A "Wrecked" tweed?

[CapnCrunch]

Hey all I posted some months back about a potential 5e5-a tweed Pro build. Craig from Collins Amps had some cool ideas about mating the cathode biased power section of the 5e5 with the pre-amp section of the 5e5-a. Along with that, there was some discussion of increasing the power supply filtering and using a power transformer which yeilds a reduced B+.

I had been thinking along these lines, but did not, and still do not know how to implement this. My thinking was pretty simplistic. If Ken Fisher took the AC 30 and stripped it down to one channel and one input, increased the filtering, decreased B+, and came up with the Rocket, I wonder what you'd get if you did something similar with say a Tweed Pro(any later model tweed for that matter, but the Pro is my favorite). I'd like to try this idea with a cathode biased power section, just because I seem to prefer the cleans, and "in betweens" of cathode biased amps i.e. my 5e3 and Rocket.

Any thoughts or help would be welcomed.

[jjman]

You could build the 5e5a with cathode bias with no real issues. The schematic is already pretty low in the B+ department for 6L6 tubes, perhaps because it calls for 6L6GB. The choke on that one is before the plates so it handles all the current and is therefore more expensive than the "standard" approach. I feel it's better to go with the more common approach on that.

I combined the Express preamp and PI to a 6v6 tweed deluxe output. I cooled down the drive to the output tubes with 82k grid resistors instead of the normal 220k. This eliminated the crossover distortion from the excessive drive from the LTPI that the tweed deluxe output was not designed for.

Needless to say I think it's cool to combine sections from different amps. Just need to be ready to adjust.

[CapnCrunch]

Anyone know what trannies and choke a standard 5e5a would take?

Mercury makes a set but they're$$$$$$

[funkmeblue]

why not build it with wreck trannies and power section, you have 400 volts and a 6.6k output......adjust the dropping string........damn....I want one!

[Structo]

Weber has a kit along with schematics and layout.

https://taweber.powweb.com/store/5e5a_schem.jpg


https://taweber.powweb.com/store/5e5a_layout.jpg

[M Fowler]

Looks like Bassman voltage. Weber uses 022798 PT 40w 200mA, 45v bias tap, 6.3v 6A and 5v 3A

OT 404248 40w rating 4k 4,8,16

I would just use the TW PT and OT

[CapnCrunch]

Thanks for the ideas guys. Mojo also has a Tweed Pro kit. I have a lot of the parts on hand, so I'm trying to avoid buying a whole kit, however. I may use their chassis, and Trannies and various other parts as well. They seem to have decent quality stuff in my experience.

What started me down this road is a vintage original Jensen P15N. I probably could have done something else with it, but I've always loved the sound of the old Pro's, so I figured I'd build one for my dad. He's an old timer and plays everything from Les Paul stuff to Chet Atkins, to hard core blue grass like Bill Monroe etc. I think this type amp will work great for his late 50's Les Paul w/ p90's.

After thinking a little while about it, I think I'll build a straight up 5e5a first, and then maybe tweak it to see how I like it. If it comes out how I think it might, then I'll build one for myself in an Express chassis with TW iron, increased PS filtering, cathode biased power, and stripped down single input useing both sides of v1 maybe on a switch as a boost. If it comes out good I may even try to throw in reverb.

[CapnCrunch]

Oh I almost forgot. Does anyone know whether the original OP tranny had a 4k or 6k primary? I'm not sure how much difference this makes. It seems in TW's that the lower primary tends to be more aggressive. The OP that Mojo, and Weber use for the pro is a 4k primary.

[M Fowler]

Find the number on the schematic and then go to Hoffman amps and down load his cross reference chart and you should be able to get the answer on the primary of the OT.

I would do it for you but can't right now.

[CapnCrunch]

Thanks Mark.

I'll see if I can track it down that way.

I appreciate your help.