Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Tbone55 on September 19, 2024, 04:20:54 pm

Title: Converting to 6L6 from EL84
Post by: Tbone55 on September 19, 2024, 04:20:54 pm

I'd like to know what's involved in converting from EL84's to 6L6's. I've got a Blues Jr III that I've done the Hoffman conversion on. Can I still keep the amp the way it is without having to change major components like transformers or should I look at building another amp instead. I could re-install the original PCB stuff and put the amp back to it's original form and keep the chassis to use it in another build.

Does anyone sell a replacement chassis if I decided to do this? I haven't been able to find one yet. Any and all thoughts and ideas are welcome. At this point I'm just chewing on the idea.

Cheers!

Title: Re: Converting to 6L6 from EL84
Post by: Dave on September 19, 2024, 04:35:33 pm

6L6's pull twice as much heater current and a lot more power. The PT likely won't take it. The OT won't take it either. You can do it, but you will be sorry.


Dave

Title: Re: Converting to 6L6 from EL84
Post by: HotBluePlates on September 19, 2024, 05:06:48 pm

Quote from: Tbone55 on September 19, 2024, 04:20:54 pm

I'd like to know what's involved in converting from EL84's to 6L6's. ...

New Power Transformer, new Output Transformer, new Bias Supply (plus other changes to the power supply).  All that stuff may not fit on the existing chassis.

Probably better to build a new amp.

Title: Re: Converting to 6L6 from EL84
Post by: Tbone55 on September 19, 2024, 07:33:50 pm

Thanks guys. You've confirmed my suspicions. I have a 2x12 quarter stack cab I built and it might be a good candidate for another build. Any suggestion for an amp head build? Not looking for huge power, 20w max. Just something with decent headroom that would take pedals well. No problem for me to build a cabinet for the head itself.

Cheers!

Title: Re: Converting to 6L6 from EL84
Post by: glass54 on September 19, 2024, 10:09:35 pm

Hi Tbone
How bout Sluckeys AB763 Lite (reliable project,good for 20 Watts ie 2x6V6) and combine it with Tubenit's Effects loop, giving you maximum flexibility. Loop is switchable in/out.
I'd use a SS Diode/Bridge with a 300V to 310V Secondary Tx, and up the uF's a little for the first and second node of Power Supply.
I'll include a sch and link to the Fx loop info.
https://el34world.com/Forum/index.php?topic=10208.msg93686#msg93686 (https://el34world.com/Forum/index.php?topic=10208.msg93686#msg93686)
Regards
Mirek

Title: Re: Converting to 6L6 from EL84
Post by: Tbone55 on September 20, 2024, 08:14:23 am

Thanks Mirek. That looks like it would be a great build for my cabinet. Thank you for providing the schematic and the links.

Cheers !

Title: Re: Converting to 6L6 from EL84
Post by: Tbone55 on September 20, 2024, 03:36:09 pm

Is the turret board and chassis For Sluckeys AB763 lite available from Doug or elsewhere? Does Sluckey have any instructions available? I'm a bit of a newbie at building this stuff and could use some help.

Thanks.

Title: Re: Converting to 6L6 from EL84
Post by: AlNewman on September 20, 2024, 03:47:15 pm

I'm sure he would have a layout and schematic on his website.
With that info you should be able to have a board built, and you might have to order a blank chassis of the proper dimensions.

http://sluckeyamps.com/index.htm

Title: Re: Converting to 6L6 from EL84
Post by: Tbone55 on September 20, 2024, 04:57:45 pm

Thanks kindly for your reply AINewman. I'll check out his site.

Cheers!

Title: Re: Converting to 6L6 from EL84
Post by: glass54 on September 20, 2024, 05:50:00 pm

Enjoy Sluckey's Lite info. (Built this for a friend BUT SS Rectifier and custom Toroidal Tx)
There is a Lite 2 if you prefer a different board/chassis (chassis from Hoffmans) see on list from AlNewman's link.
You're in the right place to get experienced help  :laugh:
Regards
Mirek