MUSE Tube 6N11 Class A Headphone Amplifier

I got one just for kicks.

There is a thread dedicated to tweaking these amps. In stock form they are prone to humming, distortion, channel imbalance, crosstalk etc, but they can be tweaked to sound better.

Tell me how is it compared to other cheap amps! :D

I wanna try if its worth it.

Well, it's quite powerful and offers a cheap way of getting one's feet wet with tubes, but the problem is that the design is flawed from the start, so it really is nothing more than a cheap amp that uses a tube.

I haven't made up my mind whether it was a waste of money or not. If I find the time/energy to research the required tweaks and carry them out, I guess it might even be worth it.

Flawed design? Please explain.

Quote:

Originally Posted by ukkisavosta 

Well, it's quite powerful and offers a cheap way of getting one's feet wet with tubes, but the problem is that the design is flawed from the start, so it really is nothing more than a cheap amp that uses a tube.

 

I haven't made up my mind whether it was a waste of money or not. If I find the time/energy to research the required tweaks and carry them out, I guess it might even be worth it.

Quote:

Originally Posted by Xymordos 

Flawed design? Please explain.

 

I don't have the knowledge to explain the details myself, but here is a certain thread (in Rock Grotto forums) outlining some of the shortcomings and required mods:

http://rockgrotto.proboards.com/index.cgi?board=m&action=print&thread=5297

Note that there are small differences in the Muse/Indeed/Bravo amps and their various versions.

I just got one from ebay.  I have a question, I get random popping sounds and static, similar to listening to old vinyl records.  Do you think replacing the tube would help?

Follow-up question.  My amp came with the pots for adjusting bias.  I tried adjusting them to get to 16v but is impossible to do.  When I adjust one side's bias voltage, the other side's voltage goes the opposite way.  They seem to be not independent of each other.  The best I could do to get them about the same voltage was at 12v.  Will that be fine?  Is it a tube problem?

Hey all,

I just got myself one of these from ebay as well =). I am still new to the world of audio but I want to try to share some of my thoughts about this amp if anyone is interested:

My first impressions are that they are pretty "ok". (But then again I wasnt expecting much for under 100 bucks)

My source is a Macbook using an Creative Xfi-Pro Soundcard.

Test Headphones : Ultrasone 550 and Ultrasone 900

I find that the highs roll off quite a little bit. But my greatest grip with these are that the bass is pretty poor. I am not a basshead by any means but I was testing them through my Ultrasone 550s and the bass was almost non existent. Even after switching to my Ultrasone 900, the bass was still pretty poor and lacking. This is pretty bad in my opinion because the Ultrasone 900s are supposed to be quite bass heavy.

On a side note, anyone know what the two orange "switches" near the tube are for?

Quote:

Originally Posted by euwemax 
Hey all,

I just got myself one of these from ebay as well =). I am still new to the world of audio but I want to try to share some of my thoughts about this amp if anyone is interested:

My first impressions are that they are pretty "ok". (But then again I wasnt expecting much for under 100 bucks)

My source is a Macbook using an Creative Xfi-Pro Soundcard.

Test Headphones : Ultrasone 550 and Ultrasone 900

I find that the highs roll off quite a little bit. But my greatest grip with these are that the bass is pretty poor. I am not a basshead by any means but I was testing them through my Ultrasone 550s and the bass was almost non existent. Even after switching to my Ultrasone 900, the bass was still pretty poor and lacking. This is pretty bad in my opinion because the Ultrasone 900s are supposed to be quite bass heavy.

On a side note, anyone know what the two orange "switches" near the tube are for?

Those two orange "screw things" are were you adjust the voltage for right and left channel, you want the two voltages to match, hopefully somewhere in the 12v to 13.5v range.

You need to get a digital mulitmeter, like the DT830, usually sells starting at $6.

The web forum Rockgrotto has more details on how to check the voltage
 

Ah I see. Thanks! By the way has anyone rolled the tubes on this thing yet? I read from rockgrotto that some people used telefunkun tubes on theirs, but alas one of those tubes cost more than the amp itself... anyone know of any tube which is similiar to the telefunkun 12AU7 but at a cheaper price? Say... USD 30 ish? My only main concern is boosting soundstage from these amps.