Swart AST Pro...after 2 weeks

[Realfi]

Hi there Swart fans.

Some of you may have seen that I’ve posted a few bits and pieces on various threads about my new Swart AST Pro. Well, having had the amp for a couple of weeks now and having played it in a number of situations from home to semi acoustic jams to full volume stage mixes I thought it might be time to collect some thoughts on Michael’s latest.

The Swart AST Pro is the result of collaboration between Greg V and Swart amps. The main changes from the “stock” AST are:-


Deeper Cab w/Recessed Chassis for Protection
Chassis Elevated to accommodate Larger Speaker
Celestion G12H-30 ~ UK Version 55hz
Pro Rear Panel with Switchable External Speaker Output & Enlarged Port
Extra Large Rubber Feet
The “Pro” is also resplendent in the SST’s black lacquered tweed with gold piping and a contrasting speaker grill-very snappy indeed!

http://i54.photobucket.com/albums/g114/Realfi/ASTProandfamily.jpg

http://i54.photobucket.com/albums/g114/Realfi/pro_638.jpg

Plugging into the new baby at home to begin with was an interesting experience. I immediately noticed a bigger, broader louder clean sound. More bottom end yes, but more than that- a broader slightly less boxy tone. Big twangy tremolo riffs had more authority and sounded more polished than the stock AST but excursions up the neck perhaps had a little less compression and give.

At this volume the extra heft of the new speaker certainly made the amp feel a little stiffer. It really felt like it wanted to be driven a little harder especially with the speaker being so new in comparison to quite a few hours that I’d put into the Mojo in my stock AST.

In the big tracking room at Kingdom Studios my home away from home here in Perth I was able to get an idea of the tonality of the Pro at higher volumes. The Pro certainly was better at filling the corners of the large room and standing in front of the amp it was less directional than my previous AST. Once again I found that the AST Pro leans more on the bottom end and low mids and the treble voice while shifted a little lower was also harder with a little less sparkle. Normal AST-prettier…PRO-.badder!

My greenback loaded ’93 AC30 reissue and 65 Amps London 2 x 12” were on hand so it was a good opportunity to take advantage of the VERY convenient switchable speaker output on the new design back panel. Plugging into the London’s G12H30 Anniversary/Alnico Blue combination immediately confirmed my impressions of extended bass & low mid emphasis of the Pro’s onboard speaker. The amp sounded of course louder but also considerably brighter through the London’s cab.

When I plugged into my Vox cab I was reminded how much these amps love greenbacks. The engineer at the studio is trying to talk me out of using these particular speakers live anymore because they’re crisp, rich, full and singing but still noise and rattle free! This combination won the day hands down but I still had feelings that there was something missing.

During the next week a strange rattle developed which with Michael Swart’s assistance I was able to pin-point to a microphonic EH 6V6. I popped in a set of NOS Brimars I’d been saving for recording, problem solved and a slightly sweeter sound to boot-cool.

Poking around the back of the amp I suddenly remembered that I’d been running a 5Y3 rectifier in my first AST. I believe that Michael originally developed this circuit with the 5Y3 but lack of new tubes availability made him go in the GZ34 direction. Well, for me a 5Y3 is much nicer. An NOS Bendix revealed a little lower volume but a sweeter compression and breakup. The final touch was an NOS RFT 12AX7. Mike from KCA put me onto the RFT’s a while back. They’re a little darker than most 12AX7’s and suit me well being as a guy who lives 80% of the time on Tele bridge pickups.

In summary I’m really growing to like this amp.For those of you with stock AST’s I wouldn’t be in a hurry to throw out the Mojo speaker just yet. My gut tells me I slightly prefer the Mojo for grit, the Brit Celestion for cleans. Time will tell how much the new speaker softens up and I’d be interested to try some other things too.

All AST owners should jump at the new back panel mod which I believe can now be ordered. That speaker output is a must for avoiding burns and tube/cable damage running external cabs and although my cab is also a little deeper I’m convinced that the bigger port helps the amp breathe a bit better.

[Frankee]

Nice review. Mike is always hitting homers.

[darkarbiter7]

Cool.
I was going to get one of these, but a half priced Chicago Blues Box popped up used at a spectacular price, so I just scooped it up.
If I ever find myself with the right amount of dough, I'll probably order up an AST

[Realfi]

Nice review. Mike is always hitting homers.

I'm sure he knows no other way to play!

[sanhozay]

Thanks for the input on the new AST. I really love the look of the older style and after the mojo speaker breaks in I think it's a tough little beast to top. I did order the new back panel with engorged port and instantly put new tubes in mine but overall have been quite pleased with my amp from the start.

[Drowned Rabbit]

Excellent review! It sounds like Swart
addressed what few minor issues I had
with the original AST combo. That black
tweed is sexy as hell too.

[Realfi]

Thanks for the input on the new AST. I really love the look of the older style and after the mojo speaker breaks in I think it's a tough little beast to top. I did order the new back panel with engorged port and instantly put new tubes in mine but overall have been quite pleased with my amp from the start.

I think you'll love that new back panel sanhozay!

[markom89]

Thanks a bunch for the great, in depth review, Grant!
You've really "pushed me over the edge", so to speak, about this amp, and I feel I'll be getting one later this year. After all, I do miss my AST, so what better way to get back into the game than with an AST pro.
Thanks again!

[Realfi]

Thanks a bunch for the great, in depth review, Grant!
You've really "pushed me over the edge", so to speak, about this amp, and I feel I'll be getting one later this year. After all, I do miss my AST, so what better way to get back into the game than with an AST pro.
Thanks again!

I think you'd like it Marko...

[cg]

Great review, Grant! I just received the new back panel for my AST and it is worth it alone just for the convenience of swtiching to an external cabinet. I also like the larger port.

[Realfi]

Great review, Grant! I just received the new back panel for my AST and it is worth it alone just for the convenience of swtiching to an external cabinet. I also like the larger port.

So do you hear much difference with the larger port?

Our bass player purchased my first AST and he's unlikely to want to run an extension speaker but he is interested in opening up the tone a bit.

[cg]

So do you hear much difference with the larger port?

Our bass player purchased my first AST and he's unlikely to want to run an extension speaker but he is interested in opening up the tone a bit.

I think the new port does open things up a bit, but it's hard to tell when you don't have a 2nd amp right there for an A/B test.

[Peppy]

I think the new port does open things up a bit, but it's hard to tell when you don't have a 2nd amp right there for an A/B test.


My friend's store is supposed to be getting a PRO next week...we'll do a comparision with my friends' ASTs.

[arniez]

I have an AST and love everything about it except the bottom end. Does the port help or hurt the bottom?
ArnieZ

[markom89]

I just sent Michael an e-mail asking when it'd be available at dealers and some other questions. Also asked about potentially getting a 'custom' amp made. I think it'd be great if he could pull it off!

[cg]

I have an AST and love everything about it except the bottom end. Does the port help or hurt the bottom?
ArnieZ I think the port helps with the bottom end.

[Realfi]

I think the new port does open things up a bit, but it's hard to tell when you don't have a 2nd amp right there for an A/B test.

My friend's store is supposed to be getting a PRO next week...we'll do a comparision with my friends' ASTs.

I was more curious how much difference the new back panel made to the standard AST rather than the differences between the AST Pro and the AST-that comparison I've done.

[Peppy]

I was more curious how much difference the new back panel made to the standard AST rather than the differences between the AST Pro and the AST-that comparison I've done.

I was responding to another poster actually but that's cool...I'll post my findings for those that may be interested.

[Realfi]

I was responding to another poster actually but that's cool...I'll post my findings for those that may be interested.

Sorry Peppy..

Sure...of course love to hear what you hear!

[kodax]

So do you hear much difference with the larger port?

Our bass player purchased my first AST and he's unlikely to want to run an extension speaker but he is interested in opening up the tone a bit.
Does the AST works for bass also?

[Realfi]

Does the AST works for bass also?

Sorry I should have clarified that-he is also a guitar player. He plays Alt-country bass for us but Blues guitar at home where the Swart AST supplements his Super Reverb reissue.

[Andre357]

Are the cabinet sizes of the AST Pro and the Standard the same ?? Or is the cab itself bigger on the pro ??

I thought i read it was bigger in your original post, but a few people have posted they've ordered the " bigger ported back panel with extension speaker output mod "......and it's opened up the sound a bit so I'm unsure.

Also, if the PRO model is bigger overall what is the approximate size and weight difference ??

I'm very interested in obtaining an AST......the size and weight is what is attractive to me for some regular gigs I do ( small supper clubs/lounges where we set up in a very tight corner ), so your answers will be most appreciated.

Also, can you confirm your earlier thought that you get more clean headroom out of the AST PRO ?? Is it a big difference ? I'm a fan of low output pickups anyway....so I'm thinking the regular AST would give me a great cleanish sound......but I'm wondering if you can expand on that as well.

This thread has been most helpful by the way to a potential AST buyer like me !

[Realfi]

Are the cabinet sizes of the AST Pro and the Standard the same ?? Or is the cab itself bigger on the pro ??

I thought i read it was bigger in your original post, but a few people have posted they've ordered the " bigger ported back panel with extension speaker output mod "......and it's opened up the sound a bit so I'm unsure.

Also, if the PRO model is bigger overall what is the approximate size and weight difference ??

I'm very interested in obtaining an AST......the size and weight is what is attractive to me for some regular gigs I do ( small supper clubs/lounges where we set up in a very tight corner ), so your answers will be most appreciated.

Also, can you confirm your earlier thought that you get more clean headroom out of the AST PRO ?? Is it a big difference ? I'm a fan of low output pickups anyway....so I'm thinking the regular AST would give me a great cleanish sound......but I'm wondering if you can expand on that as well.

This thread has been most helpful by the way to a potential AST buyer like me !

The AST Pro is about 3/4" deeper and has the new back panel so adding the new back panel to a regular AST won't do quite the same thing but I'd say the differences may be subtle.

I'd say the main reason for the deeper cab was to make it easier to accommodate the UK G12H30 and also to recess the knobs on the back of the amp which were always a little prone to getting knocked. Interestingly though the new external/internal speaker switch does protrude a little!

With regard to the circuit it is no different but the British Celestion probably doesn't break up quite as early which I guess gives you a little more apparent headroom. Remember that you can swap in 6L6's for a little more headroom too.

I'd say if you need a little louder bigger cleans the Pro definitely lends itself to that.

[sanhozay]

I played my AST with the new back panel and it's a quick & easy but overall worthwhile upgrade. You will hear a bit more open cleans and fuller mids - the bass sounds the same overall but less restricted at bigger volumes. Very cool that you can switch cabs on the fly. I personally think the more significant change comes from an upgrade of the power, V1 & rectifier tubes. Most important is to just let that mojo speaker break in. It sounds a lot better once it does.

[redgecko]

Is the external speaker output 8 ohm only or can it be switched to different output impedance?

Thanks,
Paul

[Realfi]

I played my AST with the new back panel and it's a quick & easy but overall worthwhile upgrade. You will hear a bit more open cleans and fuller mids - the bass sounds the same overall but less restricted at bigger volumes. Very cool that you can switch cabs on the fly. I personally think the more significant change comes from an upgrade of the power, V1 & rectifier tubes. Most important is to just let that mojo speaker break in. It sounds a lot better once it does.

Interesting to hear your observations on the new back panel on the regular AST sanhozay.

+1 on the tubes. I much prefer my AST Pro with Bendix 5Y3, Brimar outputs and an RFT 12AX7 in V1. I felt that the rectifier and V1 actually made more difference tonally than the power tubes which was interesting.

[Andre357]

The AST Pro is about 3/4" deeper and has the new back panel so adding the new back panel to a regular AST won't do quite the same thing but I'd say the differences may be subtle.

I'd say the main reason for the deeper cab was to make it easier to accommodate the UK G12H30 and also to recess the knobs on the back of the amp which were always a little prone to getting knocked. Interestingly though the new external/internal speaker switch does protrude a little!

With regard to the circuit it is no different but the British Celestion probably doesn't break up quite as early which I guess gives you a little more apparent headroom. Remember that you can swap in 6L6's for a little more headroom too.

I'd say if you need a little louder bigger cleans the Pro definitely lends itself to that.

very helpful info ! what is the weight of the ast pro ?? Still light and easy to carry around ?

Thanks so Much !

[sanhozay]

Interesting to hear your observations on the new back panel on the regular AST sanhozay.

+1 on the tubes. I much prefer my AST Pro with Bendix 5Y3, Brimar outputs and an RFT 12AX7 in V1. I felt that the rectifier and V1 actually made more difference tonally than the power tubes which was interesting.

My power tubes only lasted a few weeks then pooped out. They sounded pretty good but nothing like the NOS stuff. I have a similar arrangement to yours!

[Andre357]

I just sent Michael an e-mail asking when it'd be available at dealers and some other questions. Also asked about potentially getting a 'custom' amp made. I think it'd be great if he could pull it off!


Has he emailed you back and told you when it would be available ?

[Peppy]

I was responding to another poster actually but that's cool...I'll post my findings for those that may be interested.

My findings are such: Dealer just got in the PRO (#11) yesterday, I was the first one to play it. A/Bed it against the regular AST. The PRO is what it is supposed to be...louder (quite noticeable), a bit more bass, less boxy-sounding, less mid-emphasis...a different tonal focus. Replacing the 6V6s with 6L6s made even a bit more of a difference, especially with respect to limiting compression. Comes in the unique looking "oxblood" color...no other way to describe it. I have it at the house right now trying it out.
But...there's almost always a but...I've done another A/B comparision and I think the PRO is going back to the store. I A/Bed it with my '57 Deluxe reissue (with a speaker change...a G12H30...the 75hz version...the PRO has the 55hz version). No contest. I had my son listen too but had him do it w/o knowing which amp was which. He consistently...no matter the tonal settings (dirt vs. clean, humbucking vs. single coil, o/d pedal)...picked the Deluxe, as did I. It's 12 watts overwhelmed the 18 watts of the PRO...noticeably louder, fuller, much more open-sounding, surprisingly more bottom end and in general just a better sounding amp. The PRO is an improvement over the regular AST...of course depending on specific tonal needs...but not quite enough of what I need, in general, for me to buy it.

[Andre357]

My findings are such: Dealer just got in the PRO (#11) yesterday, I was the first one to play it. A/Bed it against the regular AST. The PRO is what it is supposed to be...louder (quite noticeable), a bit more bass, less boxy-sounding, less mid-emphasis...a different tonal focus. Replacing the 6V6s with 6L6s made even a bit more of a difference, especially with respect to limiting compression. Comes in the unique looking "oxblood" color...no other way to describe it. I have it at the house right now trying it out.
But...there's almost always a but...I've done another A/B comparision and I think the PRO is going back to the store. I A/Bed it with my '57 Deluxe reissue (with a speaker change...a G12H30...the 75hz version...the PRO has the 55hz version). No contest. I had my son listen too but had him do it w/o knowing which amp was which. He consistently...no matter the tonal settings (dirt vs. clean, humbucking vs. single coil, o/d pedal)...picked the Deluxe, as did I. It's 12 watts overwhelmed the 18 watts of the PRO...noticeably louder, fuller, much more open-sounding, surprisingly more bottom end and in general just a better sounding amp. The PRO is an improvement over the regular AST...of course depending on specific tonal needs...but not quite enough of what I need, in general, for me to buy it.


Who's the dealer if you don't mind me asking ?? I may be interested in the one your returning :).....

[Peppy]

Who's the dealer if you don't mind me asking ?? I may be interested in the one your returning :).....

P.M. me.

[Realfi]

Hey guys.

Has anyone either taken delivery of or tried an AST Pro with a Celestion Blue yet?

I have to say I'm still finding the G12 Heritage a little stiff for my tastes.

[Peppy]

According to a phone conversation between my dealer and Michael Swart last week he...Michael Swart...is not sure about the blue alnico Celestion. Not sure if it will hold up. I asked if it would hold up at full volume and with a booster pedal...he can't really guarantee such. Since I last played the PRO with the G12 it opened up a good bit more and is less boxy...it's at my house.

[markom89]

If you end up trying it out w/ a blue, please let me know how it turns up as I'm seriously considering grabbing a pro in the fall. I miss my AST alot, and think a Pro would be great with the added features. Perhaps a Gold would fix the problem that the Blue has with the headroom and whatnot??? Or maybe one of the Tone Tubby speakers would go well with it... I'm curious. Also, anyone try some NOS glass in these? I had some blackplate NOS tubes and thought they sounded killer.

[Dave Orban]

Nice!

[archtopjazz]

Great review.
Should have one here Wednesday.

[Realfi]

If you end up trying it out w/ a blue, please let me know how it turns up as I'm seriously considering grabbing a pro in the fall. I miss my AST alot, and think a Pro would be great with the added features. Perhaps a Gold would fix the problem that the Blue has with the headroom and whatnot??? Or maybe one of the Tone Tubby speakers would go well with it... I'm curious. Also, anyone try some NOS glass in these? I had some blackplate NOS tubes and thought they sounded killer.

I have all NOS tubes in mine Marko, makes a LOT of difference, especially a NOS 5Y3 rectifier.

[markom89]

I have all NOS tubes in mine Marko, makes a LOT of difference, especially a NOS 5Y3 rectifier.

Didn't know that! Good to hear. I could definately tell a difference when those NOS tubes I had were in it... It's gonna' be a few months before I'm able to get one of these, but boy, I can't wait!

[Realfi]

According to a phone conversation between my dealer and Michael Swart last week he...Michael Swart...is not sure about the blue alnico Celestion. Not sure if it will hold up. I asked if it would hold up at full volume and with a booster pedal...he can't really guarantee such. Since I last played the PRO with the G12 it opened up a good bit more and is less boxy...it's at my house.

Yeah good point... full volume with an Alnico Blue could certainly be an issue.

I would agree the Heritage is loosening up after having put a lot of hours into it but it still feels like it wants to be pushed harder than the volume I normally run my AST at.

Perhaps a Gold would fix the problem that the Blue has with the headroom and whatnot???

Yeah perhaps a Gold would be safer. Swart are also receiving some Scumbacks to try.

[Peppy]

I would agree the Heritage is loosening up after having put a lot of hours into it but it still feels like it wants to be pushed harder than the volume I normally run my AST at.




It took several people playing through the one I bought to loosen it up. A bit better sounding when I tried it out two weeks later...probably at the store for three weeks total. Nearly a different amp, certainly much less "boxy".
Now, one good point you bring up is that indeed it seems like it wants to be cranked...vs. the regular AST and its Mojotone speaker, which I find when cranked gets a bit "brittle". The Celestion on the other hand has a bit better bass handling and of course the bigger cab and port help out as well. I guess what it comes down to is that the PRO wants to...and can...scream its lungs out.

[Realfi]

It took several people playing through the one I bought to loosen it up. A bit better sounding when I tried it out two weeks later...probably at the store for three weeks total. Nearly a different amp, certainly much less "boxy".
Now, one good point you bring up is that indeed it seems like it wants to be cranked...vs. the regular AST and its Mojotone speaker, which I find when cranked gets a bit "brittle". The Celestion on the other hand has a bit better bass handling and of course the bigger cab and port help out as well. I guess what it comes down to is that the PRO wants to...and can...scream its lungs out.



Peppy, I've had mine since two weeks before I started this thread, so what does that make it...I guess mid-late June I took delivery of it?

It's spent most of its life at volumes much higher than the way I'd run it for the small gigs that I've used AST's for. This has partly been because we've been recording but also due to an attempt to break in that Heritage which I'd heard could be a bit stiff. It hasn't been sitting around at home used on "2". It's been cranked, hit with Timmy's, Klons, RC Boosters, Fuzzes. My Teles (of course) but also the studios LP's and SG's etc. The AST attracts a fair bit of attention sitting in a studio of course so I've encouraged all-comers to have a play through it.

What I'm saying is that I suspect that my impression of the speaker is not just based on me not having played in the speaker to at least some degree. I still think in some ways the Pro/Heritage combination is clearly superior to the stock AST/Mojo combo but not in all ways or for all people.

I guess I'm thinking maybe another speaker may let me have my cake and eat it too-may not be possible of course but I'm pretty tempted to try a couple of other speakers I have in various amps before I give up on the concept.

[Peppy]

I still think in some ways the Pro/Heritage combination is clearly superior to the stock AST/Mojo combo but not in all ways or for all people.

I guess I'm thinking maybe another speaker may let me have my cake and eat it too-may not be possible of course but I'm pretty tempted to try a couple of other speakers I have in various amps before I give up on the concept.



I hear ya, I would really like to run a blue in mine. I still may. I think that would keep up the sensitivity rating but yet add a little more "grit"...for lack of a better term...vs. the cleaner G12. I ran one in my Brit-built AC15TBX for a few years and with a boost and no problem.

[sanhozay]

Oddly....I like my regular Swart cranked and at lower volumes. I play it pretty hard, so it's mostly screaming for more cowbell. Especially since the speaker broke in. Right now an amp I can't get enough of - and one that could not be more different than the AST - is the new Vox AC15 Heritage amps. Lately, it's been my favorite with every guitar I throw at it. If I didn't own the Vox I think I'd be less satisfied with the AST but for no other idiotic reason than the Swart isn’t as chimey. I don’t think it’s ever been called that so there’s no reason that I would want it to be, other than I love chimey amps. If I keep my expectations in check then the AST keeps me happy for hours. I think of the Swart as a bowl of butter and sweet potatoes with little bitty marshmallows sticking to them. Delish.

Where do you guys have your verb set when you crank it? Is it on at all?

[Realfi]

Oddly....I like my regular Swart cranked and at lower volumes. I play it pretty hard, so it's mostly screaming for more cowbell. Especially since the speaker broke in. Right now an amp I can't get enough of - and one that could not be more different than the AST - is the new Vox AC15 Heritage amps. Lately, it's been my favorite with every guitar I throw at it. If I didn't own the Vox I think I'd be less satisfied with the AST but for no other idiotic reason than the Swart isn’t as chimey. I don’t think it’s ever been called that so there’s no reason that I would want it to be, other than I love chimey amps. If I keep my expectations in check then the AST keeps me happy for hours. I think of the Swart as a bowl of butter and sweet potatoes with little bitty marshmallows sticking to them. Delish.

Where do you guys have your verb set when you crank it? Is it on at all?

'verb tends to get switched out for me for dirtier stuff unless I'm being deliberately crazy sanhozay...love it for clean atmospheric stuff though.

[Crazyquilt]

I had a ceramic Blue Dog in my first AST, and never really liked it. Too dark, and just sounded kind of dull. That being said, I have found very few cases where I do like the sound of a Blue (either a Cele or a Weber Blue Dog.) And I'd never put one in an AST - I can't imagine that speaker would survive for long.

OTOH, one of the reasons I'm MOST interested in the Pro is the overall warmer voicing (which has always been something I've wanted from my AST) and the ability to fit larger speakers in. I'm dying to try something alnico, like a 12A125A.

However, I've been really happy with my current AST. I might get a Scumback version of the Heritage in the Pro, but I'm pretty happy with the Weber Axis 12 in there now.

[sanhozay]

'verb tends to get switched out for me for dirtier stuff unless I'm being deliberately crazy sanhozay...love it for clean atmospheric stuff though.

Same here. So happy that the verb can be dialed out with a foot switch. Great, great amp. A bangin' design out of the gate. I do like the new panel but again the speaker break in and good tubes are the ticket. :drool

[Bloomfield fan]

I am seriously considering purchasing a Swart. Have any of you replaced the speaker in the original Atomic Space Tone? Or connected a longer speaker cable to the chassis and hooked up to another cabinet? I currently own a combo which has a large cabinet and a well broken in G12H30. Buying the original Space Tone and using my existing cabinet I would be able to use both the Mojotone and Celestion speakers.

[decay-o-caster]

I liked the Mojotone once it broke in, but I just put in a vintage Jensen P12P Alnico, and it sounds killer. I'm getting a lot of compliments on the tone with the Jensen, though it was never shabby before.

[Crazyquilt]

I liked the Mojotone once it broke in, but I just put in a vintage Jensen P12P Alnico, and it sounds killer. I'm getting a lot of compliments on the tone with the Jensen, though it was never shabby before.

Tell us more ... inquiring minds, etc.

Did you have any trouble fitting the speaker in? That cab is so tight that I'm always reluctant to buy an alnico speaker for it, and even ceramics I've had to be careful..

And, of course, ... can you give some description of how it sounds, relative to other speakers you've had in the AST?

[decay-o-caster]

I punted on putting the speaker in - I bought it a year or so ago, tried to install it myself, unscrewed everything I could find to unscrew, and still couldn't get the chassis out. So I gave it to Val King and said "Helllllllppppp!!!", and he did. There seems to be adequate room in there for it. I only got it back about a week or so ago, so I'm still figuring it out.

I've never seen anything about P12Ps anywhere on the interwebz, so I know nothing about it other than the evidence is it's a medium powered Alnico, which seems to make it right for that application. I'm guessing someone pulled it out of an old organ cab or something, I bought it sight unheard from some guy on the web. Need to try to remember who it was in case he turns up more of these things!

The sound... God I suck at this stuff, but all I can say is, it's very there. Solid, balanced, rings (but doesn't chime) sweetly across the entire spectrum, nothing too bright or dark about it. Like those really good, really expensive wind chimes - not the cheap brass ones? That kind of roundness to the tone. I don't even bother bringing a foot pedal for the AST anymore - I always have a little 'verb and some slow throb going, so no point in wasting time with the on-off switches for them. The speaker made an already killer amp into something really special. Perfect grab'n'go size and configuration too.

I've use a Keef-style Tele-style and a Jazzmaster-style with it, and the cleans and slightly dirties I've heard were just yummy. Sounds perfect with a Lovepedal Super6 for hair. I'm not a high-gain kinda guy in the gigs I use it for (sorta the R&B side of blues), so I haven't had a chance to make it scream, but I'll let you know when I do.

[Peppy]

I am seriously considering purchasing a Swart. Have any of you replaced the speaker in the original Atomic Space Tone? Or connected a longer speaker cable to the chassis and hooked up to another cabinet? I currently own a combo which has a large cabinet and a well broken in G12H30. Buying the original Space Tone and using my existing cabinet I would be able to use both the Mojotone and Celestion speakers.


My buddy is using my G12H30 (70th Anniversary) in his AST and so far does not want to go back to the Mojotone.

[Bloomfield fan]

Peppy, did your friend have any issues installing the G12H? I have heard it is a very tight fit.

[blues54]

Peppy, did your friend have any issues installing the G12H? I have heard it is a very tight fit.


I'm Peppy's friend. I have had my AST since Nov 07'. After trying out almost 15 amps at Make N Music in Chicago last Oct I was hooked on the Swart.

I had kept the mojotone in the AST since then. When mjichael came out with the AST Pro and the mofified back panel I jumped on it. I really like the way the amp sounded in the little bit bigger cab and the G12H Celestion. I have since installed a Celestion G12H in my AST with the modified bigger opening in the back panel.

Yes it was tight but if you are careful can make it fit fine. I love the way it sounds. When I ran 6L6's and pedals with the AST I got more speaker howl, or speaker distortion than I wanted. The G12H has really smoothed that out. Originally I wanted an SST 30 as my next amp. I've changed my thinking. I am going to but an AST Pro and run one amp with 6V6's and one with 6L6's. The perfect combo. I've done it with two AST's and there is nothing like it.

Take your time with the speaker. be patient. Make sure the side flanges of the chassis are true and square. You can make it fit.

Good luck, Blues 54

[Peppy]

Peppy, did your friend have any issues installing the G12H?

Just that he hasn't paid me. :D

[Nathan]

I'm gonna go ahead and ask if anyone here is kind enough to read what the stickers say on the tranformers (or even take pics)? I'm dying to know what iron he's using in the AST. The size and volume are just about PERFECT. It is bar none the biggest-sounding small amp with breakup at just the right spot. Verb and trem are GREAT too! Oh and the P12P is one excellent speaker -if you ever thought the P12N was a little too dark and the Q too bright, the P is the best of all the Jensens. It uses the 1 1/2" voice coil of the N but the magnet structure of a P12Q (they came in both curved and ribbed cones sometimes with a "whizzer" too). 18 watts handling as opposed to the N's 20 watts or the Q's 15. Some people say it's the holy grail of (american) guitar speakers but they have flown under the radar forever.

[andy888]

The port helps the bottom. i have the original AST and the new panel makes it sound a bit deeper, but i think its mostly due to my speaker swap, i put in a stephenson alnico blue clone, sounds excellent and really opened up the sound, made the mojotone sound bad by comparison.

[Peppy]

I'm gonna go ahead and ask if anyone here is kind enough to read what the stickers say on the tranformers (or even take pics)? I'm dying to know what iron he's using in the AST. The size and volume are just about PERFECT. It is bar none the biggest-sounding small amp with breakup at just the right spot.

The thread is about the AST-PRO. You mentioned the AST...all of your tone descriptors fit above but the PRO is also deeper, fuller sounding and less "focused" than the AST.

[jeff h]

I just bought the Atomic Space Tone mkII (w/matching 1x12) and the low end problem is solved. Wonderful amplifier.

[Peppy]

Fair enough, but the difference is a deeper cab and G12H. I think I'd love the PRO just as much but still can't afford that model either :0

From Swart:
• Deeper Cab w/Recessed Chassis for Protection
• Chassis Elevated to accommodate Larger Speaker
• Celestion G12H-30 ~ UK "Heritage" Version
• Celestion Blue 12 Alnico for **ULTIMATE TONE BEAST
• Rear Panel w/Switchable External Out & Enlarged Port

So a bit more in the PRO (two more changes) but if you can't afford it then it's all moot. Oh well, great amp. The AST is fine of course, I just like that extra "bit" I get with the PRO. In a fairly small-watt amp it can make a valid gigging difference.

[yayo]

I have my Swart MK II with Alnico Blue for more than 7 Months and i use it hard and with overdrive pedalls, and never had a problem with it.
IMO the Blue is the perfect match for the AST.
Sounds sweet,warm sparkling and open.

[timryan257]

I was looking around this thread for recommendations for something other than the stock Mojo in the original AST. However, all the talk about the larger port in the AST Pro got me wondering, so I just pulled the back panel off altogether on my AST. Makes a nice difference, at least here in the home studio. A little brighter, not as boxy, more chimey almost. Still not quite as open sounding as my Tweed Deluxe, which up till now always won the A/B battle with the AST, but now its much closer. I feel like I got a free upgrade to one of my favorite amps !

[GA20T]

What is the actual street price of the AST Pro in Canadian or US currency? What do they generally sell for used?

[Jazztone]

What is the actual street price of the AST Pro in Canadian or US currency? What do they generally sell for used?

$2150.00 American Greenbacks new

used??? Nobody sells an AST Pro!:)

[GA20T]

$2150.00 American Greenbacks new

used??? Nobody sells an AST Pro!:)

Thanks man.

[Nathan]

Hey can anybody tell me what the black panel is that the speaker is bolted to? It is probably there to hold the grill cloth, but I can't tell how thick it is or if it's plywood. It just seemed like an odd way to mount a speaker where the speaker mounts to the panel but the panel gets bolted to the baffle from the front. Thanks :drink

[ieso]

I just took possession of AST Pro SN #78 a few days ago.

I had really high expectations for an amp that cost more than $2000 but I gotta say.....

it really, really far exceeded my already high expectations :D

This thing is fantastic! Not boxy or small sounding at all. More than enough headroom but not too loud fully cranked. I have other great amps (including a Shiva) but playing though the swart is the most fun with a guitar I've had in a long time.

I have it setup in my studio to switch to an external Bogner 2x12 open back cab for even bigger sounds. Total amp heaven.