woah, vox ac30cc convert into 36 watt marshall??

[petesake]

hey there.

heres the thing. i have a friend who bought the new Vox AC30CC combo (with the warfs) and isn't happy with the overdrive of the amp or the way the amp responds to overdrive or distortion pedals... i have to agree with him. it just sounds a little too sterile for me. don't get me wrong- very decent sounding amp- but there's just something missing (like 'punch' and 'feeling'...those things). and since he wants more of a jcm 800 sound out of it, i thought i'd talk to you all.

it already has a chassis for 4x EL84, 3x 12AX7, 1x GZ34

i'm sure i would need new trannys and a bunch of other stuff, but what am i looking at as far as the circuit?

is there a way to go in a gut this sucker and make it respond more like a 36 watt marshall with big nuts on it, or what a 36(?) watt EL84 jcm800 would be?

[petesake]

i know this question is a lot like JohnnyCrash's question, but i was trying to be more specific about what i am looking for without hijacking his thread. is there another thread i should look at?

[JohnnyCrash]

Try a 36watt with a Cascaded gainstage from the "unused" channel's half of the triode.

I finished an 18 watt 6V6 with it and, while the switch doesn't work properly, I can get it in Cascaded mode regardless...

The extra gain is very cool. I will be adding this to my 36w amp as well now! Cranked gives you the big fat cream of overdriven power tubes, while an extra gainstage in the preamp gets you into more modern tones.

Most 18watters are aiming for the "original" classic sounding circuit. Most of em go for the older Greenbacks/etc.

On the other hand I'm a big Cult fan, and Guns and Roses, and ACDC... so I'm always looking for a tad more gain with speakers more like the V30

[petesake]

Thank you johnny crash!

[zaphod_phil]

You can turn a basic AC30 into a 36W pretty easily, with just a few resistor changes in the PI/power amp section, which will give it more of the Marshall grind. The existing transformers should be fine to start with, although it may be possible to improve somewhat on the stock OT. However, for more JCM800 style punch, he may also need to add fixed bias and negative feedback. If someone can post a schematic of the AC30CC, then we can figure out what tweaks the preamp may need to make it more pedal friendly.

[Rusty-Strings]

Not wishing to hi jack the thread but, I seen lots of posts talking about pedal friendly amp and I have experience of non pedal friendly amps so what does that mean technically?

[petesake]

phil,

he has the ac30cc that has a pcb inside. it's not a hand wired version. i was thinking maybe getting a 36 watt kit or sourcing parts for a ptp marshall build inside.

has anyone done a ptp build conversion on one of these amps? (vox AC30CC)

[playazinc]

No intentions of starting a big discussion here, but the fact that it is built on a PCB makes no difference in the sound. If anything it will actually quiet down the amp in terms of hum. I dont have that much experience with Vox circuits, but you may want to look into converting it to the vintage circuitry. That is where your sound difference will be.

[playazinc]

Whoops, I totally just misread your post.

If you really wanted to, then i dont think that converting it to a PTP 36w would pose much of a problem.

[rjgtr]

Just my .02. Convert it to a PTP. They are easier to work on. Plus you can use a classic Vox or Marshall circuit.

IMHO, the AC30CC doesn't sound like a vintage or recent AC30 handwired. They lost the magic. The Marshall handwired AC30s were awesome at nailing the original tone (but didn't fry the transformer). The new CC is trying to be too modern, IMO. They should have named it something else and voiced it a little differently. oh well...

While a properly designed PCB amp can be quiet, so can a PTP amp. Noise is a function of layout and design and it makes no difference whether the amp is built with a PCB or PTP. A badly laid out PTP can also be noisey. Each is just a method of building a circuit. In large production, PCBs have the advantage of a reproducable circuit that modern cost saving building methods can be applied to. In small production, the PTP is much more convenient and is easier to service.

[petesake]

thanks guys. i appreciate the feedback. im going to go ahead and gut it out and put in a 36 watt marshall inside the thing. thanks for your help!!

i understand the good/bads of ptp and pcb; i have a suuuper smooth class A amp built by a local that has a pcb board for the circuits, but everything is hooked up ptp. he's very smart. here's a pic of the inside of my amp: