[amf.123]

Hi guys, a quick question to get some advice/opinions.

My set up is iMac > Cambridge Audio DacMagic > Little Dot Mk III > HD-650. The little dot still has all of the original tubes it shipped with. All is well with my HD-650's, everything sounds fine but I recently purchased some IE8's for late night listening so no sound leaks. I can't tell anything with the HD-650's but with the IE8's the right channel is noticeably quieter. Distractingly so. The IE8's are fine as I've tested them with two other sources. So, is my amp duff? Driver tube failing? Power tube failing? Please note I have no other spare tubes to swop in and out to test.

 

[CHRIS7509]

I was thinking on this brand when i was looking for an amp, i ended up with a Tomahawk, How old are they ? did you check the contacts ? try swapping the tubes from right to left, see if any changes ...

 

[amf.123]

How stupid am I to not think of that. Thank you Chris for pointing out the obvious. Feel a bit silly now LOL. Oh, and the amp is about 6 months old or so.

 

[amf.123]

Swopped the tubes and the right channel is still definitely quieter. However it's only noticeable with really sensitive phones. If I hadn't used the IE8's I'd never have known.

 

[tongson]

Did you change the gain settings?

 

[amf.123]

The gain is set the same on both channels. I'd imagine I'd hear a huge difference if it wasn't. Don't get me wrong, the difference in volume is very slight, and the music is still perfectly listenable, it's just that once you notice something is different it becomes very distracting and hard to ignore.

 

[CDBacklash]

your hearing is damaged.

 

[tenzip]

Quote:

Originally Posted by CDBacklash /img/forum/go_quote.gif your hearing is damaged.

I'm curious as to how you came to this conclusion?

 

[amf.123]

Quote:

Originally Posted by tenzip /img/forum/go_quote.gif I'm curious as to how you came to this conclusion?

Me too as on two other different sources the IE8's sound fine.

 

[macming]

Quote:

Originally Posted by amf.123 /img/forum/go_quote.gif Hi guys, a quick question to get some advice/opinions. My set up is iMac > Cambridge Audio DacMagic > Little Dot Mk III > HD-650. The little dot still has all of the original tubes it shipped with. All is well with my HD-650's, everything sounds fine but I recently purchased some IE8's for late night listening so no sound leaks. I can't tell anything with the HD-650's but with the IE8's the right channel is noticeably quieter. Distractingly so. The IE8's are fine as I've tested them with two other sources. So, is my amp duff? Driver tube failing? Power tube failing? Please note I have no other spare tubes to swop in and out to test.

The HD650 is a 300 ohm headphones. If you're going to much more sensitive amp, you should change the gain setting on the amp, then do the comparison.

 

[DoYouKnowJim?]

First off, the Senn IE8s are 16 ohms which is well under the recommend 32-600 ohm load impedance for the amp. When you see something like "recommended xx to yy headphone impedance", a bit higher or lower is going to be fine, but in this case we are talking quite a big difference from the recommended.

Secondly, for headphones as sensitive as the IE8s, you should use the lowest possible gain to maximize the use of the potentiometer sweep. Potentiometers have their best tracking between channels as you get closer to the mid point.