Posted by Damir [ 213.202.111.136 ] on June 21, 2006 at 01:17:38:

In Reply to: Re: tried the 6688 posted by 2wo on June 20, 2006 at 23:28:33:

Strange - as I described it, my D3a and E180F tubes sound very similar, D3a a bit more "rough", and E180F little more "smooth". But both have a dynamic, open and direct, powerfull sound.
I think that with choke load you should use bypassed cathode, if not - rp of the triode goes up, not a good thing in combination with L and Cw of the choke (both frequency extremes). Maybe try the bypass first, say 100µF-220µF.
But, I noticed in 6SN7 test that, although similar, there`re differences between the tubes of the same type. Some sound "big, open, clean", and other more in "blanket, compressed, warm, unfocussed" way.
As I said, my pair of E180F is NOS Philips, unfortunately didn`t try other types.

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