[JimL11]

   
Why? 
 
I'm not sure that the safety of the device would be much enhanced, and in a small enclosure like a stax energizer, a wee little 1va transformer is still a 1 inch piece of steel with a 50 or 60hz field across it. It could introduce noise. 

An isolation transformer with an electrostatic shield can actually cut down transmission of noise from the power line into the power supply.  In addition, there IS a safety concern with the AC line going directly into HV circuitry.  A 1 va I:1 isolation transformer is totally incapable of transferring amps of HV current through your skull, the AC line can.  What's the cost-benefit ratio of avoiding a preventable death?

 

[astrostar59]

 
An isolation transformer with an electrostatic shield can actually cut down transmission of noise from the power line into the power supply.  In addition, there IS a safety concern with the AC line going directly into HV circuitry.  A 1 va I:1 isolation transformer is totally incapable of transferring amps of HV current through your skull, the AC line can.  What's the cost-benefit ratio of avoiding a preventable death?

Not totally sure of where this advice is leaning? But i can say from my own experience that a power regenerator can and does improve sound quality a LOT. I bought a PS Audio P10 which I use to power all my system inc the speaker amp. It removed the digital haze and clinical edge to my system, and everything sounds cleaner and faster. The background is also much darker and bass depth has increased.
 
Like all things in this (complex) hobby it all costs. It is down to what is most effective for the sound improvement. My power regenerator has improved all my separates so IMO is worth the cost.

 

[JimL11]

  Not totally sure of where this advice is leaning? But i can say from my own experience that a power regenerator can and does improve sound quality a LOT. I bought a PS Audio P10 which I use to power all my system inc the speaker amp. It removed the digital haze and clinical edge to my system, and everything sounds cleaner and faster. The background is also much darker and bass depth has increased.
 
Like all things in this (complex) hobby it all costs. It is down to what is most effective for the sound improvement. My power regenerator has improved all my separates so IMO is worth the cost.

My post was only incidentally about improving sound.  The major point of an isolation transformer is to improve safety.  The Stax design dates back to the 1960s, before mandatory seat belt laws, etc.  I doubt it could be sold today as designed due to safety concerns - they would probably REQUIRE an isolation transformer.  You don't mess around when playing with AC lines.

 

[Chillzone21]

Looking for an amp to drive newly aquired SR-007 Mk1's, $1000 AUD is my budget.
 
Noticed quite a lot of 727's on the market, I need 240v for Australia, is it easy to change voltage on the 727?
 
Better to get the 717? They probably don't come up much for sale.
 
Don't want the 323s, looking for more power to drive the Mk1's. (What about the 353X?)
 
 
Recommendations please.

 

[jdhore]

  Looking for an amp to drive newly aquired SR-007 Mk1's, $1000 AUD is my budget.
 
Noticed quite a lot of 727's on the market, I need 240v for Australia, is it easy to change voltage on the 727?
 
Better to get the 717? They probably don't come up much for sale.
 
Don't want the 323s, looking for more power to drive the Mk1's. (What about the 353X?)
 
 
Recommendations please.

353X doesn't have much more power, the biggest improvement over the 323S is that it exposes the balanced inputs that the 323S apparently has internally.
 
According to Spritzer, the 323S/353X is currently the best amp that Stax makes. The 717 and 727 can be feedback modded to sound decent and have good power, but a feedback modded one would probably be outside your price range and...I tend to assume that most people aren't good enough at electrical engineering to do it themselves...

 

[Chillzone21]

I would easily be able to do the mod myself, soldering 4 resistors is not exactly difficult.
 
But I don't want to have to do that if I can avoid it, could balls it up. I read one person compared the 727 with a KGSS and found minimal difference. I mostly wanted to know about voltage conversion, or just use a step down?
 
727/45w would have to be better with dynamics than the 353x/30w wouldn't it?

 

[ericj]

 
My post was only incidentally about improving sound.  The major point of an isolation transformer is to improve safety.  The Stax design dates back to the 1960s, before mandatory seat belt laws, etc.  I doubt it could be sold today as designed due to safety concerns - they would probably REQUIRE an isolation transformer.  You don't mess around when playing with AC lines.

 
But all we're talking about here is a bias supply. 
 
And yeah, the designs date to the sixties but how late were they sold? 
 
Has anyone ever been injured by one?
 
I sincerely doubt that a galvanically isolated bias supply sounds better. 

 

[blackads]

Looking for an amp to drive newly aquired SR-007 Mk1's, $1000 AUD is my budget.

Noticed quite a lot of 727's on the market, I need 240v for Australia, is it easy to change voltage on the 727?

Better to get the 717? They probably don't come up much for sale.

Don't want the 323s, looking for more power to drive the Mk1's. (What about the 353X?)


Recommendations please.

Just use a stepdown, I did just that for over a year with a set of 009s and a 727A bought direct from Price Japan and sent here to Australia. The 727 is fine on a stepdown. Definitely do the mod, as you say its not difficult. Without the mod the bottom end of the 727 is just plain weird sounding.

 

[martyn73]

I've got a pair of Stax SR-007A headphones and after about 45 minutes the left earpad tends to become uncomfortable despite rotating it, etc. My ears aren't large and don't stick out.
 
Does anyone else have this problem and can the headphones be modified, e.g. such as larger earpads?
 
Unfortunately, if there's no solution I may have to my Stax gear.

 

[rgs9200m]

Are they the Mark 1 version (the brown ones)? I had this comfort issue also and endlessly rotated the pads to no avail. My ears would touch the driver pad surface and my ear would be annoyingly crunched.
But now I have the latest version and it is extremely comfortable not that it has the thicker pads. (I have the black ones bought domestically here in the US.)

 

[martyn73]

  Are they the Mark 1 version (the brown ones)? I had this comfort issue also and endlessly rotated the pads to no avail. My ears would touch the driver pad surface and my ear would be annoyingly crunched.
But now I have the latest version and it is extremely comfortable not that it has the thicker pads. (I have the black ones bought domestically here in the US.)

Hi,
 
I have the SR-007A SLZ-2080 so I guess they are fairly recent. As far as I know the only difference between the SR-007II and SR-007A is that the latter is silver coloured.
 
Thanks,
 
Martyn

 

[joseph69]

  Hi,
 
I have the SR-007A SLZ-2080 so I guess they are fairly recent. As far as I know the only difference between the SR-007II and SR-007A is that the latter is silver coloured.
 
Thanks,
 
Martyn

Silver = Japan
Black = U.S.

 

[Chillzone21]

 
 
 

 

[Chillzone21]

  I've got a pair of Stax SR-007A headphones and after about 45 minutes the left earpad tends to become uncomfortable despite rotating it, etc. My ears aren't large and don't stick out.
 
Does anyone else have this problem and can the headphones be modified, e.g. such as larger earpads?
 
Unfortunately, if there's no solution I may have to my Stax gear.

 
1 cm thick sponge mod, also sounds better to me. Comfort factor is way better. Cut a circle and put it under the pads the whole way around.

 

[arnaud]

Ouch, as if the O7mk1 needs to sound even warmer. I know you inquired about my 727 amp but, honestly, this is just going to sound dreadful...

Arnaud