Mustang P-51 gain settings and hissing

[Padanan]

I bought a P-51 about a month ago and when I first tried it, it was set at the medium gain setting. I noticed some hiss with my UM3X but then I switched it to the low gain setting since the UM3X is so sensitive. The hissing went away so I left it at the lowest gain and never thought about it since then.

But a few days ago I was reading the Shadow thread and some people were mentioning they could hear hissing with their IEM's. So I went to fiddle with the gain settings on my P-51 to see if it still hissed. With the medium gain the hissing is very audible, but importantly it only hisses on the right side. The high gain setting even more so.

Note, this is with NO INPUT source. Moreover, turning the volume from minimum to maximum (still with no input source) the hissing remains audible in the right ear at the same loudness (minimum or maximum volume). When I am listening to music I connect the amp to an iPhone via a LOD cable.

I am sure there is a problem with my Mustang, especially if the hissing only occurs in the right side. Helpfully, Head-Fi has made me aware of the problem, otherwise I really would have continued to use the Mustang as is, and probably only realise the problem a long time in the future. I'll be contacting Ray about this problem soon but I thought I would like to share it here on Head-fi also.

And finally, while listening at the medium gain setting, I noticed the SQ to be much improved, as compared to the low gain setting. The sound is not so muddied, much improved soundstage - especially with the UM3X's narrow soundstage, not so forward, mids/highs are clearer, and the music flows smoother.

Has anyone else noticed this? I can't believe I have been listening to my P-51 for a month and I could have been hearing a much better sound, if it wasn't because of the hissing at the medium gain setting . I was A/Bing between the two settings for a long time to make sure my mind wasn't playing the placebo effect on me, but it definately is much better at medium gain.

[3602]

...you gotta ask Ray for this problem...RSA amps should have no hiss at all.

[RockinCannoisseur]

is the shadow the best rsa?

[RockinCannoisseur]

Originally Posted by Padanan

I bought a P-51 about a month ago and when I first tried it, it was set at the medium gain setting. I noticed some hiss with my UM3X but then I switched it to the low gain setting since the UM3X is so sensitive. The hissing went away so I left it at the lowest gain and never thought about it since then.

But a few days ago I was reading the Shadow thread and some people were mentioning they could hear hissing with their IEM's. So I went to fiddle with the gain settings on my P-51 to see if it still hissed. With the medium gain the hissing is very audible, but importantly it only hisses on the right side. The high gain setting even more so.

Note, this is with NO INPUT source. Moreover, turning the volume from minimum to maximum (still with no input source) the hissing remains audible in the right ear at the same loudness (minimum or maximum volume). When I am listening to music I connect the amp to an iPhone via a LOD cable.

I am sure there is a problem with my Mustang, especially if the hissing only occurs in the right side. Helpfully, Head-Fi has made me aware of the problem, otherwise I really would have continued to use the Mustang as is, and probably only realise the problem a long time in the future. I'll be contacting Ray about this problem soon but I thought I would like to share it here on Head-fi also.

And finally, while listening at the medium gain setting, I noticed the SQ to be much improved, as compared to the low gain setting. The sound is not so muddied, much improved soundstage - especially with the UM3X's narrow soundstage, not so forward, mids/highs are clearer, and the music flows smoother.

Has anyone else noticed this? I can't believe I have been listening to my P-51 for a month and I could have been hearing a much better sound, if it wasn't because of the hissing at the medium gain setting . I was A/Bing between the two settings for a long time to make sure my mind wasn't playing the placebo effect on me, but it definately is much better at medium gain.

i havent had any problems with the predator hissing, althought i never use it high gain,, i did however had some westone 3 and they wer very sibilant and highs distorted and sensitive,,, they may have needed longer burn in but ive heard the westone iem dont need burn for some reason(their driver type),

if its that noticeable send it back and get a new one
but first try your westones with other amps which have gain settings

[ibis99]

Narrow soundstage on UM3x? Really?