Egnater Renegade very low output when 6L6 is selected on tube mix dial

V

vbf

New member
Greetings, all. I purchased a used Egnater Renegade and didn't think to turn the tube mix knob all the way left and right when demo'ing the amp. The EL34 side is robust and full sounding whereas the 6L6 side is very low output. My initial thoughts are to check the tubes, first visually, then ? I suppose I should check to make sure that they are fully seated. Are there other telltale signs I should look for to help determine if the 6L6 tubes, or possibly one of them, need replacing? Is there an easy way to check the bias to make sure that the 6L6's are getting enough voltage?

Any other suggestions or advice?

Thank you
 
First of all welcome to Rig-Talk. :yes:
Lots of smart dudes here - smarter than me, so free bump.

The easiest thing you can do right now is buy a matched set of 6L6's. Most places you buy from you can ask for a set bias range. That means that the tube seller has tested the tubes and pre-matched them so they will be as close together as possible (less out of phase, or cross over distortion).

Next, would be to get some Dioxit (electronics) contact cleaner, not WD40. Spray a little on the pins of the tube and work the tubes in and out of socket. I would do this with all tubes, including preamp tubes. Never spray inside a socket or jack. This stuff also works great for any input jack for amps, pedals, speaker cabs, etc. Again, spray the cable tip, not the hole.

Also, you can get a amp bias tester for octal power tubes. This gets inserted in the socket and then you plug the tube into the tester and hook up to a mulitmeter. There are single stripped down versions of these all the way up to multi tube testers with meter built in. So $30 - $300. There are some safety tips for doing this so make sure you read up on how to do this before attempting yourself. For example, you wouldn't want to pull the tester off the amp while the amp is running. If this amp is self biasing, you won't be able to change the bias (non-adjustable fixed bias vs fixed bias), but you can always read it off the meter - so good tool to have anyway. Also good to have spare tubes for your amps (also good for testing things out).

As far as how to tell if a tube is bad, that can be hard without a professional tube tester like the tube sellers use. If the top of the tube is black, it is probably bad. Should be silver. If you fire up that amp and it is not glowing mildly orange, then could be bad. If it is bright red or super bright then shut off the amp immediately and replace.

Additionally, I do not know much about the Renegade, although I have played several. Decent amp for sure. So I don't know if it has built in bias test points or a external variable resistor adjustment. There is an Egnater Amp Sub Forum here that has quite a bit of information in it that would be helpful for you to review (Renegade specific). I've also attached an amp biasing tutorial (for fixed bias amps*) I created that breaks down all the steps in great detail and encompasses all of the safety concerns/tips. It is specific more to amps that do not have external test points or adjustment capability but should be helpful nonetheless. *Fixed bias means you have to adjust (fix) the bias yourself.

Hope that helps and good luck :cheers:

For tubes*:
Eurotubes (JJ - 6L6s)
Tube Depot
Dougs tubes
The tube store
Tubeampdoctor
Stewmac

For testers*:
Eurotubes
Weber
Stewmac

*there are others but these are the ones I am familiar with

Bias tutorial:
https://splawnfans.proboards.com/thread/7786/amp-biasing-tutorial
 
Last edited:
Thank you very much, I greatly appreciate your time and all the helpful info. I replaced the 6L6's as you suggested to no avail. I contacted the store from which I purchased it and they gave me a full refund. Again, thank you for your time and information.
 
You must log in or register to reply here.
Back
Top