The Stax thread (New)

[spritzer]

There is a protection servo in the amp that shuts off the output if there are any issues with the ground. I had this happen when the umbilical in my old G-lite was failing as it was on the loop out. Check if there are any intermittent connections in any cables etc. It's also a good idea to clean the dust out of the amp with some compressed air.

 

[Akabeth]

^Cool thanks spritzer.

 

[LingLing1337]

Any SR-5 owners out there want to check in?

 

[98664c3yijh]

gang,

is there a circuit diagram for SRM-T1 somewhere around?
i wanted to make additional balanced input on my non-S version

thanks!

 

[edstrelow]

Quote:

Originally Posted by padam /img/forum/go_quote.gif It has the same amount of power (340V RMS) as the SRM-007t so it is unlikely to drive a Sigma or an O2 properly. The O2 would probably work better than the Sigma which would probably sound muddy with this amp, Sigmas work quite well with a SRD-7 + speaker amp combination. The SRM-717 is the second best Stax amp and it has a good amount of power (450V RMS). The current SRM-727II/SRM-727A has the same but it is not linear sound-wise. However, there are aftermarket amps such as the KGSS and they have even more power than these Stax amps so they should be even better. What I meant about cables is that one could ruin the performance of the whole system by using a cable that does not match the other components.

I run both my low bias Sigma and Sigma/404 from an SRM1Mk2 which has the 340 volt operation and it is pretty decent with these phones. The 717 is better and I wouldn't recommend 340 volts with the 007A even though it is more efficient than the Sigma/404.

 

[padam]

Quote:

Originally Posted by 98664c3yijh /img/forum/go_quote.gif thanks padam!! will try to find 717...anyone selling one :staxsmiley: ??

Getting one from Japan using a deputy service like KuboTEN is your best bet. Last time Craig had a 717 for sale, I don't think it is still available but you might give it a try and ask him. Re-setting the voltage is fairly easy.

 

[spritzer]

Quote:

Originally Posted by padam /img/forum/go_quote.gif Re-setting the voltage is fairly easy.

If the transformer windings are intact then that is the case but if they are cut (many units are like that) then it is an epic pain to wire it for anything but 100V.

 

[padam]

I thought that only the newest amps are like that, my bad.

 

[98664c3yijh]

Quote:

Originally Posted by spritzer /img/forum/go_quote.gif If the transformer windings are intact then that is the case but if they are cut (many units are like that) then it is an epic pain to wire it for anything but 100V.

additional stepdown tranny? isolating one, built to medical specs ?
then army of filters...the amp wouldn't complain

maestro, would you point me to a SRM-T1S
schematics if not a problem ? Þakka þér fyrir.

 

[98664c3yijh]

Thanks padam & edstrelow!!
One more auction site? Too much for my nerves
after Epay

Will try to fish one without bidding though..no hurry

 

[spritzer]

Quote:

Originally Posted by 98664c3yijh /img/forum/go_quote.gif additional stepdown tranny? isolating one, built to medical specs ? then army of filters...the amp wouldn't complain maestro, would you point me to a SRM-T1S schematics if not a problem ? Þakka þér fyrir.

Any oversized transformer would work, a medical unit would be ideal since they are built to a much higher standard then the normal commercial stuff. It's better to just ask the seller of the amp to remove the decorative PCB on top of the transformer and take a picture of the primaries as they enter the transformer. You can easily spot if they are cut.

The T1 schematic was floating around here somewhere but I can't remeber where. It is full of flaws like all the Stax designs so it wouldn't be wise to follow it blindly.

Verði þér að góðu.

 

[nsx_23]

I'm curious as to what modifications I can do to my SRM1 to make it sound better. Audiocats suggested some boutique caps.

 

[alcyst]

This may have been suggested before, we probably need a "Stax ear pads" thread

 

[spritzer]

Quote:

Originally Posted by nsx_23 /img/forum/go_quote.gif I'm curious as to what modifications I can do to my SRM1 to make it sound better. Audiocats suggested some boutique caps.

A Mk1 is AC coupled so better caps would help but any Stax amp would really benefit from a new PSU over all. They are just simple smoothing caps and a real regulated unit would really help. It would never fit in the existing chassis though...

 

[chi2]

Quote:

Originally Posted by edstrelow /img/forum/go_quote.gif My head is full of Wagner after spending 5 1/2 hours at the premier of Gotterdamerung in Los Angeles yesterday. That long a performance seems to really set the Opera hall sound in my head and I was somewhat bothered by the treble harshness I was hearing when I listened to my Gotterdamerung recording on the 717/007A. Some of this could be the recording itself, an A/D transcription of the old Decca/London Solti Gotterdamerung. Even my old lp vesion struck me as somewhat bright. While the Sigma/404 does not have the same level of detail and precise imaging, it has, as I have said several times, a better soundstage for opera and now realized, the right amount of treble to make this recording sound like the opera hall. The 007A has a somewhat peaky treble. However,I did notice that the treble for the 007A was better after a very long amplifier warm-up.

Sitting in an opera hall means hearing a large part of indirect sound waves reflected by the ceiling and the walls while the auditors' bodies have a strong absorbing and damping effect. High frequencies are reflected to a lesser degree than other frequency ranges which leads to a distinct tilt of the frequency reproduction. Depending on the sonic qualities of the building it does substantially matter, too, where you are sitting.

While this is just the way it is in concert and opera halls, I don't really like it

. I prefer a fresher more involving representation like the one to be found on most recordings where you have a mix of more distantly placed microphones catching more of the indirect sound and of closer placed instrument or instrument group specific microphones recording a higher degree of direct sound. This, however, is more like sitting quite close to the orchestra or just at the rim of the orchestra pit (and I love it).

While the 007A/II is markedly brighter than the 007 I wouldn't call it bright or treble peaked. It certainly is less so than any pro bias Lambda with the exemption of the LNS (and maybe the 404LE which I don't own and haven't heard yet). The Sigmas provide a more concert or opera hall like presentation but with them I just miss some of the sonic experiences that make listening to music involving. My Sigmas with Lambda 202 drivers preserve more of the sonic information at both ends of the spectrum but I still prefer both O2s and the 4070 even for large orchestral works and operas.