Ceriatone bassman small parts kit

[travis-260]

Has anybody bought this small parts kit. I thought it might make getting all the parts easier rather than buying pieces here and there. Any thought? Thanks in advance.

http://www.mojotone.com/Tweed-Bassman-S ... -Parts-Kit

[Sonny ReVerb]

With the cost of shipping these days, a kit can make good sense. It depends on the quality of the parts and how particular you are.

Your thread title says 'Ceriatone', but your link is to 'Mojotone'.

[Bear]

No direct experience with Mojo's small parts or full kits. However, the Tweed Deluxe small parts kit has orange-drops in the picture, and as the item identifies, no substitutions. If you're fine with orange drops or just getting your own favorite signal caps in there, no big deal.

I'd also wonder about whether the kits are for a build that makes the same concessions to modern life as you want to make. Do you want to install screen resistors where the original didn't? Adjustable bias? Do they give you a three-prong cord or a two-prong and a "death cap" to go with the ground switch? (Is the switch position still labeled ground or changed to standby? Do you prefer original appearance or people knowing what switch to use when they sit in or borrow your amp?)

I'm guessing the package discount makes it worthwhile to get the kit and a few extra parts to do it your way. Better to pay shipping on only one order, though, and have all the parts you want from the start.

[travis-260]

Sorry, it's a Mojo kit but I had been looking at the Ceriatone website. It's still early in the morning. IT's my first build so I'm still learning and not to critical of what parts I get. I want quality but I thought with this being my first build this kit will help me get all the parts I need without spending days just try to track down parts, that will come in later builds.

[travis-260]

Bear,
What is the "Death Cap", this is my first so I'm still learning, thanks.

[Bear]

Bear,
What is the "Death Cap", this is my first so I'm still learning, thanks.

As I understand it, on a lot of old amps equipped with only a two prong cord, there is a "ground" switch that puts a cap in between one side of the AC line and the chassis. I believe the benefit is supposed to be lower noise when its engaged sometimes. Downside is if the cap or switch goes bad, the chassis can go hot, as in voltage, and you can find yourself to be a ground path, including through a guitar to a microphone on stage. Thus the "death cap" sobriquet.

Typical modern practice is to install a three-prong chord with the ground to chassis, but the fuse on the hot side, and maybe repurpose that nice switch as a standby switch. Like so:
http://www.unclespot.com/3prongconversion.JPG

[Structo]

That mod simply bypasses the ground switch.

[travis-260]

Thanks, another question. What are screen resistors? Where can I read about what they are and how they work?

Thanks again!

[Bear]

That mod simply bypasses the ground switch.

It was my understanding that the amp shouldn't work with the third prong grounded and the ground switch engaged. Don't know the reason for moving the fuse to the hot side, but there's supposed to be a reason.

BTW, if the chassis is a straight repro, it should have three switch positions -- ground, power, and standby. So no need to repurpose the ground switch position, although I wouldn't wire up a working ground switch. (It's pretty common on 5E3 Deluxe builds to change the ground to standby, especially since the 5Y3 doesn't have the slow ramp-up of a GZ-34.)

[Structo]

The reason the fuse is moved to the black wire is because that is the hot side.
You want the fuse first in line because if it blows, nothing beyond that becomes hot, like the chassis or switch bat.

I believe that drawing is just to preserve the convenience outlet and uses the ground switch as a junction or tie off point for the fuse and outlet wires.
Yet it retains the original appearance.

[Bear]

Thanks, another question. What are screen resistors? Where can I read about what they are and how they work?

Thanks again!

Screen resistors are resistors between the B+ and the screens on the 6L6 tubes. Better for tube life, less likelihood of catastrophic failure as can sometimes occur when the screens are at higher voltage than the plates. The 5F6a schematic includes them, but not all tweed Fenders do -- for example the 5E6 version.

(Having the screens at higher voltage isn't a guaranteed tube fatality, and screen resistors don't always guaranty lower voltage on the screens than the plates, but it should improve the safety margin.)