Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Ross on May 05, 2016, 02:39:25 am

Title: Hoffman 5E3 12A type jack for Speaker. ?
Post by: Ross on May 05, 2016, 02:39:25 am

Considering the 5E3 for my next build and I noticed in the schematic (http://el34world.com/Hoffman/files/Hoffman_5E3.pdf (http://el34world.com/Hoffman/files/Hoffman_5E3.pdf))
 a shorting jack (12A type) for the speaker. Is shorting the secondary preferable to having it open?

Title: Re: Hoffman 5E3 12A type jack for Speaker. ?
Post by: sluckey on May 05, 2016, 09:40:33 am

Yes. Fender started doing that in the late '50s.

Title: Re: Hoffman 5E3 12A type jack for Speaker. ?
Post by: Ross on May 05, 2016, 10:36:56 am

So it's a good thing?

Title: Re: Hoffman 5E3 12A type jack for Speaker. ?
Post by: EL34 on May 05, 2016, 12:05:36 pm

No plug connected to the main jacks = output shorted to ground


An open output playing the amp is much worse

Title: Re: Hoffman 5E3 12A type jack for Speaker. ?
Post by: Ross on May 06, 2016, 03:43:28 am

This: http://www.head-fi.org/t/484643/why-do-tube-amps-must-have-a-load-connected (http://www.head-fi.org/t/484643/why-do-tube-amps-must-have-a-load-connected)