I changed my cab to stereo and..

Re: I changed my cab to stereo and..

The cab yes, but the amp, not necessary because it's a JSX and the speaker jacks on it are wired parallel just like any other tube head.

The cab is going to be wired series/parallel for 8 ohms total and 4 ohms each side. That's just how it works when using 4 x 8 ohm speakers in a 8 ohm cab. The second jack is (was) wired to the first in parallel. This is for daisy chaining it to another cab.

The cab was not wired for stereo operation to begin with. See here: http://www.avatarspeakers.com/wiring diagrams.htm

I believe what Avatar does is they wire each side of the cab to each jack and then connect both jacks together. Pics will confirm that but I believe that is how they come.

Looking at the wiring diagram and going by what you say about the jacks just being connected together, when he clipped the wires, he didn't do anything to the circuit, he just disconnected the 2nd jack. I really don't mean to argue, but if you look at that diagram, the 2 veritical speakers on the right are in series and the 2 on the left are in series. They are connected in parallel at the jack. If the other jack is just jumpered to the first jack, cutting those wires just took the 2nd one out of the circuit so it is just open. So, the speaker cable going from the amp to the 2nd jack is just an open and didn't change the impedance the amp saw, UNLESS, the amp has some internal wiring or switching jacks on the speaker outputs to know when multiple speaker jacks are being used (unlikely). In that case, it may have caused some kind of impedance mismatch to the amp which is messing with it. I still think the amp may be okay (if it's a new amp, the burning smell may have just been the new tubes), but I can't guarantee anything over the 'net.

As far as 4 - 8 ohm speakers always being split into 2 - 4 ohm stereo pairs, it could be 2 - 16 ohm pairs, it all depends on where/how you split them, it's possible to do either.
 
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Re: I changed my cab to stereo and..

I see what you're saying, devastone. And that may be the case. I was going by what I know as the "standard" when wiring cabs in series/parallel with 2 jacks (which usually indicates stereo option rather than biggypack in parallel).

Pics definitely would help, or just a "GOOD" sketch of the exact wiring of the cab.
 
Re: I changed my cab to stereo and..

He could also see if one jack powers all 4 speakers still, and the other powers none, as i first suggested. That would confirm that the second jack was just a jumper from the first.
And then the sketch / pictures so we can help him fix it.
 
Re: I changed my cab to stereo and..

when i post pics they never show up..

and when using 2 speakers at a time it is either the top 2 or the bottom 2 by the way, not the left or right 2.

im taking my head in today to see whats wrong with it. if its anything major im thinking about selling it for 500 USD and getting a dual recto. just a thought of mine though.. im going to the tech in about 20 minutes.
 
Re: I changed my cab to stereo and..

Unfortunately, there doesn't seem to be a standard wiring. I've had cabs that were 8 ohms but 16 ohms in stereo, I've also seen them switchable between 4 or 16 in mono and 8 per side in stereo. You also have to use switching jacks to do any of the mono/stereo jacks circuits. If I had been paying more attention when I read the first post, I would have realized that it was an Avatar cab, Dave only uses standard 2 conductor jacks, that's why you can only get mono or stereo cabs from him, not mono/stereo cabs, unless he has changed it recently.

Later,
Roger
 
Re: I changed my cab to stereo and..

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theres the wiring diagram for my amp!
 
Re: I changed my cab to stereo and..

when i post pics they never show up..

and when using 2 speakers at a time it is either the top 2 or the bottom 2 by the way, not the left or right 2.

im taking my head in today to see whats wrong with it. if its anything major im thinking about selling it for 500 USD and getting a dual recto. just a thought of mine though.. im going to the tech in about 20 minutes.
Ok, so we have one jack hooked to all 4 and then the second jack hooked to the first jack -OR- one jack hooked to the top 2 and the other jack hooked to the bottom 2? That's what I'm trying to get.

Hopefully nothing is wrong with the amp.

Unfortunately, there doesn't seem to be a standard wiring. I've had cabs that were 8 ohms but 16 ohms in stereo, I've also seen them switchable between 4 or 16 in mono and 8 per side in stereo. You also have to use switching jacks to do any of the mono/stereo jacks circuits. If I had been paying more attention when I read the first post, I would have realized that it was an Avatar cab, Dave only uses standard 2 conductor jacks, that's why you can only get mono or stereo cabs from him, not mono/stereo cabs, unless he has changed it recently.

Later,
Roger
The only cabs I've worked with went by the 16 ohms mono, 8 ohms per side stereo or just 8 ohms mono with a single jack. I know that doesn't make that wiring standard per se, but it is the most common.

On the 4x12 Special, there are two 1/4 inch in/out jacks (for daisy chaining with another speaker cab).
The 4x12 Custom is either mono or stereo as is the G412 Vintage.
 
Re: I changed my cab to stereo and..

WOW man, I've got NO idea what you did there...sounds like you don't either! LOL

My guess is that you might've wired the cab for 32 ohms, or worse...maybe 2ohms? Regardless, it's really, really bad for the tubes, output transformer and general health of the amp & cab...

Not to mention your tone!

Take the head & cab to a qualified tech or try to find someone in your area who really knows their stuff and have them help you out. Don't just have 'em "fix it" but ask questions and learn this stuff for yourself. It's not that hard...just simple multiplication & division for the most part.

Chances are good though that if everything is still passing signal, then nothing is "fried" yet...the keyword being "yet."

Good luck!
 
Re: I changed my cab to stereo and..

i posted the diagram.. did it show up? and erik.. after i clipped the 2 wires, one jack goes to the upper 2 speakers, and one jack goes to the bottom 2 speakers.
 
Re: I changed my cab to stereo and..

i posted the diagram.. did it show up? and erik.. after i clipped the 2 wires, one jack goes to the upper 2 speakers, and one jack goes to the bottom 2 speakers.

Yup, the pic shows but that diagram has one jack. ;) That's why I was asking to be 100% sure.

And THANK YOU! That's how I was thinking the jacks wired. With those 2 wires clipped, the top and bottom are either 4 ohms each pair or 16 ohms each pair. The best way to find out for sure is to plug a speaker cable in to one of them and measure the impedence with a meter (tip and sleeve) on the other end of the speaker cable. Or with the back of the cab open, just put the meter probes on both lugs of each jack and see what each pair reads.

If it's 4 ohms per pair, that's not good. Your amp saw 2 ohms (speaker jacks on amp are wired in parallel). If it's 16 ohms per pair, then your amp saw 8 ohms which is safe as long as the amp is switched to the 8 ohm setting. From looking at the diagram again, my guess is it's 16 per pair.

But since you can't run stereo anyway, well, we covered that already. ;)
 
Re: I changed my cab to stereo and..

alright, well before i use my cab again im gonna try and get it fixed up and just use the 8 ohm setting. its alot easier that way, while were on the topic.. when i got my cab i thought i was supposed to plug 2 speaker cables into it and had it like that the whole time, and when i turn my eq off now it sounds like ****, any idea what the problem would be?
 
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