Amp/Cab switcher patchbay box thingamajig

[rayc]

What about the Weber?
Are you going to buy another pair, run a loop between in the IN dial & the OUT dial or manually hook it up each time?

[Greg_L]

The thing I think maybe you're missing is nothing will ever be unplugged...

I'm not missing that. I don't believe you, though. Quoth the Greg, "Nevermore!", but then went on to say "...until I take some of this stuff to a gig". lol

(And try as we might to protect our gear, and tell the wife and the kids DON'T TOUCH THE GUITAR STUFF, there's always that snot-nosed tow-headed kid wandering off from his family who sneaks behind us and starts poking at the apparently irresistible tangle of amps and cables and power cords and shiny things while me and the band are playing a gig on the patio of the wine bar last week...good thing the rhythm guitarist caught the little pecker before he did any damage! *He* might unplug one of the cables or move the switch on your box; but I digress)


So, anyway, I realized there was a flaw in my suggestion, and you nailed it on the head here:

...But in my example there is always something plugged into every jack on the switcher box. So I'd need to make those connected but not selected amps see some kind of load in the event they try to get used without being selected. There's the rub. Actually, I don't need to do it because I won't make that mistake, but the potential is there and it's a neat brain exercise to figure it out.

Not being an EE myself (insert disclaimer/CYA here), I'm not sure if there's a solution to this problem. If there is, though, it might look like:

1a. connect the fake load to every input
1b. BUT wire the input selector switch so that it disconnects the fake load for the currently selected input
2a. connect the fake load to each output jack
2b. BUT wire the jack such that the fake load is disconnected

I'm fairly certain 2a/2b are achievable in the same way a "true bypass" (not sure about buffered) effect pedal is wired to keep the battery from draining. (http://www.tdpri.com/threads/can-someon ... in.622670/)

However, steps 1a/1b I'm not sure about, but are the trick to making this "foolproof". I have a friend (the rhythm guitarist, in fact) who is a (retired) EE; I'll ask him at our next rehearsal if there's a way to wire up jacks and a switch like this.



BTW, I know you'll do it however you want, and it will be fine, and you won't blow anything up. (Probably. Watch out for that wandering kid, though.) At this point, I'm only still thinking about it because it's an interesting intellectual problem...plus, if I ever built one myself, I'm less confident I wouldn't blow something up. When and if I build it, I can refer back here for the wiring diagram.

Yeah I don't know how to make the dummy load disappear when the switch selects an amp. And I'd like to keep this all passive - no power supplies, transformers or relays. The best I can come up with is to just have it in parallel. One dummy load with each amp's jack running to the dummy in parallel. The selected amp will "see" the dummy load and the cab load in parallel and that would be fine. I'd just have to halve the setting on the amps. 16 ohm dummy load and 16 ohm cab in parallel is 8 ohms. Any one of my amps can be set to 8 ohms. No big deal. And in the event that one of the amps accidentally be fired up without being connected to a cab through the switcher box, then the dummy load will be there. The 8 ohm set amp will see the 16 ohm dummy load, and that's no big deal.

I don't worry about gigs because I've never had anyone fiddle with my stuff. No one does that around here. Kids are not allowed at the places I play. This box thing wouldn't be at a gig anyway. This is strictly for home studio use.

[Greg_L]

What about the Weber?
Are you going to buy another pair, run a loop between in the IN dial & the OUT dial or manually hook it up each time?

The Weber will still have to be done manually. I mostly only use it behind the 73 Super Lead though, so it could just stay with that amp.

But you sparked an idea! I could very probably just incorporate all of this nonsense into the Weber box. It's basically empty inside that thing.

[Greg_L]

Dammit Greg, stop posting these lurid and lascivious pictures on this innocent forum! I totally did the cartoon wolf "aooooga!" thing here.

Lol. It's a nice room to walk into every day.

[Greg_L]

Oh look, someone already makes a fancy version. 8 amps x 8 cabs. Only $1500.
https://www.ampete-engineering.com/product/88s-studio/

Here's a 5x5 for $750.
http://www.krusekontrol.com/kruse_ampca ... her/unit_5

[rayc]

What about the Weber?
Are you going to buy another pair, run a loop between in the IN dial & the OUT dial or manually hook it up each time?

The Weber will still have to be done manually. I mostly only use it behind the 73 Super Lead though, so it could just stay with that amp.

But you sparked an idea! I could very probably just incorporate all of this nonsense into the Weber box. It's basically empty inside that thing.

Though it does get a little warm in there doesn't it? May need to manage hear dissipation if it's a heat sink.

[rayc]

Oh look, someone already makes a fancy version. 8 amps x 8 cabs. Only $1500.
https://www.ampete-engineering.com/product/88s-studio/
Here's a 5x5 for $750.
http://www.krusekontrol.com/kruse_ampca ... her/unit_5

Though I think this one has remote switching...
[BBvideo=560,315]https://www.youtube.com/watch?v=GcPOxlgirpA[/BBvideo]

[Greg_L]

Though it does get a little warm in there doesn't it? May need to manage hear dissipation if it's a heat sink.

It does get warm. Yup. Toasty, even. The attenuator is ventilated though. And I'm not sure it gets any hotter than the power tubes area in a 100w amp. Tubes run around 250 degrees maybe? US Farenheit degrees. That's like 120 C. Something like that. You can't grab a power tube after it's been running without getting 2nd degree burns. Amps live long lives with delicate stuff right next to boiling hot power tubes, so I assume a few extra jacks and wires would survive in a warm but ventilated attenuator box, if I were to try that route.

[Greg_L]

Though I think this one has remote switching...
[BBvideo=560,315]https://www.youtube.com/watch?v=GcPOxlgirpA[/BBvideo]

I could live with manual switching for $1,460 less dollars.

[einstein magoo]

I think you could simplify this by just turning on one amp at a time then you dont have to worry about a dummy load. One cab will alwYs be selected. You just neet to be sure r
Your switch is in amp B selection before powering up amp B. This is just for studio use and no one but the greg will be knob-dicking in there. The box will still eliminate all the re-patching and climbing behind the rig so you srill get that benefit.
With more than ome amp turned on i would be concerned about switching transients and thumps in the speaher as you rotate the amp knob from amd A to amp D for example.
Someone as concious of what he is doing as greg would not need to worry about blowing anything up.
Im certainly not smart enough to know this but seems to me if the amp is on but idle the chance of blowing up is slim. Yoi are not pushimg any real power out till you srtike a chord, etc.
Tell me im nuts and youre likely right. Butmreally, think about the switching thunk when rotating the amp knob?

Edit- Stupid I/pad spelling

[Lt. Bob]

Yeah I don't know how to make the dummy load disappear when the switch selects an amp.

find a double gang switch ..... there are pots for guitars that do two things at once anbd in stereo gear there are such things

[Lt. Bob]

I think you could simplify this by just turning on one amp at a time then you dont have to worry about a dummy load.

I think the point is to avoid having to do that.
he already does that basically and he'd like not to ..... the point, as I see it, is to be able to have all the amps on and switch between them and the cans without doing anything more.

At least that's what i'm getting

[Greg_L]

You're both sort of right. I will not just have every amp turned on at all times and ready to go. That's not the goal. That's a lot of unnecessary tube cooking. The goal is simply to not have to reach behind and around this wall of gear to swap cables around. That's all I'm really shooting for. I want them all connected at all times and all amp/cab combinations possible by turning a couple switches, but I don't want all of the amps on all of the time.

A "thump" when switching probably won't happen because there will be no signal being passed. And having amps simply turned on with no load is technically safe because again there is no signal being passed. The tubes and OT aren't doing anything. No danger. You can have an amp on with no load connected - especially in standby mode. In standby mode the tubes are lit and heated but nothing else is going on. The power coming in from the wall doesn't even make it to the filter caps in standby mode.

And the dummy load aspect was brought up by Tad and it's a good idea if I were ever to try to sell these things or build one for someone else, but for my own use it's not necessary. It's something good to figure out though. I was thinking about it today...even if I were to sell one, I'd simply say "don't be stupid". Lol. Use at your own risk. I'm not responsible for people doing it wrong. But I aint making these to sell, so whatever.

[WhiskeyJack]

Did the forum get bought out by popular mechanics while i was gone? Look at all this electrical engineering fuckery going on here.

[Bubba]

This is a great thought exercise Greg and it's been interesting reading through it. I'm sure it will be of real practical use to you if it ever gets made, too! I'm tending towards the same solution as Magoo mentioned - eg, only having one amp on at a time.

Then again, with a bit more imagination I can see the need or desire for a way to A/B a pair of setups, which would require both amps to be on. You don't want to be waiting for tubes to warm up or to be continually flicking the standby switches, you want an instantaneous comparison.

[Greg_L]

This is a great thought exercise Greg and it's been interesting reading through it. I'm sure it will be of real practical use to you if it ever gets made, too! I'm tending towards the same solution as Magoo mentioned - eg, only having one amp on at a time.

Then again, with a bit more imagination I can see the need or desire for a way to A/B a pair of setups, which would require both amps to be on. You don't want to be waiting for tubes to warm up or to be continually flicking the standby switches, you want an instantaneous comparison.

I could have the amps on and warmed up. Like I said before, amps can be on with no load connected. As long as they're not trying to amplify anything there's no danger with just being on. And if they're on standby, then it's really no big deal. A/B'ing would just be a matter of moving the guitar cable from on amp to another, switching the amp selector box, and flipping the amps on/off standby.

[JD01]

I did see a YouTube video recently where a guy had his space set up with a load of different heads and cabs and he just plugs into some sort of switching box and can have everything controlled from one place.

I think he was from a modern prog metal band though and I have no idea what his name is so I can't find the video again!

[Greg_L]

I did see a YouTube video recently where a guy had his space set up with a load of different heads and cabs and he just plugs into some sort of switching box and can have everything controlled from one place.

I think he was from a modern prog metal band though and I have no idea what his name is so I can't find the video again!

That Ampete thing I linked a few posts above allows for all of that. It's also the price of a high end amp all by itself.

[JD01]

I did see a YouTube video recently where a guy had his space set up with a load of different heads and cabs and he just plugs into some sort of switching box and can have everything controlled from one place.

I think he was from a modern prog metal band though and I have no idea what his name is so I can't find the video again!

That Ampete thing I linked a few posts above allows for all of that. It's also the price of a high end amp all by itself.

Could even be that system that he had wired up - the guy had about 10 or 15 really nice heads so I guess he needs something else handy to spend his cash on... I don't think he was too worried about needing a Kemper for tone options.

[Greg_L]

Could even be that system that he had wired up - the guy had about 10 or 15 really nice heads so I guess he needs something else handy to spend his cash on... I don't think he was too worried about needing a Kemper for tone options.

That Ampete switcher has it all covered. But it's powered. It needs to be plugged in. That means it has transformers and relay switching and maybe even a bunch of MOSFETs. It's an engineered piece of advanced electronic equipment. Mine will be a metal box with knobs built for under 50 bucks.