Unusual Tube Amp "No-Speaker Load" Question

[axemanvr]

I'm interested to see if any of you tube amp experts have heard of this one before...

The other day I was experimenting with matching different amps to different speakers. I hooked up my Fender Champion 600 (2010 reissue) to my Mesa Boogie 1x12 cab to see how it would sound.

Some time later I hooked up the same speaker cable to my Mesa Boogie TransAtlantic TA-15, then turned on the power (but left it on Standby while it warmed up). About a minute or two later I took it off Standby and strummed my guitar a couple times but heard no sound coming from the speaker - so I turned it off immediately!

After investigating the situation I discovered my bone-head mistake: The speaker output from my TA-15 was still plugged into the Speaker output of the Champion 600! Fortunately the Champion 600 was turned off at the time.

After reconnecting the TA-15 correctly I played it and noticed no difference in tone, etc, but it still makes me a little nervous, so of course I have a few questions regarding this:

First off, even if there wasn't an actual speaker load connected to the TA-15, can I at least assume that there was still some sort of load connected to it?

Secondly, is it fair to say that some load, even an incorrect one, is better than no load at all? And should I be concerned about damage to the TA-15 or did I dodge a bullet this time?

Lastly, is it possible to damage the Champion 600 in this way, even if it was turned off?

Thanks for any of your insights...

[Jazz P Bass]

I think that you will be just fine.
The output transformer on the Champ is a very low DC resistance.
It definitely presented a load as opposed to none at all.
As far as damage is concerned, I do not see it happening.

[pdf64]

Depending on how hard the champ OT secondary was driven, the OT primary circuit, being totally unloaded, may have been exposed to excessive voltages. But it's probably fine. Pete.

[J M Fahey]

You caught this bullet in mid air with your teeth.
Anyway , don't try your luck too often.

[kleuck]

What do you mean by "no load" ? Open circuit ?
An open circuit is by far more dangerous for an OT than a short-circuit, most output jacks are wired to provide a short-circuit when no speaker is connected.

[pdf64]

'What do you mean by "no load" ? Open circuit ?'
Yes.
In the scenario described in the OP, the champ 600 was off, as in not powered up. Therefore the output tube was not able to conduct, so the OT primary circuit was open.
Then the Champ secondary was driven by the TA-15. Pete.

[kleuck]

OK, sorry, i did not tell you that i'm french, so it's not always easy to figure precisely the "scenario" for me

[pdf64]

Wow, I would never have guessed - your English is very impressive!