Amp build for a first time builder?

[martin manning]

They'll usually give an expected ship date on a BO part. What I usually do is find another manufacturer or another value that is close enough and in stock. You can likely find a 1/2W 27k locally at a Radio Shack or maybe you can find a repair shop that will sell you one.

[yoyohomieg5432]

any suggestions on a cab? would a weber 4x10 cab be the best bet?

http://taweber.powweb.com/store/wccabs.htm

anyone know if they post pics of the tolex anywhere? They have tons of options but it doesn't really matter if you can't even see what they look like.

[martin manning]

http://taweber.powweb.com/store/wccabs.htm#combo

Click on the "cabinet" or "grill cloth" links to get a palate of colors. Click the little swatches for a covering and a grill cloth option and they will apear larger, side-by-side. Most authentic for this build would be aged tweed w/ oxblood grill cloth. Why do anything else?

Weber says their cabs are made to fit their chassis... I don't think that's an issue here, and they say that the tweed and BF cabs are pine (not birch ply) so you are good there. Weber is the place to get speakers too, so it's one-stop shopping.

[yoyohomieg5432]

http://taweber.powweb.com/store/wccabs.htm#combo

Click on the "cabinet" or "grill cloth" links to get a palate of colors. Click the little swatches for a covering and a grill cloth option and they will apear larger, side-by-side. Most authentic for this build would be aged tweed w/ oxblood grill cloth. Why do anything else?

Weber says their cabs are made to fit their chassis... I don't think that's an issue here, and they say that the tweed and BF cabs are pine (not birch ply) so you are good there. Weber is the place to get speakers too, so it's one-stop shopping.

haha, would there be a riot if i went with vintage blonde and wheat?

it's hard to judge what it will actually look like on the amp though.

[martin manning]

See 6G6-A Blonde Bassman here: http://www.thevintagesound.com/ffg/
Blonde and wheat is a legit Fender Bassman color scheme, but the 4x10 wasn't made that way. Not that you couldn't do it...

[Structo]

[img:339:319]http://www.thevintagesound.com/ffg/bass ... -A_63f.jpg[/img]

[yoyohomieg5432]

[img:339:319]http://www.thevintagesound.com/ffg/bass ... -A_63f.jpg[/img]

oh nice... that looks a lot sexier in my opinion than the tweed

[martin manning]

If it's done in Tolex you'd probably want metal corners. The front of the combo cab has a slight angle (a bit over 3 degrees according to the drawing Mark Fowler posted the other day), so there's a chance the corners won't fit tightly. They'd also have to be the no-lip two-screw type to work with the narrow-panel cab design. They're soft steel, so they might be persuaded to fit. It could be done without corners, but I think it would be a challenge. You can always ask. Nothing wrong with making it your own and giving it a boutique look, either.

...After more thought, if I were going to do this in Tolex with corners I'd lose the narrow-panel bits and mount the baffle in front of cleats run across the top and bottom, and use the lipped corners. That would preserve the freedom of movement for the baffle and give it a cleaner look.

[yoyohomieg5432]

hey guys, i got back home a few hours ago. I've been taking a look at the schematics and Martin's guide. As far as the turret board goes, you mentioned to use stand-offs. Are stand-offs included or is this something I need to pick up as well?

[martin manning]

From what I could see the Mojo parts kit doesn't include stand-offs, but you'll have to inventory what you have.

As I wrote in the build guide Fender screwed the fiber board with the insulating backer board behind it right down to the chassis. That's ok if all the leads are already soldered to the board, but if you are connecting some of them afterward it would be nice to have some clearance between the circuit board and the backer board. This will make some clearance for the under-board wires too. You can get enough space by just putting a couple of hex nuts between the two boards at each mounting point.

Are there mounting holes in the chassis for the main and cap boards? In the Mojo instructions it appears as if they wanted to let the boards float. Does the PT fit in the cut-out?

[M Fowler]

Also, you can get nylon and aluminum spacers at most hardware stores, Lowe's, Menards, True Value, Hardware Hank, and Home Depot......many other places.

Mark

[yoyohomieg5432]

I have a question with a few of the parts in the mojo kit. I was given 4 "RCA panel mount phono jacks". In the bassman picks Martin sent me it looks like these are for the 4 spots on the back of the chassis. What are these for, though?

Also, where on the chassis would the 1/4" jacks for the guitar cable to the cab go? Did they use the RCA instead of this? Should I swap out the RCA for these 1/4" guitar cable jacks?

Another part I got was three "carbon comp 1W 470 ohm resistor" that look like pushbuttons. I have no idea what these are used for either? The bottom has like 9 pins.

[yoyohomieg5432]

one more question:

what is used to hold the power cord in place? The power cord is terminated by just 3 loose wires that are fed into a hole in the back of the amp. This seems pretty dumb. New amps have that connector that is screwed into the back of the amp and you just plug the cable into that.

-comment: i didnt see anything included to secure the tube sockets in place. I'm just going to use some screws around the house. i'm assuming that's fine to do, right? same with the transformers. The PT came with some but none of the others do. I was just going to use some screws i can find. This won't cause any problems, right?

[martin manning]

The 5F6-A used 4 RCA "phono" jacks wired in parallel for the speaker outputs. In the layout I show three 1/4" Switchcraft-type jacks used instead, one for each impedance tap on the OT secondary. This will allow you to plug the amp up to other cabs until you get the 4x10 combo cab. When you get that you can make up a harness with a 1/4" plug wired to four pairs of push-on connectors. You should have four 1/4" jacks with three terminal lugs in the Mojo stuff. On the BOM I listed the three extra 1/4" mono jacks with two lugs among things to get from Mouser.

A guitar cable is not a speaker cable and will not work for that purpose (not for very long anyway). A speaker cable, OTOH, will make a crappy guitar cable.

I have no idea what the pushbutton things are. Post a picture. Post pictures of anything else you are not sure of, and also progress pics so we can see how things are going.

You should have a plastic strain relief in the kit to secure the power cord to the chassis. This is an obsolete practice, but you are building a new old amp, remember. Tube sockets are attached with #4 machine screws and nuts for the nine pin and #6 for the octals. They don't have to be fancy, just ordinary steel, but use some kind of lock washer. The same goes for all other screws... a combo cab is going to see a lot of vibration and you don't want things coming loose.

[M Fowler]

I have a question with a few of the parts in the mojo kit. I was given 4 "RCA panel mount phono jacks". In the bassman picks Martin sent me it looks like these are for the 4 spots on the back of the chassis. What are these for, though?

Also, where on the chassis would the 1/4" jacks for the guitar cable to the cab go? Did they use the RCA instead of this? Should I swap out the RCA for these 1/4" guitar cable jacks?

Another part I got was three "carbon comp 1W 470 ohm resistor" that look like pushbuttons. I have no idea what these are used for either? The bottom has like 9 pins.

The 59 Bassman used four RCA jacks for the speakers. What I did was put those in the chassis and drilled a 3/8 hole in the center of the four RCA jacks for a 1/4" jack.

Mark