Tweedle Dee 4 Filter caps or 3 ??

[rschiller]

I followed previous discussion on this website and converted one of my 5E3 builds to Tweedle Dee as best as I could determine circuit from Charlie Wilson's good work and the Ceriatone Schematic. Then I came across an ad from a shop in Nashville, Carter Vintage, where they evidently were selling one of two original Tweedle Dees as contracted by Fender directly from Dumble. Big bucks asking price.

I have attached three PDFs showing the Fender label, Letter of authenticity and the interior as presented in the original ad. Dumble replaced the board with his so he could have added the 4th filter cap we see in other Tweedle Dee schematics. Clearly though only three filter caps are shown (F&T 22ufs).

I'm curious about the use of 3 or 4 filter caps. Using 4 can give higher plate and cathode voltages for the second tube amplification stage and cathodyne PI. Is this desireable? needed? Also a separate 4th drop for the first tube can also give higher plate voltages there unless larger drop resistors are used.

My apologies for double post, I first incorrectly posted this at Dumble Files.

[hitchcaster]

i don't know the answer.. but we are talking two different deluxes... the 4 cap one is a vintage 50's amp with vintage iron.. and this one for sale is modern reissue proto for mass production using modern iron..

[rschiller]

Except for the 3 vs 4 filter caps, both have the unique HAB additions to the venerable 5E3: (1) VI Separate cathodes and (2) the
VIIB PI has increaesed value for all components plus the LNFB and an adjustment pot to fine tune voltage on the 6V6s grids.

As best as I can tell HAB used the same circuit changes but for his custom 5E3 conversions used the added 4th filter cp to separate voltage drops for VII and VI. For the possible Fender production model he left the same voltage drop by retaining the original 3 caps at 22uf. Apparently for his custom amps he went to 30uf across the board.

Just curious if anyone has experimented with this or any thoughts.

[jabguit]

HAB?

[rschiller]

Typing error. HAD. Dumble

[ChopSauce]

Thanks for the insights. You might as well edit your previous message to make the reading more seamless.

By the way, does anyone see what the tone cap is?

[gonzomode]

I think there is already a thread about this particular amp:

https://ampgarage.com/forum/viewtopic.php?f=4&t=37151

[Mr. dB]

Except for the 3 vs 4 filter caps, both have the unique HAB additions to the venerable 5E3: (1) VI Separate cathodes and (2) the
VIIB PI has increaesed value for all components plus the LNFB and an adjustment pot to fine tune voltage on the 6V6s grids.

What does LNFB around a unity-gain stage DO, anyway?