There was a builder on Ampage a couple of years ago that alluded to having a cathode follower in front of the Dumble OD stages.  He swore it was the "secret" to the bloom. Something to the effect the follower's low impedance gave a more "balanced" (my word, I forget exactly what he said) feed to the OD. Been too long to remember his name, but he did have a website selling D'clones.
I built an amp last year that had a TW Express pre feeding a cathode follower, with a switchable input into a Dumble OD stage.  
It didn't sound like either amp, but it was a cool sound.  At the time I was looking for more Dumble, so I changed it.  But, I still have the schematic, and I think I'll do this build again in one of my Peavey Triumph amps.
ampdoc
			
			
									
									
						Cathode follower to drive D*mble tone stack?
Moderators: pompeiisneaks, Colossal
Re: Cathode follower to drive D*mble tone stack?
ampdoc,
Interesting! You say it was a cool sound with the cathode folower, but how would you describe the differences in sound with the cothode follower and after you changed it to a more coventional circuit?
You also say that you have the schematic. Does that mean that you can post it here...? 
 
Take care,
Sven-Johan
			
			
									
									
						Interesting! You say it was a cool sound with the cathode folower, but how would you describe the differences in sound with the cothode follower and after you changed it to a more coventional circuit?
You also say that you have the schematic. Does that mean that you can post it here...?
 
 Take care,
Sven-Johan
Re: Cathode follower to drive D*mble tone stack?
It's been about two years since I first built this beast, but I seem to remember it had some qualities of both the TW and the D.  It rocked harder than the D, but still had some of the D smoothness.  One of my friends who had built very credible clones of both amps, said it wasn't either one, but he liked it very much.
One note about the schematic, I believe for the actual working build I changed the output tubes to 6L6, and may have swapped the first two preamp tubes to 12AT7s (I had done this in earlier TW amps to lower the hiss).
Attached is my schematic.
			
			
						One note about the schematic, I believe for the actual working build I changed the output tubes to 6L6, and may have swapped the first two preamp tubes to 12AT7s (I had done this in earlier TW amps to lower the hiss).
Attached is my schematic.
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