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Crack;Bottlehead OTL - Page 352

post #5266 of 7977
Quote:
Originally Posted by kothganesh View Post
 

Hi Matt:

 

How's the golf ? :biggrin:. I spent an hour and a half with the Crack and the HD 800. Please note that my Crack is about 3 hours old by way of use. I thought the overall sound was elevated. Don't know how to say this but the bass is still not reaching the deeper extensions that my Zana Deux is achieving. In addition, I noticed the noise floor between songs which I don't have on the ZD. I have moved the Crack to a place where I believe it will be relatively free of noise due to other equipment.

 

Interestingly, I found the HD 650 to be a much better pairing from the get-go with the Crack. I am going to persist with my Crack and 800 pairing and see where it takes me.

 

Fitting a choke and replacing the last electrolytic capacitor with a film capacitor makes a nice improvement to bass extension. :wink_face:

post #5267 of 7977

(double post deleted)


Edited by punit - 6/16/14 at 4:27am
post #5268 of 7977
Quote:
Originally Posted by kothganesh View Post
In addition, I noticed the noise floor between songs which I don't have on the ZD. I have moved the Crack to a place where I believe it will be relatively free of noise due to other equipment.

 

Interestingly, I found the HD 650 to be a much better pairing from the get-go with the Crack. I am going to persist with my Crack and 800 pairing and see where it takes me.

I had zero noise floor with Crack - HD 800 pairing. Can you try using a diff source / tube and check.Also I had a tube which initially had noise but it went away after some burn in.

post #5269 of 7977
Quote:
Originally Posted by JamieMcC View Post

Fitting a choke and replacing the last electrolytic capacitor with a film capacitor makes a nice improvement to bass extension. wink_face.gif
Great to know. Where do I get the choke and the film capacitor? I live in India and am told better off importing these items. Thanks.
post #5270 of 7977
I have a suitable capacitor and choke. Send me a PM if you are interested.
post #5271 of 7977
Quote:
Originally Posted by MoatsArt View Post

I have a suitable capacitor and choke. Send me a PM if you are interested.

Thanks. You've got a PM
post #5272 of 7977
Quote:
Originally Posted by punit View Post

I had zero noise floor with Crack - HD 800 pairing. Can you try using a diff source / tube and check.Also I had a tube which initially had noise but it went away after some burn in.
I plan to continue with the current set up. May be the burn-on will take care of it. I will keep you posted. Thanks.
post #5273 of 7977
Do you get noise from the stock tubes as well?
post #5274 of 7977
Quote:
Originally Posted by palmfish View Post
 

Phew!

 

Hey, quick question... I'm browsing online and found this "illuminated rocker switch." It's rated 15 amp instead of 5 amps at 120 VAC. I have no idea what other specs (contact resistance?) the stock switch is rated at.

 

I like the idea of having one that lights up - do you think it's compatible?

 

http://www.e-switch.com/product/tabid/96/productid/113/sename/r1966-series-illuminated-rocker-switches/default.aspx


Did you ever end up trying to install the illuminated switch (identified in your link above)? If so, did it fit in the standard switch's existing cutout opening? And was wiring straightforward? I'd really like to have an illuminated switch to help me not forget to turn the amp off. (Please, no mocking replies from youngsters -- meaning anyone under 60. There comes a time when one appreciates all the reminders one can get!)

post #5275 of 7977
Quote:
Originally Posted by guildenstern View Post


Did you ever end up trying to install the illuminated switch (identified in your link above)? If so, did it fit in the standard switch's existing cutout opening? And was wiring straightforward? I'd really like to have an illuminated switch to help me not forget to turn the amp off. (Please, no mocking replies from youngsters -- meaning anyone under 60. There comes a time when one appreciates all the reminders one can get!)

Yes. It fit perfectly and was fairly straightforward to wire.
post #5276 of 7977
Quote:
Originally Posted by palmfish View Post


Yes. It fit perfectly and was fairly straightforward to wire.

 

Did it introduce any noticeable noise as I believe that's why there is no "on" lamp included in the kit.

post #5277 of 7977

There are "on" lamps in every kit.

post #5278 of 7977
Quote:
Originally Posted by Doc B. View Post
 

There are "on" lamps in every kit.

I was thinking that.. glad you said it.

post #5279 of 7977
Oooooo need some ice for that burn there Loquah? Haha :P
post #5280 of 7977
I just modified mine for the 12bh7a per this thread http://bottlehead.com/smf/index.php/topic,5989.0.html. Previously I had replaced the LEDs in the socket for resisters, but my voltages were kind of high. Now it is running @70/68 V using a 147 Ohm resister. Maybe could go a little lower, but it is close to the ideal 75. I also switched in the MJE-5731A power transistors just in case. Seems to be running good!

I ended up buying 20 of each resister and MJE-5731A on ebay. The resisters were only a few bucks but shipping for the transistors was dumb. Would you buy 2 for 9 dollars, or 20 for 20... Yeah, so if anybody wants the 12bh7a mod components I have some extra haha. I will just send them at cost for a few bucks.
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