Nailing a Vox ACx tone with a Roadster

[Gia]

Hello,

Yesterday I played a Vox AC50. The second channel, bright switch engaged, gave me exactly what I'm after for a particular project.

So far my attempts in nailing that tone haven't been that successful. It would be great if a roadster owner who knows vox AC amps very well could give me pointers how to get there.

So far I'm looking into the mesa's two first channels, with a treble booster. I can't get to the Vox's clarity/ crispyness. Too much mid range I guess.

Thanks

Jf

 

[BostonRedSox]

I can get close to the Vox AC 30 gainier sounds by using channel 2/Brit on my Roadter; using EL34s; setting the amp for light breakup and backing the bass off tremendously; and using a Fulltone OCD for some added color and harmonic breakup.

I don't have the settings with me at the moment, but it shouldn't be tough to figure out. I was very, very satisfied with my results. Also, I use the 18 volt adapter for the OCD.

 

[Gia]

Thanks for your input.

I had sort of dismissed the brit mode for this application. Mainly because I need the reverb.

I'll try to push the other modes of the second channel again and see (backing the bass a lot as you suggested- I did not try on my loop EQ). If it does not work, well I try the brit mode and get a reverb pedal for the loop.

 

[RR]

some of the Vox mojo tone comes from Celestion Blue$, so something to consider.

Substitute speakers of Celestion Blues include Weber Blue Dogs, Eminence Red Fangs.

 

[YellowJacket]

Many people grossly underestimate how much speaker / enclosure affects tone.

My suggestions.
1) 4 Yellow Jackets and EL-84s. This will give you the AC30 warmth and chime. I'd assume and AC50 is a class AB circuit with 2 EL-34s but I could be wrong about this. If this is the case, copy the settings people called for above.

2) Build / buy an open back 2 x 12 and load it with Celestion Alnico Blue / equivalents. Proper cabinetry and speakers will get you far closer to where you want to be, at least without buying the amp you want.

 

[94Tremoverb]

Yes, the AC50 is a Class AB combination-biased (ie partly fixed and partly cathode bias) 2-EL34 amp. Some versions are tube (GZ34) rectified, some are solid-state with a resistor or thermistor in series. It uses an ECC82 (12AU7) as the V1 preamp stage for both channels (although most people probably fit 12AX7s now), then a cathode-follower stage on each channel, which gives it very little gain, so almost all the distortion comes from the power stage.

It's actually a very unusual design and I would be surprised if a Mesa could really nail it, possibly even more so than with an AC30TB. It's also one of the few amps (although another example is the Dual Rectifier!) which is unstable with no load and will self-oscillate at high power if there is no cab connected - be careful if you're ever testing one... especially as there's no standby switch.

 

[Gia]

2nd channel, clean mode, EL34 with GZ 34, Maxon overdrive, EQ in the loop and it does the job.
Yellow jackets and a Vox cab would bring me even closer but its ok as it is.

Thanks a lot