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THD Bi-Valve 30 30W Class A Tube Amp Head

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Product 481281
Product Price $0.00
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The BiValve-30 amplifier head from THD is the big brother to THD's popular UniValve model, but with one major difference: dual output tubes. Both the...Click To Read More About This Product

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Get more bang for your buck with this 30W menace from THD.

The BiValve-30 amplifier head from THD is the big brother to THD's popular UniValve model, but with one major difference: dual output tubes. Both the output tubes and preamp tubes give you free reign on endless combinations to experiment with. The BiValve-30 delivers tones from smooth and clear to very aggressive overdrive, like the UniValve, but with more power and a much more compliant output transformer which means richer, thicker lows. It's easily capable of driving a 4x12" cabinet, yet light and easy to handle unlike many other amp heads. It's built-in Hot Plate power attenuator allows for full output distortion at almost any volume, and the unique combination of THD's touch-sensitive input circuit and the wonderfully active and reactive tone control make for a front-end that really responds to subtle and not-so-subtle changes in the signal.

  • THD BiValve-30 30W Class A Amplifier Head
  • 30W Class A amplifier
  • Single channel
  • Hand built
  • Accepts almost any preamp and power tubes in any combination
  • Ships with 3 - 12AX7s (preamp) and 2 EL34s (power amp)
  • More and Less inputs
  • Volume, Treble, Bass, and Attitude knobs
  • Built-in Hot Plate output attenuator

Hear the unbeatable sound of a tube head today. Order now!

  • 15-1/2"W x 8-3/4"H x 10-3/4"D
  • 38 lbs.

Review Snapshot

by PowerReviews

(based on 11 reviews)

Ratings Distribution

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Reviewed by 11 customers

Displaying reviews 1-11

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(1 of 1 customers found this review helpful)


Bi-Valve 30 Worth It & Then Some...

By Hi, I'm Chris B...

from Catskill Region, NY

See all my reviews

Of all the amps I have played thru, this one is for me the creme de la creme! I sold my mint Mesa Boogie F-30 to buy one of these and I am so happy I did. First off, it is QUIET. Next, it produces beautiful harmonics that are rich and complex and which seem to complement my playing style. Sometimes from a familiar piece I'll hear an entirely new sonic quality, a new texture I hadn't heard before. Plus, swapping out tubes and varying the amps voice is totally cool. And it plays loud enough for a gig but can be played at bedroom levels, too! Yeah, one happy THD'er. :)

(1 of 1 customers found this review helpful)


Lovely Lively guitar Sounds

By Rattlebox

from Seattle, WA

Lunchbox style amps seem to be having a good year. This deserves the extra attention. It is the most versatile amp I've ever played and it sounds great. I use a EH 12AY7 in the input and TS 12AX7 in the driver. It gives a lovely crystal chime that's ideal for country. I use pedals to take into hard rock and metal territory. Many people who own this amp would prefer to switch the preamp tube position. That would give far higher gain and overdrive. One can control the clean-overdrive with the guitar volume. I'd like attenuator better if it didn't neuter the highs and high mids. But it's still awesome that you can put low watt tubes in it for lower apt volumes.


Smooth, clear, overdriven tone.

By THDrocks

from Orono, MN

See all my reviews

The THD BiValve is all about tone. The Hot Plate control and the Volume control work together to form an endless array of soaring overdrive, mistakably clean to extra hot. If you experiment with this amp long enough, you'll discover its secret tone. This tone can't be found in any other amp. If you hit the notes fairly lightly you'll hear a wonderful clean sound identical to a Deluxe Reverb. If you hit the notes harder you'll hear the greatest, phattest overdive ever, identical to a Marshall Plexi. The amp is truly unbelievable! No exaggeration!


Tube Tone Heaven

By Rocky Mountain Rocker

from Rocky Mountains

See all my reviews

If you're looking for gobs of thick harmonically rich class A tube tone, the ability to utilize a wide variety of tubes, and superb build quality, check out the THD BiValve. Don't be fooled by the 30 watt rating, this amp can be very loud if needed. It's also got more gain available than I would have expected from a class A non master-volume amp.


Outrageous Tone Variations

By Walt-WUqV9

from Philadelphia

See all my reviews

Incredible piece of equipment and plenty loud. I was asked to turn it down (during the warm up)during my recital of The Star Spangled Banner for a recent football game. The acheivable tones are infinite. Lower to half power and see what the hot plate, attitude, and volume knobs can do. Want to muddy it up? Lower the voltage and increase the volume. Want a crisp, crystal clear as a bell sound? Install 6550 power tubes. Without changing the bias. Simply amazing. I don't know when I'll plug back in to any of my vintage Ampegs or Fenders, or Marshall.


Pro Tube Amp for those-who-know

By Anonymous

from Undisclosed

This is a professional tube amp with a buffered effects loop... the real deal. Imagine the sweetest Marshall Plexi and the best vintage Twin together in one small box, about 40 lbs. Now picture that with less hum, top quality components and the ability to accept any tube type without a trip to the shop. That is the THD amp incarnate. This is totally professional gear for serious players or those who appreciate quality craftsmanship and intelligent engineering.The price is NOT exorbitant when you consider all it replaces. It is entirely worth every penny.



By Sheesh-ZBl3C

from Portland, OR

I've never heard clean tones that have become so addicting. I haven't even tried any tubes other than the EL-34 and power tubes it came with. I'll have a ball spending years experimenting with all other tube combinations.


Awesome amp!

By Anonymous

from Undisclosed

Really nice amp! With the right tubes, cab and pups, this amp would put a smile on the face of the most discriminating player. The cleans are really warm and harmonically rich. As you turn up the amp its got marshall growl, but it's much smoother - no fizz or hiss. You know it's built well with great quality inards - you can just hear it. Can spend hours just paying clean to slightly overdriven with my strat and a Keeley comp. Sounds awesome. My Fdr Pro Reverb collects dust. No real gripes. It's a medium gain amp, so you'll need an overdrive if you want more gain. No real gripes. Try out the new Tung-sol AX7 and put a Tung Sol 6L6 and Mullard El34 (new production) and it sounds fantastic.

(0 of 1 customers found this review helpful)


Jack of All, Master of None

By THD Believer

from Seattle

See all my reviews

You know the guy down the street. He's the one that can fix your washer and do drywall with the same tool set. He's a jack of trades master of none. That's my impression after gigs, sessions and jams with this head. At this point I would rather have a plexi clone, or JMC 800 clone. A one trick pony sounds better than this head. Don't get me wrong, It's better than owning 20 different heads.


Superb tone machine!

By Johnny S.

from GA

The BiValve is an awesome value! I simply love it. None of my other vintage or modern tube amps can really hold a candle to it. The available tones are staggering. Very fun to play too.


Awesome Amp!!!

By J Page

from Otsego, MI

This amp is seriously sweet. I was searching for an extremely flexible amp and this was it. I play 85% of the time in full distortion and this amp delivers, I put a TS808 in front of it and it blew me away even more. Sweet musical distortion and perfect clean tone that is 10 times better than my old Bassman. BUY THIS!

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