KGSShv Carbon - hows it sound with the 009s?

[purk]

The Carbon CC has been purchased already. Very fast

Very nice deal.  That volume control by itself make it a better buy than the Alpha pot, IMO.

 

[Rossliew]

Agreed but at that price perhaps one can just get a basic carbon and a used 007. Well, for me anyway lol

 

[purk]

Agreed but at that price perhaps one can just get a basic carbon and a used 007. Well, for me anyway lol

Well...very true but you get a better PSU, wiring, and attenuator which in sum is more than $1000 pricetag.  Then Birgir simply said it isn't neccessary.  I also like the look on the chassis better.

 

[Rossliew]

Well...very true but you get a better PSU, wiring, and attenuator which in sum is more than $1000 pricetag.  Then Birgir simply said it isn't neccessary.  I also like the look on the chassis better.

Definitely better parts and the silver wiring itself should cost a bomb. I was very tempted to grab it myself but it was gone in seconds!

 

[Quixote79]

  http://www.mjolnir-audio.com/products/
 

 
"Another Carbon variant, the Carbon CC.  This has been cooking for a long while now but it is basically a Carbon in a larger box with a more advanced power supply, the best volume control available and all signal wiring is solid core silver.  I will only build two of these for testing, the one pictured which has a Alps RK50 volume control and a R-core transformer.  The other one has a Penny&Giles RF15 volume control and my custom torodial transformers.  This is meant as a project for those that think the normal Carbon is simply not expensive enough so I will continue to work on this project over the coming months.   I have some things planned which will make the Carbon seem dirt cheap indeed…  This is not planned to surpass the regular Carbon and I for one think that this stuff isn’t needed.  It is an improvement but given the huge price difference I don’t think it is worth it.  That being said, we have this drive towards “perfection” so so the crazy side of my likes to play with this stuff."

Price: 5500$ plus shipping

 

PS:
 
I'm selling Opel Corsa, year 2008 in perfect condition, price 5500$, not negociable hahahahaha

Can someone here explain whats cascaded current sourcing is good for?
Someone at the other place explain it was important and the Carbon CC does not have it - but dunno what the importance might be.

 

[astrostar59]

 
Can someone here explain whats cascaded current sourcing is good for?
Someone at the other place explain it was important and the Carbon CC does not have it - but dunno what the importance might be.

Is it the same as Shunt Regulated power supply?

 

[Kerry]

The current source, in this case, allows the active device (tube or transistor) to operate more linearly.

A cascaded current source can provide a higher resistance against the load.

The designer decides what they believe to be the best choice for their application.

 

[astrostar59]

The current source, in this case, allows the active device (tube or transistor) to operate more linearly.

A cascaded current source can provide a higher resistance against the load.

The designer decides what they believe to be the best choice for their application.

Isn't it this?
 

The cascode is a two-stage amplifier composed of a transconductance amplifier followed by a current buffer.

Compared to a single amplifier stage, this combination may have one or more of the following characteristics: higher input-output isolation, higher input impedance, high output impedance, higher gain or higher bandwidth.

In modern circuits, the cascode is often constructed from two transistors (BJTs or FETs), with one operating as a common emitter or common source and the other as a common base or common gate. The cascode improves input-output isolation (or reverse transmission) as there is no direct coupling from the output to input. This eliminates the Miller effect and thus contributes to a much higher bandwidth.

 

[Quixote79]

 
Isn't it this?
Quote:

The cascode is a two-stage amplifier composed of a transconductance amplifier followed by a current buffer.

Compared to a single amplifier stage, this combination may have one or more of the following characteristics: higher input-output isolation, higher input impedance, high output impedance, higher gain or higher bandwidth.

In modern circuits, the cascode is often constructed from two transistors (BJTs or FETs), with one operating as a common emitter or common source and the other as a common base or common gate. The cascode improves input-output isolation (or reverse transmission) as there is no direct coupling from the output to input. This eliminates the Miller effect and thus contributes to a much higher bandwidth.

 

You probably right astrostar69.
Reading that it seems obvious that a cascade or shunt'ed is much better. Don't really understand why one would claim it to be better without.
Anyone heard the benefits of a shunt'ed current source? or cascaded

 

[kevin gilmore]

the input circuit with the jfet and the top current source is a folded cascode.
(one of john curl's favorite things) followed by a voltage translator which the integrated circuit folks have
a name for which I forgot.
 
the load for the (tube or transistor) at the output is a cascade.
 
not the same thing.
 
edit:  folded telescopic cascode

 

[astrostar59]

  the input circuit with the jfet and the top current source is a folded cascode.
(one of john curl's favorite things) followed by a voltage translator which the integrated circuit folks have
a name for which I forgot.
 
the load for the (tube or transistor) at the output is a cascade.
 
not the same thing.

Try and grab you while we on the subject. Do you think the additional low voltage 12v power supply boards x 2 that have been used by some on the Carbon is the better way to go, as opposed to the standard power supply feeding that 12v? What sonic benefits would you say there was to be had?

 

[Quixote79]

 
Try and grab you while we on the subject. Do you think the additional low voltage 12v power supply boards x 2 that have been used by some on the Carbon is the better way to go, as opposed to the standard power supply feeding that 12v? What sonic benefits would you say there was to be had?

Does the Carbon CC has double 12V power supply then ?

 

[kevin gilmore]

is the grlv supply better, yep also more money and more physical space.
 
some say they can hear the difference.  If you have $35k in top of the line audio precision you can
definitely measure a difference.
 
the diy-T2 had the option from the start of dual mono power supplies.  Don't know anyone crazy enough
to build it that way.

 

[JimL11]

  You probably right astrostar69.
Reading that it seems obvious that a cascade or shunt'ed is much better. Don't really understand why one would claim it to be better without.
Anyone heard the benefits of a shunt'ed current source? or cascaded

 
 

 
Isn't it this?
 

No, you're both wrong.  Here's why.  The quote from Astrostar describes a cascode AMPLIFIER, where the bottom of the cascode is connected to ground and the signal goes to the grid (tube) or gate (MOSFET) of the bottom device.  However, with a cascoded current source, the bottom of the cascode circuit and the grid/gate of the bottom device are BOTH connected to the signal output from the driver.  As a result the bottom device doesn't "see" the signal so it runs a pretty constant current, or tries to.  However, even though it doesn't see the signal via the bottom and grid/gate, it still "sees" some signal from voltage variations across it as the output device swings voltage.  The cascode top device greatly increases the effectiveness of the bottom device because it provides a relatively constant voltage across the bottom device, isolating from signal voltage swings, so as a result the cascode current source is very effective, resulting in an effective impedance in the 10s or 100s of megohms.  Now if this isn't a sufficient explanation, I suggest you look at Gary Pimm's website where he goes into more detail including measurements that show how good a cascoded current source is.  Incidentally, as far as I am aware there is no such thing as a cascaded or shunted current source.  The bottom line is, a cascoded current source comes close to an ideal current source with a minimum of parts.  The idea of a current source load is to completely  decouple the current from the voltage.  Why is this good?
 
Consider the usual output stage where an output device is biased by an output resistor, and drives an electrostatic headphone load.  Normally the resistor is on the order of 50 kilohms (example:  the Stax SRX circuit from the 1970s), whereas the headphone is on the order of hundreds of kilohms or even megohms.  With a resistor, every variation in voltage requires a variation in current - that's what Ohms law tells us.  In practice, this means that most of the output current is used to drive the resistor because it is so much lower impedance, and the current "scraps" feed the headphone.  In effect, with a resistor load, the amplifier drives the resistor and the headphones are along for the ride.  Not only is this wasteful, it also increases distortion.  An ideal current source has an infinite impedance, meaning that ALL of the output current goes into driving the headphones and NONE of the current is wasted driving the current source.  This is much more efficient and also decreases distortion significantly.  So a current source load converts an amplifier for driving the output resistosr into an amplifier for driving headphones. This is the reason that Stax went to current sources in all their solid state amps and their legendary T2, and the reason that all of Dr. Gilmore's solid state and hybrid designs also use current sources.

 

[JimL11]

 
Is it the same as Shunt Regulated power supply?

A shunt regulated power supply is a completely different thing from the cascode current source, which is used as an output load.
 
A regulated power supply basically keeps the power supply voltage constant regardless of the current draw of the amplifier.  There are two types of regulated supplies, series regulated and shunt regulated.  A simple series regulator ( parts wise) is a 78XX IC chip regulator.  A simple shunt regulated supply is a resistor in series with a zener diode.  All of Dr. Gilmore's designs use series regulated power supplies.