[VictorHalgaard]

Hey there, I'm having some serious trouble with my SR-71B. For some time I've been noticing a lot of pot noise between 10 and 3 o' clock with my low impedance headphones. Now today I got my new pair of Beyerdynamic T1's which are the first 600Ohm headphones I've used with it. My first intuition was to switch to high gain, and so I did. I played SYNC24 - Walking On Spheres and all hell broke loose. I turned the volume up, and it slowly got lighter/thinner sounding until 12 o' clock where it suddenly got very light siunding, and beyond 1 the sound was just gone. And the bass just rattled (so badly that I don't dare to connect my cans to the amp again), and all of it got worse, the higher the gain setting i was on, and was completely gone at low gain, but then the volume obviously wasn't all that loud.
It seems extremely strange to me... I made sure that its not my source or the headphones by checking with other gear and that all the settings and charge was right on the amp....
 
Any thoughts? :S
 

 

[65535]

Unless you actually have a damaged SR71 which you would have to send to RSA for repair, something is wired wrong.

 

[spkrs01]

I have been told with these new breed of high powered portable amps and the 71B surely is at the pinnacle of this category, that when changing headphones, its is best to switch of the amp rather than just detach the plug as these amps have quite a high possibility of shorting itself and from what you have described, its sounds as it has?! 
 
As said by 65535 best thing is to send it back to RSA for it to be checked out.
 
Irrespective, good luck and hope it can get resolved ASAP as missing such a superb portable amp for a few days is bad enough, but RSA I have been made aware of having excellent customer service and hope they can turn it around for you quickly.

 

[VictorHalgaard]

I will probably be missing it for almost a month because I'm shipping it from Denmark, and its the only amp i have. But yea, I will be shipping it to him as soon as i am able to.
 

 

[spkrs01]

Sorry to hear that, but they will look after you and Ray Samuels is a stellar human being!

 

[65535]

You know that makes me think that the headphones may be wired wrong.
 
A similar effect happens when the drivers are wired across the positives on one side and across the negatives on the left side. That would cause the drivers to be driven by the differential signal from the two channels rather than the actual signal. It would also produce some very strange sounds as it was turned up. 
 
Double check all the wiring.

 

[VictorHalgaard]

I kinda doubt all my headphones and all my speakers are wired wrong... As i said, I've tested all of it with other equipment to make sure the problem is caused by the amp and not something else.

 

[65535]

Have you tried the single ended output?
 

 

[VictorHalgaard]

Thats all I'm using, because I cant get a hold of the balanced plugs anywhere at the moment (I go the amp recently).
 

 

[Jalo]

If it is pot noise as sometimes dust can get into the pot.  Have you try to turn off the amp and then turn the pot up and down really fast a few times and then turn it back on to see if it makes a difference?

 

[VictorHalgaard]

Yes, I've been doing that for a long time, but it makes absolutely no difference...
 

 

[scootermafia]

Just FYI, the T1 doesn't sound great to my ears single ended on a big amp (it needs to be rewired balanced) and perhaps even worse from a small amp.  But if it sounds at least decent through other gear (even an iPod, God forbid) then perhaps it's the amp.  Does the amp have problems with other cans?