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Matrix M-Stage amp review: simple, cheap, and excellent. - Page 251

post #3751 of 4889
Quote:
Originally Posted by Taowolf51 View Post

Stupid question, are you sure you're at 0 gain?

Even stupier question: are BOTH switches on 0 gain..wink.gif

post #3752 of 4889

Yes, I'm at zero gain on both channels, but as mentioned in the original post, the gain settings are irrelevant/don't change the hum. Neither does the volume setting -- with no source, the hum is the same if the volume knob is at min or max or anywhere in between. And it doesn't matter what source I use, or which input it's on, or if there's no input connected at all. 

 

And changing where I'm plugged in, or changing AC cords doesn't help.

 

I don't hear this with the Panasonic cans.

 

@ChrisJ: You may be right that this amp can't do sensitive, low impedance IEMs. That's why I asked if anyone out there used this amp with such IEMs without hum -- trying to determine if its just a bad fit/synergy vs a problem with my amp.

 

 

Quote:

Originally Posted by LCMusicLover View Post

I just got an m-Stage (amp only), and it has a low-level hum that is probably at 60Hz.  It's there regardless of what's plugged into either input, or even if there is nothing on the inputs.  Its level isn't changed when I change the gain dip switches, and it doesn't change with the volume know (0 - full, hum is the same level).  It also doesn't go away if I plug directly into the wall, or into a power strip, or into a computer UPS, or another wall plug in a different room.  (I haven't tried a different house -- that's a 'to-do').

 

I've searched this thread and several others.  The only idea I saw was to tighten and loosen the screw on the bottom of the case, which I believe holds the transformer in place.  That didn't help.  I opened up the case because...well, who can resist doing that when they have a problem, and didn't see anything obvious.  The op-amp was well-seated.

 

BTW, I only hear this with my 1964Ears V.3s, not with my Panasonic RP-HFT600 -- that may be an isolation factor as I have fantastic isolation with the V.3s and the Panasonics may be allowing enough ambient noise in to mask the hum.  I'll check that tonight when the house should be quiet enough to tell.

 

Any ideas?

post #3753 of 4889
Quote:
Originally Posted by LCMusicLover View Post

Yes, I'm at zero gain on both channels, but as mentioned in the original post, the gain settings are irrelevant/don't change the hum. Neither does the volume setting -- with no source, the hum is the same if the volume knob is at min or max or anywhere in between. And it doesn't matter what source I use, or which input it's on, or if there's no input connected at all. 

And changing where I'm plugged in, or changing AC cords doesn't help.

I don't hear this with the Panasonic cans.

@ChrisJ: You may be right that this amp can't do sensitive, low impedance IEMs. That's why I asked if anyone out there used this amp with such IEMs without hum -- trying to determine if its just a bad fit/synergy vs a problem with my amp.

Yep,
I don't like the M Stage with my Shure SE210s!
It's the power supply noise.
I would use Either an amp with a much quieter power supply (you don't usually see this in the spec sheets) or an amp that runs off batteries and does not use a DC-DC converter in it.
post #3754 of 4889

Is it possible that you're picking up some radio signal? My integrated amp sometimes picks up radio stations (it doesn't have a tuner in it), and the volume doesn't change how loud the radio station is.

post #3755 of 4889
Quote:
Originally Posted by Taowolf51 View Post

Is it possible that you're picking up some radio signal? My integrated amp sometimes picks up radio stations (it doesn't have a tuner in it), and the volume doesn't change how loud the radio station is.

 

That would probably be intermittant and should change if you move the Matrix around, say, to another room.

He did say that he moved it to another room, no success!

Radio signal would probably sound like a higher pitched type of noise than 60 Hz buzzzzzzzz.


Edited by Chris J - 2/28/13 at 9:22am
post #3756 of 4889

@Chris J:

 

No, certainly not radio noise -- it's definitely a single frequency hum.  In addtion, I live in a rural part of Oregon -- I can barely pick up radio signals on a radio :)

 

I'm communicating with Matrix, trying to figure out if it's just a "doesn't work with such IEMs" kind of problem.

post #3757 of 4889
Quote:
Originally Posted by LCMusicLover View Post

@Chris J:

No, certainly not radio noise -- it's definitely a single frequency hum.  In addtion, I live in a rural part of Oregon -- I can barely pick up radio signals on a radio smily_headphones1.gif

I'm communicating with Matrix, trying to figure out if it's just a "doesn't work with such IEMs" kind of problem.

Sounds like you hear what I hear:
power supply noise, i.e. 60 Hz plus harmonics of 60 Hz: 120, 180, 240, 300 Hz, etc, etc.


Sounds a bit like a very quiet Bzzzzzzzzzzz?
post #3758 of 4889

Yep, sounds just like that

 

But on the other hand, my OP-627 which arrived today and is now in the amp makes the hum quieter, as do my new Aurisonics AS-2s.  So maybe I can live with it. And, on the gripping hand, I also just snagged a RSA Shadow on eBay which I'll receive next week.  Maybe I`ll decide the matrix with the 627 is ok, or maybe I'll end up with the Shadow.

 

I'm sure loving the Ultra-fi and the AS-2s.  It's weird to hear music you're very familiar with and have it be 'different'.   Between the 1964Ears v.3s and the AS-2s it's brighter (1964) vs darker, more staging (AS-2) vs more presence,  There's a sort of 'false detail' in a bright sound -- you hear the flash of the cymbal or hot hat, but you don't hear the tone.  At the same time with a darker sound the vocals can end up seeming a bit recessed.  I've definitely come to believe that I have to learn to hear the music on each system and let go of how I remember it sounding before.  

 

Right now I'm listening to Van Morrison's Astral Weeks and it's just wonderful. The hum is annoying  between the tracks, but it isn't audible once the music comes back in, except in the most delicate pieces.

 

Moonlight Sonata is a good example a piece where the hum comes through.


Edited by LCMusicLover - 3/2/13 at 12:11am
post #3759 of 4889
Quote:
Originally Posted by LCMusicLover View Post

Yep, sounds just like that

 

But on the other hand, my OP-627 which arrived today and is now in the amp makes the hum quieter, as do my new Aurisonics AS-2s.  So maybe I can live with it. And, on the gripping hand, I also just snagged a RSA Shadow on eBay which I'll receive next week.  Maybe I`ll decide the matrix with the 627 is ok, or maybe I'll end up with the Shadow.

 

I'm sure loving the Ultra-fi and the AS-2s.  It's weird to hear music you're very familiar with and have it be 'different'.   Between the 1964Ears v.3s and the AS-2s it's brighter (1964) vs darker, more staging (AS-2) vs more presence,  There's a sort of 'false detail' in a bright sound -- you hear the flash of the cymbal or hot hat, but you don't hear the tone.  At the same time with a darker sound the vocals can end up seeming a bit recessed.  I've definitely come to believe that I have to learn to hear the music on each system and let go of how I remember it sounding before.  

 

Right now I'm listening to Van Morrison's Astral Weeks and it's just wonderful. The hum is annoying  between the tracks, but it isn't audible once the music comes back in, except in the most delicate pieces.

 

Moonlight Sonata is a good example a piece where the hum comes through.

 

Astral Weeks!

Excellent!

 

I'm using an LM4562, which obviously still buzzes. But very quietly. I agree, I find it doesn't usually interfere with my music listening.

I can imagine that it does come thru with Moonlight Sonata................frown.gif

post #3760 of 4889
Quote:
Originally Posted by hifimanrookie View Post

Yep i think so also..so good reason to buy urself a hifiman full size can nowwink.gif

 

  Thanks for the incredibly helpful suggestion biggrin.gif

post #3761 of 4889
Quote:
Originally Posted by LCMusicLover View Post

 

  Thanks for the incredibly helpful suggestion biggrin.gif

Ur more then welcome..ps..a he300 isnt expensive..very_evil_smiley.gif

post #3762 of 4889
Quote:
Originally Posted by hifimanrookie View Post

Ur more then welcome..ps..a he300 isnt expensive..very_evil_smiley.gif

 

Sure, that's how it would start ... This is head-fi after all. 15 months ago I 'upgraded' from iBuds right out of my iPod to $35 SoundMax IEMs. Look at at sig now eek.gif

post #3763 of 4889
Quote:
Originally Posted by LCMusicLover View Post

 

Sure, that's how it would start ... This is head-fi after all. 15 months ago I 'upgraded' from iBuds right out of my iPod to $35 SoundMax IEMs. Look at at sig now eek.gif

I know what u mean..look at my profile..and this started with a simple ipod shuffle first version..and two years later i have the stuff i have now..my wallet is bleeding but my ears are joying..wink.gif

post #3764 of 4889

Anybody have any idea how to open up the newer m-stage? The old version had the screws on the side like so

 

 

The new one doesn't, it just has screws on the back and front plate.

 

post #3765 of 4889

You take out the top two screws on each side, then lift the top half of the case out.

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