Tube Amp Archive

I suggest you seek clarification from DrZ. If the circuit architecture shown in this schematic is correct, you’re under a misapprehension in thinking the amp bears any relationship with JTM45. https://www.flickr.com/photos/49108115@N04/4501477895 Stephenl is right,that's a Route66 model, the Antido...

To the original question, the issue might be that the bias circuit doesn't have enough swing to get the bias voltage you need… The g1 bias voltage required by 6L6 tends to land somewhere between that of KT66 and EL34. So if the bias supply can be adjusted for KT66 and EL34, then it can also accommo...

Got it, making it selectable goes deeper than I'd go... Thanks!

If your interested in trying it, you could add another power supply node for the screens and change to pentode operation. You might find you like the sound of KT66's better that way. I'm not a fan of UL for guitar amplifiers. I built one that had selectable UL / Pentode with KT66's into an 8K prima...

Thanks so much Martinl!

Would you say high enough to prematurely wear out the tubes? I guess if I like the sound better with 6L6's and leave them in permanently I could put some resistors in line to get them to see 6,3V right?

Output power is not a problem for me, this amp is plenty loud for my needs. Could it be some different than traditional wiring at the tube bases that would not work for both kind of tubes?

Hi guys, new member here. I've got a Dr Z Antidote, its a JTM45 style amp that runs KT66's (ultra linear OT) and I recently contacted DrZ customer support about putting a set of 6L6GC's in there but they replied that it can't run 6L6GC's but can take EL34 with proper bias changes. This sounds strang...