Time for another surprise

[Doc B]

As I mentioned when asked this recently, if budget allows Mainline is our best amp. If the budget is not quite there and you are interested in an amp specifically for high impedance headphones Crack-a-two-a is a less expensive alternative that is a step up from the Crack kit.

 

[caffeinator]

Hey Doc,

How would this compare to the SEX Amp as a headphone amp (usually w/ Sennheiser HD-600's)?

thanks,

David

 

[Doc B]

I'd put the Crack-a-two-a a bit ahead of the S.E.X. for HD 600s. The S.E.X. is great with them too, but the shunt regulation in Ca2a really does a nice thing for vocals.

On the other hand S.E.X. will also work great with Audezes and other lower impedance planars and dynamics as well as efficient and near field speakers.

Depends a bit upon how you weigh versatility vs. performance for a specific application.

 

[modestmeowth]

Will we be able to modify this to accept a 6SN7 like the Crack?

 

[Paul Birkeland]

Will we be able to modify this to accept a 6SN7 like the Crack?

Yes, you'll still need to punch out the hole in the chassis (the bigger of the 2 punches available at your local hardware store ought to work), but there is actually a bit more room for everything, so the octal socket should be easier to install.

 

[Aeolus Kratos]

Hi Doc,

I just sold my highly-modded Crack yesterday and is planning to get another amp soon. My budget is somewhere ~$1000, but I can wait and save a bit more to get a Mainline.

I'm using a HD650 and HD800 and frankly, I don't plan to buy ANY other headphone (I've heard as well as owned various premium headphones and now I've settled to the Senns).

Between the Crack-a-two-a and the Mainline, what would you recommend me for using JUST for my Senns (i.e. HD650, HD800)? I don't plan to use my next amp to drive other headphones.

Best regards,
Kratos.

 

[Doc B]

As I mentioned when asked this recently, if budget allows Mainline is our best amp. If the budget is not quite there and you are interested in an amp specifically for high impedance headphones Crack-a-two-a is a less expensive alternative that is a step up from the Crack kit.

 

[Aeolus Kratos]

As I mentioned when asked this recently, if budget allows Mainline is our best amp. If the budget is not quite there and you are interested in an amp specifically for high impedance headphones Crack-a-two-a is a less expensive alternative that is a step up from the Crack kit.

Thanks for the clear answer. I guess I'm gonna save for a while and get a Mainline soon!

Cheers.

 

[NightFlight]

Dang. I sat on selling my modded Crack too long.  :

But thanks for finally offering a solution to the Cracks power supply. It's been the weak point of the Crack for a while now, there's only so much you can do with the stock Crack power supply on the AC and DC sides.... in the space provided.

Nice looking amp. I think it will look even better with an ST bottle on there!

 

[Hornet900]

hello all

I'm interested in the new amp and have couple questions ... and  sorry i don't know much about this stuff !,  I  have a crack amp with hd600 connected to my high end PC with a creative ZxR soundcard and really like it   and was think of rebuilding it soon but may change my mind


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. 
with changing the tubes on the normal crack really changed the sound for me, / i was thinking with these other new  tubes the crack tube rolling may be different  , sorry I don't know alot with this stuff guys.

Also can you change the 6AQ5  for different types and makes? ,  will this change the sound as well?


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 ?  My crack about 1 foot away from my computer but its dead silent,  I can turn the amp up near full wack with no music and only then only hear a little noise  (the last 1 cm of volume travel  and thats blown up headphones loud and no hearing!  shes perfect ....shes quiet as a mouse with good tubes)
so I'm worried about this with new amps near my pc  I read valve amps can pick up noise ,  more chance of this happening with new amp design?  :-*

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
I listen to my music loud and hope it has lotsof  big power and can go loud

Guys does the mainline amp have  bigger bass fatter bass with  hd600  than the old crack speedball and 5998 tube // using  high impedance headphones ?
When I installed the 5998 on my crack  speedball  I got a bigger sound better bass and it was less harsh with my hd600s  smother sound darker sound I think you call it..
sounds awesome with my  italo disco  8) 8)  it thumps

Im not really interested in analyzing my music  I  like a rhythmic musical tubey sound, warm detailed

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

I've read a little about stepped attenuator but still dont understand it ..... difference with a  shunt course fine ,  I may build my own stepped attenuator one day  for my crack but have to learn it carbon film resistors and things
I have no problems with my cracks channel balance though  still use the standard pot 

I was even thinking of buying one but with  the money I could be put towards this new amp plus I always wished i painted my top plate and was think of adding a choke soon never got round to that, and fancy building an amp again as I enjoyed building the crack

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

 

[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  ;D

 

[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  ;D

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