Crack;Bottlehead OTL
Feb 13, 2013 at 6:57 PM Post #1,486 of 12,347
OK, I'm looking at committing apostacy and install portions of the crack speedball kit into my WA3. The two amps are very similar, with exception of maybe the B+ and tube bias points. They both use 6AS7 output tubes with simple cathode follower resistor bias...crack with 3K and WA3 with 1.5K. My question is if the speedball instructions contain enough information for me to choose proper resistor values to match my current Woo bias? With 193V on my plate, I'm seeing about 35V on the cathode. Thoughts?
 
Feb 13, 2013 at 9:20 PM Post #1,487 of 12,347
Quote:
OK, I'm looking at committing apostacy and install portions of the crack speedball kit into my WA3. The two amps are very similar, with exception of maybe the B+ and tube bias points. They both use 6AS7 output tubes with simple cathode follower resistor bias...crack with 3K and WA3 with 1.5K. My question is if the speedball instructions contain enough information for me to choose proper resistor values to match my current Woo bias? With 193V on my plate, I'm seeing about 35V on the cathode. Thoughts?


Thoughts? You probably wont find much help here on the matter, but you should check out this thread: LINK
 
Feb 13, 2013 at 9:39 PM Post #1,488 of 12,347
Quote:
 
I'm no DIYer, have no tools, and no electronics fabrication or soldering skills. My Crack was built by someone else (who did a supreme job BTW!). My solution was to buy a pair of Harrison Labs 12dB line-level attenuators. They'll be here on Friday, so I don't have long to wait to see if they do the trick without compromising sound quality.

Hi,
 
Can you tell me who build your amp? I'm new to this forum. Just got a pair of HD650, a step up from Audio Technica M50. I am interested in this crack amp but I am too not a DIY person... Thanks!
 
Feb 13, 2013 at 9:42 PM Post #1,489 of 12,347
Quote:
 
Can you tell me who build your amp? I'm new to this forum. Just got a pair of HD650, a step up from Audio Technica M50. I am interested in this crack amp but I am too not a DIY person... Thanks!

 
Check out the Amplification For Sale Forum here, and your PM.
 
Feb 15, 2013 at 12:53 AM Post #1,491 of 12,347
Been toying with the idea of getting an HE-500 recently however I don't really have an amp to drive them (Nuforce HDP, Crack).  If any of you own the Crack and the 500s can you give the combo a green light?
 
Thanks in advance for the help.
 
Feb 15, 2013 at 1:20 AM Post #1,493 of 12,347
Not the Crack, no... but the HDP should be good to go. 
 
I don't have an HE-500, but I have an HE-6 and the HDP does surprisingly well with it. If it can handle the HE-6, I think the HE-500 will be ok. If not, it will still be enjoyable and you can always upgrade later.
 
I actually have my HDP feeding into the Nuforce Icon speaker amp to drive my HE-6. It's a nice little combo. 
 
Feb 15, 2013 at 2:29 AM Post #1,494 of 12,347
Quote:
Been toying with the idea of getting an HE-500 recently however I don't really have an amp to drive them (Nuforce HDP, Crack).  If any of you own the Crack and the 500s can you give the combo a green light?
 
Thanks in advance for the help.

 
No. The crack is optimized for high voltage. The HE-500 need high current. Build the Smack or Sex (or any number of other fine designs), but not the Crack for this headphone. 
 
Feb 15, 2013 at 2:06 PM Post #1,495 of 12,347
Quote:
 
No. The crack is optimized for high voltage. The HE-500 need high current. Build the Smack or Sex (or any number of other fine designs), but not the Crack for this headphone. 

I haven't heard the Crack, but I do have a S.E.X. and it does wonderful things with my LCD-2s and with the HE-500s I originally auditioned it on.  It also does a very good job with my HD650s and HD800s.  I am thinking about building a Crack just to compare the two.  
 
Feb 17, 2013 at 7:37 AM Post #1,500 of 12,347
Quote:
Has anyone tried one of the Psvane 12AU7s or CV181s/6SN7s (using a 6SN7 adapter)? If so, what are your impressions?

Best regards,
Adam

I've tried some 6SN7 tubes with an adapter.  Very, pleased with the sound.  To me they seemed to open up the soundstage.  Kind of a "bigger" sound. I have an old Motorola in there now.
 

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