Guytron GT100 Head

This is a 2 channel 3 stage amplifier.It's composed of a 20 watt(2xEL84)cathode bias/Class "A" power amp as its "preamp".The 20 watt amp is then attenuated via a resistive load,and then re-amplified through a 100 watt Class "AB/2" power amp.Of course the signal is filtered through a global set of tone controls prior to final amplification.
It's equipped with 2 effects loops.one "low-power" for pedals,and one "high-power" for rack style gear.The loops are a series/parallel grouping,with a "mix" control on the front panel of the amp.
The rear impedance can be set at 4/8/16 ohms.DO NOT MISMATCH THE IMPEDANCE BETWEEN THE HEAD AND CAB ON THE GUYTRON AMP...EVER!
The channels are switched via a front panel switch,or a standard "on-off" foot-switch.
There is a total of 13 tubes.7 x 12AX7 - 2 x EL84 - 4 x EL34.
There are 2 speaker outputs.
All pots,jacks,and tube sockets are PTP wired,and chassis mounted with "flying leads".
The preamp,and power-amp boards are the highest quality PCB's I've ever seen in any amplifier.
The pilot light is purple...very cool!
I'm giving this an 8,as I'd like to be able to assign the 2 effects to the individual channels.

I've said in other reviews: The Guytron amp nails Edward's tone to the T!".Yes,it will give you EVH's early tones with ease. But! DO NOT THINK THAT THIS AMP IS A ONE TRICK PONY...IT IS NOT! The Guytron GT100 FV model excels in what I call GTA - "Global Tone Acquisition".This however is not a critique of the FV model.The GT100 does not give you the options of "focus",and "voicing".The introduction of FV was the result of repeated requests by players who wanted to do various mods to their GT100 amplifier.I will post a review of the FV model,as soon as I get it back from the Guytron shop.It has a minor problem with at the preamp.
The GT100 has been in short "the amp of my dreams"! I've owned just about every "high-end" amplifier offered on the market,and have played them all quite extensively.TO inclue:Carr "Hammerhead",Bogner Ecstasy 101B,Soldano SLO,VHT Pitbull,Victoria,Cameron modded Carlsbro 100,68 Marshall "Plexi",Mesa/Boogie Mark IIC+,Roccaforte,Fender "Pro-Sonic",Zinky "Mofo",Orange,and Diezel.All of these amps are wonderful amps to be sure...but there was always something either missing-or some tonal element that I wanted to remove from the sound of the amp? Sure,I could add an EQ,and shape tone to my personal satisfaction-but I wanted an amplifier the could quench my tonal thirst by just plugging directly into the amp.You cannot compare the Guytron GT100 to any other amp on the market...period.Its overdrive/distortion circuit is the smoothest,sexiest sounding gain possible in any amp I've played to date.The clean channel(A)is by far one of the greatest clean sounds I've ever had the pleasure of tasting.That's right...tasting! You don't just hear the GT100-you "become" the GT100.This amp has brought back all of the wonderful feelings I use to get in my youth of playing guitar.When I'm done working,I can't wait to get home and plug into my GT100! You actually learn how to play the GT100-just as you would any instrument.Every nuance of you picking,and fingering style comes through!
With the FV model,you can emulate the voicing characteristics of Fender,Marshall,Mesa/Boogie,and Dumble.The FV also has the stock GT100 setting...which is my personal favorite.If you're not playing 2,or 3 amps at a time-then the GT100 FV will be the last amp you will ever need.The GT100 alone will cover ANY musical style the seek-it's that simple! NOTE: It won't give you "Nu-Metal" sounds.You can't get a GT100 to sound "bad".There's no such thing as having to "dial-in a good tone" on the GT100 amplifier.You cannot get a GT100,or any Guytron amp to sound "bad".I would never purchase any amp that can! Guytron is now owed by Graydon Stuckey of GDS Amplification.I have never played any GDS amps...but I did get to hear a local player using one of Graydon's GDS 18 watt amps live.Sounded like a Dumble to me! Guy Hedrick obviously wasn't going to sell the Guytron line to just anyone... I'm sure there's going to be some magical things going on at GDS/Guytron.
My complete rig consists of my Guytron GT100,a GT100 FV,and a 2008 Bogner EL34 "Shiva".(I do like to use a Tube Screamer to cut my input low-end...not to boost my signal).
Once I get the GT100 FV back-the Bogner may be up for sale?

Mine is a Rev B 1996 GT100,that was owned by Mark Chatfeild of The Godz,Rosie,and The Silver Bullet Band.It's been used extensively on tour,and operates flawlessly!

I haven't had to send this in for repairs.I sent my FV in for repairs 3 weeks ago.Once I get the FV model back,I will post a customer service review...
For me,customer service is a defining factor as to whether I will keep an amp,or go to something else.I have a good feeling about Graydon,as he has been most helpful with all my inquiries.

I've been playing,and recording for over 26 years.
I've already put a hex on this amp-so to properly deal with any would-be "gear thieves".
A new GT100 FV runs $3,299.00 It'll be the best $3,299.00 you've ever spent...as long as the customer support is as great as the amplifier itself? I get good vibes!

everything I need

great

no problems

Well its been 10 years of Guytron reviews and the company just changed hands. I am original owner of an early one. I bought it for home use and good distortion at any volume was the main factor in my purchase. Sounds great by itself and even better in stereo with old Marshalls.

Incredible!

indestructible!

Graydon Stuckey of GDS Amplification has recently purchased Guytron.You won't find a finer engineer...period!

This is an "older" Guytron GT100, according to Guy Hedrick, that happens to have been on a Steely Dan tour with Jon Herrington ("Two Against Nature" tour, etc.). Jon has signed the chassis (I communicated with Jon about it, and he still raves about this amp). I think I got it at such a great price because the owner before me thought it was failing because the EL84's were worn out (Of course, I could be wrong. Maybe it was just a great deal.). Although there are lots of reviews here, I felt compelled to add another because I think this is such a great amplifier, which I'm comparing to the countless amps I've owned--from very high-end "boutique" to low-end production & everything in between. You can read about all the features in the other reviews, but, strangely enough, this "feels" like a pretty simple, straightforward amp. It's the first amp--though many have made the claim--I've heard that really does have the best sounds of about 10 or 15 other amps in it AT ANY VOLUME! It has the unusual design--which I don't pretend to really understand--that includes 2 EL84 OUTPUT (which Guy explained to me) tubes in the preamp; and four EL34 OUTPUT tubes in the main power section. This amp is as versatile as they come--it really can make the great sounds of everything from a perfect "bedroom" amp to a monster stage amplifier, and, again, everything in between! 2 channels that are footswitchable, effects loop (which I don't use). Plenty of power if needed. 100 watts output.

I know that tone is a matter of taste, and I'll spare you all the flowery superlatives in describing the sounds of this amplifier. I'll just say that the Guytron GT100 is the best-sounding amp I've ever played through, and that includes a lot of great amps from Allen to Carr to Matchless to Soldano to Zinky to Zwengel & HUNDREDS of others. The clean channel has the best clean & "tweedy" overdrive. The drive channel has the best-sounding & widest-range overdrive. All this at low volume, moderate volume, thundering volume--no matter what. It must be something about the design that others don't know about. -- I'm sure you don't care what guitars I own, but, as you'd expect, this amp sounds great with humbuckers or single coils. It's not particularly noisy. It can make so many sounds with lots of subtle shadings with the "double" EQ and master volume/gain controls that it's mind-boggling. Playing through this thing is such a religious experience that I almost feel like I'm playing different instruments than I was before. It would be nice if this head wasn't so BIG, but maybe it has to be; I don't know. I forget about the size and weight as soon as I hear the first notes. I haven't heard the newer "FV," but if it's better than this, it must be incredible---no, BEYOND incredible!

I haven't had it long enough to know, but, from the testimony of others, I expect it to be very reliable. This one has been around the world with Jon Herrington & Steely Dan as well as with other working musicians, and it still sounded great when I got it--even with the original EL34's that Guy put in it when he first built it.

Guy is great to deal with & very willing to share his knowledge w/re: problem-solving, voicing, history, repair, etc. Soon after I got this amp, Guy suggested I send it to him to fix a loose wire on one tube socket & to go over it in general. He added an "external resistor & a "high grade 12AXT to smooth the sound," which made it sound even better (I didn't know it didn't sound "smooth" to begin with!). Guy couldn't have been more responsive, helpful & pleasant to deal with.

I've been playing for a very long time (as if you care). I also own a Roccaforte & Joe Naylor-modified Naylor SuperClub 38, and a John Martin (Martone) Spitfire right now. Nothing much else seems to satisfy me anymore. I've owned everything--just about--in the past, and this one comes out on top when A/Bing with any of them. Not only would I get another one if it were lost or stolen, I'm thinking about buying another now JUST IN CASE so I wouldn't have to wait for another. If you're one of us who drives himself or herself near-crazy going through amp after amp looking for a great sound, you owe it to yourself to try one of these Guytron GT100's. Whenever I see somebody selling one in any of the various net marketplaces (usually at much higher prices than I paid), I really can't understand why!

This amp is from 2003, serial number *408 the main features are told by the 22 other reviews.
I switch the 2 channels by the A/B function on my T-rex Bigfoot/mac1 system. I like the amp very much altough there are only 2 channels, the sounds are very usefull for what i do. I will buy some barber/menatone/fulltone pedals soon to get more sounds.

I use mainly a custom build Haar stratocaster with 2 Suhr lowpeaks and a Hausel humbucker (www.haarguitars.nl) these are very good guitars with lots of tone! (i am thinking of buying a tele soon)
The amp and guitar suits my style of music good thats why i bought it!
The A channel is good, the B channel is a bit noisy cause of the groundloop from my rack, i should work on that soon!
The amp is a real 60's stock amp sound like those old fenders and marshalls. I like it prety much!
The gain from channel B isnt as hi gain as a Uberschal but its okay for me!

I think (as said before) its build like a tank! realy well build and there is a very good case included!

No opinion yet!
But the dealer was very usefull (www.haarguitars.nl)

I play with lots of gear ( see http://groups.msn.com/ieme )
If it would be stolen i would get another one, maybe now because i have only 2 channels now and i prefer to have 4 from these!

My head was made in 1999. The features on this amp are all you need, period. Two speaker outs, two effects loops mixed via front knob, presence.

I play classic rock and this amp does everything. The balance between Channel A and B is perfect. For fine turning use your volume knob and a good overdrive pedal like a Blackbox Cobalt or Fulldrive 2.

Built like a tank and just as heavy. 1000 years from now they will have these things in a glass case at the Hard Rock Cafe on Mars.

The company is friendly, no issues here.

I have been playing 25 years. This is the only amp I have ever played that sounds great at both low and high volumes. I have several high end low wattage amps but they don't come close to the girth, low end, and huge round tones the Guytron produces. Trust me, this head is a 10 and you will sell all your other feeble amps after you get one. Plus, I just made $600 selling all my vintage pedals which I don't need anymore. This head is truly something special... pair it with a quality guitar like a PRS McCarty (my preference) and you can do anything.

100w Head, 2 channel footswitchable w/2 separate channel EQ's, gain, channel volumes; Separate channel controls feeds to the Master volume section w/adjustable EFX loop level, Bass/Mid/Treb EQ, Gain, Presence, Back of head has 2 EFX loops (for pedals and rack gear) can use both simultaneously; 2 speaker output jacks, Switchable speaker Ohms 4-8-16, Switchable power (US/UK); Channel LED's, rock solid chassis and excellent venting. Built like a tank, 65 lbs.. Combination all tube preamp, feeds to dual EL84 pre-output, cascading to EL34's power section (!) How big can you say woody..

Hamer Archtop (Duncan 59'ers/JB Neck p/up), Les Paul (Dimarzio SuperDistort/PAF), 70's reissue strat w/HS1's/HS3's; EXCELLENT EXCELLENT VERSATILE AMP TONES !! Great 3 dimensional tasty distortions, glassy cleans, just about every variation you can dial in between (PSSST: AND THEY ALL SOUND GREAT) You can't get a bad tone out of this amp. Honest. Violin sustain, AC30 crunch, glassy clean, ominous power chords, I even forgot I wasn't using any effects yet either..When I added them on it was better than (___) (fill in your choice here)..

Excellent pick attack texture, breakup, SUSTAIN for days if you want it, excellent glassy clean tones, (Check out the great guitar tones on .38 Special Live at Sturgis CD; All the songs, (especially Wild Eyed Southern Boys); THIS AMP SOUNDS EVEN BETTER THAN THESE LIVE!) I tried an EQ and a tubescreamer in front of the amp to hammer the input stages (it doesn't need it - trust me) and whoa ! created a monster (whew..)

This amp has put back all the enjoyment AND BREATHED NEW LIFE in every guitar I own; I'm 45, have played about every amp on the planet as a performer and a partner in a major full line music store. I've been playing clubs regularly since 1977, I SHOULD HAVE BOUGHT THIS AMP YEARS AGO (argh); I waited 5 years from reading the Guitar Player 1998 excellent review of this amp to keeping tabs on it and finally spent the money getting my hands on one in 2003; IT WAS ABSOLUTELY WORTH IT. NO DISAPPOINTMENTS. Only that I tried everything else and waited until now to get one! The Guytron amp is super responsive to your volume roll off, attack, and playing nuances (Maybe that why John Herington in Steely Dan uses one..) I'm saving my $ for a 2nd one for backup.

Guy Hedrick was nice enough for a nominal fee to work my new amp in for a drop ship and rebiased the EL84/EL34 cascading power stages to my preference, and DEMO'D THE SETTINGS OVER THE PHONE AS HE TWEAKED THEM ! (Hey when's the last time you had a company president take the time to listen to how you wanted your car tuned up ? etc.) The amp's built like a tank and I have never yet met someone so genuinely interested in the thrill factor and satisfaction of their customer. Period.

See above comments. Besides answering his own phone It's a nice surprise to have someone (the President no less) take the time to LISTEN to the customer's view, questions, etc.

Anything else said would be redundant. Opens up a new world of playing. Excellent versatile great sounding amp. Period. I'd even pay more (if I had to).

Mine's about 5 years old. I requier an extremely clear clean sound for the majority of my songs and on the occasion when I do a solo I generally want it FAT and Full and Lush. Once I traded out the 12ax7 in V2 to a 12at7 the ultra clean at high volume went from 90 % there to 99 % there, it'll still overdrive slightly but so little I can live with it. It is a superior beast this amp. Makes the rivera I was using before seem like just an okay practice amp, but it would never do for shows now that I've used this guytron exclusively for the past 6 months.

The guitars I play are Gretsch with TV Jones filtertron pickups. I built my own Cabinet with 2 JBL E120's. I fingerpick many of my songs, sort of an older slightly sloppy country color I guess, hence the need for clean. In other songs I suppose a good example would be sort of neil young thickness. The amp pulls it all very well, so well that it gets much praise at the drunk end of a night. I should also add that I've used it to play a couple of acoustic things and it's wonderful, as good as any strickly acoustic amp I've tried, and I've tried 'em boy. Channel 'A' is not noisy at all. Channel 'B' is a bit noisy but it is the 'Stoner' channel so once a band is up and running and you switch over for a lead part you certainly wouldn't notice. The other guitar player in my band plays through a deluxe or an AC-30, both of which are pretty hissy when idle. The guytron compaired is wonderful in my view, he likes his and I like mine, it works. A channel can get pretty loud before it starts any sort of breaking up. 'B' starts off breaking up and gets downright thick as mud, very cool oozing sort of distortion - think of the slightly late compressing goo that Neil young gets, it's like that in my ears. Brutal, but I say good.

I've only owned it for just over half a year but the guy I bought it from played the hell out of it since new and I use it out a lot. I feel very confident in it reliability. The guys who builds them seems to have done his job extremely well, better than the whole lot of top dollar retro looking class A things the kids are so crazy about at the moment

Can't say!

I've been playing music for many years. I'm only interested in equipment for how it'll do what I need it to do. I would get another one of these if mine were lost, that is once I could afford another one, they are very expensive amps for your avarage working musician. I compaired it through a many long years of having this or that amp. This is the best amp I've ever owned hands down for what I do. I wish it had a beer holder on the side because if you spill anything on the top of it, it's going into the works of the thing and that can't be good.
To end I'll add this: I normally wouldn't leave a review, but I thought, 'Ya know, this product desirves high praise. Guy runs a small company and I hope he has lots and lots of success. He's building such a nice amp, the most favorable amp I've used both on stage and for recording. If you're reading this because you're thinking about trying one for yourself, I highly recommend that you do because it's a great piece of quality equipment, far and above the corporate music gear nameplates and better thought out than the many jump on the ol' band wagon class A boutique, trend of the moment type company products.

I've had the amp since new in the fall of 1999 so I've had plenty of experience with it.
Here are some of the details others haven't mentioned:
It has two channels but they are completely seperate unlike most amps. Meaning that it uses different pre amp tubes (12ax7s) for the two channels. The advantage of this is that Guy didn't have to compromise at all when voicing the individual channels. Also you can suff different 12ax7s in the two channels. I use the Sovtek Lp for the clean channel and the 12ax7EH for the Gain channel. JJs sound (overall) best for the EL84s.
Also this amp is all tube unlike Boogie for example who use LDRs (solid state) for switching. Guytron uses relays that don't swell, pop, or delay when switching channels. The EL84s are hybrid biased (both (adjustable) fixed and cathode biased) while the EL34s are (adjustable) fixed biased. Guy has conveniently put one ohm cathode resistors so you can easily measure the cathode current in the power tubes. For me this is a great convenience cause power tubes (bias) do drift (cold) and being able to adjust them to keep max tone is a must and yes you can hear when they drift cold. This is just one of the reasons Mesas non adjustable fiixed bias scheme is so bogus. I could write a white paper on how much bs is in Randy's "White paper on Biasing" -what a joke. Also this amp sounds harsh with the master near zero. On reviewer noticed this. This is easily fixed by simply running (EL34) the bias a bit hotter. Guy sets it at 28 -32ma but 35-40 will sound better at lower volumes. The 45 -50 ma setting of the EL84 (yes 50 ma) that Guy sets em to seems to be perfect. If you let the EL84s drift below 40ma and they will you should hear the sound degrade. This is why being able to adjust the bias on a tube amp is in my opinion important.
Also to note: Some people have mistakenly said that Guy uses New Sensor trannies. So I asked him about this while on the phone. Guy said that he has an "old army guy" custom wind em for him. This makes sense because the one for the EL84s has two secondary taps. One for a 7.5 ohm resistive load (to dissipate signal) and one for the signal to contunue on through to the effects loop. So without a doubt that trannie would have to be custom ordered.

The early configurations of this his amp generate some compression ala an AC30. Some people like it some don't. I didn't. (See customer support)
But the one produced in the last few years don't due to customer feedback. There is an "X-mod" avaliable to address this and a few other issues (again see customer support).
But how does it sound?
The cleans are the best I've ever heard and I've extensively A/B this amp with some nice amps (Kingsley, B-faced Deluxe, and a Tonemaster). I'm not kidding!
The gain stuff is tone city too. I extensively compared the Tron with a TSL (at gig volume) and the Guytron sounded more like a classic Marshall than the TSL did. The Tron has a darker and warmer brown sound while the TSL has the brighter and harsher browns to it. While the Tron has lotsa gain if you want it Id look else where if you just want the NewMetal tones. The Tron is better at the stuff from Glassy cleans up to VanHalen gain. Maybe it's cause the it's hard to get a harsh tone out of it. Seriously!

I use mine almost every day anywhere from 20minutes to 3 hours I've haven't had a hint of a problem yet and don't anticipate anything in the near future. I've had this amp apart a number of times (usually to adjust or check the bias). So I can tell you that the workmanship is what you would expect in an amp of this price to be.

This amp came to me without the X-mod. After I had the amp for about a year Guy told me he had developed an X-mod for it. So I asked him if he could send me the details so I could perform it.
Guy sent me a shematic with the changed parts highlighted, included the parts, wrote a letter explaining the details and gave me phone support on a Saturday! Needless to say the X-mod was an outstanding success! I can't say enough about Guy's customer support!
Here are the details about what the X-mod does and some of how it's done:
The EL84s were being driven hard and this caused the AC30 type compression so we lowered the signal to em from the phase inverter/ driver. To compensate for this the phase inverter is slammed a bit harder from the pre-amps. Apparently some users wanted more "focus" (I thought it was just fine as is) on the gain channel. So Guy added just a touch of mids to it and I mean just a touch. I used this oppurtunity to play with the new, old and inbetween resistor values to see what I liked and the difference was only subtle to me. The non X-modded version get's a bit grainy when you crank the clean channel's gain so a preamp cathode bypass cap was changed to eliminate this. I didn't detect any compromise in the tone by changing the cap.
All new Trons are now X-modded. If you get an older one and it sounds too compressed for you. I'd seriously look into getting it X-modded you won't be dissapointed!

I've been playing for about 20 years, have a good knowledge of tube electronics (specifically tube guitar amp electronics) and work as a tech. If this amp was lost or stolen I would research the market like I did when I got this amp but I'd be very supprised if I didn't get another Guytron. Simply put this amp sounds incredible from Glassy cleans all the way to Van Halen from near bedroom volumes up to stadium levels.
If your cleans don't sound incredible with this amp most likely look at your pickps.

2 channel head with a rather unique architecture: there are EL84's before the EL34 power section. This means you can pre-saturate before you drive a cab.
2 effects loops, 100 watts, yada yada.

This amp has given me back two guitars which I haven't used in long time - an ancient Gibson ES300N and a Strat with a set of EMG SV's - because they sound terrible and thin through my Bradshaw rig. My Tele's and Strats sound amazing, and my Danno's sound silly as well.
Grounded correctly, it is clean and quiet even on high gain settings.
The topology of the amp makes it a pleasure to wank on at any volume.

As a matter of fact, I find myself leaving Channel A (basically the "clean" channel) on the same setting, and using the guitar's knob to clean it up completely. This amp can even do what I have never heard another amp do: get the sound my Super Champ made through a big tube power amp for the three weeks before it blew up. Like Stevie on steroids.
The distortion is not brutal - it's beautiful.

The cab is a 212 of Guy's design, with a 30 and a 75 watt Celestion in side.

No idea as to reliablility, as I just got it, but it seems to be made like a Mac truck. Military grade parts throughout.

I've never spoken to Guy, but we have exchanged emails a few times. A truly nice and talented fellow, from what I can tell.

I've been playing for years, and I am a working session guy. My other rig is based around a Bradshaw 3+SE pre and an old Mesa Triaxis, with a TC Gforce and a DP4+ as effects (among other pedals and such rot), routing through one of Bob Bradshaw's switching systems to a 2:90 power amp. I have five cabs to choose from.
If this thing were lost or stolen I would definitely replace it. In fact, I am thinking about getting another one and running them with my Bradshaw amp switcher into the same cab (four Guytron channels!).

Let me just say that I might have to write an article in Guitar Player next year saying "Guy Hedrick saved my life" or something. I have not cared about playing guitar in a number of years, even though I continue to play on a number of records, because I haven't had a sound that I liked. I had no problem getting tones that people liked in the studio, but they never spoke to me.

Now, I feel like I was 22 again! I just want to play loud angry notes! This amp is both spanky and spungy at the same time, and gives you a nice fat transient to float when you strike the string. It is an absolute joy to play this thing, and it has given me new vigor - literally. I no longer feel old (and I'm not old, that's the thing...I've just felt it for a long time)!

Go to guytron.com and check these things out - then order one.