Line out for an AB763 amp?

[72Blazer]

Is it possible to add a "line out" capabilty to a AB763 amp?  For example a line out to go straight into a mixer/power amp and use a home built dummy load to connect to the speaker output jack.  I searched the forum.  I did run across this on Robinette's site:  https://robrobinette.com/Generic_Tube_Amp_Mods.htm#Line_Out_Jack

[SILVERGUN]

Yes.
R1 and R2 are just a simple voltage divider.


Read Rob's notes about why it's not the best method.

[72Blazer]

Thanks.  If you are talking about his warning:  "WARNING: A speaker must be attached to the amp's speaker jack when using the Line Out jack to prevent output transformer damage. This tiny little circuit cannot load the transformer properly to run speakerless."

That is why I mentioned plugging a "dummy load" resistor into the speaker output jack.

Is there another method that you know of besides this?

[SILVERGUN]

This:
Line outs work well for feeding effects boxes but don't work that great for recording or amplification because an amp's guitar speaker does a lot of tone shaping, high frequency de-emphasis and adds speaker breakup distortion.


I think an integrated load box with cab sim and line out is the preferred method.
Tubenit had success with a RedBox.
I have no first hand experience.

[72Blazer]

Ok thanks again.  I think I remember reading some of his thread about this but I don't recall if he built this device or it was something he purchased.

[SILVERGUN]

here's a couple gems from the search box:

Red Box cabinet emulator VS. speaker (el34world.com)

Speaker Line Out (el34world.com)


I enjoyed this:
Designing a Reactive Speaker Load Emulator (aikenamps.com)