Valve Junior

[theGeek]

So, my valve junior is dead. I don't know why. The tubes aren't getting power (they aren't glowing)... I don't know what that means or any of that. But instead of tediously going through the old board and trying to find the problem I was thinking that I could finally rebuild it with one of the kits from turretboards.com

This would, however, be my first build. I have successfully built 5 or 6 effect pedals ranging from a very simple germanium boost to a digital delay. My question is, what are some good suggestions for beginner amp makers?

Would the Valve Junior Build be too complicated? It seems simple enough to me... but I've been wrong before

Thanks!

[FunkyE9th]

Building a Valve Jr is a good way to start a 1st build, but my suggestion is to 1st get your Valve Jr working. IMO, it will be a good learning experience debugging your Valve Jr. And if you get it working start modding it.

Have you checked the fuses? It has several fuses. Make sure they are all OK. If fuses are OK, start checking power supply and heater voltages with the tubes removed. If it checks out OK, install tubes, recheck supply voltages etc etc...

BTW, sewatt.com is good place for Valve Jr info.

[theGeek]

Building a Valve Jr is a good way to start a 1st build, but my suggestion is to 1st get your Valve Jr working. IMO, it will be a good learning experience debugging your Valve Jr. And if you get it working start modding it.

Have you checked the fuses? It has several fuses. Make sure they are all OK. If fuses are OK, start checking power supply and heater voltages with the tubes removed. If it checks out OK, install tubes, recheck supply voltages etc etc...

BTW, sewatt.com is good place for Valve Jr info.

I checked the fuses... they are all in good shape. How would I go about checking the power supply and heater voltages. I'm still VERY new to this stuff and I'm not great at troubleshooting yet.

[Structo]

Do you have a DVM?
Did you check the continuity of the fuses with a meter?

Are you aware of the hazards of the high voltage inside?

You can check the various voltages inside coming off the power transformer.

AC voltages before the rectifier and DC after.

Filaments will be AC.

First thing to do is look it over carefully for burnt components.

If nothing visually is wrong, measure voltages.

There have been a few revisions to this amp and I don't know what the changes have been but here is a Rev. B schematic.
http://www.schematicheaven.com/fenderamps/blues_jr.pdf

[selloutrr]

if it's the power transformer, I have some good news and some bad news! lets get the bad news out of the way.... your amps dead! and it's going to cost some $$$ to get it up and running. oh well!!!
now the good news!!!!
YOU get to rebuild your amp!!!! hammond makes a nice transformer set and mercury makes an expensive transformer set. the best part of this project is that so many people have already done the same thing you about to attempt that how to and DIY information is abundant. It's not a bad idea to switch to a turret board both for looks and function. it should help stabalize some ground issues and make for a fun build. the most noticable changes you can make to the tone are going to be in the tube compliment and the output transformer. GO BIG and you'll be happy!!! since it's a simple circuit this is a great place to A/B tubes!!! make a list and order all the parts and plan for a nice weekend build.

happy building!