[astrostar59]

Hi guys,
I noticed there is a buzz when I turn volume up past 5.5 mark in my SRM-T1. At 10 it's quite noticeable. Is it normal?
Also, I noticed distortion at really loud volumes sometimes. For example in one of my test songs @ 00:41 onwards ( https://www.youtube.com/watch?v=S8WY03aUsHc ). Not sure if it's the headphone's problem or the amp's. What do you guys think?

I would look at the tubes first. More gain will show up problems wirh aging tubes. Also check the bias, and clean rhe tube pins and sockets.

If the tubes are quite new, it could be a ttansformer related issue, or a dirty volume pot. Or old capacitors. The anp is well over 10years old so might be due a recap. I would PM Spritzer for more detailed tech help.

 

[edstrelow]

   
In my opinion the Sigma Pro is one of the best Stax models and i prefer it on a modifided SRA-12S sometimes over a SR-007/KGSS combo. The Sigma NB is also very good with a wonderful midrange and for aggressive rock/metal maybe the best choice.

 
 

Listening time in my case

60% Sigma with ED1 Signature und T1
25% Lambda Pro with SRM-Monitor
15% 007 Mk2 with Pawel HP-1 different amps

Regards Georg

Just finished listening to Frank Sinatra at the Sands on a low bias Sigma with the somewhat cheesy SRDX ( the transformer/amp that plugs into a conventional headphone jack.)  Sounded great!  I like the SRA12 but mine unfortunately is in need of repair.

 

[schorsch]

Just listened to my Sigma normal upgraded to PRO with SR 007 Cable in the SRA 12S.

Phantastic with female voices.

Regards Georg

 

[edstrelow]

Just listened to my Sigma normal upgraded to PRO with SR 007 Cable in the SRA 12S.

Phantastic with female voices.

Regards Georg

Have you raised the bias on the SRA12S?

 

[schorsch]

  Have you raised the bias on the SRA12S?

Dear edelstrow,
 
yes it was raised to PRO by the former stax distributor (Germany) during an general overhaul.
 
I like this amp very much.
 
Regards Georg

 

[blackads]

Just wanted to say a THANK-YOU to Spritzer for the mod he suggested back in 2010 for the feedback loop on the stax 727 
 
I bought a 727A and set of 009s from price japan a couple of weeks ago and have used them in stock form until today when Id had enough - I found the bottom end truly lacking and the overall sound to be uninspiring and weirdly without foundation, even at high volume.  Ive previously heard a set of 009s thru the 007tii and thats what convinced me to get my own pair, the unmodded 727 does not IMO measure up to the stock 007tii, and Ive spent the last week hoping Id made the right amp choice and that the mod was going to be the fix it needed.
 
Today I bit the bullet and did the mod, it was very easy, the boards just lift out and theres plenty of space to work,  I managed to use the existing 150k resistors by simply unsoldering and lifting one end and soldering the lifted end of the resistor to some cut off resistor lead which I then soldered  to connect to the board edge contacts.   
 
I did the right channel only first so could directly compare with the unmodified left side, there is a huge difference in bass presence and impact with the mod.  Both channels are now modified and the amp IMO sounds like it should for its price..
 
So again, thanks Spritzer...

 

[astrostar59]

Just wanted to say a THANK-YOU to Spritzer for the mod he suggested back in 2010 for the feedback loop on the stax 727

I second that. I didn't know which Stax amp to buy and Birgir told me to get a 717, which is still very good and running fine. The modded 727 is the same as a 717 soundwise.

It makes me wonder why Stax do things like this in the first place. I know plenty of Stax owners who bought a Stax amp with the phones, and got fed up with the amp.

You know, if you wanted to go another step, you could get a DIY KGSShv or buy a Woo or BHSE if you like tubes. The jump from the 717/727 is not subtle.

 

[kothganesh]

I second that. I didn't know which Stax amp to buy and Birgir told me to get a 717, which is still very good and running fine. The modded 727 is the same as a 717 soundwise.

It makes me wonder why Stax do things like this in the first place. I know plenty of Stax owners who bought a Stax amp with the phones, and got fed up with the amp.

You know, if you wanted to go another step, you could get a DIY KGSShv or buy a Woo or BHSE if you like tubes. The jump from the 717/727 is not subtle.

+1. I have a 717 which sounds very good with the 007. I also got the KGSShv (by that master Geoff Clarke 

) and the jump is noticeable.

 

[David1961]

If it hadn't been for the SRM-007t I once had in which I got that amp along with the SR-007mk1, I'd have probably still had the 007mk1's.
I felt that amp made the 007's sound veiled with not much energy.
I've since heard the 007mk1's with my BHSE and that amp turned them into completely different sounding Earspeakers.
Regarding Stax amps, I've only heard two with both the 007mk1's and 009's, those two stax amps were the SRM-007t and 717, and with both those Earspeakers I found the 717 sounded the better of the two Stax amps.

 

[astrostar59]

The 717 or modded 727 sounds harsh compared to the KGSShv. It also sounds thin and a bit lifeless,
and synthetic / clinical. I have both here and use them side by side. The 717 is my 'portable' amp, so I will keep it.

The KGSShv sounds real, warmer, wider sound stage, massively bigger head room (goes very loud with no sign of clipping or compression)
and the bass is in another league. It has incredible control over the 009 drivers, an iron fist.
It is a different world in my view, not subtle. It makes me wonder why Stax still don't have an amp to show off their top headphones
in their range, it seems insane. Demoing to the masses with Stax amps, it's tragic. Leaving it to the DIY community and small niche companies
to make amps that match the quality of their headphones instead. No wonder so many go of and buy dynamics or planar systems!

Today I am testing it against David's BHSE, so should be fun.

I don't imagine it will beat the BHSE, rather from memory at different locations, it will be a different signature,
possibly not as transparent and maybe not have the tube magic in the midrange. If it gets to 90% close
I will be very happy.

Watch this space.

 

[kothganesh]

The 717 or modded 727 sounds harsh compared to the KGSShv. It also sounds thin and a bit lifeless,
and synthetic / clinical. I have both here and use them side by side. The 717 is my 'portable' amp, so I will keep it.

The KGSShv sounds real, warmer, wider sound stage, massively bigger head room (goes very loud with no sign of clipping or compression)
and the bass is in another league. It has incredible control over the 009 drivers, an iron fist.
It is a different world in my view, not subtle. It makes me wonder why Stax still don't have an amp to show off their top headphones
in their range, it seems insane. Demoing to the masses with Stax amps, it's tragic. Leaving it to the DIY community and small niche companies
to make amps that match the quality of their headphones instead. No wonder so many go of and buy dynamics or planar systems!

Today I am testing it against David's BHSE, so should be fun.

I don't imagine it will beat the BHSE, rather from memory at different locations, it will be a different signature,
possibly not as transparent and maybe not have the tube magic in the midrange. If it gets to 90% close
I will be very happy.

Watch this space.

Yes, please do post on your findings vis-a-vis the BHSE. If its 90% close (or better), I will not pull the trigger on the BHSE. Further, the wait is reportedly 12 months

 

[David1961]

With the K-01 being used, I've a feeling the difference between my BHSE and Julian's KGSSHV might be quite close. I believe my iPod might be the better of my two sources to use even though ( IMO ) it's no match to my K-01.

When doing this comparison, obviously my XLR and RCA interconnects will be used, ( from using the K-01 only ) so we'll be using both interconnects with both amps.

 

[eric65]

  Yes, please do post on your findings vis-a-vis the BHSE. If its 90% close (or better), I will not pull the trigger on the BHSE. Further, the wait is reportedly 12 months

 
And me, I would wait only 15 days to get the all-new AudioValve Verto box http://www.head-fi.org/t/727630/audiovalve-rkv-ii-otl-amp-2014-version-audiovalve-box-adapter-verto-for-stax-headphone-and-for-low-impedance-orthodynamic-eletrodynamic-headphone#post_10756994 , which coupled to the AudioValve RKV-II (OTL) amplifier and the headphones Stax SR-009 (that I already own), that would do better than all the amplifiers Stax currently in production (including SRM 727 and SRM 007t2) if one believes the first trials and listens in France. 
http://www.homecinema-fr.com/forum/casques-haute-fidelite/verto-le-boitier-audiovalve-pour-casques-stax-t30052030.html
I would affirm you soon.

 

[paradoxper]

I would affirm you're full of schiit.

 

[wink]

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