Page 2 of 2
Re: Planning my first build
Posted: Fri 04/02/21 1:48 pm
by Bieworm
You're right. But as I don't have a reference or any particular sound in mind I'm not expecting something ...
Re: Planning my first build
Posted: Fri 04/02/21 2:56 pm
by TriodeLuvr
Bieworm wrote: ↑Fri 04/02/21 1:48 pm
You're right. But as I don't have a reference or any particular sound in mind I'm not expecting something ...
I understand that now. And hopefully you'll hit on a combination that works really well. One other thing worth mentioning is that the higher Ra of the 6L6 might adversely affect damping. That could result in "incoherence" caused by speaker overshoot and/or ringing (similar to what happens when a series resistor is added in order to reduce sound levels). If you feel that this is occurring, it might be worthwhile to temporarily install a more robust feedback network. Replacing the typical Marshall value of 100K with something like 33K would be a good start for experimentation. Of course, NFB can produce other effects when the various stages are overdriven, so this might or might not work out.
Jack
Re: Planning my first build
Posted: Fri 04/02/21 5:17 pm
by JMPGuitars
TriodeLuvr wrote: ↑Fri 04/02/21 2:56 pm
Bieworm wrote: ↑Fri 04/02/21 1:48 pm
You're right. But as I don't have a reference or any particular sound in mind I'm not expecting something ...
I understand that now. And hopefully you'll hit on a combination that works really well. One other thing worth mentioning is that the higher Ra of the 6L6 might adversely affect damping. That could result in "incoherence" caused by speaker overshoot and/or ringing (similar to what happens when a series resistor is added in order to reduce sound levels). If you feel that this is occurring, it might be worthwhile to temporarily install a more robust feedback network. Replacing the typical Marshall value of 100K with something like 33K would be a good start for experimentation. Of course, NFB can produce other effects when the various stages are overdriven, so this might or might not work out.
Jack
There is no NFB in that amp, nor should there ever be. The stiffness that would add, would kill the character of the amp.
Just a side thing... About a decade ago I modded a Traynor YCV80. It came stock with 6L6 tubes in a quad. But it could run with 2 or 4 tubes...and my mod was to add a switch to change the bias to allow use of EL34 or 6L6. The OT was a 1.6K primary into a 4 ohm speaker.
https://youtu.be/_pM1KmdKPHE
Thanks,
Josh