Looking for amp ideas for a 5e3 chassis

[jukelemon]

Hi all. Hope everyone is well.


So.. I built a Proluxe head a while back to use with a touring Leslie. It works really well but I’d like to get more clean power and am looking at ideas as far as a new circuit but with existing PT and OT.


OT is a 40w Pro Reverb spec. PT is for a BF Bassman.


I don’t mind redoing the chassis labels so in essence I have three controls available and 4 inputs.


I thought about changing to fixed bias but in the past I really have not noticed a big difference between that and a cathode/bypassed power section with the same preamp design.


Thoughts?


Something to consider too .. I do not need a tone stack. The original Leslie amps just had a Volume control. Right now my tone knob is dimed.


Thanks!

[jbrew73]

What about using the 6g5 or 6g5a pro power amp?
I would think the ltp phase inverter, negative feedback and fixed bias would give some additional headroom.

[Adrien]

By Proluxe do you mean this?  https://robrobinette.com/images/Guitar/5E3P_Build/5e3p_Schematic_small.png  So basically a tweed deluxe with 6L6s. 

Looks like you've got 2 preamp tubes and 2 power tubes, 3 controls to work with.  Fun project.

I agree with jbrew that stepping up to a brown/black panel bassman/pro style power section would get you more clean power.  My choice would be the normal channel of an AA864 Bassman: https://el34world.com/charts/Schematics/files/Fender/Fender_bassman_aa864.pdf 

Compared to the 6G5 pro or 6G6 Bassman it doesn't have a presence control so that leaves just Treble, Bass and Volume which fits your chassis and would sound great with pretty much anything.

Or for something similar but a little more outside, you could look at a single-channel version of the Selmer Treble 'n' Bass 50, those are pretty cool: https://el34world.com/charts/Schematics/files/Selmer/Selmer_treblenbass_mkii_50w.pdf

[jukelemon]

Very good ideas guys. Thank you!


I don’t have any of my board making tools any more. Is there any interest in making a board for that idea ie a Bassman normal channel only board? Fee based of course.

[Rontone]

a board for that idea ie a Bassman normal channel only board? Fee based of course.

Doug has AA864 type boards, if you just leave the unused areas blank:-

https://hoffmanamps.com/MyStore/catalog/EyeletBoard.htm

Or there is the custom board link at the bottom also...

[dogburn]

You might look at Rob Robinette's Blackvibe layout - it's pretty much the same layout you would need, with just some minor differences (like it includes the bias circuit on the board rather than as a separate board, and it includes a coupling cap between V1b and the phase inverter). He includes a DIYLC file for just the board, and you could upload that and have Hoffman make the board.

[Adrien]

Blackvibe is a great suggestion, it has the filter caps on the board and everything.  Doug already has the blackvibe boards ready to go: https://el34world.com/Forum/index.php?topic=24873.msg270122#msg270122

Note that the Hoffman boards are always 3-1/8" wide so depending on your chassis internal width Doug's boards may be a bit tight.  I would double check that first.

Also check out this layout from Sluckey, it's a narrower alternative that would fit great in your tweed chassis:  https://sluckeyamps.com/misc/AB763_Deluxe_Lite.pdf

You would just need to figure out where/how to mount the filter caps.

[dogburn]

I was thinking that the Blackvibe board would work for a single channel AA684 Bassman build, but the Blackvibe itself would certainly be a fun option.

[jukelemon]

Great ideas guys.  Much thanks!

All my board making tools are 900 miles away so i really don't want to reinvent that tool supply :)


Doug's board would be really really tight.  The board in there now is less than 3" wide and it's tight.


Good things to think on though.  It may just have to wait until I am back in the other shop.