THE SIGMA/404 A NEW STAX HEADPHONE?

[John Buchanan]

I did an experiment comparing the efficiencies of the Stax Lambda Nova Signature, the Stax Sigma and the SR007. Although the 007 is supposed to have the same efficiency as the 404 or the LNS (as per the Stax handbooks), the 007 and the Sigma non pro have the same efficiency when plugged into the pro and non-pro outputs of an SRM 1 Mk 2, with the LNS much louder at the same volume setting. Something is awry with Stax specifications - we've seen this before with the diaphragm thickness for the Stax Signature phone. According to Stax, the Sigma is supposed to have a 94dB efficiency compared with 100dB for the 007 and LNS. In reality, this doesn't appear to be correct. Any ideas about the relative efficiencies (in real life) of the 4070 and the 404 compared with the 007 or Sigma?
Do the 4070 case holder/arc set fit the Sigmas? That would look very cool with the Sigma upgraded to Pro specificiation with that arc set.

 

[Carl]

Quote:

Originally Posted by John Buchanan I did an experiment comparing the efficiencies of the Stax Lambda Nova Signature, the Stax Sigma and the SR007. Although the 007 is supposed to have the same efficiency as the 404 or the LNS (as per the Stax handbooks), the 007 and the Sigma non pro have the same efficiency when plugged into the pro and non-pro outputs of an SRM 1 Mk 2, with the LNS much louder at the same volume setting. Something is awry with Stax specifications - we've seen this before with the diaphragm thickness for the Stax Signature phone. According to Stax, the Sigma is supposed to have a 94dB efficiency compared with 100dB for the 007 and LNS. In reality, this doesn't appear to be correct. Any ideas about the relative efficiencies (in real life) of the 4070 and the 404 comparedd with the 007 or Sigma? Do the 4070 case holder/arc set fit the Sigmas? That would look very cool with the Sigma upgraded to Pro specificiation with that arc set.

The 4070 is odd that the volume doesn't seem to increase as you increase the volume at the same rate as my other electrostatics (if that makes sense), but I haven't compared it with the other circumaurals like 007, 404 and HE60 on my system.

 

[Spare Tire]

Yeah, the 4070 arc would look cool on sigmas, and the pin looks small too, perhaps the same size as the original sigma arc, unlike the lambda arc which is larger and i suppose would need some drilling into the enclosure.
But i bet it'd cost a lot. Maybe i'll ask yamas inc see how much they'd charge for that mod. Though i wouldn't do it myself, cause i don't like the whole "self adjusting" concept, and the cost probably.

 

[John Buchanan]

Carl,
what are the dimensions of the 4070 "arms" of the case holders? In particular, the distance between the pins into the cases and the horizontal connecting bars as well as the distance between the two vertical arms? I am wondering if they WILL fit the Sigmas?

 

[Carl]

The forks are 2.25mm by 2.25mm (measured, and almost exactly that). 77mm from the tips to the outside end and 68mm to the inside end. The forks are 82mm appart on the inside. The pin is almost exactly 1mm in diameter.

Hope you can picture that.

 

[John Buchanan]

The Sigma forks are 82mm apart (check), 65mm from the centre of the 1mm pin to the inside of the horizontal bar. These are the most critical dimensions, so that the horizontal bar will engage the wings on the cases to prevent uncontrolled movement. Could you check again that measurement from the centre of the pin to the inside of the horizontal bar?

 

[Carl]

Quote:

Originally Posted by John Buchanan The Sigma forks are 82mm apart (check), 65mm from the centre of the 1mm pin to the inside of the horizontal bar. These are the most critical dimensions, so that the horizontal bar will engage the wings on the cases to prevent uncontrolled movement. Could you check again that measurement from the centre of the pin to the inside of the horizontal bar?

66.5mm. So ever so slightly longer. I can't imagine that it'd cause any problems.

 

[John Buchanan]

The "wings" on the Sigma engage the arms of the case holders, not the horizontal connecting bar, so it sounds like all will fit, including the smaller pins. I guess the only other thing to check is that the cases are not trying to rotate away from the head, as the 4070 has no rotational adjustment I suspect (much as per the 007 headband/arc assembly). The length of the arms, as you say, shouldn't be a problem, as long as they are not shorter than the original Sigmas - and they aren't.
I have sent an email to Accutech requesting the cost for this modification.

 

[John Buchanan]

Tats from Yamasinc/Accutech posted back saying that 4070 arc assembly doesn't fit Sigma cases - not secured by pins, but some other method of fixation.

 

[Carl]

Quote:

Originally Posted by John Buchanan Tats from Yamasinc/Accutech posted back saying that 4070 arc assembly doesn't fit Sigma cases - not secured by pins, but some other method of fixation.

Sure looks like pins to me. Considering I'm looking at it...

 

[John Buchanan]

Carl,
can the cases and arms be separated ala the Sigma just by pulling the arms gently apart and removing the cases from the pins? Tats implied there would be some internal fixation that did not allow them to be interchangable. I've never even seen a 4070, so what would I know?

 

[Carl]

Quote:

Originally Posted by John Buchanan Carl, can the cases and arms be separated ala the Sigma just by pulling the arms gently apart and removing the cases from the pins? Tats implied there would be some internal fixation that did not allow them to be interchangable. I've never even seen a 4070, so what would I know?

The arms are cast metal, and unfortunately all my superpowers are out on loan right now, so I can't bend it.

 

[John Buchanan]

The Sigmas arms are just gently separated a little and the pin is cleared from the pin receptacle in the case - repeat for the 3 other pins and the cases and the arc assembly/arms are separated (as per the normal Lambda situation).
The 4070 sounds different, as the metal arms don't appear to be flexible enough to do this - there must be some other way (that is unique to the 4070) to assemble the arc assembly and arms to the cases as Tats said - it should not require any real force if it was as per the Sigma or Lambda assembly.

 

[kintsaki]

Can Koss ESP 950 drivers be installed in Sigma shells?

If not, can scaled Sigma shells be made to accomodate
Koss drivers?

Could that be an interesting experiment?
(given the ability of the Koss drivers to combine the speed of electrostatic phones with the impact of
dynamic phones, and the out of the head feeling of the Sigma shell)

 

[Duggeh]

I miss Carl