LSS: No Sound on 5w and 15w Setting

On my 5 and 15 watt settings, on both channels, I had no sound, but the 30w settings worked just fine. :?
Anyone else had this problem?

When I was switching the amp on, the 5Y3 tube would flash bright blue for an instant (but it didn't do it the next day). Replacing the 5Y3 tube fixed the problem; so how does that tube allow sound through the 30w setting but not the other two settings?

Is the 5Y3 the 'rectifier' tube - aka a pre-amp tube?

Cheers

The 5Y3 is the rectifier tube. It is not a pre amp tube. The LSS uses the rectifier tube in 5 and 15 watt settings, but uses a solid state rectifier on the 30w setting.

Well, that explains it, then. Thanks. I didn't know the 30w rectifier was solid state.

Now I do!

I just found this in the instructions:

...maximum headroom of the SILICON DIODES when the 30 watt setting is called up and brings up the 5Y3 rectifier tube for increased dynamic character and a juicy feeling sag when either 15 or 5 watts is chosen.

Click to expand...

Kind of handy when the rectifier tube blows that you can still play in 30w mode

Buy an NOS 5Y3. It'll outlive you.

Don said:

Buy an NOS 5Y3. It'll outlive you.

Click to expand...

That sounds good.
Do non-mesa tubes void the amp's warranty?
What makes them last so long where others won't?

mARKw said:

Well, that explains it, then. Thanks. I didn't know the 30w rectifier was solid state.

Now I do!

I just found this in the instructions:

...maximum headroom of the SILICON DIODES when the 30 watt setting is called up and brings up the 5Y3 rectifier tube for increased dynamic character and a juicy feeling sag when either 15 or 5 watts is chosen.

Click to expand...

Kind of handy when the rectifier tube blows that you can still play in 30w mode

Click to expand...

Yep, the one criticism i've seen about the ls series is that the rectifiers aren't user assignable. 30 watt is automatically solid state and 5/15 are automatically tube. The user can't make that determination. It's not a big deal to me though.