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Eddie Current Balancing Act
Nov 26, 2009 at 1:13 AM Post #301 of 1,499
Scottsdale. I'd be happy to make the drive out to CA, either SoCal or NorCal. Craig mentioned he'd try to coordinate something with you. Having listened to the BA with the various 300s for a while, I can say it is an entirely different beast with the PX4s. And I heard that you've had a similar experience with the AD1s.
 
Nov 26, 2009 at 2:18 AM Post #302 of 1,499
You guys are doing God's work!
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Nov 26, 2009 at 2:32 AM Post #303 of 1,499
Quote:

Originally Posted by Icarium /img/forum/go_quote.gif
Where are you located? I'd love to do an AD1/PX4 shootout
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Quote:

Originally Posted by eaglejo /img/forum/go_quote.gif
Scottsdale. I'd be happy to make the drive out to CA, either SoCal or NorCal. Craig mentioned he'd try to coordinate something with you. Having listened to the BA with the various 300s for a while, I can say it is an entirely different beast with the PX4s. And I heard that you've had a similar experience with the AD1s.


we'll we will be having a meet in NorCal in January, maybe then would be a good time? We could probably rustle up a quiet room for this purpose.
 
Nov 26, 2009 at 12:31 PM Post #304 of 1,499
Perhaps I should have gone with the 300B or PX4 option rather than the 307A
 
Nov 26, 2009 at 2:12 PM Post #305 of 1,499
I'll plan on attending the NorCal meet then. I've got plenty of friends up that way. What's the weekend?
 
Nov 26, 2009 at 2:47 PM Post #306 of 1,499
Quote:

Originally Posted by Rob N /img/forum/go_quote.gif
Perhaps I should have gone with the 300B or PX4 option rather than the 307A


I am very happy with my 307A BA. It is definitely the quietest amp I have ever owned and probably the quietest I have ever heard but meet conditions do make that one a little iffy. It is also clear, resolving and gets the instrument timbres correct. Although not exactly a low-priced amp, I consider it a great bargain given both the build quality and the exceptional sonics.
 
Nov 27, 2009 at 1:31 AM Post #308 of 1,499
Quote:

Originally Posted by eaglejo /img/forum/go_quote.gif
I'll plan on attending the NorCal meet then. I've got plenty of friends up that way. What's the weekend?


Awesome! Will be glad to see you. There's no official weekend yet.. there's a thread with a poll and some options in the meets forum.
 
Nov 27, 2009 at 5:58 AM Post #310 of 1,499
Just got some clarification from Craig which I think will answer the same question from many of us.

Quote :

The PX-4 has a 4 volt heater, the 300B is 5V. The 300B in the BA requires a 750 ohm bias resistor, the PX-4 470 ohms. The true old stock PX-4 socket will not work with the 300B. The KR PX-4 is available with a 300B socket.

If you used the KR PX-4 the heater can be adjusted for 4V, but switching back and forth would be tricky. The short answer is yes the BA can be setup for either tube, but you need to decide which one you want.

Unquote.

So this should clarify the picture. Tough decision to make though....

F. Lo
 
Nov 30, 2009 at 4:08 PM Post #312 of 1,499
Quote:

Originally Posted by eaglejo /img/forum/go_quote.gif
Scottsdale. I'd be happy to make the drive out to CA, either SoCal or NorCal. Craig mentioned he'd try to coordinate something with you. Having listened to the BA with the various 300s for a while, I can say it is an entirely different beast with the PX4s. And I heard that you've had a similar experience with the AD1s.


Thanks eaglejo for the great comparison on the 300B and PX4 impressions. This certainly tempts me to go down the PX4 route, especially that I also plan to use the BA with my K1000s.

You seems to be able to switch the BA back and forth with 300Bs and PX4s. Can you tell us if you do it yourself, and you asked Craig to do it for you ?>

Thanks in advance.

F. Lo
 
Nov 30, 2009 at 7:34 PM Post #313 of 1,499
Craig was in town and changed the heater voltage and swapped out the resistor for me. I checked out all the 300B tubes and then Craig made the noted changes (voltage and resistor) that allowed me to check out the PX4. He was in town for Thanksgiving and the idea was that if I didn't like the PX4 he would change things back to run 300Bs. Again, I'm very happy with the PX4s and haven't thought abt going back to the 300Bs. Although at this level, it's a matter of personal preference. I could see some preferring the additional clarity of the AVVT 300Bs.
 
Dec 1, 2009 at 4:14 AM Post #314 of 1,499
Quote:

Originally Posted by eaglejo /img/forum/go_quote.gif
Craig was in town and changed the heater voltage and swapped out the resistor for me. I checked out all the 300B tubes and then Craig made the noted changes (voltage and resistor) that allowed me to check out the PX4. He was in town for Thanksgiving and the idea was that if I didn't like the PX4 he would change things back to run 300Bs. Again, I'm very happy with the PX4s and haven't thought abt going back to the 300Bs. Although at this level, it's a matter of personal preference. I could see some preferring the additional clarity of the AVVT 300Bs.


Your proximity and access to Craig is truly admirable. Having read what you wrote about the PX4 and then discussed with Craig I think I am jumping ship from 300Bs and migrate to PX4. My pair of AVVTs should see better use with my Woo Audio 5 so it won't be wasted.

Thanks a lot for your sharing.

BTW, I also inquire about Sophia Electric's PX4 mesh plate and they also came with a UX-4 base. Although Sophia Princess is not in general the same class as KR or AVVT, it is nevertheless a cheaper alternative to the KR PX4.

F. Lo
 
Dec 2, 2009 at 12:53 AM Post #315 of 1,499
Quote:

Originally Posted by fkclo /img/forum/go_quote.gif
Just got some clarification from Craig which I think will answer the same question from many of us.

Quote :

The PX-4 has a 4 volt heater, the 300B is 5V. The 300B in the BA requires a 750 ohm bias resistor, the PX-4 470 ohms. The true old stock PX-4 socket will not work with the 300B. The KR PX-4 is available with a 300B socket.

If you used the KR PX-4 the heater can be adjusted for 4V, but switching back and forth would be tricky. The short answer is yes the BA can be setup for either tube, but you need to decide which one you want.

Unquote.

So this should clarify the picture. Tough decision to make though....

F. Lo



Thanks, I am glad to hear that~

So you mean we can replace PX4 by myslfe without changing bias resistor?
 
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