no headphone would require anywhere near 5W of actual power, but I'm more worried about safety. Like sudden surge of power, random act of gods or alien =p.
 
So let's say a 50W @ 8 ohm integrated, when volume is turned to 50%, will output 25W. Is that the same case with a preamp + power amp combo?

 

[wuwhere]

Quote:

Hello again,
 
I've been wondering: does the wattage of the resistor matter?
 
The Duelund cast 10 ohm is only available at 5W, while the Mills is at 12W. I've ordered both, but won't try the duelund anytime before I can confirm the safety. How does the Watt of the (paralleled) resistor interact with the power of the amp anyway?
 
Do I need a higher Watt resistor for a high output power amp? Say if the amp outputs is 350W @ 8 Ohm, do I need a higher spec resistor or the 5W Duelund will still work?

 
The Duelunds cast are 0.5 to 1.2 ohms at 5w, 1.5 to 30 ohms at 10w, here http://www.hificollective.co.uk/components/duelund_cast_resistors.html