2 amps, 1 cab

Revolutions

Couldn't resist the title 

This may be a ridiculous question... I have a few valve heads that I enjoy using pretty regularly. I was thinking today it'd be cool to have a simple switching system so I could connect multiple heads a single output to my cab.

Is there such a thing as a multi-input attenuator & switcher with dummy load on each input?

louis_LLM

https://www.two-notes.com/en/reload-ii/

Not sure for definite but I know this can run 2 amps in - less sure how you’d run them both into a single cab though.. some sort of AB box? 

Dave8

The two notes will only let you load one amp

there are a few switchers out there… radial do probably the most simple one
https://www.radialeng.com/product/headbone-vt

Khe do some too
https://www.khe-audioelectronics.com/

and ampete 

https://ampete.com/

Among others 

Danny1969

If you can trust yourself to turn an amp off before you use it then a simple patchbay with one output and multiple inputs is the simplest solution. The speaker is connected to the "to speaker" output socket. 3 amps are connected to 3 "amp out" sockets. (Can be more) You move the patch cable between any of the 3 amp outs (or more) depending on what amp you want to use. 

Each input  socket uses a switched jack socket. Connect an 8Ω 25 watt wirewound resistor on the switched side between ground and hot. This means with no patch lead inserted the amp has an 8Ω load. When the patch lead is inserted it lifts the contacts off the resistor so it's not in parallel with the speaker load. 

That's the easiest way I can think of doing it  .. if you move the patch lead then there's a split second when the amp has no load which is why I would turn the amp off first. 

The patch lead needs to be made from a bit of 3 amp twin core or similar rather than a thin signal cable 

A posh version would use a rotary switch 

andyman

Nm

louis_LLM

Dave8 said:

The two notes will only let you load one amp

there are a few switchers out there… radial do probably the most simple one
https://www.radialeng.com/product/headbone-vt

Khe do some too
https://www.khe-audioelectronics.com/

and ampete 

https://ampete.com/

Among others 

My mistake! The Radial was in my thoughts but couldn’t remember the brand name, have a wis! 

Jalfrezi

I have 2 amps to 1 cab using this from Thomann, seems to work well.

https://share.google/sBzT4OeDCsGvPJNIe

I also have another head, but prefer it with a different cab, so just run that alone.

It would be cool to run more amps, as I have a few others, but bigger switches are mucho dinero!

Revolutions

Dave8 said:

The two notes will only let you load one amp

there are a few switchers out there… radial do probably the most simple one
https://www.radialeng.com/product/headbone-vt

Khe do some too
https://www.khe-audioelectronics.com/

and ampete 

https://ampete.com/

Among others 

Ah, awesome thank you. Felt like it should be a solved problem, especially within the studio world.

For some reason my Google skills weren’t bringing back any useful options or advice.

And thanks @Danny1969 - I was considering a switcher but even in my current world of swapping power & speaker cable from amp to amp I've managed to power one up without load plenty of times 

robinbowes

I can vouch for the Radial Headbone-VT. It works great!

I've had one for some time, although it was on-loan for a few years (I used a Helix live, so no amps to need switching).

I'm back using amps again, and if I could be bothered to lug two valve amps and a cab to gigs I'd have no hesitation using the Headbone!

77superbass

Delisle do a bunch of them 

https://delisleguitar.com/shop/amp-and-speaker-cabinet-selectors/

I’ve been using the Palmer TINO, it’s decent enough and can be used with a remote foot switch 

https://www.thomannmusic.com/palmer_tino.htm

Dominic

I think all the Palmer stuff is excellent

ecc83

As Danny says, provided you can be sure you are not driving the unloaded amp you can use a simple 5A DPDT* foot switch. I actually helped a guy on another forum with this. He just wanted a convenient way to swap amps into one cab and would ensure the non speaking amp would be off and even the guitar unplugged. 

In my experience you really have to go some to bugger an unloaded valve amp, although I understand there are some particularly feeble models? 

*Double pole because you don't want to combine two amp's grounds. 

Dave.

ICBM

ecc83 said:

In my experience you really have to go some to bugger an unloaded valve amp, although I understand there are some particularly feeble models?

Yep, don’t try this with a Marshall . They’re a bit prone to failure anyway - although I think the awful impedance selectors and generally crappy speaker cables used in the 70s have a large part to play in it with the old ones - but I would never switch one under load, if there’s even a momentary break in the signal path.

Even given that, most other amps are considerably less fragile. I would guess that at least three quarters of all the transformers I replaced over the last 40 years were in Marshalls - the problem persisted at least up to the JCM2000 series.