THD UniValve Head

Bought new in Australia for $1400, not cheap but nothing here in OZ is!!!!! Think you all know the features by now, serial #1178

I had no idea what to expect from this amp as we dont have a dealership anywhere near by, just bought it based upon several reviews in guitar mags and here on H/C. I`m using a warmoth tele custom with a hotrails in the bridge, a 2x12 cab loaded with celestion vintage 30`s. I play mostly hard rock/blues, this amp is almost perfect for this style of music as far as i`m concerned. It`s only 15watts sure but has plenty of volume to keep up with a band, the only issue you may have is a lack of clean headroom at high volumes. I`m using EH 12ax7 preamp tubes and an old RCA 6v6, boy does this thing scream with the 6v6, i love el34`s and have been using a svetlana el34 with great results also. Can get a great AC/DC back in black album tone easily so id be pretty stoked if thats all it did. The clean sounds are also nice and you could just about swear that it has a built in reverb, sounds very 3d. Have read some reviews below about this amp being bright but i havent had an issue with this at all, i`m just running most of the tone controls around 1/2 way and the volume at 11 o`clock on the rock input, using the volume on the guitar to clean it up when needed. I love this amp and would buy one immediately if it were stolen or lost. It`s perfect for my style of playing but thats not to say it`s for everyone

This amp seems very well constructed, i have only had it 2 months and no problems so far, from all accounts the people at THD are very helpfull.

I have been playing for 17 yrs, like most of you have tried every amp under the sun, I have owned DSL and TSL marshalls, Boogie dual recto`s, line 6 and a few others. This is the most satisfied i have ever been with my tone, I`m not knocking mesa or marshall as they have great products but THD have something special here. If your into full on metal or just a great clean sound you`d probably be best to try something else but the univalve can cover quite a bit of ground with all the different valve options and do it damn well

Serial #0280. Sat at the shop I bought it at for quite a while...probably a couple of years old by now...I've had it for a year or so. If you don't know the features by now you need to get out more often! It will take boxes and control fiddling if you use it live. I (like most reviewers here)wish there was some channel/gain switching. It won't do Hendrix or Dime Bag (RIP) but with boxes you can make it squeal like a stuck pig! The Roll (low gain) input is for mellow stuff...works fine for the player with the right touch(not me).

I hated this amp to begin with! It took a lot of tubes and cabinets to find the right tone. It's a little bit noisy up loud (input slammed)& is real picky about pedals. I use an old tube screamer into a Boss DS-1 (to add more gain and roll off treble for some lead stuff). This is a BRIGHT amp. Did I say bright? My settings :( clock settings...no numbers) vol. 2 / treble. 10 / bass & attitude at 1 or 2. I can't stand the sound through anything but a 412, but others have used it and loved it in my studio with just about everything. I run a 4 ohm cab thru the 8/16 setting - sounds way better this way to me. Comes across a little noisy the way I play it and feeds real bad if I'm close enough to hear it over the drums...but exactly what you would expect with a little amp cranked like this! I've used everything you could imagine for tubes...I'm the guy listed in Myles' site as the 'unknown' sponsor for Roby with all the NOS tubes (he forgot my name...it's Don?hi Myles?LOL http://www.guitaramplifierblueprinting.com/clinic3.html). I had my Univalve there too. Right now I've got a Sovtek 6550 WA with a very old RCA 12ax7 for input and an old Sylvania 12ax7 for driver. Loved an old Mullard 12ax7 at the input stage too. An old Sylvania 12at7 cleans it up nicly if you're that kind of player. Everybody is blown away by the sound, but I'm soon to try a Flexi for the needed volume & crunch. Players used to an old Fender Deluxe type of sound love it in my studio, but the Marshall guys don't. It certainly has it?s own unique mid range sound. Like Myles says: it's great as a pre-amp for old clean tube amps. I have to admit that I was ready to give up on this until I finally found the combo that I liked. If you've been used to old tube amps this will take some getting used to and a whole lot of testing, but I've decided to keep it now. Obviously I like lots of gain (UFO/Humble Pie/Deep Purple/Montrose/Sabbath/Gallagher) but I don?t want to lose too much more of my hearing!
I?ve been around for way too many years and have tried it all. This thing is a good sounding little amp. Even an old head-banger like me can find a tone if they try hard enough! By itself, you better have 2-412 cabs if you want to be heard without a PA, if you like to crunch like me. In the studio players way better than me love it. If you suck, this amp will show it up better than most. It's improved my playing...enough said.

This thing died on day 2...I was very unhappy. It got delayed in getting back from THD, but they were cool...no complaints. It's hard to blame them for a bad cap...they use the best stuff in this amp. I don't think it will ever need a shop again. I'd bet on it. Built like a freakin' tank. You'd have to prove it to me before I'd believe anybody could build something to better standards. Period.

Ed will talk to you and answer your e-mails. I've been dealing with people in this business since the 70's, these guys are the real deal, you'll never find better! They did a xformer fix for free while it was there (remember, mine is kinda' old...new ones won't need this, I didn't think mine did either, but they didn't charge). I'd give them an 11 if I could. I called on a Saturday and talked to Andy's wife...like I said before, these people are the REAL DEAL. We'd have world peace if everybody acted like them.

I?ve played through Mesa combos (hate them) and lots of old Fender amps. I went half deaf with a Boogie combo slaved to a Boogie M180 power amp in a rack rig, I have a 1958 410 tweed bassman (the real thing!)and the basket case tremolux shown on Myles' site. I'd buy a Flexi if my uni was stolen, but I'm glad to have it. You could buy 6 of these for the price of some of my rigs...nothing out there will touch what it does for twice the price. No, it ain't a Marshall...get a Flexi if you need(I'm going to).

WOW! This amp can do just about anything. I bought this head off ebay second hand. The guy I bought it from owned it for one month. He was looking for that chugga chugga sound. This amp does not produce that kind of distortion. However, the distortion that you can get out of this head is amazing. I can get that early Marshall tone along with the Stevie Ray Vaughn blues tone that I love.

The options on this amp are amazing. So many choices and the tube switching that you can do makes this amp a blast to mess around with. Be prepared to get addicted to tubes after you buy this amp. I have spent a lot of money on tubes and it has been money well spent. You will be amazed at how versitile this head is with just the simple switch of a tube.

The built in attenuator is such a cool feature. Especially when you are playing at home. You can still get great overdrive at a reasonable volume.

This is the best sounding head that I have ever owned. I have been playing for 25 years now and I was skeptical at first but I am a believer now. I am having so much fun with this amp.

Here is a quick description of what I am using. A fender double fat; a 59 strat; and a Gibson 335. I am using the THD Univalve along with my JDesign 2x10 cabinet (2 10' webers). Check out www.jdesigncabs.com for the best custom built cabs on the market today. Speak to Jeff Earl and he will set you up. This is a great combo. The THD through the 2x10 puts me into tone heaven.

Here are the best tubes that I have found. Tung Sol 5881 for that beautiful blues tone; RCA 6V6GTA; and the NOS EL34 Siemens (awesome sounds) Choose your tubes wisely. Be prepared to spend a little bit of money. I am a believer in NOS Tubes. Check out www.kcanostubes.com; www.tubedepot.com; and www.thetubeshop.com. All three of these companies carry some great stuff. You can also get some great deals on Ebay.

For the preamp tubes I am using the GE 12AX7; 12AU7 and the 12AT7. I am also using telefunken. Great preamp tubes.

The coolest thing about this amp is all of the variation of tubes that you can use. You will spend hours looking for amazing tones and when you finally find that great combo it will blow you away.

My favorite so far; NOS Tung Sol 5881; A Telefunken ECC82 and a Tunsgram ECC81. Great tone.

Make sure you check out www.jdesigncabs.com You will not be sorry. I was blown away by the quality; craftmenship and tone of this cab.

Solid Head! I had a case built for it. This is just to great of a head not to protect. I am out on the road a lot so I need to take care of this baby. She found a nice home.

Haven't had to contact them yet. I have heard great things.

If this head were to get stolen or destroyed somehow I wouldn't hesitate to buy another one. This will be a classic in the years to come. If you love music and great tone than run out and get one of these heads. 15 Watts is plenty of power. I play gigs that require a lot of sound and this little 15 Watt head puts out enough tone to stand out in the mix. Do yourself and favor and buy one of these heads.

Number 1287. Traded a guitar for it at guitar center...used..hated the guitar anyway..so hey, it's a deal! Love the simplicity of this..that's the best feature i've ever seen in an amp. The tube switching possibilities are endless. i'm happy with the stock groovetube 6l6. I also purchased an EH6V6 and run it at 5 watts...still kicks ass.

Guitars: 83 MIJ Strat, 77 Electra WorkingMan X290, and 79 Epiphone Genesis. All guitars stock and saved from pawn shops. Amp goes ANYWHERE i want it to. Sound is anything i want or can think of...even that thin crispy critter 60's beach sound if wanted. Would love to try a 34 or 6550 in it. I don't find it too noisy...it's a REAL amp. Hey, just for THD, harmony central should put this number up to like 20 for this rating.

So far so good!

This is almost a given that they will be great to deal with. If someone can create an amp that sounds like this and put the "love" into like they do, do you think they'd suck at customer service? NO! I bet THD guys love to help you and talk about their products. They have to be very proud of it so why not!

You know..this is very subjective. Some "kids" may not ever appreciate this amp. They didn't grow up hearing "real" amps in their sleep. I'm 39, playing since i was 10, youngest of 7 and with older bro's and sis's, i've heard lots and lots of music over time. Solid state was not what was on the radio growing up. now you hear nothing but modeling amps and "close" sounds but nothing like the real thing. So kids today "think" that line6 models are faithful. I've played EVERYTHING imaginable in amps...solid state, tube, hybrids with tube pre-s, hybrids with tube power. and YES, i'll confess i was getting close to really liking the valvetronix vox ( a very respectable hybrid amp by the way) It's a sad truth though that there are a lot of kids playing who have never heard or played through a real amp because they are told by the stores that "models" are just as good. well in the case of thd's univalve, it's as versitile as any modeling amp..but the thing you feel in your heart and soul when you play it that it's real...it's not a model and your life will be much better having it around. Thanks THD for rescuing me and all the rest from being buried in the crap that's on the market...thanks for letting our sound climb back on top and even if i don't make another dime playing, every time i plug into my univalve, you'll know i'm smiling!

Single output tube class A head with attenuator and direct/line out. Two inputs voiced differently.

No effects loop. No onboard effects. No channel switching.

Great clean to crunch sounds especially with 1 x 12 Jensen PN 12 or Celestion Blue. The Roll input with 2 ECC83's in the preamp and a JJ/Tesla blue EL 34 yields glassy clean sounds with Strats and Teles.

I have an old Magnavox 6V6 tube that I pulled from an 1950's record player that sounds absolutely killer with an ES-335 thru the Rock input.

Overall, this little amp is like a science lab for tube enthusiasts. Its fun to explore the subtle differences among various preamp and power valves.

You can make this amp sound fizzy and ugly if you use the attenuator too much with certain valves. In general though, it is fairly easy to dial in great tone. I love the clean sounds that this amp does thru the Roll input.

Looks pretty solid.

I have emailed them for information about other products and have gotten prompt and courteous replies from Andy Marshall.

I have collected all kinds of guitars and amps in my 38 years of playing. Guitar playing is my lifelong passion, and I don't skimp or compromise when purchasing guitars, amps, and effects. I own 3 Les Pauls, an ES-335, 2 Strats, a 52 Tele reissue, 4 Rickenbackers, and a CIJ Jazzmaster (my only import). I perform through a Vox AC-15 TBX and a Marshall JCM 2000 DSL most of the time, but my beloved Vox is getting pretty beat up, so I decided to replace it with the Univalve and a cab. It sounds as good as the AC-15 TBX for clean to medium gain sounds. I still carry the Marshall to gigs when serious drive is needed.

I really like this amp. I have had it for about 6 weeks, and I am still working with various valve combinations and different speakers. It pushes my 4 x 12 easily, and has more clean headroom than you might think. But if REALLY LOUD AND CLEAN is your thing, look at the BiValve or the Flexi.

Here's a link to a photo of some of my gear:-)

http://www.coe.unco.edu/jeffbauer/group2.jpg

I give it a ten because even though the number of knobs is limited, it will get any sound I want, from sweet and clean through sweet and singing to as raunchy as I want. No channel selecting is provided, but I change the tone in real time as I play using a volume pedal to provide the desired amount of overdrive.

I've used it with a variety of Gibson and Fender guitars and all styles. It gets beautiful, diverse sounds with all of them. Using an ES175, I can sustain any note as long as I want and bring in beautiful feedback harmonics an octave or two above the note I'm playing, at will. Fantastic. And the built-in Hot Plate is the "master volume" control I've always wanted: It controls the final loudness without affecting the tone, so I finally get as much singing or crunching or wailing as I want at a volume suitable for a modest-sized practice room. I have concluded that the people who complain about its tone just don't know how to use tone controls.

I've had it only a few months, but it seems very solid. It has only three tubes, and they are easily replaced. So, I would not bring a backup amp--just spare tubes, in case they are needed.

This is based on wishful thinking and hoping. I've never needed to call them, but they have a great reputation. I often think of calling them just to tell them how much I love this amp.

I've been playing about (gulp) 40 years. I have tons of guitars and amps. This is my current favorite. I could probably ditch all the other amps and be very happy with just this one. There's nothing like real power tube distortion, and this provides it at comfortable loudness levels. The only thing I would change is to have protection for the knobs, so they don't get broken when taking the amp to another location. This has not been a problem because I keep the amp at home, but they do look vulnerable sticking out there. Maybe a custom road case should be offered (cheap!).

serial 1233.... i have tried ab'z of later model... (silver thd logo) white thd logo and found that one (marginally) thinner (despite substituting my valves) .. perhaps it was that amp only....
Loud as my 50W JMP-Mk11!!!!
Try rca 6v6's...dual getter mullard el 34s....

63 Duo
62 Duo...freak (custom order) paperweight swamp ash xtra factory winds, steel klusons... this is a gem!!!
92 Carruthers handbuilt strat... swamp ash/ antiquities.

amp has a fair bit of noise, but the tone is a killer... from blues to rock to jazz to anything.. the preamp stage is a gem, albeit not for novice dialing.
Yhe secret .. as with all valve amps is to use micro adjustments... Want darker? Dial more gain... realise that this ofcourse affects all the followint tone stages.. adjust!!... remmember micro adjustments... if you use this method you can focus any guitar just yummy!
There are some cool sounds using the noise reduction and attenuator (not too much of it) ..BUT!!! the tone really lives when you let the power amp breathe... so you are better off getting lower output valves...
I use my marshall quad...original greenbacks.... tight cool ...great bottoms...well everything....from brit shimmer (it is class A after all...)
I use 2 vintage screamers and a quadreverb gt .. this for reverb only... what can i say? this combo is sublime to delicious...
Clean shimmering tops , bottom end to spare, and the mids are there if youhave the knowhow to fucus them... just use fine touch not brutal knob turning...

very cool amp.. built with attention to detail.

over and above and beyond service at its best!!!!

a future clasic!

At first I was a little nervous purchasing this amp because i am used to using channel switching amps that have many knobs that do many different thing. i have used Mesa/boogie amps for many years but have always had volume issues at gigs and with other bandmates. the operation of the amp is very simple and very no-frills. I have read reviews on here where people have complained about the price and i find that a bit odd. if you compare it to other class A amps out there, it is very reasonably priced.

I am mainly a hard rock/blues player. I use a 61 reissue gibson sg with a dimarzio tone zone pick up in the bridge. i have been running it through a mxr micro amp (just to boost the signal for lead work) and then right in to the rock input. it took a little while adjusting to the old school method of rolling back the volume knob on the guitar for clean sounds, but is no problem now. for me the amp is plenty lound for small to medium size gigs. I have been using it at all gigs because it always gets mic'd up and run through the PA anyways. I may run it into my mesa on larger stages, just because I can.

I have experimented with a few different tubes and found the sound of a 6L6 works the best for me, its a little warmer sounding than the el34. I tried a 6v6 in it and found the sound to be amazing but I have my doubts that it will be loud enough on stage.

the only complaint I have in regards to sound is that the treble can be hard to control, and can get a little piercing at times.

no problems so far

havent had to deal with customer support, but univalve.net is a great resource for this amp.

I think this is a great little amp. fun for experimenting. I think sounds best being used for clean to hard rock sounds, not enough gain for metal. if you love great guitar sounds in the realm of ac/dc, aerosmith and guns n roses, this is a great amp

-Dual independant inputs for clean or dirt
-Built in power attenuator (hotplate)
-selectable impedance speaker out (use any cab in your collection)
-Line out w/ volume control
-Noise reduction circuit (simple yet effective)
-AUTO BIAS circuitry (swap pre or power amp tubes to taste)
-Bass, Treble and Attitude (how hard you drive the power tube)
-Low/high voltage selector switch

That's a lot of features for a little 15watt tube amp!

Sounds fantastic. The amp is not a modeling - it won't go from blackface to soldano tones at the flip of the switch (or swap of a tube). It can go from a Fender-ish sound to a Marshall-esc sound fairly easily though. For higher output crunch tones try using a pair of 12AX7's and an EL34 in high-voltage mode. For more Fender Deluxe type tones try a 12AT7/12AU7 and a nice 6V6 in low-voltage mode. Either way - whatever your prefence it sounds good.
I was just in the studio with several really nice amp and the THD. The Univalve is no slouch in the studio and ended up being my go to amp despite being in a room with a vintage Plexi, a vox, a deluxe reverb, a matchless....you get the picture. I wouldn't say the THD sounded "better" than any of the other amps - it sounded comparable and for what I was doing it worked better in the studio. My Uni really shines with a telecaster, plenty of nice tones from a Les Paul too but the chimey quality of a single coil is very pronounced through the Uni. This isn't an amp for rookies - if you want crazy flexibility go get yourself a Line6 amp - or a Zoom! If you are familiar with quality amps and would like a solid 15watter in your collection this is a great amp a very reasonable price.

I've owned my Univalve for about 8 months. I practice with it a couple times a week, I gig with it regularly, I use it in the studio. It's never given me any trouble at all. I've swapped tubes many, many times and never had a problem. I don't suspect I ever will either - the design and build of this amp is top notch.

Haven't had to deal with support at all - but there is an on-line bulletin board run by fans of the univalve and a few THD employees are frequent contributors. They are very knowledgeable and very cool about answering questions.

Been playing since the late 80's and own many guitars and amplifiers. Most of my amps are Fenders which is sort of why I bought a THD this time out. I wanted something that had a great clean sound (that wasn't the fender clean sound) and had a nice tube distortion. I decided on the Univalve because it sounded great, cost about 1/3 the price of other boutique 15watters, and had so many cool - useful features. I would buy another if stolen. heck I might buy another just because they're too damn cool.

Hotplate, great line out, loud 15 watts

Sounds good clean, but I though channel two should be called "clean 2". Maybe I'm too modern, but that's how I feel on the distortion. It's too damn noisy. I have to keep the controls less than half way up. I use a Gibson LP.. The hotplate is a piece of shit. Talk about fake! The thing makes your dynamics flabby and timing off. It's like an old computer...you can notice it takes longer to respond. The notes seem to have a delay. I tried other tubes but I don't care for those either. People have mentioned it has that hi-end fizzle or buzz sound...That's not part of the sound it's the freaking white noise.
I got this at musicians friend and they got it back 2 weeks later.

Built like a rock... I know why. Cause you feel like you want to beat the hell out of it because it's an annoying amp. The controls and such are a pain in the ass.

Who cares.. never tried nor needed to.

Clean with controls never over half way = great clean amp.
Distortion? hah.