[sheldonkreger]

Hi,
 
I'm excited to say that a local engineer is letting me demo and review a new headphone amplifier he has made. I have spent some time reading amp reviews and want to make sure that I have all my bases covered for my writeup.
 
Here are the things I'm planning to do with the amp, and the topics I plan to cover:
 
- The design, including selection of tubes, ins/outs, and the casing.
- The manufacturing process, where and how the amp is made.
- The "goal" of the amp - what kind of sound is the engineer seeking to achieve?
- Demo the sound with a variety of headphones, and discuss how the amp affects them.
- Try many different kinds of music.
- Take lots of photos.
- Maybe some photos of the shop where the amp is made, if I have the chance.
- Turn the volume up high with no music playing to test for noise.
 
One question I have is - are there any headphones that are "standard" for testing purposes? I mean, something that many people are familiar with so that I can describe how the amp affects the sound in a way people can relate to?
 
Please share your thoughts if there is anything else I should be looking for or include in my post.
 
Thanks!
 
-sheldon

 

[kramer5150]

IMHO you should test it with a broad range of impedances and sensitivities. A good percentage of the popular OTL amps sound semi-bad with Grados and AKG K70x cans.... IMHO. I always think its best to state a reference point for comparison when making subjective comments. Understandably its not always easy or financially practical to do either though.

 

[hodgjy]

I agree with Kramer that you need to use a variety of headphones.  But, I would make sure to include the Sennheiser HD600s.  These are very linear and were once upon a time considered a benchmark set of headphones.  Their neutrality lends itself for testing amps.  Also, the HD600s scale very well with amps--the better the amp, the better the headphones sound.
 
I also like to throw in 600 ohm Beyerdynamics.  These are often hard to drive, and lesser amps really show their weakness with them.
 
Then, throw in some orthos.  These are often tough to drive.  They can show an amp's limits as well.
 
For good measure, throw in some low impedance headphones.  They require high current, and some amps fail to supply it.

 

[sheldonkreger]

Thanks for the ideas! I'll keep them in mind when I get the amp.
 
Are there any good resources where I can learn about headphone amplification in general? I don't see much on the wiki.
 
-sheldon

 

[fabio-fi]

Quote:

Thanks for the ideas! I'll keep them in mind when I get the amp.
 
Are there any good resources where I can learn about headphone amplification in general? I don't see much on the wiki.
 
-sheldon

 
Something specific about headphone amps?