Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: kagliostro on August 03, 2023, 05:30:53 pm

Title: There is a female jack with additional switch to ground the exit of a gain stage
Post by: kagliostro on August 03, 2023, 05:30:53 pm: In reference to this schematic I would like to know if there is a female jack that used at the Organ Keyboard Input can act like intake and also have an additional switch to ground the output of the previous stage (directly or via a resistor) when a jack is inserted

(https://i.imgur.com/9NBXobH.jpeg)

THANKS

Franco
Title: Re: There is a female jack with additional switch to ground the exit of a gain stage
Post by: sluckey on August 03, 2023, 08:24:18 pm: This will work...
Title: Re: There is a female jack with additional switch to ground the exit of a gain stage
Post by: kagliostro on August 03, 2023, 10:18:34 pm: Switchctaft 13B

Many Thanks Steve

Franco
Title: Re: There is a female jack with additional switch to ground the exit of a gain stage
Post by: PRR on August 03, 2023, 10:47:48 pm: Why do you think it needs to be shorted?

Sluckey's clever plan does what you ask but dumps the preamp signal(*) into the keyboard sleeve, which is never dead-zero impedance. A little dirt or tarnish and that unwanted signal will bleed-through.

(*)It is a guitar input? What guitarist will keep playing into an input which is muted? (Aside from Neil Young, Jorma Kaukonen, and others who can hear their guitar without sound waves.)
Title: Re: There is a female jack with additional switch to ground the exit of a gain stage
Post by: sluckey on August 03, 2023, 11:15:44 pm: :think1: Seems to me that there is a much simpler solution. Whenever the keyboard guy plugs into the amp, he should just turn the guitar volume to zero.
Title: Re: There is a female jack with additional switch to ground the exit of a gain stage
Post by: kagliostro on August 04, 2023, 01:02:15 am: Oh, I understand

As this thing is planned the Keyboard input is what will be used near always, the gutar input is only to be used very few time

The guitar input is more as an ability than a real need as the guy is not a guitarist but he asked to have one

Franco
Title: Re: There is a female jack with additional switch to ground the exit of a gain stage
Post by: kagliostro on August 04, 2023, 03:33:39 am: Does someone knows the commercial reference of a female jack intake that has both a NO and a NC switch ?

Looking around I've find info and reference schematics about the existence of this kind of device but not the code of an existing item

Thanks

Franco
Title: Re: There is a female jack with additional switch to ground the exit of a gain stage
Post by: pdf64 on August 04, 2023, 05:13:35 am: The Fender super 60 has several (stereo) jack sockets with built in dpdt switches.
I’ve bought maybe 6 in the past, to repair a super 60, and for a couple of headphone amps I built, used to power the unit up when the input was plugged in.
Title: Re: There is a female jack with additional switch to ground the exit of a gain stage
Post by: kagliostro on August 04, 2023, 07:05:31 am: Thanks pdf64

I'll try a search for Fender Super 60 input jaks

Do you have a code or a brand for such item ?

Thanks

Franco
Title: Re: There is a female jack with additional switch to ground the exit of a gain stage
Post by: kagliostro on August 04, 2023, 02:41:41 pm: Find one that correspond

a guy gived me this indication

Franco
Title: Re: There is a female jack with additional switch to ground the exit of a gain stage
Post by: kagliostro on August 07, 2023, 05:44:31 pm: Arrived here I would like to know if I've draw correctly the Organ Keyboard input with the CUI SF-63043F Female Jack assuming that I want to short to ground the output of the guitar gain stage (useful or not useful it is, it is only to see if my draw is correct this way) when a Keyboard is connected to the devoted input

Will it be better to add an in series resistor that acts as a load, to the path that connect to ground the signal ?

(https://i.imgur.com/uRv5zgM.jpg)

THANKS

Franco

Quote
EDIT: Seems there is a simpler way to arrange this thing :BangHead: :BangHead: :BangHead:

(https://i.imgur.com/Xn2O3qd.jpg)

So the correct Female Jack will be the

JALCO YKB21-5076 5 Pin
(https://i.imgur.com/nfsfFbh.jpg)

(https://i.imgur.com/kW2mQiD.jpg)
Title: Re: There is a female jack with additional switch to ground the exit of a gain stage
Post by: sluckey on August 07, 2023, 07:43:14 pm: A lot of trouble for a non-issue. Just turn the guitar preamp volume down. Better yet, do nothing! :icon_biggrin: