5E5-A Tweed Pro recomendations

[CapnCrunch]

Hey all,

I have a late 50's Jensen P15N and have been wanting to build a late 50's Tweed Pro clone around it. I'd kind of like to buy a kit for simplicity sake, but the only two kits that I've run into are Weber, and Mojo. Weber is considerably cheaper, but I suspect there is a good reason for that.

Anyone have any advice. I wouldn't be opposed to sourcing parts from various places, and I'm not in a huge hurry. I built a 5E3 clone a while back, and it is a really cool little amp. Anyone here built a Pro (or similar Tweed) from scratch? If so, do you have any advice on where to go for schematics/layout and parts? I have found a couple of different Schems and layouts but they are just that. Different. I'm not sure how to go. I'm guessing the Schem/Layout on the Fender Amp fieldguide is probably pretty accurate, but I've seen at least two others that differ. One has one 12ax7 and two 12Ay7's. The other has two 12ax7's and one 12at7.

Anyone have experience with the Mojotone Kits?

[Structo]

Well here is the official Fender schematic and layout.

http://www.schematicheaven.com/fenderam ... _schem.pdf

[Andy Le Blanc]

Its relatively easy to fabricate just about any of that class of amp. You've already
defined your load and chosen your tube type, bias and relative watts for a design.
Whats left is inverter type and pre-amp. You'll need a few terminal strips to
complete the dress, the power supply can be mounted on the terminals of
the filter cap can.

1 5u4
2 6l6
3 octal sockets
2 12ax7 or 12ay7
2 ninepin sockets
1 3x40uf 450v can
1 022778 pt
1 018343 opt
1 125c1a choke

cathode bias the 6l6 with 12ax7 heaters all in series.

what a great time to step past kits, and have an opportunity to layout and
dress your own amp.

The trannies can be sourced nearly any where, you can use a bias resistor
or fix the bias as desired, you can choose a host of preamp configurations
and have a wide selection of invertors, various paraphase, cathodyne and
even see-saw like an ampeg. You even have choices of how to complete
the dress, point-point, terminal strips, or a component board.

[collinsamps]

Mojo's kits are as good as you'll find anywhere. Webers chassis are ok but I wouldn't use anything else.

Personally I would go hybrid and use the 5E5-A chassis with bass/treb/presence layout(or 5F6A chassis if you want a middle control) up to the power stage and then use the 5E5 cathode biased power section with the 5E5-A choke instead of the 5E5 resistor and slightly bump up the PS filters to 22/22/22/10. I build them all the time with a lower voltage PT's and 5U4's to get 25, 30 or the standard 798 PT and GZ34's for 35/40 watts.

I can recommend that build as one Leo never built that sounds crazy good and breaks up at just the right spot.

[ER]

I'm building a similar project from scratch, a 5e7 bandmaster.

I found a baldwin leslie cabinet (with single 12 and 6l6 booster amp) for 12 bucks. The trannies are perfect for the lower powered 6l6 fender amps and the old sylvanias won't hurt either. There is a 14.2 volt tap on the power tranny that with a voltage doubler will give me -39 volts for the bias.

There was a nice jensen in the cabinet that I replaced with an old alnico EV with whizzer and hooked it up to my Hammond L-100, I also replaced the leslie motor with a separate variable DC motor. Sounds great.

Now I have the 2-12" jensens from the Hammond that will go with another pair of organ pulls for a 4-12" pine cab, the single jensen 12 to go in a pine cabinet, and a leslie cabinet, all to go with my 8 ohm bandmaster head. I'm going with a single input and adding a "boost stage" from the second half of V1. Using a hammond aluminum chassis, hammond choke and going with a trainwreck style layout in case I want to mod it later (6l6 rocket? plus it makes sense as a good way to do a layout).

My working theme is a "what if" scenario of Leo Fender making a tweed half-stack. I always liked the bandmaster since Montrose used one on the first album (that wicked bad motor scooter tone) and I'm generally a blues guy so the tweed thing works for me, and being less power than my vibroverb I'm hoping I can get it turned up to the sweet spot (12) without driving people from the room (I'll let my playing take care of that).

If you can find an old baldwin booster amp for cheap, it's a nice source for iron.

I would definitley reccomend a scratch built and make it how YOU want it.

-Erik

[drew]

I build them all the time with a lower voltage PT's and 5U4's to get 25, 30

Any particular make or model PT?

[CapnCrunch]

Thanks all for the suggestions. I am in the process of building a Rocket and have built a 5e3, but I am far from an amp builder. The Rocket is the first non kit amp I've built, but with all of the documentation here it actually feels much easier then the 5e3, which I built from a Mission Amps kit.

That being said, the 5e5 seems a little daunting to me because I don't have the same crutches I have here for the Rocket. Oh well, I guess it's a good excuse to stretch myself and gain some knowledge. I'm not an amp designer for sure, but I do like to learn.

Thanks again

[CapnCrunch]

Hey Structo:

I have the schem and layout that you linked to. I suspected it was authentic. Thanks. I've started sourcing parts and I think I'll slowly gather them so I can build this in a couple of months. I think I'll use an eyelet board, and I'm going to try to do a hybrid build as suggested by Craig above.

By the way, I visited your web site Craig, you do some nice work, both with amps and guitars. Thanks again for the suggestions. I may hit you up for more info on trannies and such if you don't mind.

Thanks again.

[M Fowler]

Captian,

It doesn't look to bad but to make it a whole lot easier, send the file to a Kinko copy type of place or at work if you can and blow the layout up to 11x17. Then take a handful of different magic markers and color the wires going to the proper places that will eliminate all those dashes within the board area. You can figure out some other means of marking the under board wiring.

Or you could use visio and make your own nice layout.

Just don't wire your pilot light and filament wires like they have with one leg to ground and 4/5 pins going to ground.

Mark

[Structo]

Cool, glad I could help Capn'.

I bought a blank piece of G10 board from Hoffman and 50 of his tall 1/8" eyelets.
He only sells it in 3 1/8" width, you just tell him how long of a piece you need and he cuts it to length.

What I did was draw the layout on paper to scale for the board I was using.

I had to draw it backwards because of the way my chassis was built.

Then I taped the layout onto the board and center punched everywhere an eyelet would go.

Then off to the drill press. Be sure to use a piece of wood under the board when drilling for backing.

I didn't make or buy a fancy staking tool. I have a small ball peen hammer that worked really well for flaring the eyelet on the back side, then I smacked it with the flat end of the hammer to flatten out the flange.

Worked pretty good and only took me minutes to do it.

[CapnCrunch]

Hey Thanks again. I just gotta keep reminding myself that when I put this thing together, I will be forced to actually learn what is going on inside the amp. I was kind of starting to get an inkling when I built my 5e3, but that was about two years ago, and I forgot pretty much everything I learned. I finally have a bit of time to work on this stuff again, so I'm wanting to dive back in.

On another note, I recently finished the cabinet for my Rocket. I will post some pics of it soon. I'm really excited to get it up and running.

[collinsamps]

I build them all the time with a lower voltage PT's and 5U4's to get 25, 30

Any particular make or model PT?

I use Heyboers exclusively in my tweed builds. Depending on the wattage you want you can look at the various original Fender schematics output stage as a guide and raise/lower plate voltage & bias to get where you want. Keep in mind that power supply dropping resistors, filtering and preamp voltages will need to be planned based on the PT secondary voltage and the application you are using it for.

[collinsamps]

I'll use an eyelet board, and I'm going to try to do a hybrid build as suggested by Craig above.

By the way, I visited your web site Craig, you do some nice work, both with amps and guitars. Thanks again for the suggestions. I may hit you up for more info on trannies and such if you don't mind.

Thanks again.

Sure, feel free to pick my little brain anytime.

[Kregg]

I gotta tell you, the Pro sounds great with the JBL D130-F.
Too bad they don't put that speaker into production with a vintage RI (down to the paper).