The Amp Garage

Have you tried swapping the power tubes to see if the screen current diff follows the tubes?

That will at least eliminate whether it's a design or wiring issue.

Best regards,
Mike

With a rectifier, if you don't have a reservoir cap connected to the rectifier output (or if the cap cathode isn't grounded or is out of whack in some other way) the AC volts on the rectifier plates will equal the DC volts on the rectifier cathode. You're seeing the RMS voltage, rectified to ripply...

Me too. Big red screen.

If you click on the details, will get a message saying even sites that used to be safe can become unsafe (or something like that). It then gives you an option of assuming the risk and proceeding to site.

mike

OK, see now the ab switch he's using is only switching the guitar input. The weber box or the Aiken design headswitch or similar are the way to switch heads using same speakers, still some risk as Leo describes. I was thinking about building something like this for my apartment. I have my amps and c...

What kind of AB box?

Weber sells this head switching box
specifically for using two different amp head with the same speaker/s.

http://www.tedweber.com/two-head-fs

If he's using something like this should be no problem.

thanks
mike

The normal and bright channels of the JTM45/59 bassman feed separate sides of the first triode. If one side of the tube is dead you would hear nothing from that channel. I spent a lot of time chasing a non-existent wiring problem once because of this. In your case, you can hear the hiss increase wit...

[quote="ampdoc1"]I always recommend using a refrigerant spray first,..to see if any components or contacts react thermally. This is a quick way to find minor problems.


Not trying to derail the thread, but this sounds interesting. Would appreciate more details.

Thanks
Mike

robrob wrote:Cool, glad you got it working. Nice catch bcook.

+1

Glad you got it sorted out.

How's it sound?

Thanks
Mike

A couple of good pics and we can probably sort this out pretty quick.

At least you know where the problem isn't.


Mike

In the normal two channel version, the signals from each channel run through separate 220K resistors before going to the phase inverter. If you made a mistake on this part, you could be sending a signal directly to the phase inverter and bypassing the volume and tone stack. Try disconnecting the inp...

Glad the info was helpful. Hope the repair goes smoothly.

Mike

Here's a schematic for one of the YGL-3's. There seems to be several variants. The trem part number looks to be the same on all the schems I could find though.

Hard to read, but looks like

NSL PL-2H36-1

Found a data sheet for that part number -attached.

Hope this helps.

Mike

+ 1 This can work. Another approach, which I like is to use one of the input jacks as the "jumpered" input. How is your switch setup - where located and how is the shielding grounded? This is a great circuit, probably my favorite, although I more partial to the original 5f6a version, with some tweak...

You have c1 grounded - try removing the ground from the r2/c1 junction.

Mike

Thanks. This post just reminded me to turn off my soldering iron