Three words.......Impedance, impedance impedance.

The Fender will operate at 8 or 4 ohms...the Marshall is a 16 ohm cabinet...the amp is working twice as hard to produce the power you're asking it to produce. It can only get hot in order to do so. This would also explain the early breakup of the sound. STOP using this setup or risk taking the amp to the repair shop. I'm sure you have shortened the life of the tubes somewhat if not the transformer.

Isnt there a warning tag on the backplate of that amp saying not to operate it at any load other than the ones listed on the panel????

I think there is.

This advice is worth a LOT more than two cents................ :evil:

yikes! i won't do that anymore!

thanks for the response. i thought that the marshall cab was a 4ohm if powered in mono?

"A little smoking" is like "a little pregnant"...! Look at the back of the cabinet and see what Marshall states the impedance is! Also, did you use an UNSHIELDED cable to connect the cab? If not, and you used a regular old geetar cable, this will heat things up real fast and smoke shit. You CANNOT use a cable that's using its' shield as one of the conductors (like a typical guitar/unbalanced line cord) for speakers! You need to use a minimum of 16-gauge, 2-conductor, unshielded cable for a speaker hook-up. This is AC current coming out of the amp, not a 6K pick-up. If you can't tell what you have, go to your local GC and tell them you need a SPEAKER cable...NOW!!!!

Just to get into things... I feel a bit troubled by the fact that I'm contradicting Dave, BUT, for all I know about electronics, and considering the fact that the Deville (I read it's manual) can operate at 4ohm, it won't have any trouble in powering a 16ohm cabinet - actually, it'll be using LESS power when driving a higher impedance load. The problem arises actually only when using a lesser ohm load than the amp can provide (as in using a 4 ohm speaker on a amp that can operate on a minimum of 8 ohms). The fact that the speaker is 300W and the amp can provide a max. of 60W is a bit beyond me - for all I know, the 300W rating is the cab's maximum power, so the fact that that amp can provide only 60W shouldn't pose a threat to either the amp, nor the load (speaker)... But you should double check on this.

Link to some impedance/power FAQ:
from http://www.lalena.com/Audio/FAQ/Wiring/)

Also, in case of a normal guitar cable used instead of a speaker cable, the cable would get hot (because of exccessive current passing thorugh the cable because of not enough conductive surface - a blatant simplification of the fact, but close enough to reality), and eventually the amp would be in trouble. USE SPEAKER CABLES! :-)

Here's a pretty good resource I googled (it's for bass cabs, but impedance&power is still impedance&power, regardless of it's uses)
http://www.tunemybass.com/bass_amps/how_to_hook_up_heads_and_cabinets.html

Also, read page 7 of the Deville's manual for speaker wiring - you may have made a mistake on that:
http://www.fender.com/support/manuals/pdfs/manuals_elec/guitarpdf/Hot_Rod_DeVille.pdf

My guess is that you used the Marshall in the 4 ohm setting, and didn't insert an open plug in the "V" socket of the Deville (as instructed in the manual)... A somewhat informed assumption is that this forced the Deville to operate at 2ohms, below it's minimum impedance, which is a BIG nono (as pointed by my first URL).

I'm NOT an electronics guru, and this is my two cents' worth. Hope it helps.

OK, Dave, once again we have a musician who knows just enough about electronics to be dangerous. I guess that we have to explain to these guys that the DeVille is NOT a bass amp, 95% of which are SOLID-STATE output sections. A modern solid-state power amp section will drive many different loads other than the "nominal" stated output load. And, yes, that available power will vary according to the design of the amp and the load presented to it.
But the DeVille is a TUBE power amp, and, as such, has an OUTPUT TRANSFORMER (NOT present on the solid-state bass amps!). This transformer HAS to "see" a very specific load or it will heat up the windings inside the transformer, and start to smoke the wax-like material
and paper around said windings and between the plates. POOF!
And as far as the Marshall 1960A cabinet is concerned:
There are (2) jacks and a switch. Using the cabinet in MONO, you can select it to be a 16-ohm load or a 4-ohm load. This is done by taking each pair of 16-ohm speakers and wiring each pair in parallel to yield an 8-ohm load. Then the 4 and 16 ohm jacks select whether the 2 pairs are wired together in series (yielding a 16-ohm total), or in parallel (4 ohms). As an alternative, the cab may be operated as (2) speaker systems ("stereo"), using each of those (2) 8-ohm pairs independently.
SO, to use the 1960A as your ONLY speaker using ONE SPEAKER cable, is to use the "4 ohms" jack on the cab, and plugging it into the "external speaker" jack on the Deville, AND observing the amps' manual instructions and plugging in an 'open' 1/4" plug into the 'main' output jack. You know, there is a simpler way to do this...
Use the 1960A as 2, 8-ohm speakers, plugging each stereo half of the cab into the 2 speaker outputs on the DeVille...
And while we're on the subject, YES the cabinets rated power of 300 watts is due to the 75 watts/speaker MAXIMUM that they can handle before they blow. Pumping 60 watts into the cabinet is certainly OK to do.
Personally, I think that the original poster made 2 mistakes:
Not connecting the cabinet to the amp the way that the DeVille's manual says to do, and not using the proper cable. PEACE.

Hmm... My bad - didn't notice (temporary blindness/chronic sleep depravation, I assume, now that I re-read Dave's post) that the Deville is a tube amp, thus needing to be used at a specific impedance. :-(

If moonbaby was referring to me (my guess is the plural "guys" was aiming at me and the original poster), I do not seem to realize what the "bass amp" comment is all about - certainly, there are both bass and guitar amps that have output transformers which need to "see" a specific load. My bass cab hookup link was provided because I (mistakenly) assumed that the Deville is solid state amp (be it a guitar amp).

I'm sorry for providing false info - I'll definately try to be a bit more attentive next time. And, yes, PEACE is good. :-)

This site use to be informative, helpful and had a feel of people wanting to learn from more experienced people willing to help out.
Unfortunately it has gone to shit, because there are two or three reguraly posters who throw their hands in the air and say "f***king morons"(yes you can almost hear it) as soon as someone puts up a post that maybe inaccurate or amusingly ill informed.
Moonbaby,(and a few others) you obviously have a lot of knowledge and experience, can you please pass it on in a thoughtful and pleasent manner. Get off your high horse!!!

there has been some great info on this thread, thanks everyone.

first off, i was using a 12 gauge speaker cable, not an instrument cable.

so from what i'm reading, it looks as if it is OK to play the fender through the marshall as long as it is hooked up correctly. the safest and most correct way to do this would be to use BOTH the speaker outputs on the fender running to BOTH the inputs on the marshall, making the marshall run in 'stereo' mode at 8ohms, which is the impedence output on the fender - do i understand correctly?

now the question of the hour - i probably played the amp in the WRONG configuration for about half an hour. and it was pretty cranked. can one estimate how much damage was done to the amp? it's a fairly new amp, doesn't have much use out of it. how much life will i have left? and if i did in fact shorten the life of the transformer, how expensive is that to fix?

OK. First to DJ. What you're doing when you use the Marshall as (2) seperate systems is putting an 8-ohm load on each of the speaker jacks ('V' and 'W'), which are internally paralleled. These 2 loads yield a total of 4 ohms on the amp. This is good-see the "Fig.2" under the DeVille 410 speaker output listing in the operators manual that Mandachuva so thoughtfully posted in his reply. And go ahead and play the amp, just start it off gentle and see how it does.
To Mandachuva: You were quite insightful to provide said information, especially in regards to the Fender manual. And yes, there are some bass amps-the original Ampeg SVT tube head, the Mesa bass tube amps, and the Fender/Sunn Model T tube bass amp they used to make- that utilize tube power sections. A solid-state power amp (which is the design in MOST bass amps today, even those that use a tube preamp) doesn't use an output transformer. They are "direct-coupled", and the design of the unit lets them run different levels of power into different loads, with no transformer issues at low frequencies. Tube amps do not have this advantage.
And to all: I do not think that that anyone here is/was a "f***king moron".
I initially took offense with Mandachuva's opening statement, but after reading it through a couple of times, I think there was some misunderstanding in that regards. God knows I've opened up my mouth and let my size 11 in when I shouldn't have. My apologies.

Well I'm not offended.

It always helps to describe fairly completely the scenario one is asking about in the first place.

In my experience with Marshalls, the 1960 cabinets have all been 16ohms. This works well with a stack as you get 8 ohms with two of em and Marshalls all had FOUR speaker outs so you could make a 4 ohm load with FOUR cabinets. Also they provided you with an impedance matching shorting jack right next to the voltage plug.

Anybody wanta guess how loud a Marshall 100 watt with FOUR cabinets hooked up is????

So these newer cabinets are set up with two jacks at 8 ohms each??? And one cabinet with all the speakers flying gets you 4 ohms??? Doesnt make sense . What if you want a stack?

I must investigate this...

Now lets talk about a higher impedance than the recommended one and a tube amp. In response....Yes, the power from the amp will be cut in half. It wont like it at all and will respond with earlier breakup in its tone, it will produce heat as it struggles to develop its power curve, and will eventually eat itself up, especially when driven hard. The good news is it makes a certain sound when used like this and records really well as the noise floor becomes non-existant. I will, at times, use my Blues Jr.(which wants to see 8 ohms only) through a 16 ohm 4-12 cabinet. I play a 66 Fender Jaguar through it like this and it makes wonderful bed tracks . I just dont use it for long periods of time or very loud as it produces heat ....

i think its great that everybody who chimed in went through the trouble of research and posting links to support the points....except that 'Shindog' guy...

Hey, if you dont like it and you think its gone to sh** then dont come here....K? Its just that with such an opinion we (the rest who do like it) simply dont need to know how you're feeling. Its your business and your choice to feel that way and to make such statements in the middle of someone elses thread is a pathetic effort at getting some obviously much needed attention. Okay, theres your attention. Feel better?

Back to business. Maybe the resident guitar god will chime in here.....

" Tommy can you hear me?? "

Yes, DD, they DO have a kinda strange jack system on the 1960 cabs these days. I had to go online to check it out because I, too, thought that they were all simply 16 ohms. They must use some sort of switching jacks on them. You can still set them for 16 ohms, but you have the option of using one cab as a 4-ohm load, as well as (2) 8-ohm loads. For the price that they go for these days, they should plug themselves in, too.
I once saw this group called The Blue Cheer who had a wall of Marshall stacks with a Super Lead 100 head for every other 8x12 stack. I couldn't hear the dog barking for a week.

moonbaby wrote:
I once saw this group called The Blue Cheer who had a wall of Marshall stacks with a Super Lead 100 head for every other 8x12 stack. I couldn't hear the dog barking for a week.

Yes! Blue Cheer are awesome, they rock harder and play louder than any band today, and they have been doing it for allmost fourty years.

And, good luck with the cab, this stuff is beyond me.