Patchbay for Guitar Amp Speaker Cable???

[ltemma74]

I'm putting together a direct recording studio in my apartment. I have four different tube guitar amp heads that I record with. Because I cannot crank them in my apartment, I run the speaker cable from the amp heads directly into a Palmer PDI-03 and bypass the speaker cabinet. The Palmer is a load box (protects the amps' output transformers) and speaker simulator (advanced EQ) that simulates the sound of an SM57, more or less. The Palmer then sends a balanced signal out to the mixing board/computer interface/what have you. I prefer this to the sound of modeling devices.

I would like to use a patchbay to route my amps into the Palmer so I don't have to go behind the rack to plug and unplug amp inputs into the Palmer everytime I want to use a different amp.

My question is this -- since the Palmer accepts a speaker level signal, is there a special type of patchbay I would need to use? Should I use a standard TRS patchbay? Or will I mess up the patchbay or the signal? I'm willing to dedicate the patchbay to this use only, so I wouldn't be mixing and matching other non-speaker level signals in there (in case that's relevant). I'm relatively new to patchbays and different types of cables and levels and I'm confused about this!

I did a search and couldn't find an answer. Any advice or suggestions would be greatly appreciated. Thanks!

[paully]

I can't think of a reason not to use a regular balanced PB, with one caveat. I'd avoid the common ground point(if it's so wired), and use just the TR. Then mult the outputs(again TR only) to the Palmer. Oh, and make sure this is the only thing you use this PB for, and only one amp at a time is jacked up.

Best, Paul

[Jay Kahrs]

Yes... I have seen speaker level patchbays. Ampeg made one for a while but I don't know if it was available commercially... I don't think it was.

Frankly, I wouldn't try routing the output of a cranked tube amp through a passive TRS patchbay. There's a good chance that things could eventually fail & when they do, take an output transformer & possibly a lot more along for the ride. Typically load boxes & speaker level devices have overbuilt glass PCB's with big traces & are filled with 5 & 10 watt resistors... none of which are found in a $100 patchbay.

On the flip side, you could build a bay or have one built... but it'd be a LOT less money to just move the cable. Probably sound better too... less stuff in the path.

[ltemma74]

Thank you both for your input so far.

If anyone out there knows of a speaker level patchbay that can be purchased (new, used, custom built -- whatever), please let me know as I haven't been able to find one anywhere. Thanks!

[Jay Kahrs]

Try Jim & Dan at Sommatone, tell them what you want and that "Moose" sent you along. They'll build it... for a cost... but it'll be 110% solid. I've found their work to be 1st rate & they're more then fair... mega cool cats!

Sommatone

You could also try some of the custom box builders like CAE (Bob Bradshaw); Pete Cornish... maybe Coleman audio... start calling around!

One of the things I fear with this kind of setup is that the amps need to have a load on them when powered otherwise they'll blow up. $moked output transformer, power tube$, screen re$istor$, rectifier... Generally, bad thing$ happen.

Oh - There's the Radial "switchbone" or "ampbone" or whatever... pedal that takes two amps & switches between one cab.

Never tried that but generally the Radial stuff is good quality.

[TornadoTed]

I used Speakon connectors hard wired. I just brought a blank panel with 'D' holes punched in it.

I like using differnet connectors for differnet applications so there is no danger of accidently using a thin 1/4" audio patch cable to connect the speakers to the amps.

[Max_Power]

Originally Posted by Jay Kahrs

One of the things I fear with this kind of setup is that the amps need to have a load on them when powered otherwise they'll blow up. $moked output transformer, power tube$, screen re$istor$, rectifier... Generally, bad thing$ happen.

If you switch a powered (tube-)amp to standby, does it still need to have a load?

[Jay Kahrs]

Originally Posted by Max_Power

If you switch a powered (tube-)amp to standby, does it still need to have a load?

By all means... YES!!!


Now, some newer amps like a Rivera or Soldano, they'll generally withstand that kind of abuse... but I wouldn't dare try it with a '73 Superlead or a Blackface Fender... lest you wanna see some smoke.

That's why the whole thing seems pointless to me.

The amps need a load, or you have to switch them off anyway before patching.

I'm sure someone can build a speaker level bay that can generate a load for whichever amps aren't active... I mean, I KNOW it's possible because I've seen them... but generally speaking, talking about a passive patchbay; TRS or Speakon (better idea!) it's just one more layer of connections & doesn't really add anything beneficial in the long run.

[themaidsroom]

i would go to btx.com and buy a bunch of neutrik connectors and 12 gauge wire
and some panels for mounting the connectors and build a patch bay.


be well


- jack

[ltemma74]

Thanks for the leads. The Radial headbone switches between two amps only. CAE makes one for about $1,500 that allows you to switch between 4 or 5 amps and cabinets. There's also the Headtrip by sound sculpture.

I am aware that a load must be connected at all times and understand the potential dangers to the amp's output transformer if I screw up my connections and have an amp on without a load.

However, for me, it is much easier to switch an amp on/off + change the patchbay input than it is to switch an amp on/off + reach behind the rack and change the speaker inputs on the palmer. Maybe I'm just being too lazy over here...

[Max_Power]

Originally Posted by ltemma74

I have four different tube guitar amp heads that I record with.

Originally Posted by ltemma74

However, for me, it is much easier to switch an amp on/off + change the patchbay input than it is to switch an amp on/off + reach behind the rack and change the speaker inputs on the palmer.

There's another factor to consider if you choose to work with one load for 4 amps: short run cycles for each amp when auditioning them one after another.
Unless you know your amps well and know which one to fire up for tracking. (you probably do)

Vacuum tubes need some time to reach ideal operational temperature.
That's when they perform best sonically and mechanically.

When I switch on a high powered amp, be it solid state or vacuum tube, I always leave it on for at least half an hour to prevent stress on the components.

Someone with more knowledge about electronic engineering please correct me if I'm wrong.

[gforcrazy]

ltemma74, what did you end up doing/using for a solution for this? You described my situation to a "T"...I was either going to build a "custom" patchbay just for this use, or else fork over the cash for a CAE switcher at some point.

Essentially it totally comes down to convenience and I too am lazy

Any feedback/info on your outcome would be greatly appreciated.

Thanks!

[brianroth]

I have seen (and even built) patch panels using dual banana sockets for this sort of application. But, Speakons are another good choice...and I forget...are there Speakons with any sort of "normalling" contacts? There certainly is NOT any normalling with banana sockets.

As a general rule, every tooob guitar amp I've seen disconnects the B+ voltage from at least the power amp section when the "standby" switch is flipped. Example:

http://www.schematicheaven.com/fende...b763_schem.pdf

Hence, having a "speaker load" is not required **IF** the amp is in standby, and *IF** you don't accidentally flip standby off and then begin wailing away on the guitar without the required load.

And, if required/used, the "dummy loads" (8 or 4 or whatever Ohm resistors) have to have a high wattage rating to avoid burning up.

Another thing to notice on that Fender schemo (and I've seen the same thing on many other brands) is that if nothing is plugged into the "main" 1/4" speaker output, then the "normalling" contacts place a short across the transformer secondary. It is slightly better (but FAR from correct) for the output transformer to be driving into a 0 Ohm load than an open circuit to avoid arcing transformer windings, output tubes, tube sockets, etc.


Best,

Bri

[ripple_fx1]

I'd use the speakon or bananas in a rolled-edge panel - you can get the connectors mounted if you order from Horizon or similar pre-fab shop. Your mic/line patchbay is not a good choice because the switching jacks aren't rated for that much current - not to mention the potential for disaster. A metal quarter inch jack (plastic ones are junk, imho) in a metal panel will connect transformer windings and allow temporary patching shorts - speakon & bananas are insulated from the panel, don't allow patching shorts, and you can add a switch to each connector that'll let you drop in a dummy load and reduce the chance of knocking the headstock off the telecaster while reaching for a standyby switch.

[TAVD]

Look for an Ampeg SB2 speaker selector on ebay. They often sell for $20 or so.

[ltemma74]

Originally Posted by gforcrazy

ltemma74, what did you end up doing/using for a solution for this? You described my situation to a "T"...I was either going to build a "custom" patchbay just for this use, or else fork over the cash for a CAE switcher at some point.

Essentially it totally comes down to convenience and I too am lazy

Any feedback/info on your outcome would be greatly appreciated.

Thanks!

I never solved this issue. I now rent a studio where I mic everything. So I just leave my amps connected to speaker cabinets at all times. I'm interested in hearing about how others have addressed this though...

[drbob1]

I have one of the Ampeg selectors. Having a little trouble with wiring (one input seems distorted) but otherwise works great. Have 10 heads and 5 cabs hooked up right now. You can also use two cabs with one head...

[Wavebourn]

Buy as many Palmers' as you need, wire them to all your amps carefully and robustly, and use any patchbay after them without worrying about your amp heads.