AC30 questions

[miamidevice]

Hi all,

A few questions concerning my AC30...

1) Is it possible to add an additional speaker output jack to this fella? Will the OT accept multiple taps? I greatly prefer the sound of my marshall 4x12 to the stock greenbacks, but it would be nice to be able to run all 6 speakers at once.

2) Just how silly/dangerous/potentially component frying is it for me to bridge the normal and brilliant channels? I do like the extra burly sound the amp produces that way, but I am afraid of hurting the li'l fella. They're not exactly known for their robustness.

Thanks,
Michael

[???????]

Hi all,

A few questions concerning my AC30...

1) Is it possible to add an additional speaker output jack to this fella? Will the OT accept multiple taps? I greatly prefer the sound of my marshall 4x12 to the stock greenbacks, but it would be nice to be able to run all 6 speakers at once.

2) Just how silly/dangerous/potentially component frying is it for me to bridge the normal and brilliant channels? I do like the extra burly sound the amp produces that way, but I am afraid of hurting the li'l fella. They're not exactly known for their robustness.

Thanks,
Michael

What is the impedance of your cab? I will preface this by saying that while I'm pretty well-versed in Fender amps, I'm no vox expert. However, all of the old Fender amps and many others had over-spec'ed output transformers that would accept a 100% mismatch in impedance either direction. You will of course lose some efficiency but things shouldn't fry... HOWEVER, on a Vox i'm not sure if they're this bulletproof in that regard.

The "lack of robustness" of an AC-30 is a result of its poor ventilation. There is very little room for heat to escape, which is why they blow up. You will not hurt anything by bridging channels, it's unlikely that this will produce any more heat than just running it cranked up. You might consider getting a little clip-on battery powered fan and aiming it into the vents on top. This will extend your tube life and make your amp less prone to fry-age. When you bridge channels it is basically the same thing as using a "y" cord to run your guitar into both inputs at once. This will produce actually less signal than if you had two guitars plugged in, one into each channel... and since there are multiple inputs it was certainly designed to handle THAT. So bridging your channels isn't dangerous at all.

The extension speaker thing might be, however... i'd have to hear more details about the rated impedances of the loads in question. You might wanna talk to a vox guy about that, too.

[miamidevice]

What is the impedance of your cab? I will preface this by saying that while I'm pretty well-versed in Fender amps, I'm no vox expert. However, all of the old Fender amps and many others had over-spec'ed output transformers that would accept a 100% mismatch in impedance either direction. You will of course lose some efficiency but things shouldn't fry... HOWEVER, on a Vox i'm not sure if they're this bulletproof in that regard.

Both the extension cab and the stock speakers are rated at 16ohms, hence it's no problem to disconnect the stock speakers and run my 4x12 from the one speaker jack. I'm wondering if it's possible to wire up a second speaker output jack so I can run both the stock speakers and the ext. cab. I mean, it's not like I really ever *need* 6x12s, but it sure would be fun sometimes.

m.

[???????]

what are the impedances of each individual speaker? You could probably come up with a wiring scheme for them that was very close to 16 ohms total, but that might be more trouble than it's worth.