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post #901 of 2102

A very high impedance mismatch could stress the trafos to overheat.

post #902 of 2102

As far as I remember, Skylab did mentioned that connecting HE-6 to the speaker terminal give best result, but not so good with LCD-2 as it increases noise floor.  Maybe he revise his statement Skylab will clarify.

post #903 of 2102
It SOUNDS good, but I was warned it might damage the output transformer over time, so I stopped doing it.
post #904 of 2102

How long must i burn in the CS300x?

post #905 of 2102

Quote:

Originally Posted by Skylab View Post

It SOUNDS good, but I was warned it might damage the output transformer over time, so I stopped doing it.


Just for my knowledge, do you know why is it?  I thought the speaker tap is designed to deliver 4 or 8 ohms and 50 ohms load should be easy peazy? no?

post #906 of 2102

Tried using Mullards for both 12AX7s and EL84s today (both sets from the '50s). For acoustics, the combination sounds great, but for pop music, the bass sounds incredibly slow and a bit fat even on my Monitor Audio speakers. Sounds quite horrible on the already fat LCD2's (Rev 1) bloated bass range - so I switched back the 12AX7s to the Amperex Bugleboy (also 1950's) and everything is fine again. I also got the Sylvania 12AX7s and the pair sounds more balanced than with the Amperex on my speakers, but for the LCD2s, I prefer the Amperex due to LCD2's rolled off highs (again the Rev 1, so the same combination may not suit the Rev 2).

 

Conclusion: in my experience the following combination is the best for LCD2 Rev 1:

 

12AX7: Amperex Bugleboy Long Plate D-getter 1950's

 

EL84:  Mullard 1950's - they are quite rare so get whatever you can as long as they are from 1950's.  

 

FYI I also have and tried the following tubes - Sovtek 12AX7s and EL84s (stock tubes from Leben), Gold Lion EL84s, Mazda 12AX7s, Telefunken smooth plates, Sylvania 12AX7 and Brimars. 

post #907 of 2102
Quote:
Originally Posted by Torero View Post

How long must i burn in the CS300x?


I thought 10-20 hours was plenty.

 



Quote:
Originally Posted by RedBull View Post

Quote:


Just for my knowledge, do you know why is it?  I thought the speaker tap is designed to deliver 4 or 8 ohms and 50 ohms load should be easy peazy? no?


Supposedly that is not ENOUGH of a load for the transformer.

 

post #908 of 2102

I really like using 5751s in my Leben.

post #909 of 2102

I've used exclusively 5751's for the driver tubes.

post #910 of 2102

I have used 5751s exclusively because Rob told me to! o2smile.gif

post #911 of 2102

Sylvania Gold Brand 3 Mica Grey Plates, as well as the Black Plates, have pretty much what I've been using in my Leben.  They have a real smooth, dynamic, extended sound to me.  I love them. I'm torn on the output tubes, I had Mullards in for a while, now I have Tungsram E84Ls in.  I have bounced back and forth between these and for a little while I had Sylvania 6BQ5s which were a tad less smooth, and little more neutral.

post #912 of 2102

Quote:

Originally Posted by Skylab View Post

Supposedly that is not ENOUGH of a load for the transformer.

 


Hmm, sorry, I'm an electronic noob, so the transformer can't release energy large enough, thus will damage the transformer, is that the correct analogy?

post #913 of 2102
I believe so, RedBull, but it was a concept I also had a hard time getting my arms around. It is an issue for sure related just to output transformers.
post #914 of 2102

Thanks Rob.

post #915 of 2102

Is this amp still the best for lcd2 rev2?

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