Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: chocopower on May 13, 2014, 09:06:23 am

Title: Two channel amp with EF86´s. Mixing resistors size.
Post by: chocopower on May 13, 2014, 09:06:23 am

Hi there!


In the attached schematic, do you think i picked the right value for mixing resistors?


After the Send/Return jacks i have a 1M resistor to ground. I know that with both volume pots in both channels just before the 12ax7 there is no need for it, but if i use the amp as a tube "power amp", that means, connecting the signal to the "return" jack, i will need a grid leak resistor. If some one have any idea to make it better without loosing signal due to the voltage divider, i will thank you a lot.


thanks!

Title: Re: Two channel amp with EF86´s. Mixing resistors size.
Post by: sluckey on May 13, 2014, 09:18:32 am

Quote

If some one have any idea to make it better without loosing signal due to the voltage divider

If you make the mixing resistors 220K you will have less signal loss due to the voltage divider with the 1M. Isolation between channels would still be good too.

Title: Re: Two channel amp with EF86´s. Mixing resistors size.
Post by: chocopower on May 13, 2014, 09:44:30 am

Thanks!  I´ll give a try!