I want to know is this the amp Keef is so fond of?

If it is I WANT ONE!! (It'll have to join the want queue tho' )

They may have used to be, but I've read in several different interviews with his guitar tech, Lee, that he now sues the Fender Custom Shop model off the shelf.

Circuit-wise, they are very different --  different preamp, different PI design, different power-supply design.  Obviously the F is when the Twin went to high output, with 80 watts.

With the Twins, the 5E8a is nothing more than a 5E6a Bassman with a different output transformer to handle the different speaker load. 

But with the 5F8a, Leo finally made a distinction between the Bassman and the Twin, giving the Twin two extra power tubes.  So the 5F8a is nothing more than a 80-watt, 2x12" version of the famous '59 Tweed Bassman.


The real comparison is between the 5E6a and 5F6a Bassman amps, these are what the Twins are based on.  What are the differences between these, you ask next?  Tonally, the latter amp design is much tighter and brighter with more clean available, the former is smoother and mellower with a weaker attack and less aggressive, softer overdrive.Both both are Tweeds, lots of midrange, big but loose bottom end and high end that rolls of early.

5E8a=Low Power Twin (40 watts, 2x12)...modern Clapton

5F8a=High Powered Twin (80 watts, 2x12)...modern Keef

They weren't made simultaneously, the High-Powered Twin replaced the Low-Powered Twin, so their circuits are different. 

Wasn't here for a while... nice discussion

Something about the 5F8-A High Powered Tweed Twin. I just build one of these. Amazing amp, sound wise it's already deep into Marshall territory, especially with the right speakers (I use Celestion V30 and G12H30). Keith's speaker also look like Celestions (and sound like). With Jensen P12N it stays more "tweed". The circuit is very close to Marshall Bluesbreaker (this one got tremolo) or Plexi (solid state rectifier) amps with only a few differences (tone stack).

If you want one, get the Bassmann-Kit from Nik and build it into a 2x12" cab. Nik's output tranny supports different impedances if I'm right. And forget about the two extra output tubes, you won't need them. Mine is incredibly loud even with 2 tubes pulled. It usually starts feedbacking itself when set on about 9 no matter what tubes I use. I run it with a power soak now.

One question about Nik's 5E8 kit: Does the chassis have the same dimensions as the Dizzy30? Thinkin about gettin the 5E8 and puttin it into the Dizzy's headshell. The dizzy would become a 2x12" combo. Other kit's from Nik that have same dimensions as the dizzy chassis?

Greetings...