[goobicii]

  You can't get the 1968's for less than 20$ a piece period, so no it's not "hipster swag" there aren't any parts left
 
These questions should be asked in the stax thread not here, and they already have been answered in either that or the BHSE thread

 
I was just joking,tell me how much more deadly the cyclotron is?

 

[kevin gilmore]

time flys
 
the kgss(hv) dates to 2001, so its 14 years old
the BH(se) dates to 2004, so its 11 years old
the original stax T2 dates to 1994 so its 20 years old
 
all of them are filled with obsolete parts.
if you have a stock of those parts, great, otherwise...
 
Ayre and Schiit are also examples of many companies
that use lots and lots of obsolete parts.
 
Thank the Solar energy thing for forcing parts to
be available that we need.
 
The Cree part, one of 3 is actually a 1700v jfet.
if it really was a mosfet it would have at least 2000pf
of gate capacitance, and it has only 10% of that number.
 
So the carbon is in fact very close to a BHSE except
fully solid state.
 
Others have determined that you need to run the output
stage at 20ma. With the previous parts, this really
is not possible with a solid state amp.
 
With the new parts, 25 or 50ma no problem.
 
So the carbon is definitely in the same class as the T2 or BHSE
but way easier to buld.
 
Now the circlotron is faster and lower distortion.
But the power supplies are an integral part of the output
stage. And as such the current design has the power supply
board less than 2 inches from the output stage board.
 
The first version of the power supply would not fit in the box.
The current version of the power supply which has been posted
uses Kemet 550V caps. Which are brutally expensive because
you need 20 of them. Some will build the thing with lower voltage
caps and run the amp at 800v.
 
The power supply has to be as close to the output stage as possible
to avoid interesting issues with the capacitance of that power supply
respect to signal ground. Each of the 4 power supplies has 550 joules
of energy storage. Way more than the 300 joules necessary to start
or stop your heart. The kgsshv has much less stored energy, but
also deadly. 
 
So it has to be a one box thing.
 
And if birgir is going to charge $10k for it, so be it.
There is another amp coming out in the near future that is also $10k.
 
Less than 10% the price of a Z07, and will likely last far longer.
although the Z07 is more fun.
 
if people really want 2sa1968 I would be happy to sell some for $25 each,
1/4 the ebay price for what are likely fakes from a disreputable company.
(limit 5)

 

[gepardcv]

  You can't get the 1968's for less than 20$ a piece period, so no it's not "hipster swag" there aren't any parts left

To be fair, bdent has 1968s for $16 (I think: http://www.bdent.com/2sa1968ls-sanyo-high-voltage-amp-transistor.html, right?), and can be exchanged for IXYS parts on all recent full-size KGSSHV boards. Your overall point stands, of course.

 

[jgazal]

There is another amp coming out in the near future

Well, there is always something new under the sun, if you know where to look. For example, with a few more advancements, carbon nanotube field-effect transistors (CNTFET) will become available and they could be used in a Circlotron amplifier. Today, we can buy Silicon Carbide (SiC) transistors and MOSFETs, which can also be used in a Circlotron amplifier
http://www.tubecad.com/2013/10/blog0272.htm

Are there "carbon nanotube field-effect transistors (CNTFET)" suitable for high voltage ciclotrons?

 

[NoPants]

  To be fair, bdent has 1968s for $16 (I think: http://www.bdent.com/2sa1968ls-sanyo-high-voltage-amp-transistor.html, right?), and can be exchanged for IXYS parts on all recent full-size KGSSHV boards. Your overall point stands, of course.

 
Yes I was just taking into the account the public opinion that the BJTs are the "best" option, when it's not a realistic option at the end of the day. Also there are <20 pieces at bdent last I checked.

 

[jcx]

diamond devices seem likely closer than carbon nanotube, one diamond semi company:  http://www.evincetechnology.com/tech_overview.html still could be more than a couple of years away
 
actually IXYS, OnSemi, others have hi V mosfet with reasonable characteristics for ES amps in current production - engineering trades have to be made with all devices

 

[kevin gilmore]

there has to be a massive volume production reason for any of these devices to exist.
There is none yet for nanotube based devices.

 

[mikek200]

Not to side track the topic ...but..a note to say thanks to Birgir>
 
Last Monday Birgir,shipped out my Dual Differential amp-I received it on Thursday--talk about fast shipping from Iceland,very nice..it landed in JFK in less than 48 hours
I'm using it with a Parasound 1500 dac,and the Stax 009's.
 
Birgir,want to say ,,,many thanks for all your help with my setup
Since,I started in this hobby,I've never achieved the sound quality,of what I'm getting now,your amp is just outstanding,giving me a warm,yet,detailed sound.
The tubes you've chosen for this amp are excellent.,,& give a nice balanced affect...with strong detail,yet smooth,
absolutely NO NOISE
 
Thanks again Birgir,you've done a great job,as always
 
Mike
 
My apologizes for going off topic

 

[NoPants]

It's not off topic, the thread is about his shop
 
Do you have any pictures? The amplifier name is a bit on the vague side

 

[wink]

Bump

 

[paradoxper]

Mike, where are you. Anyways, I can relay pics he sent. No innards, unfortunately. I believe 12AX7 are used.
 

 

[mikek200]

Sorry guys,with the new amp/parasound 1500 dac,looks like I'm at end-game...
Listening sessions ,now last 10-12 hours,only end,when my bride turns of the electricity to the apartment
This hobby ,has taken on a new meaning for me...I buy music now,instead of gear.--thank you Birgir !!!
 
 
With the 009's,and some tube rolling,I'm getting spectacular SQ
The amp takes 2-6CG7 tubes..and 2-12AX7's.
Birgir delivered them with 2-RCA 6CG7's ,and 2-JJ ECC83's
 
AS of today,I'm using 2-Mullard Longplates ,& 2-Sylvania Blackplates-6CG7's.
 
I have many amps/dacs over the last few years..this combo definitely gives new meaning to my music
 
Birgir did an outstanding job ,I tip my hat to him,he's the best !!
 
Mike

 

[gerb0075]

So, are Spritzer and Birgir the same person (Spritzer the HF "handle", Birgir his real name)? Thanks.

 

[MacedonianHero]

So, are Spritzer and Birgir the same person (Spritzer the HF "handle", Birgir his real name)? Thanks.

 
Correct. 

 

[bmichels]

 
I'm curious as to how a Carbon mates better with the 009s better than a BHSE or KBSSHV. What's the word on the street?

me to I'm curious    Carbon or BHSE for a SR009 ?