Kustom Tube 12 Combo

Well, as we all know, this little guy has only one 12AX7 tube, in the clean channel preamp, and the rest is all solid-state. So, basically the clean channel is a hybrid, and the dirt channel is solid-state diode clipping. Did this stop me from purchasing it? Nah. After spotting the Tube 12 in a pawn shop amongst a bunch of other little amps (primarily the TransTube Peavey stuff), I read all the reviews here on the Tube 12, went back to the store and tried it out. I was actually a bit surprised by the clean tone, and walked out with it for 40 bucks.

Originally I thought that this might make a nice little home practice amp and be another amp to bring to studio dates, since I still don't (sob) have a Valve Junior. I played with it at home first, and I do agree with many other reviewers that the clean tone is very good, notes sing wonderfully at loud volumes with the tube nice and warm. I also agree that the dirty tone is lacking; in fact it is not that great at all. I was able to dial in a decent sound for practicing at home, but certainly no distortion tone I would use live or in the studio. I got a wild hair and brought it to a gig to use in conjunction with my '65 Bandmaster and I was pleasantly surprised at how good the little bugger sounded with my live pedals and effects going through it. Definately couldn't be used on it's own live, but it did sound very, very good. Gotta give the little Celestion Super 8 some credit, it didn't fart out and, while a bit boxy (duh-it's an 8" speaker in a tiny cabinet!), it gave out very good guitar tone. I kind of regretted not bringing the little sucker with me to a studio date the previous day after hearing it live with my effects. Running good dirt pedals throught the clean channel at a loud volume sounds quite good. It may be a little beginner practice amp, but the clean channel shines.

I got it for 40 bucks, I think it can take what I can give.

I've been playing almost 25 years now, been gigging a long time. I play mainly strats through my Bandmaster and a 4-10 Peavey cab with some effects. I've had some little practice amps before, and I am fairly impressed with the Tube 12. No, it's not a '60's Champ. Heck, it's not even a Valve Junior, but I like it. Certainly not an amp to give a 10 to, as it has it's limitations and the dirt channel sounds are pretty uglynastygrossickypoopy for the most part, but after blasting it live in the clean channel with a Bad Monkey and occasionally an old Shredmaster, at the same time as my Bandmaster, I was shaking my head, grabbing musicians on break going, "Hey, you have to hear this little bastard, come here!" "BRANNNNGGG!!!" Yep, crank up the clean channel, hit it hard with a good overdrive or distortion pedal and this thing is more than just acceptable.

Not too much to speak of. I really can't tell you what the 'SHIFT' switch does..but who cares the amp sounds great without it. It would be close to the perfect little practice amp if it had a reverb tank on ot, and 2 foot-switchable channels. But hey it is a bedroom blaster!!!

I use a Epi Les Paul Standard, Fender Strat H/S/S(Dimarzio Tone Zone, and Duncan Stacks for SC's), Fender Tele (Lil' 59 / 1/4 Pounder) and a few others...but that is besides the point. It is a nice sounding little practice amp. I did swap out the tube for a JJ/Tesla ECC 803S and that made a WORLD of difference, nice warm PHAT tone. I tried the JJ/Tesla ECC83S and it sucked (might have got a bad tube or something). But the 803 ROCKS...can't recommend this combo enough. The amp is easy to swap the tube out in 4 screws and your done (UNPLUG IT FIRST!!!) Kind of want to try a Tung-Sol in it. ANYWAYS for what this amp is meant for it sounds amazing!! I haven't tried it lined out or anything fancy like that, I have a Marshall AVT50 and a 66 Super Reverb (the real thing baby) for shaking my eardrums into sonic orgasms. This thing sits in my living room for me to noodle on while I watch TV. But it does that very well.

Good so far...like I said I have other amps I jam and gig with...but you know this thing does have some decent headroom...I might take it along one night, just to see if it can keep up with the whole crew...it would be close...definitly wouldn't gig with it though.

Never used it....

For a little practice amp at this price I would give it a 9, only because my brother has a VOX AD30VT, a little bigger and more expensive, but a nicer amp...I would like to try the VOX AD15VT...more "bells and whistles", but twice the price...This little Kustom is definitly allright. Makes me want to try out some of their bigger amps. I think amp manufacturers should put a little more time and R&D into their little practice amps...having a good small beginner amp will lead to brand loyalty. My first amp was a little Peavey (can't even remeber what kind), I hated it and have never owned one since, never even tried one. My first "real" amp was my 66 Fender Super Reverb (had it for over 20 years now...still going STRONG) but I have tried countless little fender amps and think they have all sucked (although the little G-Dec has intrigued me). Same with low watt Marshall's. Come on boys do a little R&D this is a HUGE market...under $200 tube pre-amp, real reverb tank, 2 channels (footswitchable), external speaker jack, maybe some effects...is that too much to ask for???

Bought this amp new last year to supplement my other amps (newer Traynor YCV40, 1964 Gibson Falcon) as a quiet home practice amp. I use the headphone out into an Alesis mixer for home studio playing/recording.

Good features for the price. OK sounds. Even though it's got a 12AX7 in the preamp section, make no mistake, this is a solid state amp. Not a bad one - IMO, better than other SS Traynors and Fenders I have owned over the years.

I wish it had built-in reverb.

I'm playing: a Fender Strat (3xsinglecoil), an Epiphone Les Paul '56 Goldtop RI (2xP90's), a Fender Deluxe Active Jazz Bass. I play classic rock and blues mostly with a bit of funk and R&B in there...

My guitar signal chain is guitar > Boss TU-2 tuner > Voodoo Labs Sparkle Drive > Voodoo Labs Microvibe > Electro-Harmonix Deluxe Memory Man > amp. Bass > TU-2 > amp.

Stock with no effects in front, the Tube 12 sounds sterile and weak on either the clean or dirty channels, 12AX7 preamp tube or not. What do you want with a small solid state box and an 8" speaker? It can get loud, but that's when I killed the speaker.

Decent clean sound with my Sparkle Drive (using clean boost), but not what I'd call tube warm. I have been running the headphone out into my Alesis mixer to "warmify" the sound and to add reverb using the headphone out of the mixer. I have plugged this baby into a crappy old 1x15 bass cab that I have sitting around and can get a rich Marshall-like gainy sound with the gain channel kicked in. Nice. I could probably bring this amp, cab and effects setup to a gig and sound not too bad. But why? I've got a nice portable 40W combo to do that...

Here's a crazy thing: I plugged my BASS into this thing and sent it through the 1x15 cab via the speaker out (bypassing the internal speaker) Not only did I get a nice warm, thick "vintagy" bass tone, it got loud. LOUD, I say! I brought this setup to band practice and, believe it or not, it was powerful enough to hang with a loud blues/rock band playing at volume. I have half a mind to bring this to a gig and see how it works out. It's probably a function of the active electronics on my bass, but wow!

I'm giving this a 6 based on the fact that this is a budget practice combo amp and what do you really expect....except, it absolutely NEEDS a better speaker/cab setup to really rock. And rock it does - for guitar OR bass. Who'da thunk?

I blew the speaker in less than a week. But since I mostly play it via the headphone or speaker out, no loss. It's dead simple to find and install another beter quality speaker, if I really wanted to.

Otherwise, it seems pretty indestructible...

Never bothered to call....

Been playing 25 years as a hobby. Gigged my fair share over the years in rock, blues and rockabilly bands as a guitarist and bassist. Owned a crapload of gear over the years, lots of it cheap and crappy. Finally have some decent gig-worthy gear yet not overstating my level of talent.

I have thought of just outright replacing this with a little Marshall practice combo, but I've got it working the way I want it right now, so not necessary. I am really intrigued by this bass thing - why is it so loud and decent sounding??

I still wish it had reverb.

No need to get into all the specs here, see other reviews. Mine is a 2002 model with no line out or external speaker jacks. It would have been nice to have them, but I agree with others that adding a reverb unit to this amp would not make much sense. The tone controls are sensitive. I rarely use the midrange button for either clean or overdriven sounds, but it is nice to have when a particular guitar needs a little mid-boost.

I bought this amp 3 1/2 years ago just to have a decent practice amp. I do mostly recording and was using a POD at the time. Around the same time I also bought an Orange Crush 15R for a bandmate. I A/B'd them and the Kustom had a much warmer sound although the Orange's reverb did not sound too bad. I used it off and on mostly for practicing by myself. About a year ago I purchased a Kustom WAV 212 amp for gigging (also a very good and underrated amp!) but found that it was bit too loud for recording and I had begun to do a lot more amp miking in my studio. So I pulled out the Tube 12 to use in that application and found that it was sounding pretty noisy. Only recently I decided to do some mods to improve the amp. I had no idea so many others were doing so and it is quite a kick to read all these reviews. I find it interesting that so many reviewers want to compare it to the Marshall AVT20 (not a great sounding amp anyway IMHO) or a Blues Jr. The Tube 12 is a $100 practice amp after all. I knew the noise was probably due to the tube and went about replacing it. The tube in my amp had no print on it so I assume it was the crappy high gain Chinese tube and not the Ruby. I never was very impressed with the Gain mode but always loved the clean sound of this amp. I have a friend who is heavily into NOS tubes and he is going to send me some of his picks to try. But I wanted to get some new production tubes and I ended up with two Russian tubes, the Tung-Sol 12AX7 and the Svetlana 12AX7SP (supposed to be ultra low noise). I broke both of them in a little and found that the Svetlana had a slightly more interesting clean tone but the Tung-Sol had a much smoother overdrive tone, still with a much-improved sound on the clean setting. I settled on the Tung-Sol for now. But they are both very nice sounding. I always felt that the stock Celestion sounded decent but did break up early with higher volume and bassy tones. So I set about looking for a replacement speaker even though I knew it would probably not make a huge difference. I looked at the new Jensen MOD and the Eminence Legend 875, both of which seemed like decent speakers. But I had heard so many great things about Weber speakers that I went to their website and saw that they make many models of 8? speakers. In fact it was a little overwhelming to have so many choices so I emailed them and received a response the same day from Ted Weber who recommended the Signature Series Alnico 8 ?S?. I could have gone with one of the Vintage series speakers but I was concerned that the depth of the magnet would not fit properly or might be too tight a fit against the electronics chassis of the amp. I could have also gone with the Signature Ceramic speaker but I?m happy I chose the Alnico. It was on sale for $25 (+$12 s/h), which is a damn good deal for such a high quality product. The results are a more open sound and the ability to handle louder bass. It sounds warm and full and the clean tones are way beyond what you would expect from this amp. The overdriven sounds with the Tung-Sol tube are tight and rich in harmonics. I am able to get some pretty fair mild OD tones from rolling off the guitar volume. I should point out that this speaker needs about 4 or 5 hours of break-in to get the best sound, don?t judge it right away. My Tube 12 sounds excellent with effects pedals, and I use tons of them. Unfortunately my Electro Harmonics Holy Grail Reverb pedal, which should be a great accessory for this amp, sounds a little noisy for my tastes. There may be some other reverb pedals that are quieter, but I?m not about to dump $300 on something like a Van Amps Reverbmate unless I had other applications for it. This has not been a problem for me though because since I am using this amp for recording I am able to add some nice post-reverb to my tracks using my rackmount TC Electronics unit.

Compared to some of the other reviewers here (some of whom I?m wondering if they?re comparing this to a Bad Cat Mini!) I think the build quality is fine. Perhaps I got a good one, but my unit never had any noticeable rattles or loose screws, etc. As a budget, Chinese made PRACTICE amp this is decent quality for sure. I did tighten all the screws just as a matter of practice. When removing the baffle to mount the speaker, I decided to simply replace the existing baffle screws with a slightly wider #8 ?? wood screw and carefully tightened them by hand. I?m sure you could strip the originals in the particleboard if you aren?t careful. But I was able to get a very tight fit with no rattles whatsoever. Worst case scenario I think the idea of drilling through and bolting the baffle to the frame is ok, but I had no need to do this. I also used some electrical tape to secure the tube cover just as a precaution as per the other reviewers? suggestions. My amp is now tight as a drum and there are no rattles of any kind. Also, the new tube and improved speaker seem to have solved all the noise problems. The amp is dead quiet on the clean settings, even at high volumes and the Gain mode is only marginally noisy at high levels, obviously better with humbuckers than single coils.

Only contacted them once regarding my other Kustom amp (WAV 212)and they responded in a reasonable time frame.

I have been playing for 20+ years and have more than a dozen guitars and a very extensive collection of high quality pedals. For what I paid this amp is a tremendous little bargain, even with upgrades. I would put it up against an older Fender Champ any day. And as I?ve stated before I don?t consider the Marshall AVT20 to be anything special. Same for the Blues Jr. Until I find something like a mint Trace Elliot Velocette to reign as my recording amp of choice, this will do very nicely. For less than $150 total I have a toneful, responsive recording and practice amp that suits all of my needs. Highly recommended.

This is just a simple tube amp. No footswitch for turning the gain off and on, just a button on the amp. It has a midrange boost button as well. This is a basic 12w amp. No frills, all tone.

I play a G&L Legacy with single coil pickups. I do very blues based stuff, and this amp fits that bill perfectly. If you crank the gain up, you still get a fairly ringing sound from full chords. This amp is not muddy. The clean channel rings like a bell.

Many people who have reveiwed this amp suggest you change the tubes. I see no need to do that. The gain is very sensitive, but if you just make subtle changes slowly, you'll get the kind of break up you need. I turned this thing all the way up with the gain cranked, and the speaker took it well. Not bad for an 8 inch Celestion. This amp is so loud, I doubt you'll need to crank it that high unless you play with Keith Moon at practice!

The clean channel is pretty clean even when you turn it all the way up. The distortion will get you heavy blues sounds at the most. Using a fuzzface or an overdrive pedal with this amp will give you a great Cream or Hendrix sound, just at lower volume.

Still pretty new to me, so I don't know yet. There is one tube, so it won't cost you an arm and a leg to have some back-up tubes handy.

I bought this to record with, and for practice. I never tried Kustom amps before, and this amp has made me a convert. The sound is pure warm tube. If you play the blues, this amp will set you right. Many people talk about how many watts they have when bragging about their amps, but if a blues amp is what you're looking for, the watts don't mean a thing. Don't be fooled, this amp is loud. I got it for cheap used, but even the new ones are only 100 bucks, and worth every penny. The people who complain about no reverb on the amp are just being silly. This amp is a steal for what you get out of it, pure killer tone.

This is a recent K12 tube 12 , I bought it new in July 2005 in UK.
I had been looking for an amp that would supply me with a sound that had `more life/feel` for home practice. I like a blues sound but nothing too distorted. I was never really happy with my Roland Cube 30. Then a friend bought round an Ashdown Peacemaker20. The impact on the sound of my Parker P38 HSS was massive. It gave the sounds I was looking for but it was ?399 !!and is no longer made. So I looked around and came up with 2 choices in my price range - FenderPro Jnr or a Laney LC15r. But i really wanted to use it at home & people say they are quite loud & they have no headphone option - all valve amps. By chance I heard a Tube 12 in a guitar shop , tried it and for ?75 decide i coudnt really go wrong ...i was really pleased with it seemed to meet all my needs , a reverb would be nice though.

I use a Parker P38 HSS & my daughter has EPI LP custom. Both sounded good through the amp giving my desired Blues sound but I decided I would like a lillte less distortion & more control of the gain knob & a little more mellow sound. The postings below suggested I could change the valve from the original 12AX7 ( Ecc83). But I am new to valve amps & was a confused by AX, AU , AT , AY etc notes . So I searched the net -
3 sites ,http://thetubestore.com/gainfactor.html , watford valves & www.guitaramplifierblueprinting.com each explained a lot to me .
But I was a worried by a posting below that suggested an AT valve had screamed `like a banshee`. In the end I decided to buy 2 valves a Ruby 12AX7A-c ( ECC83 better quality chinese ) and a 70 % gain factor Groove 12AT7 ( Ecc81) from guitarworlduk - good service they arrived within 36 hrs.
I tried the new valves (just take out the 4 screws to drop the amp section down). Compared to the original valve , the Ruby AX was a little more mellow/ cleaner when the mid range button was on, it was also a little lower on volume - But the best sound for me was with Groove AT. Both Clean and gain sounds were great and I got the control over the gain control . Volume decrease was not really noticeable & this valve didnt scream.
I now have the sound I want for an outlay of ?80.I plugged in my daughters Korg ampworks effects unit,added a little reverb & reacehd the end of my sound journey (for now..speaker change next ?)Best of all I still had over ?100 in my pocket.

Dont really know - its new , but my original Kustom 10 that came with my first guitar is still going strong after 3 years & for ?70 who`s really that bothered.

3 year warranty in UK - good by Uk standards

Ive been playing for 3 years (Parker P38 HSS). Fro only ?70 this amp has finally given me the sound i wanted - i think i need just that valve !!. My Roland Cube 30 now sounds dead by comparison at low volumes in home use & I cant seem me ever looking at solid state again. There is no other valve amp in UK for this money - nearest is a Laney LC15 ?200. Its fitted with headphone,line out and extrenal speaker outputs.So when the family moans i can shut them out. It is easy to adjust/ modify the sound with a valve change for about ?10.What more do i need for home use at this price ?? If it had Reverd I would give it 10

I have dozens of amps ranging from over 40 years old to boutique new stuff. I only need the overdrive sound for recording slide guitar. Cheap is good when it comes to the sound I want and use. I'm not concerned with much else, except switchability would be good for rehearsals.

I use anything from old single coils to humbuckers and hotrails. This amp sounds very sweet on semi acoustics [Epiphones and 335s great] with the top rolled back a bit and is particularly effective on tele's - again with the top rolled back and the drive up. Great valve compression.Work at it a bit and there's a sweet spot there.

Too early to say. I tried 3 identical amps in the store and one was faulty.

Again, too early to say yet. We'll see. It's not going to get hard use. Studio mostly.

I've been playing for [christ, really that long?] 40 years in just about every situation and type of venue imaginable. I tend to blend amps to get the sounds I need, for example, even for festival gigs I'll use a 4w [yes four watt!] 40 year old Jennings Domino valve bass amp for slide guitar, through am Electrovoice 15 inch cab, with an Ashdown Peacemaker 60w combo on top for the gain button control over solos, and some top back up in the overall mix. But I have a selection of anything from rare Gallien Kruger to old Selmer, basic Peavey and oddball Trace Elliot. I had a 60s Fenton Weill 7watt amp from almost new that I used to use for everything. Recording, even miked in a chair for big gigs. It got stolen, along with the car it was in, over 20 years ago. I have now found the perfect replacement in the form of the Kustom. In fact I bought two to use them in stereo - cheaper than a crappy effects pedal! I may yet use them live, miked into P.A.

I like the fact that it's simple, without a lot of effects and complicated stuff. Being a beginner, I just want something simple.

I just want a clean, undistorted sound. As others have said, the warm, soft sound of tube amp is great. I bought a Kustom KGA30 as my first amp (solid state) from a pawn shop, and then I saw this Tube12 at another pawn shop and had to have it. I'm now selling the KGA30, the Tube12 is better.

I don't know anything about amps, but I could tell the difference between these two. I found some old NOS tubes in a box that I got with a tube stereo receiver I once bought, and I replaced the stock 12AX7 tube with an NOS Sylvania 12AX7 made in the USA, and it definitely made the sound cleaner and clearer. I have a Japan made 12AX7 that I might try too, but I'm happy with the USA Sylvania.

The gain dial(distortion) isn't great, but with the new tube it's much better cleaner and more distinct.

Seems to come on when I want it to and hasn't given me any trouble so far. All the dials are smooth and the cabinet seems very solid.

N/A

I've only been playing for 2 months maybe, and this is only my second amp. I think I'll stick with tube amps from now on as I like the sound better than my solid state amp. I like the small compact portable size and the solid feel the unit has. Nice and inexpensive and gets the job done. Actually seem to have quite a bit of volume to it....sounds like more than 12 watts.

12 watt practice amp with tube preamp and Celestion Super 8 speaker. This amp is really small and handy to carry around.

I disagree with previous posts that this amp needs a different speaker. I liked the warmer tone of the Celestion Super 8. I controlled the farting by adding a 200 uF nonpolarized electrolytic cap in series with the speaker. It rolls off the lows in the bass guitar and extreme lower guitar range without affecting the higher frequencies and protects the voice coil from over excursion and jumping out of the magnet gap, which is what farting really is. You can also just back off the volume or at least the treble. Adding the cap allows more lower midrange while still preventing ultra low frequencies from getting to the speaker. The Super 8 can't handle much power, but it sounds so good and is rather efficient. It goes as loud as I want to play in a small room. There is some hum when you turn the amp up loud, just like in an old tube amp. This isn't boutique quality sound, but for $100 it is very good.

Reliability should be about average because of the tube preamp and cheap crumbly particle cabinet and thin tolex covering. Adding the cap protects the speaker. You are protecting yourself by not carrying around an expensive amp that can get stolen. I have two of them, so I'm covered in case of breakdown or theft. I generally keep one in my truck.

No breakdowns yet.

I needed a couple of amps cheap enough that I didn't need to worry about them and without the hassles of a full tube amp. These are cheap and light. You will have to tighten and secure some screws and chase down a rattle or two, but very good sound when you tweak it a bit. The baffle board is weakly held in place by 4 very shallow driven screws, so I glued my baffle board in place on both my amps. I like the fact that changiong tubes affects the sound, so it's cheap to experiment there. I feel the stock speaker is very good for such a cheap amp. I can't give it a 10 because it still needs a reverb and better QC on the cheap particle board cabinet. Your effects unit will probably cost more than this practice amp, so it's a winner for the price. It takes the place of an old Fender Champ rather well and can actually play louder than most Champs.

I quit seeing these on eBay, so you might have to cough up the $105 or so that is now being charged for a new one. I think it would be worth building a nice plywood cab for the power head and speaker, and I might just do that. If I do, I will add another Super 8 speaker for a 2x8 combo, and also add an Accutronics reverb unit.

I also tried a Marshall AVT20 combo. If you have the money and don't mind the extra weight, go that route before dumping a lot of extra money into the Tube 12. It has a reverb and 10" speaker with better bass and true Marshall tone. A used AVT20 at $200 is a better buy than a new Tube 12 at $105. It's just that the Tube 12 is so small and handy to pick up and head to a friend's house for some practice. I don't think the Tube 12 could ever equal the AVT20 no matter how much you modded it. Problem is, the AVT20 not only costs 3 times as much, it weighs 3 times as much as well. The AVT20 circuitry is much more complex and it has a DI jack, so it can actually be gigged at a fairly large venue through the PA system.

Bottom line: nothing else this small and light at anywhere near the price has ever sounded as good to me. Just don't think you can get it all from such a package. Compromises had to be made.

It's a little practice amp. Really the basic stuff. No reverb or tremolo. If you need more, plug in some effects. The best feature is the portability, low price, and decent sound.

The stock Celestion red label speaker has a warm tone, but it's not for extreme styles or it will fart and break up. At low practice sound levels there will be no problems. It sounds best if you run it through a good 12" speaker cab, and it mates well with a 15 or 20 watt alnico speaker like those sold by Eminence. I use mainly the clean channel, as the distortion comes on suddenly and there is very little adjustment in the low end of the gain knob. It is best for roughly distorted gain, and the adjustment range is large enough for more extreme styles of rock. A low gain tube like a 12AY7 is what you need if slight amounts of distortion is what you are after. An Electro-Harmonix 12AX7 will work well for high gain styles. An Ei tube works the best on the clean channel for sparkle and high end. The JJ tube gives the most versatility on both channels for a well rounded sound, but the differences were not greatly noticeable between the tubes. Except for a high gain Chinese 12AX7, which is what you want for extreme metal styles, but everyone else will probably hate it. The roughest preamp tube I ever heard with extremely high gain.

The particle board cabinet is of low grade material that's soft and breaks easily. My baffle board was falling out when I got it, and there was very little material to sink a screw into, so I drilled through and bolted it all together. It developed the tube cover rattles which some tape took care of. Electrically, it has worked well and I installed a JJ tube that sounds great in it. You will have to put a bit of work into it when you first get it to make it bug free.

If you get a used one, you can't go wrong for the price. The 8" speaker is what upsets me, as the amp can cause it to break up too much. My favorite speakers are 10" or 12" speakers, so I have decided to look for a speaker cab with a good low wattage alnico speaker. I'm going to cut off the lower portion of the cab and make a little amp head out of it, or just switch the electronics box over to a good speaker cabinet and create a 1x12" combo amp out of it. Don't buy one of these new and pay close to retail when you can get a really clean Roland Blues Cube amp for around the same price in used condition. You'll like the Roland better for the money, but this Tube 12 is very small and that makes it extremely easy to carry to a practice session. The REAL value of the tube is that it allows the electronically challenged a cheap and no-brainer way to alter their sound. You can try any tube in the 12AX7 and 12AY7 families as long as they are compatible with AC heaters. Switching over to DC on the tube heater will get rid of some buzz at high gain settings. I tried a 12AT7A that was only made for DC heaters, and the amp howled like a banshee. 12AT7 tubes can work, but they are made for higher currents than the other two tubes, so they will have a current starved sound. Whatever that turns out to be. 12AY7 tubes will probably have too little gain on the clean channel only, but the 12AY7 tube works great for bluesy distortion when the gain is used. Basically a good amp, but it needs to be fitted to the player to get the most out of it. The latest amp I saw had a JJ tube in it as standard, and it is light years ahead of the Chinese tube for my tastes. Would make a great first amp for a beginner.