Help with switching ideas..

[dschwartz]

Hi all..I´m designing a new version of the double shot tube preamop, but i´m stalled on this issue..
for channel switching i need 3 switches....2 of them are covered by a DPDT relay, but i need that 3rd SPST that connects the high gain to ground..

I need that switch to be driven with the relay´s control voltage..i tried jfet, but i´m not sure about it..at least in simulations, they dont completely shut the channel....using a 4053 is not possible cause of the voltage swing of the signal..it may be just 1 switch, but i´d feel wasting those 2 extra switches..

in other words..i need a simple, nice, and cheap electronically controlled switch..
help, any one?

[petemoore]

  Call TI ?  Perhaps there's an elegant new switching solution they want you to try out...

[Unbeliever]

Err ... another relay?

[anti-idiot]

Hi all..I´m designing a new version of the double shot tube preamop, but i´m stalled on this issue..
for channel switching i need 3 switches....2 of them are covered by a DPDT relay, but i need that 3rd SPST that connects the high gain to ground..

I need that switch to be driven with the relay´s control voltage..i tried jfet, but i´m not sure about it..at least in simulations, they dont completely shut the channel....using a 4053 is not possible cause of the voltage swing of the signal..it may be just 1 switch, but i´d feel wasting those 2 extra switches..

in other words..i need a simple, nice, and cheap electronically controlled switch..
help, any one?

go to schematicheaven and look for:

Groove Tubes Trio Preamp (3 channel switching)
este es el que pienso usar cuando haga un preamp con 3 canales (el tercero es 'high gain')

Trace Elliot Trident (Clean/Overdrive-Ultra)
Casi todo el circuito de switching usa relays. Eliges entre limpio o saturado, y ultra ( 1/2-3). Revisa el esquematico y el manual. Jamás había visto tantos relays.

Supongo que quieres usar el circuito para la opción de "Foot Switch", verdad?

[dschwartz]

gracias.. echare un vistazo a ver si encuentro algo similar a lo que busco..

yes, it has to work with a footswitch..

[sean k]

I just got a box of old electronics mags and one of the articles was about making your own relays from coils around reed switches. Maybe it'll work for this as its an on/off thing. Maybe you could google reed and relay and the article will come up otherwise I'll copy it and post the page if you're interested.

[anti-idiot]

gracias.. echare un vistazo a ver si encuentro algo similar a lo que busco..

yes, it has to work with a footswitch..

déjame ver si entendí: lo que quieres hacer con tu preamp es que sea de 2 canales seleccionables y un 3er modo para los solos? Creo que los esquemas que te recomende cumpliran en cualquiera de los casos. El trident te puede servir si lo que quieres es C/O-U o si lo cableas de otro modo tendras C-O/U.
[Clean, Overdrive, Ultra).

El FS se haria con 2 SPDT (uno para elegir entre limpio y saturado, y el otro para elegir entre el canal seleccionado y el modo ultra)

El Trio de GT usa 3 MOM Sw (N.O.) y te serviría más si tu preamp fuera de 3 canales (como el TSL, cuyo switching es algo dificil para mi)

Suerte.

PS. Te escribí hace un tiempo, soy THChrist

[dschwartz]

no no..
en ingles mejor para que todos entiendan:

For just the channel switching, i need a dpdt, but at the same time, i need an extra switch that shunts the high gain input to gropund to avoid oscilations when using the clean channel..they all have to work at the same time..

i´m leaning toward using just another relay..not cheap..but simple and effective..

[frank_p]

I am not sure to understand the question:
You want a 3rd  switch SPST, because you don't want a "side" of dpdt that is not used and because you will use only 1/4th of the total switches?
I have a relay that is only a spst Normally Open (four leads): two for the coil and two for the switch.
7mm D. x 20 mm L. black tube.
Brand: Electronic Applications Company
Is that the kind of part you are looking for Daniel ?

[frank_p]

It is looking a bit like this one:
http://www.alarmsystemstore.com/12VDC-SPST-Reed-Relay-p/reed-relay.htm

[dschwartz]

i´m going to use 2 dpdt relays..the extra switch is going to be used for the channel pilot lights, i ussually use the relay control voltage for pilot lights, but this time i´m gonna use that extra spdt..