[musky1963]

I have a freshly rebuilt G.A.S. Thaedra preamp that has over 1.5 watts of output for the hp section. What is about the limit on headphone ohms? I am looking at many new cans for an upgrade over my vintage Sansui's. is that enough output for stats? Thanks!

 

[KG Jag]

This may be a useful tool to answer your question:
 
http://www.headphone-amplifier.com/calculator.htm

 

[tomb]

Quote:

I have a freshly rebuilt G.A.S. Thaedra preamp that has over 1.5 watts of output for the hp section. What is about the limit on headphone ohms? I am looking at many new cans for an upgrade over my vintage Sansui's. is that enough output for stats? Thanks!

No, it's not enough for stats.  Older stats work on an energizer that's used to connect into the speaker terminals of a power amp - a preamp is not suitable.  Or, they use their own dedicated headphone amp, but stats need about 500V to the cans.  There's no "regular" pre-amp, amp, receiver, or headphone amp that can provide that unless it's been specially built for stats.

 

[KG Jag]

Right--standard headphone amps won't work with electrostatic headphones.  I originally read "stats" to mean "statistics".

 

[musky1963]

So what regular phones would fall in the range since my preamp's output is 1.5w? In other words, what is the max impedance I should be looking for?

 

[KG Jag]

Assuming that your number is accurate, it's still not that simple.  Here's another tool to use:
 
http://www.apexhifi.com/specs.html
 
If you don't want to do the work, call or email the maker of your amp and ask.
 
Didn't know that pre-amps alone could drive headphones.

 

[PurpleAngel]

Quote:

So what regular phones would fall in the range since my pre-amp's output is 1.5w? In other words, what is the max impedance I should be looking for?

At the price that GAS sells for, it better drive headphones up to 600-Ohm.
But I would say (best guess) 150-Ohm to 300-Ohm headphones would be a safe choice.
(but I'm far from an expert on this stuff)
 
EDIT, per the user manual, headphones of 100-Ohm or higher is recommended.
http://www.davidsaudio.com/html/gas_line.html

 

[musky1963]

Do you think that the HE-500's would be okay? I am sure down the road, I will get a good dedicated amp, but just isn't in my budget right now.

 

[KG Jag]

Quote:

Do you think that the HE-500's would be okay? I am sure down the road, I will get a good dedicated amp, but just isn't in my budget right now.

Probably not--have you used the second tool I provided above?

 

[musky1963]

I think I used it right. It comes out to 178mv for the HE500's? I assume that is 1.78 watts? I can find out from the GAS tech what the actual output is on the pre. Thanks! Jeff