[saxophone]

I guess the only way I'll know for sure is by bringing my headphones to a meet and seeing what I prefer. Thanks, @spacequeen7

 

[i luvmusic 2]

I have the DT880 600R nothing special about it with the CRACK not like the HD650 and CRACK.

 

[JamieMcC]

If looking at Beyers consider a pre owned T1, with the stock Crack its ok but if running a modded Crack it makes for a superb combination.  I hardly ever listened to my HD650's afterwards.

 

[wwmhf]

  If looking at Beyers consider a pre owned T1, with the stock Crack its ok but if running a modded Crack it makes for a superb combination.  I hardly ever listened to my HD650's afterwards.

 
I really wanted to know this. Thanks for sharing.

 

[saxophone]

What mods did you use, @JamieMcC ?

 

[JamieMcC]

  What mods did you use, @JamieMcC ?

 
Couple of pics of my how my original Crack ended up with a stock version alongside for comparison.
 
Changes were film out put caps with Teflon bypasses in place of the stock electrolytic ones, Valab stepped attenuator, choked power supply (replaces one of the cement resistors) and the last electrolytic capacitor in the power supply swapped for a film one. The Speedball pcb's also have switchable operating points to optimize for running 12au7 12bh7 and E80cc input tubes.
 
All these mods are essentially pretty easy to do and really involve no more than swapping out one part for another or adding a small switch and a couple of resistors for the Speedball mods.  All these Mods were taken off of the Bottlehead forum essentially I just implemented what a few others had done before.
 
Roughly the changes mounted up to around $150 worth of components but these costs and the modifications were spread over about twelve months.  I found with both the hd650 and T1 they both scaled well up to a point when the hd650 kind of plateaued but the T1's just continued improving. 
 
I might add the enjoyment  factor of building and then hot rodding the Crack was right off the scale, its a really satisfying and rewarding process and the end results were well worth the effort. I definitely would never have contemplated building a Sex or Mainline if the Crack hadn't paved the way.
 
 

 
 

 

[JamieMcC]

Just noticed there are two Mainlines listed in the classifieds that must be a first! Its a pretty rare occurrence to even see one listed. 

 

[skeptic]

  Just noticed there are two Mainlines listed in the classifieds that must be a first! Its a pretty rare occurrence to even see one listed. 

 
No kidding - and George's asking price is an incredible steal.  I'm half tempted to buy a second one for my office.

 

[NightFlight]

And miss out on the joy of building one?
 
I've thought about building another and auctioning it off on ebay just for kicks.

 

[JamieMcC]

You know you could take those Teflons out and probably get $400-$500 for them alone. The 10uf value is incredibly hard to come by only a very limited amount were ever available in the first place due to a mix up in a batch order originally produced  by RTI for Audio Research then discreetly moved on by TC tubes who are based close by.
 
A few of which were snapped up by Bottlehead builders

 
If you google image search "Audio Research Teflon" you can pull up a few pics of them in $20k plus amps!
 
If it was 240V I think I might have been very tempted myself.

 

[GeorgeNapalm]

No kidding - and George's asking price is an incredible steal.  I'm half tempted to buy a second one for my office.

Thanks skeptic, I'm not trying to make a profit here, just want to pass the amp to the next Bottlehead enthusiast.

 

[Kyno]

   
Couple of pics of my how my original Crack ended up with a stock version alongside for comparison.
 
Changes were film out put caps with Teflon bypasses in place of the stock electrolytic ones, Valab stepped attenuator, choked power supply (replaces one of the cement resistors) and the last electrolytic capacitor in the power supply swapped for a film one. The Speedball pcb's also have switchable operating points to optimize for running 12au7 12bh7 and E80cc input tubes.
 
All these mods are essentially pretty easy to do and really involve no more than swapping out one part for another or adding a small switch and a couple of resistors for the Speedball mods.  All these Mods were taken off of the Bottlehead forum essentially I just implemented what a few others had done before.
 
Roughly the changes mounted up to around $150 worth of components but these costs and the modifications were spread over about twelve months.  I found with both the hd650 and T1 they both scaled well up to a point when the hd650 kind of plateaued but the T1's just continued improving. 
 
I might add the enjoyment  factor of building and then hot rodding the Crack was right off the scale, its a really satisfying and rewarding process and the end results were well worth the effort. I definitely would never have contemplated building a Sex or Mainline if the Crack hadn't paved the way.
 
 

 
 

 
And your Crack sounds as good as ever by the way, still here safe & sound 

 

[JamieMcC]

   
And your Crack sounds as good as ever by the way, still here safe & sound 

 
Hey thanks your reply gave me a big smile

  its great to hear its still going strong and being enjoyed, I had a blast building it.
 
Cheers
 
Jamie

 

[Loquah]

I wonder where my old Crack has made it's way too.
 
I've been quietly contemplating relinquishing my SEX recently as it doesn't get much use, but that might be a bridge too far...

 

[theblueprint]

Just noticed there are two Mainlines listed in the classifieds that must be a first! Its a pretty rare occurrence to even see one listed. 

I am now the happy owner of George's Mainline. George's work is not only extremely beautiful, but has been a monumental upgrade in sound quality for my HD650.

It actually feels pretty weird to be at the summit, with not much to look forwards to (without spending thousands more). Haha.

Can't wait to try an HD800 on the Mainline too, but I'm pretty certain that I'll be sticking with the HD650.