New listening impressions of Stax C32 prototype and Shipping SR-009 - Page 51

livewire,

Based on Justin's specs, I was under the impression that the KGSS was 1200Vp-p which is over 400Vrms. Is this incorrect?

What you describe for the sound of the BHSE certainly seems appealing.

Quote:

Originally Posted by purrin 

Heh, don't sweat it too much. Your experience is just as valid as any one else's - and it's quite possible that I'm just utterly insane and was imaging things. If your comparisons confirm that KGSS = 323S, then you get to save a lot of money too.

Well, I already bought the KGSS years ago, so no savings...

I don't know how much you can really tell from short sessions at a meeting. A lot of comparative info that people post on top stats setups is based on meetings rather than owning the equipment, so it's hard for me to interpret the comments.

I'm not completely done yet, but I've been doing a pretty careful analysis of the sound of the SR-007 mk1 on the 323S and I haven't heard any deficiencies so far, and nothing that sounds worse than what I remember from my KGSS. If I don't hear any differences in side-by-side listening with the KGSS, I will be ready to conclude that 323S=KGSS in terms of sound quality, and 323S>KGSS in terms of convenience.

Like most manufacturers, he does not publish all the specs.

1200 volts peak to peak looks impressive, but the RMS voltage is what does the work.

(and is what I go by)

I have pictures of the KGSS boards and +/-350 volts is the actual rail voltage employed here.

I have read about variants that were produced with the psu outputs bumped to 400 volts.

So I am sure that is possible.

I am about to pull the plunge on the 009 but amp is an issue here. We do have 727 here but the distributor is ripping me off, instead, I can go for the 600, 006 and 323. How do these three compare to the 727?

The 323S may actually sound better (more balanced) than the 727 without mods. (spritzer will be able to confirm/deny when he receives it) So I would probably go for that.

Thanks. Then I will get the 323 as a temp and wait until I get the BHSE or the next gen amp from Stax comes out.

Quote:

Originally Posted by livewire 

t it simply - the all transistor amps have a more clinical sound, faithfully reproducing the source.

 

The tube amps add that extra "something"  three dimensionality? warmth? presence?

I cannot put a finger on it, but the Blue Hawaii does this without sounding "too tubey"

that is without losing control of the upper or lower registers. It just sounds convincingly real.

 

 

The BHSE ss/valve hybrid design.  The Aristaeus is a valve-only.  Perhaps that's part of the reason.  But you can roll both of them to tune that to whatever balance you desire between warmth vs. detailed SQ.

A follow up on the Pricejapan,  I have received the SR009 today.  I would like to say that there is

no problem at all for this purchase.  I only entered their website , filling their form and you can choolse the method

of S&H. Then you paid the deposit of $1,000.  I have ordered mine on last week of April and was informed the arrival

of SR009 on third week of May. You paid the remaining balance of 3258$.  The SR009 was shipped on the same

day of payment and 3-4 days later the SR009 has cleared the custom

Now I am listening the great SR009 via the Boybee (same as Woosee energizer) which is connectted to the

speaker post of my balanced beta 22 .  I will have more chance to listen the SR009 comparing to HE90, SR Omega ,

Omega II mkI, Stax 507 later with the boybee, Stax SRM300 and 727t (Spritzer modded, Stax headphones only).

I also heard from the owner of the first SR009 from pricejapan that the deal went smoothly as butter.  His arrived

2 days earlier than mine and we are only 2 hours apart.

Comparing the Aristaeus and the BHSE based on those specs is like comparing an apple and a golf ball.  They are both round but that's about the only thing they have in common.  The Aristaeus is an old school tube amp (could have been built in the 50's/60's) while the BHSE is ultra modern amp with more in common with modern ultra high end SS amps then a tube amp. 

While tubes do have certain characteristics their "sound" is almost always down to how they are used rather then some sonic traits tubes have.  Let's for instance compare a 717 to a 007t, the 717 is pretty colored for a SS amp but the 007t is clearly a more colored amp so it must be "tubey".  To me this couldn't be further from the truth, how the 007t sounds is much more down to how the tubes are used.  I have here amps which are pretty much cleaned up versions of the same circuits, a KGSS vs. the KGST.  Both built using the same PSU design and they they sound remarkably similar.  Sure the 6CG7 tubes are gone in favor of the 6S4A but the biggest difference is in how the tubes are used. 
 

Quote:

Originally Posted by TheAttorney 

A simpler solution to reducing all that heat is for the amp to have a standby switch, which drops or reduces the high powered circuits, but allows the amp to stay warm and ready for action - more subtle and generally less stress on the amp than frequent use of an on/off switch. This seems so obvious to me, I just don't understand why the BHSE and many other "hot" amps don't do it - because there are plenty of amps that do.

 

It's a good idea but it would never work here.  You could kill the HV rails and just run the LV but there is nothing to be gained from doing that since the amp is designed for minimal thermal drift.  The power consumption is also close to zero. 

I also don't agree that the BHSE is a "hot" amp.  Place it next to a Firstwatt F5 and it runs pretty cool by comparison let alone something like the T2 (both stock and DIY version).  The top panel of the SRM-T2 reached 60+°C which is enough to cook eggs!!  That is only running at 50% power compared to the DIY version so we are indeed mad...

Btw, out of curiosity, what is the surface temp on your amp spritzer?

I vote that all DIY T2 owners need to put a warning sticker on all their amps ;)

Yes, but place the BHSE next to the 323S, and you'll draw a different conclusion. Also, you have a different perspective as someone who lives in Iceland... BHSE heat is a lot more problematic in many parts of the US and much of the rest of the world in the summer.
 

The question that I would like to answer for myself (by listening) is whether the BHSE is essentially a Rube Goldberg machine, or whether it truly offers a noticeable improvement in sound quality when compared to more efficient (even if less sophisticated) solutions.

The BHSE is noticeably clearer and has a more controlled sound then any STAX made amp I've listened to or the KGSS builds I've heard. I've had plenty of time at meets and in more private environments to listen to it. I love that amp, though I haven't run across a 323S yet. The BHSE's heat hasn't really concerned me while listening indoors each time either, I've never even thought to check the top panel for its heat output. Anyone that listens to speakers with power amps at all would not be concerned with the amount of heat leaked from the BHSE.

The DIY T2 on the other hand... its heat output had me intimidated while only touching the volume's knob. That is a real space heater.

Quote:

Originally Posted by manaox2 

The BHSE is noticeably clearer and has a more controlled sound then any STAX made amp I've listened to or the KGSS builds I've heard. I've had plenty of time at meets and in more private environments to listen to it. I love that amp, though I haven't run across a 323S yet. The BHSE's heat hasn't really concerned me while listening indoors each time either, I've never even thought to check the top panel for its heat output. Anyone that listens to speakers with power amps at all would not be concerned with the amount of heat leaked from the BHSE.

 

The DIY T2 on the other hand... its heat output had me intimidated while only touching the volume's knob. That is a real space heater.

My power amps are based on ICEpower modules which run in Class D, so very little heat...

If you have good air conditioning, then none of this is a problem, but if you don't have it, then heat from electronics becomes a problem and it adds up when you have multiple components in the room. Particularly when there's no air movement, electronics that normally don't run so hot can start running really hot. One such example is my Benchmark DAC1 which runs at just 8W normally and 16W maximum. It's typically just warm to the touch, but when the temperature in the room rises somewhat and there's no air movement, it becomes so hot that it's uncomfortable to touch (it uses its chassis as a heatsink), so even that little thing becomes a bit of a headache in the summer.
 

I will find a way to listen to the BHSE since I'm very curious... The SR-007 already sound crystal clear to me out of the KGSS/323S and I don't detect any lack of control, but I guess sometimes you don't realize that a device can perform better until you experience it.

Spritzer was speaking of the original T2 heat before.

My DIY T2 runs around 50C at the hottest spot, about a 35C rise.  It's not gonna be a summertime amp without AC.

Had a standard Headamp KGSS before and the T2 is in another league.