Time for another surprise

[Paul Birkeland]

Does having the  exrta 2 tubes 6AQ5 affect the tube rolling on the new crack? ..  will it be the same any different,  I liked the way the 5998 changed the sound and wish to use these. 

The 6AQ5 is audible, though significantly less so than the 6080 and 12AU7.

one of the biggest things I'm concerned about is interference noise pickup from computers and stuff?  does the extra tubes effect the amp near  computers ? 

There is additional shielding employed, which should improve this over the normal Crack.

also does the new amp have loads power like the normal crack 
is the bass any different. I'd plug in a 5998 and work ok

Power output will be identical, but with the regulated power supply, bass definition is significantly improved.

Guys does the mainline amp have  bigger bass fatter bass with  hd600  than the old crack speedball and 5998 tube // using  high impedance headphones ?

I would not say that the Mainline has fatter bass.  It is very resolved, with very tight, well defined bass.

How does the new amps volume control and balance  work ......  is it  like a normal amplifiers  left and  right balance ....  does the upgrade change this? / course and fine  I dont understand it anyone have a link to explain how it works ?   i will look up later but its late tonight sleep soon

Yes, the stock amplifier has a level control, and a balance control that function in the familiar fashion.  The upgrade has two level controls.  One has larger steps in attenuation and the other has smaller steps of attenuation.  The two together give many steps of attenuation all with perfect channel balance.

finally does the upgrade part the stepped attenuator  come with a black top plate like the mainline? with  writing dials,
if so will it look like the mainline design  or like beequiet and others  ,  the mainlines  top plate looks  nice

The upgrade will come with the black plate as found on the BeeQuiet, which makes the operation of the attenuator more intuitive.  The Mainline's plate was allowed to be much larger because it is installed during the initial build, which allows it to sit under the headphone jacks.  Doing this as an upgrade would require removing components that could otherwise be left alone.

[Hornet900]

thank you

[hwaitung]

I wonder if there are some more pictures of the new Crack? E.g. the underside of it 

[adam1016]

Hey Doc,
I ordered one of these and have been waiting for a while, on your site it says that they will ship late september.  Any word on this?

[Paul Birkeland]

Josh is home working on finishing the manual today.   Other than that, we [probably] have all the bits and pieces here that we need to get these rolling. 


Edited to fix possible factual errors.

[Paul Birkeland]

I wonder if there are some more pictures of the new Crack? E.g. the underside of it 

Surely someone will find a film cap that won't fit, but we left tons of space!

[caffeinator]

Bigger Caps?  Are you kidding me?  With all that space and the Seattle real estate market, I'll sub-let!

Beautiful layout - love the symmetry!

[Rocketman248]

Very nice.  All sort of room for activities under there.

[mcandmar]

Nice looking layout, the main current reg PCB has me curious with all the film caps hanging off it, it looks more like a mainline regulator than a speedball. What are they for?  ....figured i would be first to ask, because you just know people are going to wonder if gigantic films will do anything there

[Paul Birkeland]

Nice looking layout, the main current reg PCB has me curious with all the film caps hanging off it, it looks more like a mainline regulator than a speedball. What are they for?  ....figured i would be first to ask, because you just know people are going to wonder if gigantic films will do anything there

Yeah, that's certainly a fair question.  The large PC boards with big heatsinks are the high current C4S loads.  One half of each loads each cathode of the 6080, then the other half is the C4S between the raw and regulated B+ supplies. 

The center PC board has the C4S load for the driver tube, and the remaining components for the high voltage shunt regulator.  There's a little RC filter at the output to provide some impedance compensation at high frequencies.  You sure could mess around with different caps in that position, as they ought to be audible.  There is also a 2.2uF cap on each channel that feeds any residual noise on the regulated B+ back into the regulator to make things just that much quieter.  I don't believe I would spend much time or money messing around with that cap. 


-PB

[mcandmar]

Thanks for the explanation.  My first thought was that you are a sucker for punishment with all those PCB's to trouble shoot

One thing i am not keen on is shield drain wires for the input wiring crossing the output cap leads, i can see people accidentally shorting those out.

[netosullivc]

Hi some sweet parts it the kit - good stuff. I'm interested to know why the seemingly fancy hv reg cap Cc?  Low value would short hf noise but wouldnt any old cap do?
Second cap -the radial cap 100uF - why the choice and what exactly is a radial cap?
Thanks

[Paul Birkeland]

Hi some sweet parts it the kit - good stuff. I'm interested to know why the seemingly fancy hv reg cap Cc?  Low value would short hf noise but wouldnt any old cap do?

This does indeed short HF noise to ground, which improves the stability of the TL431 regulator.   That film and foil (fancy!) capacitor does a nice job of handling HF noise.

Second cap -the radial cap 100uF - why the choice and what exactly is a radial cap?

I've seen a lot of our Crack customers struggle with how to fit a pair of 100uF coupling caps inside the Crack, so I took great pains with the Crackatwoa to ensure that there were two vast regions on the chassis in which one could install a large variety of 100uF capacitors.  To really be helpful in achieving that goal, we added anchors to the chassis that are bolted to the plate so that the weight of those large film caps can be supported by the chassis plate instead of terminal strips. 

The 100uF radial (radial has the leads poking the same ends) capacitors are intended to have dimensions that are somewhat similar to a film capacitor, so that swapping caps is quite easy.

[Doc B.]

Axial is a cap with a wire poking out of each end (the axes of the cylinder). Radial is like most of our lytic caps, with the wires both at one end of the cylinder so they can be bent (radially) to an attaching point.

[lextek]

So I own and love my Crack w/Speedball.  I think it is amazing with Sennheiser HD600s.  What would I notice moving to the Crack -A -Two-A?  Also adding the HD800s to the collection.