[HDMan]

Thanks John, I hope I can build my next one as good as yours. What are your blue resistors you used, are they expensive?
 
I have noticed that running the amp with the lid on and off produces a 5v difference from the outputs, so I have been dialing it back 5v then putting the lid on and testing further. How accurate do the voltages have to be to zero.
 
 
These are my voltage readings after 1 hour operation:
 
Left Balance
 

 
Right Balance
 

 
Left Offset
 

 
Right Offset
 

 
 
P.S really need to get some KGSSHV badges, I'm on a budget so engraving is not happening.

 

[sachu]

^ you are plenty fine with those readings IMO

 

[ujamerstand]

Looks like a good rig. How'd you like it with the smyth realiser thus far?

 

[HDMan]

Quote:

Looks like a good rig. How'd you like it with the smyth realiser thus far?

 
Yeh it works tremendously well with the Realiser. I know now why Lorr from Smyth Research recommends Stax with the Realiser. Previously I was using some AD-700's from the headphone jack on the Realiser, although this worked quite well, it is no comparison to the KGSSHV/007-MK1 combo. The rear channels are so much more out of head, the front seperation between channels so vivid and the speed and resolution of the Stax are amazing.
 
This is a cliche, but it serves true, that I am hearing so much more detail now that I never recognized was there before. The Stax have allowed the Acapella Excalibur Spharon (PRIR), to really show there true potential in this sytem. Although the realiser can adjust any headphone to equalize the frequency range, headphones themselves still add a type of influence to the end result.
 
After I get a balanced DAC, I will be using the balanced XLR's on the KGSSHV, should give some more gain there, still some room for improvement.

 

[Victor Chew]

Readings look good to me.
 
Just trying to understand where the Realiser is placed in the chain. Since it is an audio processor, you use the Realiser between the CD player/source and the KGSShv correct? As the Reaslsier is SE only it means that you will have to use an adaptor to the balanced input at the KGSShv? Inshort, the realsier is like an equaliser but with surround function capabilities.
 
If the above is correct, then if you use an XLR DAC how would you implement it with the Realiser?

 

[HDMan]

Quote:

Readings look good to me.
 
Just trying to understand where the Realiser is placed in the chain. Since it is an audio processor, you use the Realiser between the CD player/source and the KGSShv correct? As the Reaslsier is SE only it means that you will have to use an adaptor to the balanced input at the KGSShv? Inshort, the realsier is like an equaliser but with surround function capabilities.
 
If the above is correct, then if you use an XLR DAC how would you implement it with the Realiser?
 

 
Yes that's right, the Realiser processes the source material and outputs it to the amplifier or DAC > Amplifier. It has no decoding capabilities of it's own, so for example DTS-MA from a bluray source must be decoded by a BD/CD player or SSP and then transfered to the Realiser as decoded PCM up to 8 channels at 24/192khz, but it only outputs as 24/48khz. It can accept 7.1 analogue or HDMI as inputs and has Toshlink and L/R RCA as outputs, the Realiser will use it's onboard DAC if you output via the RCA's.
 
If you use the analogue inputs there will be a D/A > A/D > D/A conversion process. If you use the HDMI in and Optical out to a DAC, the will only be one D/A conversion by the DAC
 
There are a few variations that can be applied before the Realiser, but I am trying to keep the signal digital until it reaches a High End DAC. At the moment I don't have a DAC, so I am using RCA to XLR adaptors.
 
So it will go, at least for me:
 
PC Bluray/Xonar HDAV1.3 (HDMI) > Realiser (Optical) > DAC (Balanced XLR) > KGSSHV
 
 
I realy wanted to add a SSP in between the Bluray player and the Realiser, but none that I know of output multi channel PCM over HDMI, only 2 channel. You could use the analogue outputs of the SSP, but that would break the digital chain. I did try a SSP, but returned it as it was a faulty unit and have now decided to keep the signal digital anyhow. There a lot of people using the Oppo Bluray Player as a source to the Realiser with great success.
 
 
To finish off my system, I have yet to aquire a DAC and the SR-009's

 

[spritzer]

Stax say +/-10V for adjusting their amps and even that is a miniscule amount compared to the voltage these amps can swing. 
 
The IXYS version of the amp will not settle down until it's fully warmed up so expect quite a bit of drifting.  The 2SA1968 is a better part is every way except its limited power handling, "low" voltage and price.  There is a reason why some of us have hundreds sitting around. 

 

[HDMan]

Quote:

Stax say +/-10V for adjusting their amps and even that is a miniscule amount compared to the voltage these amps can swing. 
 
The IXYS version of the amp will not settle down until it's fully warmed up so expect quite a bit of drifting.  The 2SA1968 is a better part is every way except its limited power handling, "low" voltage and price.  There is a reason why some of us have hundreds sitting around. 

 
Spritzer in your opinion is there a real world difference in sound with the 2SA1968 compared to the IXYS?
 
Can you actualy here a difference?

 

[sachu]

I think Headamp BHSE uses the IXYS parts..having heard the BH with the 1968 version of the BH i do my "The Rock" eyebrow raise at all the praise that folks seem to heap on the part. 

 

[kevin gilmore]

The difference is very tiny, but if you listen long enough you might hear a difference.
To be fair about it you would have to listen to both at 450v power supplies.
Some people are still going to like one over the other anyway.
You could use the 10m90s part instead also at 450 v supplies, it is more thermally
Stable than the other ixys part.

There is a very slight difference in the distortion characteristics which most
Would consider at the noise floor level

If you are nelson pass and want the worlds most perfect current source that
has 100 volts of compliance, and an output of about 2 amps, sure you can
make something absolutely fantastic.

But if you want to make a current source with 900 volts ( or 1000 volts) of compliance
that runs at 2.5 ma and you want it to have a constant impedance for the entire
frequency range, then things get way tougher.

You can do a 2sa1968 with an led as a voltage reference and you end up with
something that is very stable with temperature, and with a 10pf capacitance, its
virtually flat with frequency.

You can do the same thing with a 10m90s but performance at 2.5 ma is not the
same as using it on a BHSE where it runs at 15ma. It is a sharp cutoff device
and is very stable with temperature.

You can do the same thing with the ixtp01n100d but it has more drift with
temperature.

You can also do it the way the T2 does with stacked 600 volt pnp transistors feeding
a 1000 volt npn transistor. Works great, but is more parts. And more heatsink. Very low
capacitance and absolutely flat with frequency.

You can do it with a simple resistor and then the thd goes up. Way up.

The T2 has a pair of servo's to keep the output voltages and offsets under 5 volts.
It takes a fair amount of board space. Maybe a future version of the kgsshv will
also have the same pair of servo's.

 

[johnwmclean]

Quote:

What are your blue resistors you used, are they expensive?

 
Just your bog standard xicons from the BOM.

 

[HDMan]

I have some noise at full volume, 5 steps back from full volume is quite, I am using the Realiser as a volume control (digital) and will be using the Buffalo DAC (future build) with digital volume control also.
 
Would it be worth removing the Khozmo if I want to use the KGSSHV at full volume permanently?

 

[kevin gilmore]

Noise at full volume is usually fixed with 100 ohms in series with the wiper of the volume control.
To maintain full signal to noise, the volume control is usually a good idea. Then you turn up to
full blast the dac, and adjust the volume control for just past your maximum listening level.

 

[spritzer]

Quote:

I think Headamp BHSE uses the IXYS parts..having heard the BH with the 1968 version of the BH i do my "The Rock" eyebrow raise at all the praise that folks seem to heap on the part. 

 
Facepalm was invented for comments such as these.  I know for a fact that you did not hear these two amps side by side so you are comparing current sources based on memory?  Let's just throw out any possibility for difference in the circuitry elsewhere in these amps (which are substantial), different parts used, different sources and the list goes on.  This is even more stupid than people comparing dac's based on the actual chips used and not worrying about any of the other circuits. 
 
It is a simple fact that the Japanese parts are almost always superior.  Just compare the Toshiba BJT's vs. the Fairchild alternatives, far better specs but with almost all of the Japanese parts at end of life we have to make do. 

 

[sachu]

did i even mention that i heard them side by side (facepalm moment!!??).. just said i heard the BH with your famous 1968 devices...it sounded meh. SO maybe its just that the BH does just sound OK to my ears.
 
Hope you smacked your head hard with that facepalm.