[Sonido]

  I wanted to start dabbling in the DIY stuff. This is a fantastic place to start (the quickie)... I'm really turned off by the idea of a random colored board though, anyone know if I can pay more to have a specific color or something?

You could try emailing them a request. They're a small business and responds well to email in my experience.

 

[Drsparis]

  You could try emailing them a request. They're a small business and responds well to email in my experience.

Yea ill try after the holidays when i have a bit of money!

 

[preproman]

Seems I will end up with a emotiva upa-2 for a little less than 300. Wish me luck. Does it have common ground?

 
Good buy if you ask me.  I have 2X UPA 2s and 3X UPA 1s.  HC convinced me to try them with the HE-6.  They did have a lower noise floor and did sound much better than the a-100.  I guess we should expect that right.  Anyway, they are used for my 7 channel Home Theater rig.   

 

[davidsh]

Never got that upa-2. You know what happens when you accidentally short a 125 watt power amp with he-500? It blows. Well, not the amp, but the phone does.. Just don't hope my x-can has taken damage as well. There's literally blown a hole in one of the diaphragms. Cannot figure out whether my x-can works properly either. Let's see how good Hifiman warranty really is :S

 

[john57]

I sure that headphone manufactures are not crazy about users blowing their headphones on speaker amps. There are methods that I use to help safeguard against accident overload. I always check the settings on equipment each time I have visitors especially afterwards even if the equipment was not being used at the time.

 

[SolidVictory]

Since we're talking about speaker amps here, I was wondering what type of resistor would be sufficient for the HE-500 running on the speaker taps of the Yamaha RX-V1200 (see specs here). They list the Main output at 80W + 80W @ 8 ohms.
 
Since the HE-500s are 38 ohms, how much of a resistor would be sufficient here? 200 ohms? Considering that the amp would be supplying ~16.8 watts based on a 38 ohm headphone? I'm thinking: 16.84 watts = 80 watts x (8 ohms / 38 ohms)

 

[potterma]

  Since we're talking about speaker amps here, I was wondering what type of resistor would be sufficient for the HE-500 running on the speaker taps of the Yamaha RX-V1200 (see specs here). They list the Main output at 80W + 80W @ 8 ohms.
 
Since the HE-500s are 38 ohms, how much of a resistor would be sufficient here? 200 ohms? Considering that the amp would be supplying ~16.8 watts based on a 38 ohm headphone? I'm thinking: 16.84 watts = 80 watts x (8 ohms / 38 ohms)

Depends on how much attenuation you need.  Lots of good discussion over in the "speaker amps for headphones" thread.
 
Also, check out RobRob's  headphone resistor network calculator that he put up recently.

 

[Sonido]

Never got that upa-2. You know what happens when you accidentally short a 125 watt power amp with he-500? It blows. Well, not the amp, but the phone does.. Just don't hope my x-can has taken damage as well. There's literally blown a hole in one of the diaphragms. Cannot figure out whether my x-can works properly either. Let's see how good Hifiman warranty really is :S

Wait what happened? Did you damage your HE-500? Did you accidentally connect common ground when it shouldn't? Or was 125 W too much for the HE-500? Since we're playing with speaker amps to headphones, it's good to know if there's an upper limit in power the headphones can take.

 

[SolidVictory]

  Depends on how much attenuation you need.  Lots of good discussion over in the "speaker amps for headphones" thread.
 
Also, check out RobRob's  headphone resistor network calculator that he put up recently.

 
Thanks for the help. Looks like for this amp, I should go with a 2 ohm for Resistor 3, and 6 ohms for Resistor 2. This reaches the effective speaker load of 7.9 ohms which is nearly 8 ohms.
 
This creates an attenuation of -12.37 dB, which I think should be sufficient.
 
Can this even be done on a single cable or would you need some type of enclosure?

 

[davidsh]

Nope, accidentally switched the banana plugs so it was +r to +l and -r to -l. Was running it balanced

 

[Sonido]

Nope, accidentally switched the banana plugs so it was +r to +l and -r to -l. Was running it balanced

Good to know. I've accidentally switched channels before, but luckily not shorting. Gotta be extra vigilant now when I'm switching amps. Sorry about your mishap, hope they'll replace it.

 

[SolidVictory]

Nope, accidentally switched the banana plugs so it was +r to +l and -r to -l. Was running it balanced

 
Ouch, that sucks! Hope they replace it.

 

[Anda]

There's literally blown a hole in one of the diaphragms.

 

[Taowolf51]

Never got that upa-2. You know what happens when you accidentally short a 125 watt power amp with he-500? It blows. Well, not the amp, but the phone does.. Just don't hope my x-can has taken damage as well. There's literally blown a hole in one of the diaphragms. Cannot figure out whether my x-can works properly either. Let's see how good Hifiman warranty really is :S

And that's why I want to move to a Mini-X over my XPA-200.

 
 
Quote:

   
Good buy if you ask me.  I have 2X UPA 2s and 3X UPA 1s.  HC convinced me to try them with the HE-6.  They did have a lower noise floor and did sound much better than the a-100.  I guess we should expect that right.  Anyway, they are used for my 7 channel Home Theater rig.   

I'm surprised the UPA-2 has a lower noise floor considering how much power it has. How audible is the noise floor on the UPA-2 and the Mini-X?
 

Nope, accidentally switched the banana plugs so it was +r to +l and -r to -l. Was running it balanced

 
I don't quite understand, you switched channels and it blew your headphones? How does that work?

 

[john57]

  I'm surprised the UPA-2 has a lower noise floor considering how much power it has. How audible is the noise floor on the UPA-2 and the Mini-X?
 

On paper the specs for S/N at Emotiva the specifications is as follows:
 
For the the UPA-2
Signal to Noise Ratio (8 Ohm load):
> 92 dB at 1 watt (A-weighted).
> 106 dB at rated power (A-weighted).
 
For the Mini-X
Signal to Noise Ratio: 95 dB (it does not say but I believe it is for full power)
 
Not a concern for me at this point.