silly amp question (AC30)

[Indie P Bass]

Ok, I got this Vox AC30TB, from before they went Chinese (it's supposed to be an accurate reissue of the AC30TB/6) and I've got a footswitch jack on it, I never really thought anything of it, now I'm wondering: what the hell would a footswitch do on this amp?! There's no channel switching, distortion, boosts or anything that switches, other than the power and standby. I attempted to pull up a product manual online, but I can't really find anything. The best I can figure is it'll switch the trem on/off or switch the bright on/off, but I can't figure out how that'd work....

Any ideas?

 

[J Moose]

Re: silly amp question (AC30)

It switches the vibrato on & off. I've got the same amp w/Celestion Blues & it rules but it hasn't gotten a lot of use as of late. Great amp... but LOUD! I'll plug into the Brillent channel & jump it to normal... crank the volumes to about half and get the rest of my gain from stompboxes. Amazing. Nothing else like it... but it's sooooo LOUD...

 

[Indie P Bass]

Re: silly amp question (AC30)

yeah, for 30watts, this thing really cranks. I generally only run to the brilliant, but what's this jumping nonsense? how does that work out?

 

[James Rock]

Re: silly amp question (AC30)

Well jumping it (as in going from one input to the other in the same way u jump plexi's) means you can mix the tone of the darker bassier flubbier normal channel with the tighter bright brilliant channel.

 

[J Moose]

Re: silly amp question (AC30)

Yup. Each channel has two inputs... plug into one channel and then take a patch cable and go from the input you're not plugged into to one of the other channel inputs... blend & EQ to taste. I prefer to use the brilliant channel as my base since that's the one with the bass & treble control. Normal & vibrato only have the "cut" for EQ.

 

[LesStrat]

Re: silly amp question (AC30)

:cool3:

 

[Indie P Bass]

Re: silly amp question (AC30)

I really like this patching thing. I get ALOT more tones out of the amp that way. Plugging into the hot or normal and then patching to the hot or normal in differant combos can give me a cooler tone, a brighter tone... I like it. Makes the amp more versatile. I'm suprised this info isn't more readily available on the internet (I googled, didn't find anything). I've had this amp for 5 or 6 years and JUST NOW learned this, I just gotta get some better patch cables... this adds a whole lot of hum to the amp.

Speaking of hum:


It seems that the tremelo channel bleeds into the brilliant channel. I don't know exactly how to describe it, but I'll try. There's a sort of... thumping that gets much more pronounced as I turn the volume up. Below about 1/4 volume, it's barely noticeable, but above that it gets pretty bad. I was wondering if there's any known quick fixes for this (didn't find any on googles) or if it's something that I just have to leave with (please, don't tell me that) or if I should take it to a tech. I'm also curious what would cause this.

PS. it's a mid-late nineties AC30/6 TB, it's pre Korg buyout, but post Marshall Buyout. I've got a pick of the control panel to give you an idea.

that's the amp itself:

this is what the control panel consists of:

 

[glassman]

Re: silly amp question (AC30)

It sounds like your Vib/Trem is bleeding through...switch it off with a footswitch and it will go away. One way to make certain this is what you are hearing is to see if the speed of the thumping changes as you adjust the "speed" control. If so...this is nornal operation.

 

[ericmeyer4]

Re: silly amp question (AC30)

Are you running your acoustics through it? How does that sounds?

Also what does your sticker say in the avatar?

 

[Indie P Bass]

Re: silly amp question (AC30)

Are you running your acoustics through it? How does that sounds?

Also what does your sticker say in the avatar?

The acoustics sound terrible, not a very useable tone.

The sticker says, "This Machine Kills Facists"

and I know it's the tremelo bleeding through, but I'm not sure if the footswitch will kill it. It's not like the tremelo is active on my brilliant channel, it's just a thumping hum under the tone. I just gotta get my hands on a footswitch.

 

[J Moose]

Re: silly amp question (AC30)

The sticker says, "This Machine Kills Facists"

and I know it's the tremelo bleeding through, but I'm not sure if the footswitch will kill it. It's not like the tremelo is active on my brilliant channel, it's just a thumping hum under the tone.

Mmmk there Woody Guthrie... hahaha

Interestingly enough... I live a little over a mile away as the crow flies from Greystone Park, if that picks up on your radar. It should...

Anyway...

There is no pre/post Korg era... Korg & Marshall were under the same umbrella at the time these amps were made.

Every AC30 is kinda noisy... but the noise doesn't really, or at least shouldn't change in level. As the volume goes up, the volume of the hiss/noise should stay "about" the same. The thumping you hear could be a few things... coupling capacitors, or possibly tubes. AC30's run hot and chew through the suckers. Not just the older ones but these '90s issues too, though not quite as badly since the vents are larger & ventilation is improved over the '60s era.

I had a really weird problem with mine earlier this year and couldn't solve it. Had the amp on the bench probing around, calling techs, nobody knew what the source was. Turned out to be a failing preamp tube that only died when I put it in another amp.

Does the 'speed' of the thump change when you adjust the vibrato controls? If it doesn't then it's not the channel but something else entirely. Without the footswitch the vibrato is always on, just plug in. If the volume for that channel is all the way down, then it's entirely out of the circuit... but the tubes won't be out of the circuit.

Jumping the channels is pretty badass huh?

Old-skool cats know old-skool amps...

Those new 'custom classics' aren't the same...

 

[LunaticFringe]

Re: silly amp question (AC30)

The acoustics sound terrible, not a very useable tone.

The sticker says, "This Machine Kills Facists"

and I know it's the tremelo bleeding through, but I'm not sure if the footswitch will kill it. It's not like the tremelo is active on my brilliant channel, it's just a thumping hum under the tone. I just gotta get my hands on a footswitch.

Anti-Flag eh? Gotta ask, where in the hell did you get this amp?

 

[Indie P Bass]

Re: silly amp question (AC30)

Anti-Flag eh? Gotta ask, where in the hell did you get this amp?

antiflag? Where in the hell did you get anti-flag from? In anycase, I picked this amp up from a shop in chicago about 5 years ago. Since then, the only work that needed to be done was a retubing, but this amp has been hauled all up and down the chicago-land area and central and northern illinois.

As for the "thumping," I know it has something to do with the tremelo, as playing with the tremelo knobs effects the rate and intensity of the thump, and it only happens on the bright channel, not the normal channel.

Now, I picked up a 2 button footswitch, which should work with the AC30, just... the second bottom will do nothing at all. And playing around with my marshall (I'm at my parent's house, the vox is at my place down south), I find that after 3 months of non-use, almost all the knobs on the marshall are crackly and poppy...

it's been a fun time for amps with me.

But, I know the noise from the vox has something to do with the tremelo channel. Any other noise, I cleaned up using planet waves and monster cables.

 

[Pink Unicorn Horsey]

Re: silly amp question (AC30)

Keep in mind that, with the AC30, the volume knobs are interactive. You should experiment with the knobs of even those channels you're not plugged into.

- Keith

 

[Indie P Bass]

Re: silly amp question (AC30)

Keep in mind that, with the AC30, the volume knobs are interactive. You should experiment with the knobs of even those channels you're not plugged into.

- Keith

if that were the case, I doubt I've be posting here. I tried, I thought maybe the volume pot for the trem channel bled into the other channels when it was at 0 (what an odd thought, but when you're talking AC30's, any little tweak or thought might help), and... no. No matter what any knob the amp is set at, the thumping in the rhythm of the tremelo persists.

 

[James Rock]

Re: silly amp question (AC30)

Dad's got a late sixties AC30 and yes it is noisy they make a lot of noise as being non master volumes any noise created after the preamp volume comes through the power amp section. Which is why thumping occurs on no volume its just the sound of the background noise going through the tremolo similar happens with old phasers even if the guitar volume is on zero you can hear the phasing of white noise inherent in either the pedal of further down the chain.

 

[Pink Unicorn Horsey]

Re: silly amp question (AC30)

My AC30 is probably my favorite amp, but it bugs me that it's by far the noisiest. Makes me wonder if there's an amp out there that does everything the AC30 does, but more quietly.

- Keith

 

[ericmeyer4]

Re: silly amp question (AC30)

My AC30 is probably my favorite amp, but it bugs me that it's by far the noisiest. Makes me wonder if there's an amp out there that does everything the AC30 does, but more quietly.

- Keith

What about some Dr. Z amps? They are suppose to have a pretty good AC30 sounds.

 

[Indie P Bass]

Re: silly amp question (AC30)

Don't Laney, Bogner, Dr. Z and THD all make AC30 clones that have cleaner sounds? IIRC, they're more expensive than the actual AC30's. The new AC30's are quieter than the older ones, they just sound a little more... sterile to me, though. The CC models are quiet, as are the new HW models (which actually sounds just... fantastic). It's the older models that are REALLY noisey.

I've heard of ways to quiet them, but they're all very nonimal differances and take a lot of work.

But yeah, I love the way my AC30 sounds, I just hate all the noise.

PS. I'll let you guys know whether or not the footswitch helps in about 3 hours. I've gotta drive back down to Normal from my parents' house. Just took my Marshall into a shop, 3 of the tone controls need replacin' and the rest got a good cleaning and are fine... what a fun time for my amps!

edit: I just got back to normal, and the footswitch does solve the annoying tremelo issue, so, that's a good thing. Now I just gotta find a way to get the money for gettin' my marshall fixed.

 

[J Moose]

Re: silly amp question (AC30)

Good to hear 'ya got the pulsing noise sorted out...

And 'ya know... the AC30's are noisy, but it's never ever bugged me 'cause once I start playing the noise disappears! Maybe ya'll need to turn it up more... hahaha

I use an attenuator with mine around the house & in small clubs... otherwise I go without one and turn it sidewerds so it blows across the stage & not at the audience...