How much you looking to spend? That's the crucial question.
I was just around some kids at church today and one had a Line 6 Spider. It has lots of bells and whistles on it, but it lacks one very important thing - good tone. It had not guts, the feel when playing it was just lifeless. Avoid that one.
Don't be fooled by power ratings. I have a Fender (clone) Brownface Deluxe that I'm set up at about 18 watts and it will shatter eardrums if you turn it up. It's louder than the "120 watt" Line 6 Spider.
I've owned all of the following combos:
Fender Hot Rod Deluxe - excellent amp for the money, but I sold it (why?). My son owns one now and loves it. Gives great Fender clean sound and very organic overdrive. If you want crunch and Marshall tone, get a Marshall or get a Marshall emulating pedal. Used Hot Rod Deluxes can be had for $400. I recommend that worship guitarists start with Fender clean and work from there. Most don't listen.
Mesa F-50 - A really good amp, built very well, but noisy on the clean channel and the drive channel was not good at low to medium overdrive.
Laney VC-30 - I really liked this Vox-like amp. But it didn't work well for worship for me. I really thrive on the nice warm Fender cleans and it just didn't have them. The overdrive was nice and Vox-chimey, but for what I was doing, it didn't work. Still, I like Laneys a lot.
Mesa Subway Blues - I hate playing through 1x10" cabinets.
Fender Blues Junior - People use these in worship, but I couldn't make it work well for me. Too dark, even after the treble mods that I did. Great amp for crunch and overdrive, but just not enough gutsy clean for me.
Marshall JTM 60 - Kind of a nightmare. All of your overdrive comes from clipping diodes. Very complex inside with tons of cables and circuitboards. If you ever need repair, you will pay as much for the repair as you did for the amp.
Fender Deluxe Reverb Reissue - 80 lbs of "what?" No character, boring. Avoid, too heavy and dead sounding. A pot started to go bad and I opened it up to replace it and couldn't really get past all the complex layered circuit boards and cables. This is when I boxed it up, sold it and bought my hand-wired Allen amps (I built them from kits). Anything can be replaced inside of 30 minutes!
I now own these combos:
Allen Fender Brownface Deluxe clone - Superb country or rockin' American overdrive sounds. Good for punchy country riffs when you want pop and jump. I sometimes use it in worship, but the Vibrolux wins most days. I thought this amp would be my smaller "gigging" amp that I could lug to church, but it doesn't replace the Vibrolux.
Allen Fender Vibrolux Reverb clone - I love this amp and it's my main amp today. It handles blackface clean to rockin' country to Stones twangy rock very well. It's a lovely amp with a soul. I just played through it in church on my humbucker equipped AR300 today. It really hit the spot! It's a 2X10 and just sounds swell all the time.
I also recommend:
Fender Bassman Heads - Silverface versions of this classic amp can be had for $300-$500 on ebay. They are excellent choices with lots of guts and tone for days.
Go out and try a good tube amp. There are good ones out there for not a lot of $$. Check Vox, Orange, Egnater, etc.
I'm going to start from the same viewpoint from Stevo - how much do you want to spend, as this will largely determine how exotic you can go.
If you're currently using a Cube 30 then you're playing one of the better digital modelling amps available. You say you have a fairly small church (I assume you mean 80-120 people) so I'm surprised you need to mic it unless it really struggles to deliver a good clean at higher volumes. But anyway.
From the sound of things you want something both louder and better sounding. I presume you want essentially an amp with good cleans, and will then add a separate chorus & overdrive or distortion as required - or do you want something that will provide more options with separate channels?
You have the choice to go either valve or solid state.
Although SS has a bad reputation, there are some very good SS amps available, and if you're not to become a dedicated valve freak then you should check products from Tech 21, Polytone and Roland. The Polytones are essentially clean amps, used by a lot of Jazz pros, and will give a fat warmth to your tone. Tech 21 make the Trademark series of channel switching amps, are all analogue, and can cover a wide range of classic amp tones. They're made to a high standard (in NYC I believe) and I'd have thought something like a Trademark 60 would be right for you, with a second self-powered 1X12 cab if that's not loud enough. Finally, since you already have a Roland I'd look at the JC120, probably used, for a great classic amp tone.
I own a Trademark 60, and it's a nice amp that can fill a good size hall, yet is light enough to carry comfortably in one hand and can cover Jazz to EVH tones, if you set it up properly. Get the settings wrong (and the controls necessarily have a wide range of adjustment) and it can sound like a high quality Marshall MG30.
When it comes to valves I'd suggest , just as Stevo did, you'll need a lot less power. 15 watts will likely be plenty if you like natural overdrive, and 30 watts through a 2X12 could leave your front row with ringing ears (yes, I'm being serious). My Vox AC30 was too loud for every church except 600+ celebrations, and even then it was unfair to crank it for the sake of the rest of the worship team.
I have a few smaller amps too, most of which I've built myself. One of my faves is a 15 watt 2 channel job using 6V6s through an eminence Redfang. For similar tones (but with a single channel) I'd look at the Jet City Amplification 20 watt amp (JA20 IIRC). This is available as a combo or head and cab, and my inclination would be that this could do a lot of what you wanted, just possibly requiring a speaker swap to something alnico to get the best possible tone. There are some good youtube clips to get an idea of what it can do.
Another fave amp is a Marshall 18watt clone (from Ceriatone) that I have in a 1X12 open back combo. This is based on EL84s, but is a nice warm, toneful rock amp, rather than being jangly with a pop vibe like a Vox. The trem is also a nice feature, and it offers a very musical modulation - I would choose a trem over a TMB tone stack (also an option on 18watt clones). Once again, the speaker here is all important: for good rock tones then a Celestion G12H works well, but I personally prefer something a little smoother, and would recommend either another Redfang or a G12M heritage (20W). This amp doesn't have a master volume (although it does have 2 channels) so you'd need to get your overdrive/distortion from a pedal unless you can crank it a bit. Mine is quite a bit louder than a Vox 50 watt modeller, with a lot more cut in the open air.
I also used a couple of home-built single ended single channel amps running a single 6V6/6L6/EL34/6CA7/6550 depending on the tone and power I wanted (that covers 6 to 20 watts). You could get approximately similar tones using a THD univalve, if you'll experiment with different valves and speakers. However it may be a less convenient amp than you're used to, and you may not wish to fiddle so much or invest in different valves to make it sound the way you want.
Just one more comment: if you buy a head then do invest in speakers carefully to get the maximum benefit. It's an area that's often neglected, using budget cabs and speakers, and can make the most marvelous head sound a bit lifeless and naff. If you're not sure about speaker types and whether to go open or closed back (I prefer open back, as it makes the sound less congested and spread more close to the amp) then research the subject carefully. As a rule of thumb, Celestions seem to have more cut, edge, bite, while Eminence are more rounded, a little smoother on the top. However both companies make a wide range (especially eminence) and should be able to supply what you need. Do not consider 'food grade' speakers like the Rocket 50 from either line.
My Vox AC30 was too loud for every church except 600+ celebrations,
I assume you mean "when overdriven"
Would the Vox AC15 be roughly equivalent in tone and perhaps a good choice? I've been tempted more than once to buy one.
When run at low-ish volume (the sort of level suitable for about 150-200 people) it produced a clean, somewhat dryish tone - not particularly nice - probably with the volume control around the 2 out of 10 level. It didn't start to become responsive until around 4 - 4 1/2 out of 10, at which point it was still quite clean (with a single coil guitar) but starting to compress a little. It's quite a beamy amp, and at this level those getting caught in the focus of the sound would be unable to hear much else of a worship band. It wouldn't really start to overdrive until around the 6+ out of 10 level, at which point you're at rock band gigging levels.
I've happily used it side by side with Marshall 100 watt heads and half stacks, and it'll hold it's own. An older style AC30 is really surprisingly loud when given it's head - the Brian May special version (single master volume and 1 input only) is reckoned to be too loud to crank for all but the biggest gigs. When I was using it for rock I'd run a coloursound Tonebender fuzz on minimum fuzz as my overdrive and use a crybaby close to the max treble as a treble booster while plugged into the 'normal' channel. Without these it was ridiculously clean at silly high volumes.
The AC15 is a great amp, but tonally it's probably closer to a Marshall 18 watt (depending on speaker) than an AC30 (different preamp design in the older versions, although I think some of the reissues have been fitted with the top boost circuit).
What? The sag is evidence that you're running a tube rectifier. If you replace it with a solid state rectifier, you won't get any perceptible sag. I think there are a lot of myths about sag and Class of operation. Until I got my Vibrolux, every one of my amps was Class AB and none of them had any perceptible sag. You can simulate it with a drop resistor in just about any amp. Also, I've played a few champs and some Epiphone single-ended Class A amp and they have plenty of sag. It's almost all in the tube rectifier.
By the way - 90% of amps that are reputed to be Class A, even by their builders, are not Class A. Usually cathode bias is equated with Class A.
How does the 47k tail resistor in the phase inverter contribute to clean sustain?
There aren't enough Fenders in worship settings. I think people should consider it - they really work well.
The raspiness is usually due to Celestion blues - they can sound raspy and smooth at the same time (and no other speaker does this). My AC30 had greenbacks, which sound roughly similar, but with a harsher edge (in the 25 watt variety).
I loved the sound of warm thunder it produced when the volume was around 6ish and the front end is being pushed a bit, but unfortunately it couldn't really be used that way outside a band context. I remember playing a gig when I was 19 with it on a chair behind me, having gradually wound the volume up during the evening to around 8ish - my ears rang for several hours afterward, and I couldn't hear people talk at the post-gig party.
FWIW I know what chime is, but I don't hear it from most combinations of guitars & amps - I think it's very much a result of guitar/amp interaction, and probably requires a Rickenbacker 12 string. My amp certainly never produced chime with a strat.
I've always heard the raspiness in my EL-84 amps even without Celestion blues. More so in my Laney, but still even in my Blues Junior. Of course I might be using the wrong descriptor. It's about their character when clean (in my mind).
Now I'm savoring the memory of those NOS GE EL-84s that I still have - thinking of perhaps building a Brown Note kit and plugging them in. They were warm and toasty when overdriven.
You know toasty, right? It's sort of like jangle with fatness and warmth added in. It has a small relationship to crunch and thunk, but more on the creamy side.
Describing guitar amps is so much fun...
My EL84 based 18 watter is smooth, while my 6V6 based 15 watter is raspy (it has a conjugative smoothing switch on the back for more or less rasp) but a lot of that is down to speakers too.
Yes, it was there in the originals. But I question if it really contributed that much to the sound - people hype it a lot, but it's nothing really. If you look back at the golden era of Vox, - the greatest contribution to the tone would be cathode bias (easily demonstrated), speakers (alnico blue, who can argue), ef86 preamp tube (well known) and EL84 tubes. The EF86 tube is used in many "Vox clones" today to "create the magical vox tone" and you can really hear it.
It is true that Dick Denney chose to go without negative feedback when he designed the original AC-15 and it was a big part of Vox for years. But I question if they're doing it now. The newer amps are merely "based on the original AC30". Plus, I can't find anything to substantiate it and since to me, they really don't have the original sound any more, perhaps they've added in some negative feedback. I do know that the newer ones don't have EF86 preamp tubes that appeared in the AC30/4 that I can tell.
I suppose every design is different and will react differently to the lack of negative feedback, but I suspect that the difference in tone is mostly negligible. I think this because I have an Allen amp that has a negative feedback control on it and it's really nothing. When I built it, I called Dave Allen and told him how the build went and he asked me about the negative feedback control. He said it was somewhat of an experiment and didn't think it ended up doing all that much. Mind you, this is a 6G3 design instead of a Vox, but I would have thought it would have made more difference than it does given all the hype about amp designs that people throw around.