[Tinkerer]

My backup earspeakers are a pair each of SR Lambda Signature and SR Lambda Nova Signature which I use with my BHSE. The older "plain" Lambda's occasionally produce very low level "hash", which I can *not* hear when music is playing, but generally hear only when music is not playing. The volume of the hash does not change with changes of the input selector or volume control. The hash is not there when the earspeakers are not plugged in. (I.e., it is not some sort of mechanical noise, like from the cable rubbing on something.) I can kind of simulate the hash by putting my upper teeth lightly against my lower lip and gently sucking in air through my mouth, so sort of a buzzing, and very intermittent. Does anyone know what this might be and/or how to fix it?

Sounds like could be a rare legitimate dust problem. But if it's the same volume in both channels then more likely just some slight background noise in the amp itself. If you're using a single ended input, maybe try a simple ground lifter of low ohm power resistor +tiny cap in parallel.

I did have a similar problem with my old Lamba Spirit once and it was because the internal foam was disintegrating and sticking to the dust shield making weird intermittent buzzes every once in awhile. After I opened it up and cleaned out all the old foam, never had that problem again.

 

[Don Quichotte]

Sounds like could be a rare legitimate dust problem. But if it's the same volume in both channels then more likely just some slight background noise in the amp itself. If you're using a single ended input, maybe try a simple ground lifter of low ohm power resistor +tiny cap in parallel.

I did have a similar problem with my old Lamba Spirit once and it was because the internal foam was disintegrating and sticking to the dust shield making weird intermittent buzzes every once in awhile. After I opened it up and cleaned out all the old foam, never had that problem again.

I expect it to be because of the phones. I had some buzzing / squealing problems with my 303's in the past. If you hear the noise and quickly unplug the phones, if it's the amp the sound should stop instantly, while if it's the phones the sound may continue for a second or maybe a little less.

 

[statfi]

I expect it to be because of the phones. I had some buzzing / squealing problems with my 303's in the past. If you hear the noise and quickly unplug the phones, if it's the amp the sound should stop instantly, while if it's the phones the sound may continue for a second or maybe a little less.

Thanks to DJ The Rocket, Dib Quichotte, Jones Bob and Tinkerer for the quick response. The issue persists. Some diagnostic notes...
I do not understand why you would suggest thermal noise in this case. In my mind, hiss is the archetypal thermal noise, which is random and uncorrelated, i.e., the autocorrelation would be a delta function. This noise is random, but the autocorrelation would have some real structure. As with the simulation I suggested with my mouth, some the can's noise has some pitch to it.
Only the right channel. Pro Bias.
When Tinkerer "opened it up and cleaned out all the old foam", what is "it". You are correct, all of the inner and outer foam is badly dilapidated: if you try to grab it with a tweezers it disintegrates so you cannot even pull out chunks. I have now blown out all that will blow out with canned air, and the same intermittent noise persists. This model had a nice fairly coarse polymer protective screen on the insides. Some of the foam bits got inside this screen, between it and protective "mylar" over the driver, which does not blow out. So did you open the protective screen, or get inside the mylar, or even open up the stators?
Interestingly, on at least two occasions, when I unplug the cans from the BHSE, the noise seems to stop immediately, and then, after ~1min, can come back for about a minute, and then go away for ever. (I.e., I've been typing at my computer with the cans on but not plugged in for ~30min, and they have been quiet except for that last minute of gasping that started about a minute after unplugging. Weird, but it suggests that charge stored on the diaphragm was the source of that last gasp.
Related to the last paragraph, how do I remove and replace the ear pads on this model? It seems that they are held on with some adhesive, that would need to be replaced in the best case.

 

[Jones Bob]

/snip/
Only the right channel. Pro Bias.
/snip/
Interestingly, on at least two occasions, when I unplug the cans from the BHSE, the noise seems to stop immediately, and then, after ~1min, can come back for about a minute, and then go away for ever. (I.e., I've been typing at my computer with the cans on but not plugged in for ~30min, and they have been quiet except for that last minute of gasping that started about a minute after unplugging. Weird, but it suggests that charge stored on the diaphragm was the source of that last gasp.
/snip/

Thanks for the info.

Only right channel localizes the problem.

With Pro Bias, the diaphrams are connected in the cable.

Strange about the phantom noise coming back after unplugging. When you disconnect the headphones, do you use your finger to short out the jack plugs to drain the diaphragm charge?

 

[martyn73]

Hi,

I've just purchased a used SRM-300 and SR-404 Signature as a bedside system. The SRM-300 seemed appealing because the energiser is vertically mounted and acts as the stand for the SR-404. However, it's not possible to place the dust cover over the headphone and energiser with the phono cable and power cable attached. Am I missing something?

The SRM-300 seems to be a considerable upgrade over my old SRM-212 and Basic headphones. The bass seems to be fuller and the soundstage reasonably wide. The treble is extended without annoying sibilance nor the awful 'etch' that affects (to my mind) the SR-L700 if combined with the SRM-727II.

I'd be grateful for any thoughts on how to protect my SR-404 (or soon the SR-L500) from dust. The SRM-353X is too large and the SR-252S may lack the power to adequately power the SR-L500.

Thanks,

Martyn

 

[SeaWo|f]

Acrylic? Like people use for turn table covers.

 

[martyn73]

The SRM-300 has two sets of cables snaking out the back so it would need to be a big acrylic dust cover.

 

[SeaWo|f]

use 90 degree connectors for the RCA and IEC so the cables go straight down then notch out the bottom of back acrylic piece.

 

[martyn73]

Thanks, that's a great idea. I'll try to find some adaptors unless you have any recommendations

 

[martyn73]

Unfortunately even the sockets are mounted vertically so I'm not sure if 90 connectors will work

 

[SeaWo|f]

If I wanted adapters these would work.

https://www.amazon.com/Cerrxian-Fem...17273744&sr=8-35&keywords=angle+iec+connector

https://www.amazon.com/Electop-Fema...id=1517273810&sr=1-9&keywords=angle+rca+cable

Right angle RCA cables are a diam a dozen so that is another option and if you searched for a while you might be able to find a power cable with the length and orientation you need.

I prefer to make my own cables though.

Edit:: I see the pic, RCA cables rotate super easy just angle them a touch.

 

[martyn73]

Thanks so much

 

[Tinkerer]

When Tinkerer "opened it up and cleaned out all the old foam", what is "it". You are correct, all of the inner and outer foam is badly dilapidated: if you try to grab it with a tweezers it disintegrates so you cannot even pull out chunks. I have now blown out all that will blow out with canned air, and the same intermittent noise persists. This model had a nice fairly coarse polymer protective screen on the insides. Some of the foam bits got inside this screen, between it and protective "mylar" over the driver, which does not blow out. So did you open the protective screen, or get inside the mylar, or even open up the stators?

You want to lift up the corners of the ear pads and unscrew the 4 screws that hold the ear cup together. Then it all comes apart and you can clean it. Don't puncture the dust shields or take apart the stator.

 

[Pokemonn]

darn I was dead wrong. EQing is not so importart.
now my 009 sounds like super rich/fuller/euphonic 8K resolution TV without EQ...
all i did is remove metal made wired rack and put Stax rig on wooden made rack and cork made floor and tweaked power cords. Bingo. Just sound 95% right!
it takes 3 years journey to reach this setup....phew.
I noticed expensive wooden made rack for audio and expensive power cords are not joke at all...
Stax is full of mystery...Lol

 

[Rossliew]

Which brand of power cord are you using?