Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Colas LeGrippa on March 28, 2020, 11:09:14 am

Title: Building an A/B/Y switcher
Post by: Colas LeGrippa on March 28, 2020, 11:09:14 am
( I had first written a/b/y  snatcher.... :laugh:  too small the letters of my tel. and my motorbike ride yesterday caused my eyes to be infected...
hopin' not having caught THE virus.)


Ok getting to the point now, what would be most important in the building of a passive aby switcher (I got it right this time) to do and not to do ?


Would it be possible to build a 12V powered
unity gain buffer using a 12AU7 ? I have already designed the power supply with regulated 12vdc  heaters . Thanx


Colas
Title: Re: Building an A/B/Y switcher
Post by: d95err on March 28, 2020, 12:31:52 pm
Not sure what your question is. Are you building a tube buffered A/B/Y switch?
Title: Re: Building an A/B/Y switcher
Post by: DummyLoad on March 28, 2020, 12:44:38 pm
cathode follower is a unity gain buffer. see the fender 6G15 stand alone reverb schema for an example of how to external bias with a pair of resistors. 


--pete
Title: Re: Building an A/B/Y switcher
Post by: DummyLoad on March 28, 2020, 12:46:12 pm
and another note - Op-Amps are simpler, lower volt, and much more reliable.


--pete
Title: Re: Building an A/B/Y switcher
Post by: jjasilli on March 28, 2020, 06:40:48 pm
www.geofex.com > 12/8/04 | A quicky - updated hum free splitter/A/B/Y
Title: Re: Building an A/B/Y switcher
Post by: Colas LeGrippa on March 28, 2020, 06:59:49 pm
I admit my post is a bit confusing.
I don t know much about aby switchers but the one I had built many years ago was messing my guitar tone, especially in the Y mode. It was a passive one, two switches , three jacks ad two leds.


I d prefer an active  one if there would be no signal loss when using two amplifiers at the same time.


But, there MIGHT EXIST a manner of building a passive box with good results, that I don t know.


 :icon_biggrin:


Be prudent with the virus.