Time for some Stax SR-Sigma love......

[edstrelow]

I see the ad in HF for the Sigma/404 is closed. It's not clear if they were sold or taken off the market. They had been marked down to $1325. The seller had a number of other things recently on the market, but not necessarily sold, including a BHSE amp. I looked up his early ad to buy a BHSE and it actually states "Willing to pay top dollar." So I assume he did.

Considering that the Sigma/404 ad says the Sigma pro that was cannibalized to make the Sigma/404 cost $1250.00, that's a good deal for someone. But I can't see why the hurry to sell unless a cash infusion was needed. And it's only been a couple of weeks since they were made! I think I would have waited several weeks to see if they didn't grow on me, or kept the Sigma pro for several weeks to be sure that this was the general direction I wanted to go before turning them into a Sigma/404.

My Sigma/404 has no serial number because the arc assembly was replaced by Yamas. My low bias Sigma, which I did not buy new is 00906 a pretty early one I would think. There may be a number on my pro but it's at work and I am home for the weekend. Its number would be for a low bias model, since that's what it was before it was rebuilt as a pro by Stax.

I have never been too bothered by the mineral wool and I have not worried about replacing the inner mesh which is gone in all my models except the 404. The stuff in no. 906 is actually pretty soft.

One of the odd things I find about amping both the Sigma pro and the Sigma/404 is that the SRM1Mk2 is all I feel I need to run them. The pro sits in my office with an A series SRM, the Sigma/404 sits in my living room with a B series SRM. The bigger and more powerful Stax 717 amp sits upstairs running the 007A. While I can hear the 717 giving the Sigma/404 improvements, mostly making it faster and crisper, it isn't that big a deal and I will happily put down my 717/007A and go downstairs and listen to the SRM1Mk2/Sigma/pro. I have the same DAC's for both although different cd transports The SRM's and Sigmas just have a good synergy even if not the last word in high-fi and even though the Sigmas are less efficient than the 007A. On the other hand, the 007A really needs the 717. It loses too much quality on the SRM1Mk2.

Synergy among audio components is a pretty elusive concept. I guess it just means the combination of components you actually like to listen to most.

Edited September 12, 2011 by edstrelow

[John Buchanan]

The SRM 1 Mk 2 is an excellent amp (and comes recommended by no less then Birgir), but if you ever get a chance to snap up an SRD-7 professional or SRD-7 Mk 2, do so. If you have a reasonable power amp. Listening now to the Sigma Pro through one and it sounds very powerful.

With the Sigma series, the sound is smooth enough to avoid picking at bits of the frequency spectrum as sounding wrong. It just sounds good.

Can't wait for the 2 new Jimi Hendrix CD sets, "Winterland" and "In The West" to arrive. Am listening now to the old RYKO Winterland single CD and I suspect the latest Eddie Kramer remix will be tremendous.

[complin]

The SRM 1 Mk 2 is an excellent amp (and comes recommended by no less then Birgir), but if you ever get a chance to snap up an SRD-7 professional or SRD-7 Mk 2, do so. If you have a reasonable power amp. Listening now to the Sigma Pro through one and it sounds very powerful.

With the Sigma series, the sound is smooth enough to avoid picking at bits of the frequency spectrum as sounding wrong. It just sounds good.

Can't wait for the 2 new Jimi Hendrix CD sets, "Winterland" and "In The West" to arrive. Am listening now to the old RYKO Winterland single CD and I suspect the latest Eddie Kramer remix will be tremendous.

Yes I have to agree! One of my setups might sound a little odd but works great. I use the NVA 10 PA http://www.nene-valley-audio.com/ which is a SS headphone amp that also has 15 watt speaker outputs. I use several of my non-es headphones through the hp output with great results, and connect up an SRD-7 to the speaker output to drive my Sigmas. It does a great job of both for $450, and as John says I have found the Sigmas perform very well via this route, particularly the normal bias version which to me does not sound so rolled off at the high end as other combinations.

[edstrelow]

Yes I have to agree! One of my setups might sound a little odd but works great. I use the NVA 10 PA http://www.nene-valley-audio.com/ which is a SS headphone amp that also has 15 watt speaker outputs. I use several of my non-es headphones through the hp output with great results, and connect up an SRD-7 to the speaker output to drive my Sigmas. It does a great job of both for $450, and as John says I have found the Sigmas perform very well via this route, particularly the normal bias version which to me does not sound so rolled off at the high end as other combinations.

Yes I have noticed a similar improvement of the frequency response of the low bias Sigma with an SRD6 transformer.

[Spychedelic Whale]

Can't wait for the 2 new Jimi Hendrix CD sets, "Winterland" and "In The West" to arrive. Am listening now to the old RYKO Winterland single CD and I suspect the latest Eddie Kramer remix will be tremendous.

Are you talking about the Winterland 6 Cds version from 2006 or there's a new one?

[John Buchanan]

The new one

http://www.amazon.com/Winterland-Box-Set-Amazon-com-Exclusive/dp/B0055PL5KO/ref=sr_1_1?ie=UTF8&qid=1315867488&sr=8-1

[edstrelow]

I am currently listening to some Hendrix "The Ultimate Experience" comparing the Sigma/404/717 vs low bias Sigma/SRD6/ Sherwood receiver. The transformer system does sound pretty good. Compared to the Sigma/404 it is somewhat rolled off in the treble, has less detail and a narrower soundstage, but it certainly gives a good overall presentation. At the risk of adding still more confusion to audio vocabulary I would say it gives a highly "coherent" presentation which just works. It is in no way an obsolete set-up. You are right John, I must try a high bias transformer for the Sigma/404.

[John Buchanan]

I am currently listening to some Hendrix "The Ultimate Experience" comparing the Sigma/404/717 vs low bias Sigma/SRD6/ Sherwood receiver. The transformer system does sound pretty good. Compared to the Sigma/404 it is somewhat rolled off in the treble, has less detail and a narrower soundstage, but it certainly gives a good overall presentation. At the risk of adding still more confusion to audio vocabulary I would say it gives a highly "coherent" presentation which just works. It is in no way an obsolete set-up. You are right John, I must try a high bias transformer for the Sigma/404.

Agreed, Ed. The transformer solution is very very good. The bottom end seems a bit better for some reason and the sound dynamics are great. Do you get any hum at all with your transformer based setup? The Studer amp is dead silent, the Audio Research valve amp hums a bit.

[edstrelow]

Agreed, Ed. The transformer solution is very very good. The bottom end seems a bit better for some reason and the sound dynamics are great. Do you get any hum at all with your transformer based setup? The Studer amp is dead silent, the Audio Research valve amp hums a bit.

No hum and I am using the SRD6 mains operated unit.The amp is not high-end, all I can say is that it is better than the previous one I had and gives very clean sound sound through both the phones and the small Spica speakers I use in the bedroom.

[John Buchanan]

Still loving the Sigma Pros through the SRD-7 Spritzer. The bass has a kick to it that I'm not used to in the lambdas - it's more of a physical "whack" to the ear drums, without sounding boomy. The new Jimi Hendrix Experience "Winterland" set is sounding fabulous here. Mitch Mitchell's bass drum has the sharp dynamic thump it should.

[edstrelow]

John, like you, I am getting increasingly annoyed with my 007A, (although I believe you had the 007Mk1.) Sure they have more detail and better frequency response than either the Sigma pro or Sigma/404. But you know, that's not enough. They are just not that pleasant to listen to, Too dry and bright. That's why I am so far underwhelmed by the reports abnout the 009, since it seems even brighter than the 007A and that I can't see enjoying anything brighter than the 007A. even if it has even more detail.

I am tempted sell the 007A and cannabalize my Sigma low bias and try to fit in one of the newer drivers such as the 507 which seems to be reported as fairly bright. I believe you can feed a lot of high frequencies into a Sigma and get a good result because it doesn;t send the sound straight down the ear canal and adds some of its own ambience. This was part of my hope with the Sigma/404, the 404 driver was fairly bright. Although evidently John Buchanaan's experience with transformer set up doesn't make it sound brighter than the Sigma Pro. I understand that the 507 driver doesn't fit well, in the Sigma box, but my thought is to take the 507 driver with its baffle and cut the baffle, if necessary, to fit the front of the Sigma.

Probably my main disincentive is that I don't like the idea of sacrificing a perfectly good low bias Sigma, although I have no hesitation sacrificing a Lambda.

Edited October 12, 2011 by edstrelow

[John Buchanan]

The Sigma normal bias was just too rolled off in the high end for my liking. The Professional drivers (both the 404 and the Lambda Signature) added just the right amount of treble response for my liking (and IIRC, that's exactly what you said it would do - you were right). The Sigma Pro is an excellent phone as is the Sigma/404. I don't know whether MOAR treble here would be a good thing, and I'm sure that if a 307/407/507 implant was doable without lots of dramas, Birgir would have had a crack at it with his latest (instead, he used a 303 driver).

I know it's not what everybody agrees on, but the Spritzer modded SRD-7 with the Sigma high bias sounds fantastic. They also sound terrific through the SRM-Monitor.

Thoughts on the SR-007Mk1 - the earpads had too small a listening cavity and because they were well sealed also, my ears started to sweat very quickly. They were a nice sounding phone and did all the "parts" of the sound picture (apart from that magic midrange) better than the Sigma/404. But the Sigma/404 did the whole picture better and I found that I was keener to listen to music through the Sigma series than the SR-007s. Therefore, the SR-007s were the first to go.

PS Ed, if you ever have a spare excellent condition Lambda arc assembly (the early thin armed version used before the Lambda Nova series), let me know, please.

Edited May 9, 2012 by John Buchanan

[deepak]

Have you guys tried playing around with the dampening material inside the earcups?

Does the material inside tend to deteriorate like the Lambda foam?

[John Buchanan]

Have you guys tried playing around with the dampening material inside the earcups?

Does the material inside tend to deteriorate like the Lambda foam?

It doesn't deteriorate. Made of mineral wool (I'm guessing that the stuff is fibreglass insulation), it appears to be forever. I've left it alone, as the person experimenting with building his own Sigmas mentioned that it was quite difficult to get the correct amount of insulation soundwise. I've let Stax decide that for me. The netting that forms part of the Sigma earpads tends to fall to bits, much like the penultimate Lambda pads' netting did. Ear pads are still available new.

The original Lambda and Lambda Pro (IIRC) also had mineral wool behind the drivers, as well as earpad netting and the netting on the inside of the lateral wall of the headphones. It's the netting that deteriorates.

Edited October 15, 2011 by John Buchanan

[spritzer]

Using the new drivers is certainly doable but you need a special rig to glue them together in and you also have to completely open them up to get the glue onto the parts. This exposes them to dust so one wrong move and the drivers are fubar. I've seen speculation about retrofitting the new driver cages into a Sigma chassis but somebody proposing that has never worked on a Sigma frame. There is no room inside it and the normal drivers barely fit.

I used a 303 as a donor set because I had one sitting in Japan and aesthetically it's the best fit to a normal bias Sigma with the gray cable. Since John asked me about the sound, well it is a very good Sigma but with the 007 and 009 here it's in tough company. The midrange is glorious as ever but in other area it is rather colored though never in a bad way. I do think this is the best Sigma I've ever had though and it does look damn good after all the work I put into them (even painting part of the chassis). Here it is with some of its younger siblings...

[John Buchanan]

Lovely work, Birgir.

[ujamerstand]

Out of curiosity, what was the thickness of the aluminum plate used to hold the driver?

[John Buchanan]

Out of curiosity, what was the thickness of the aluminum plate used to hold the driver?

I think it's the same as a standard Lambda plate

[ujamerstand]

so 3mm thick. Got it.

[John Buchanan]

Loving listening to the Sigma Pros energised by the Stax SRM-Monitor. Bill Frisell's "All We Are Saying" CD is packing a nicely done smooth wallop with superb definition to well recorded cymbals which are totally devoid of the "spray-can" sound. Mr Frisell seems to inhabit excellent musical and recording circles - wonderful sidemen and superbly recorded. "Gone, Just Like A Train", "Good Dog, Happy Man" and "East/West Live" are fantastic jumping off points, as are the two Ginger Baker Trio recordings.

[deepak]

I have some normal bias Sigmas on the way from Japan, can't wait to hear them

[John Buchanan]

I have some normal bias Sigmas on the way from Japan, can't wait to hear them

Let me know what you think. They are my least favourite of the Sigma series - a Sigma/404 upgrade is a good way to go.

[flecom]

Let me know what you think. They are my least favourite of the Sigma series - a Sigma/404 upgrade is a good way to go.

I dunno, I have a set and they are ok, great sound stage, but things seem like they are "missing" when I listen through them...

so I end up listening to other headphones 90% of the time (ex HE60)

but I did get them at a garage sale so I can't complain lol

[deepak]

Let me know what you think. They are my least favourite of the Sigma series - a Sigma/404 upgrade is a good way to go.

They should be here any day... (fingers crossed)

n3rdling is a big fan of the unmodded normal bias Sigma so I will be spending a lot of time with them before making any decisions to swap drivers.

Though I will only be running them off an SRD7 transformer box. I will need an adapter cable to use them with my KGSS.

[John Buchanan]

They should be here any day... (fingers crossed)

n3rdling is a big fan of the unmodded normal bias Sigma so I will be spending a lot of time with them before making any decisions to swap drivers.

Though I will only be running them off an SRD7 transformer box. I will need an adapter cable to use them with my KGSS.

I run the Sigma Pro and Sigma/404s from an SRD-7 Pro. They sound very good.