THD Flexi 50 Head

For a 1 channel head, this amp is loaded with features:
-Boost with its own gain level and tone control (on footswitch too)
-Defeatable master Volume (on footswitch too)
-High and Low gain inputs, which can be assigned to the boost switch so that boost on activates high gain input, boost off turns it off.
-Accepts most power tubes, so mixing a 6L6 with an El34 can be done to finally get that wider range response with the screaming more compressed mids of the El34.
-Accepts a bunch of preamp tubes for changing the gain structure.
-Full boat of tone shaping controls
-Effects loop
-INCLUDES footswitch
-Well vented design, does not need fan, and is easy to carry.
-Huge transformers for getting those harmonic tones out of your guitar.

If you can't sound good through this, then you really, really need to figure out which side of the guitar those strings go on. This amp has the best slight overdrive sound of ANY amp out there, and I mean any of them. Bad Cats through Bogners, none of them get this rich sound that works with your pick attack and vomue control. But crank up the gain and turn the volume up/master down a bit, and you have heavy Marshallesque crunch with so a huge wall of sound around it. Tremendous amp, the best thing to come out of THD yet.

Don't know yet ... built like a little Sherman Tank. Big trannies in this one ... but two side handles make it sturdy and easy to carry.

NA

Been playing for 30 years, made very good bucks playing and teaching, and tried every freakin amp that exists at least once, and owned a bunch of them to boot. This is a tone monster ... it beats the living snot out of those expensive Plexi clones from Fargen, Reeves and Mojave .... it is really Andy Marshall's greatest achievement. It drips tone ... and the price is SOOOOO reasonable on these. Get one before it wins a Guitar Player award and the price doubles! If you don't believe me, check out the price jump on the Budda Superdrive II 80 watters!

THD Flexi 50 #0210. hand built in seattle. it has a hi/lo input switch, volume, treble, middle, bass, a bright switch, a footswitchable boost circuit (NOT a second channel) w/ gain and tone controls, a master volume also defeatable via footswitch or the switch on the front panel, a cut knob (which is NOT a presence control, it controls the overall brightness, but not the gain), the amp can be run at either 20 watts, or 50 watts, it has an impedance selector, a line out, an effects loop, an option to switch the hi input with the boost when it is engaged, AND if that is not enough, there are external bias points because you can use almost any kind of power tubes ( as well as many kinds of preamp tubes, which can be swapped without biasing). i never use the footswitch, because i always have the boost on, and control the breakup with a volume pedal. it is capable of wonderful cleans as well as ferocious overdrive.

i use humbucker equipped guitars and no effects pedals - only the aforementioned volume pedal. this amp is perfectly suited to my playing style, which is very dynamic. the amp is very touch sensitive, so i can go from soft and clean to a raging distortion very quickly and smoothly. it's been said that the flexi has Fender blackface cleans, Vox chime, and Marshall overdrive all in one amp. well, it does. sort of. the overall voicing is sort of a combination of all of those things. it's not like a modeling amp where you can switch from "marshall" to "vox"...or whatever...the option to use many different types of tubes makes the flexi very user tweakable. i personally prefer it with NOS GE 6550A's, and mullard 12ax7's.

the amp has never broken down, and i don't expect it to. the build quality is absolutely great. i've heard that thd uses FAA approved techs to do it's circuit boards, they have higher standards than the military...so i guess it's build like a plane, not a tank. i will only give it a nine, because i've only had it for five months, so i can't be POSITIVE it will never have problems....

ed @ thd is great. best customer service around.

i've been playing for twelve years. i'm not a big gear whore. once i find something that works, i stick to it. i had my previous amp (a HIWATT) for ten years before i decided i was ready for something new. after much research, i found out about the flexi and i knew it was the amp for me. if it were lost or stolen, i would replace it immediately!

My Flexi #102 was hand-crafted in '03 and, outside of my former '65 Fender blackface Twin, is the first tube-amp I've owned in nearly 40 years. After "experiencing" the tone-shaping opportunities of this one-channel amp, I'll never settle for solid-state again! I use no special effects, as the Flexi's boost/master pedal meets my needs for tonal & gain effects.

I play a modified '94 Les Paul ClassicPlus w/ '57 Classics, and tend to play classic rock/blues/tad-o'-jazz-type style. I admit to being a better rhythm than lead player, and this amp fits the bill! I always liked the "cleans" of the Fenders, but have been lured by the "crunch/overdrive" of the Marshalls, and the THD Flexi affords the best of both (IMO)!

My Gawd!...it's built like a tank, and I have experienced NO PROBLEMS in more than 6 months. From what others have shared, I think I can honestly expect total reliability.

I've conversed with a few folks at THD, and they are ALL TOP KNOTCH! Very responsive to my inquiries, and I forsee no problems.

10-In nearly 40 years of off-n-on playing, from '60's rock through country and jazz-fusion experimenting, I really think that this amp "covers them all!" I really can't find anything "wrong" with this amp. And complementing it with a fine Avatar G212H special cab has made this purchase all the more sweeter!

2004, #166. Plenty versatile with the switchable boost and master functions for my needs. To me, it seems to work as if you are playing a single channel amp and the boost functions like a really good overdrive pedal. It's not as complex to dial in as a two channel amp.

I'm using this with several guitars, a Les Paul, Tele, Strat and 335. I have yet to be able to get a bad tone from this amp. Definately a Marshally sounding amp, but not dead on. Mine seems a little sweeter than most Marshalls I have played, kind of like a Marshall with a touch of Dumble thrown in. I play classic rock and blues and am able to get all the tones I need straight into the amp. I have used a clean boost with it to equalize the volume difference between single coils and humbuckers. I also have found that I prefer a 12ax7 in the second preamp slot instead of the stock 12at7, this change made the amp a little more versatile for me. I wouldn't say this is an extremely loud amp. It is certainly loud enough for gigs, but I am using it with out an attenuator in the 50 watt setting and have had no complaints about excessive volume. Of course, if you turn everything up to ten, that may change.

I've had it for a month with no problems and I don't expect any. This company has a good repuation and for very good reason. I've owned a UniValve and still have a BiValve and have had no problems with any THD product

Again, this is one place that I can't see anyone having a problem with. Tone may be subjective, but these guys really care about their customers and go the extra mile to try and make them happy. Ed Degenaro has the patience of a saint

I've been playing for over 20 years and since I bought this amp, it is the first time in a while I've stopped looking for new gear. All my guitars sound better, so I would have to replace it if it were ever stolen. I was looking at Germino, Aiken and Demeter, but the features and price point on the Flexi won out. Plus, these amps are really small and easy to carry around.

Mine's an early model, probably early '04 with red lettering. It's my 3rd THD amp having gone through the Univalve > Bivalve > Flexi path and each one is better than the last (and they're all good). The Flexi suits me best as I can get huge clean sounds with master and boost off, but dirty them up with the boost/master combination, then get into serious overdrive with a pedal. Or of course put lower power tubes in and overdrive the amp more, and just use the footswitch and the guitar's volume control. Or anything in-between, and that's the key to this amp; as you can reconfigure the pre-amp and power stages totally you can turn it into absolutely anything you want! In 50w mode with 6550s it is *very* loud even when running crystal clean. With 6L6s pushed hard in 20w mode it is loud and beautifully dirty. The fx loop is great with some units, not so great with others - parallel would be better than series. It's only the fx loop that makes me give it 9 rather than 10 here.

I play in a rock covers band that gigs 1-2 times per week. I use mostly Les Pauls. The Flexi is great as a sonic canvas on which to "paint" all the different sounds I need with various fx pedals, and has plenty of headroom for all the venues I play. I also occasionally play in blues outfits and it's equally good for that without any fx pedals, given the right tube choices - anyone who doesn't like this amp just hasn't put the right tubes in to suit them.

I've never had a problem with a THD amp. Built to last.

Whenever I've needed missing parts or whatever they've sent them without hesitation. They are an outstanding company for customer support and advice.

I've been playing since the early 70s and have owned pretty much everything, and the Flexi is the best to date. If it were stolen I'd buy another like a shot. Because of the ability to reconfigure it and alter its sound there's really nothing to equal it - it's as good as you make it. The only thing I really wish it had is a parallel fx loop.

This is a brand spankin? new Flxi-50. I assume it was built in ?04, as they do sell well, from what I understand.

I have, by virtue and many thousand dollars worth of trial and error, and serious leaps of faith of buying amps based on reviews, or word of mouth that one amp cannot be all things to all people. I have an original ?64 Fender Super Reverb, and a Dr. Z Maz 18 jr. I have gone through probably 10 amps before this is nearly 20 years of playing guitar; however NONE of them was a Marshall, or an amp with a Marshall vibe (go figure!).

I was pleased to find an effects loop, along with a lot of other features with this amp. Some of them are pretty subtle, but they really add to the ability to shape the tone, as well as, to a great extent compensate for different rooms when playing live.

This amp is LOUD, particularly when you play this without the master engaged (which I greatly prefer). Of course my Dr. Z, at 18 watts is damn loud too. How much volume do you need? I imagine that, for me, the Univalve would be plenty loud, and mic it if you have to!

The only thing that I really miss is a reverb. If you call Ed at THD he will tell you that they reason a reverb was not added was that they prefer reverb to be added in the mix, as opposed to at the amp. He also asserts that reverb is generally more beneficial to a clean tone than a dirty/distorted tone. I don?t know about this, as all but one of my previous amps had reverb and I use it nearly all the time ? except during recording, where I agree that you should record as dry as possible.

Beyond this, what more do you want?

Tone. After a week, my initial impression has been: WOW! This amp is fantastic. This amp just drips tone. It really has so many faces! The clean is, well, not too clean (which I generally dig?). This amp absolutely NAILS the semi-dirty Hendrixy tone that I grew up loving. This is, in my opinion, one of the most difficult sounds to get out of an amp. It is probably the best tone out of the Flexi.

The distortion is pretty thick. Not a hard core grind like a Mesa (duh! It is not a Fesa Boogie!), but sweet and singing. I am generally skeptical of any ?boost? mode in an amp or pedal, as they generally disappoint, however this one is fantastic. The separate tone control for the boost really makes this a 2 channel amp ? but it isn?t, get it? Me either, but suffice it to say that the boost gives you all of the distortion you will need unless you are a shredder, in which case you would (should?) never consider this amp in the first place. (If you ARE a shredder, stop reading here and nav to the Boss Metal Zone reviews?). I have a Fulltone Fulldrive II as my overdrive pedal, and, in the past I have really liked it, however, it does not, in my opinion, mesh well with this amp. The Fulldrive sounds kind of ?transistory? with this amp, which is ironic, because I thought it was the most transparent overdrive pedal that I had heard. Good deal! More stuff to buy?

One other thing I have noticed about this amp is the unbelievable dynamics I get out of my pickups. Single coils, P-90?s, HB?s all are awesome. And all totally different. I thought this would be an HB amp (it is?), but I TOTALLY dig the single coils out of this amp as well. Really really nice, and not at all noisy. Then, there are the greatest pickups on the planet (P-90?s). STUNNING! Try a Guild Blues 90 with this amp for rhythm guitar, with boost off and mild distortion and you will cream!

The additional switches really allow you to shape the tone. The 50 watt/20 watt switch does alter the tone a lot! The 20 watt is nice, but smoother than the 50 watt. The 50 watt is ballsier, though, and more fun! The master volume is defeatable, and this is a FANTASTIC option ? one of the best of the amp. This amp (and most amps) behaves totally differently with a Master than without one. If you have never tried a NON- master volume amp, do yourself a favor and try one TODAY! The touch sensitivity is wonderful.

The other caveat about this amp is that it NEEDS to be turned up. This really is not (to my disappointment) a bedroom amp. It is like having a Ferrari (for $1500?). It HAS to be driven fast, and will never be satisfied going slow. I have a Hot Plate, and this does help, but it EATS the sensitivity of the amp. The tone is good, but the feel is lost. It is a sacrifice we have to make?.damn it!

I have no idea. It is new. But is weighs a TON! And looks cool!

I am really pissed at Harmony Central for only having a 1 ? 10 here. There are a few manufacturers that are unreal in their service, and THD really is one of them. When I was considering this amp I called THD, and talked to Ed DeGenarro. We chatted for nearly an hour about all sorts of things about their amps, the design decisions they had made, caveats about their products, and traffic in Seattle. All sorts of stuff! To think that you can call a company and have a receptionist (a human, non-computer, non-recorded receptionist) answer the phone, and transfer you to the guy that designs the stuff is ridiculous. You cannot ask for more. I have not had to deal with them when things have gone wrong, but, based on my conversation, I have no doubt that they stand behind their product 100% and truly want to help (what a novelty! Try calling Mike Fuller at Fulltone sometime! OUCH!).

The only other person that has support to this level that I have encountered is Mike Zaite (Dr. Z). If you call him, he will talk to you all day! To the point that you will actually have to get HIM off the phone! Go figure!

So far, this amp rocks! Of course it is the new kid on the block, and we are still in the honeymoon stage?but I think that this is a marriage that will last. This is not a 1 trick pony, appears to be rock solid, sounds fantastic, and is a BLAST to play. Seriously, what more could you want????

Well let me tell you! You can try different tubes,. Not just different EL-34?s but 6L6, KT-88 (these are really cool, BTW?.), 6550?s, 6V6. Nearly anythin you can think of! You can even MIX AND MATCH. An EL-34 and a 6L6 AT THE SAME TIME, for example. You can even bias the amp yourself ? in about 3 minutes! So if you are bored and feel the need to change your setup, you can pop a few tubes (pre and/or power) and see where it takes you rather than getting a totally new amp!

Talk about FLEXIble! This amp is cool! There is enough to keep you busy for years with this amp. Complex tone, great vibe, extensibility. Get one and feel the power!

I believe this amp was made in '04. I've had it for about 3 months now. Features-wise, it's not too bad, but has just the basic stuff. The tube-biasing feature is cool, but nothing all that special.

I've spent 3 months trying to dial in a sound I could love, but have not been able to succeed. I have an old 70's Les Paul and an '89 American Fender Strat, both which are fine guitars, but neither really seems to shine with this amp. I play mostly classic rock and bluesy oriented stuff and thought this amp could cover those grounds, but I've decided that this amp just doesn't have it. It's rather flat and two dimensional and kind of harsh on the highs. I went by the hype of what I read on the Internet and now I know how foolish I've been going by that. To me, it's a pretty flat-sounding amp, certainly not what I had in mind. I plan to ebay it pretty soon.

Didn't have any problems with it, but I baby all of my amps. Seems that it's a pretty reliable amp.

Haven't had to deal with the company as I haven't had any problems with it in the 3 months I've had it. Just doesn't have the tone as far as I'm concerned.

I been playing for 20 years and have owned various Marshalls, Fenders and Boogies. Thought that this could cover them alll but I was mistaken. Not a bad amp, but certainly didn't live up to the hype and the expectations. The master volume on this amp is useless. Doesn't work well at all. I live in Montana and bought this amp based on all the hype I read on the net. Guess that's what I get for living out here and just reading stuff on the net. Could never get this amp to sound warm and lively. It's just flat and not really happening compared to my Fender Deluxe and Marshall JCM2000 Dual Reverb. I'll be ebaying it pretty soon. After 3 months, I've done all I could to make it sound good and just couldn't do it. A disappointing experience but I know that I can't win 'em all.

This has been covered pretty well, but here goes: Basically a simple amp that has some neat features. Two channels, like on a Bivalve, but they are switchable, along with a switchable boost and master volume. This is handy, because you can switch the master volume on when you go to the boost channel and avoid having a huge jump in volume. Makes it like a two channel amp.

I am using it with a THD 2x12 cab and various guitars. I have yet to find a bad tone out of the amp and I found it very easy to dial in. The amp is quiet and does have a nice clean tone, not quite as lush as my Fender pro reverb, but definately very nice. Of course, the overdriven tones is flat out awesome. This amp likes to be turned up! Not an all out metal amp, this amp definately sounds more like a Vintage Marshall when cranked up. Great for classic rock sounds and heavy blues. If you like those classic Marshall tones, you owe it to yourself to check this amp out. If you are into Nu-Metal, look elsewhere.

Hasn't had any problems yet, but I haven't had it for very long. I have a lot of faith in THD products. Their amps are very well constructed.

THD has the best customer support I've ever seen. Ed Degenaro is easy to get a hold of and seems to be happy to help out customers.

This amp is the one for me. Finally an amp that gives me classic Marshall but also has a good clean tone when I need it. If it were stolen it would be replaced

Features: see the THD home page. I wanted to play with this amp a few months before I commented on it. It has an extraordinarily "flexible" set of features for delivering great vintage tones.

My main guitars are the basic food groups: Strat (Custom Shop '60 with Joe Barden PU's; LP (Historic '57 with Seymour Duncan Antiqity PAFs); and Tele (Muddy Waters Tribute Telecaster). When I bought the head, I thought I was buying a Plexi clone. To my ears, I bought the best Fender clean/overdrive amp I have ever heard. Back in the day (late '60s and early '70s), I had a mid-60s SuperReverb that I "dimed" to get the best tone I ever heard. This amp exceeds ny recollection and is controllable in volume.

"Built like a tank" is such a cliche. Let me say: I have owned THD amps for more than a decade without any problems.

It's been a while since I've spoken with Andy and/or Ed, but I think they are top flight and very accessible.

I've have been playing loud rock'nroll for a long time. I have owned a lot of amps. I wish there were a 4x12 cabinet to go with this head. (I have THD's 2x12, which sounds really good.)

Mine is #234. I have found this amp to be very versitile great full clean tone with gain for days. It is a one channel amp with Boost and Master volume on off switch. I use this as my main gigging amp. This amp has more then enough power to handle any live show situation. More details can be found at the THD web site or Univalve.net

I am using a Godin LGXT and Fender American Deluxe Fat Strat. The tone suits my style just right. I love the clean and gain and other tones in between I can dial in. This amp is very quite and has great headroom when used Clean up to 1:00 with no Master Volume. It then goes into a beautiful distortion and combined with the right twist of the knobs and on and off switches this amp will provide a fantastic lead tone which doesn't get mushy when strummed.

This Amp is a THD, like all there products first rate with great build and design. I would feel fine with out a back up.

First Rate all the way. Ed DeGenaro helped me get mine. I live in Utah where there are no dealers he helped get me this one to demo which I compared it to a Bogner Shiva and a Bad Cat Hot Cat. I ended up keeping the Flexi which I thought sounded as good and better for less money.

I have been playing for over 20 years and owned a THD BiValve, and a Mesa Boogie Rack, before I purchsed this fine amp. I was looking for a nice open clean tone and fantastic gain out of one amp under $2000.00. My gain needed to go from just to the edge of break up, to spongy, to tight lead tones with out a ton of tweaking. The Flexi does all this even with stock tubes. I haven't even thought of swapping tubes in this amp because it sound so good out of the box. As stated earlier I was comparing it to the Bad Cat Hot Cat and Bogner Shiva. I found this amp to be as equal or more in all catagories. The Hot Cat seemed to have a more full sounding Clean tone and can switch from Clean to Gain using a ABY switch which I liked over the Flexi however was $650.00 more. The Bogner Shiva was a true two channel amp which also sounded great but I found the Flexi tone more to my liking both in clean and gain. I also demoed a Mesa Boogie Lonestar and the all three blew that thing away. I don't know what is going on with the people who have been slamming this fine amp. I just ignored there reviews and tried one my self. Now I am a happy owner.