DigiTech GFX-1 TwinTube

If you ever ****** with a preamp then you'll catch on quick. Its old so you gotta scroll, scroll and scroll some more to get where your going. But even with the inconvenience factor, it sounds so good that who cares about the editing?

Les Paul and Strat are the guitars. It's noisy with high gain but otherwise it's pretty damn quiet. Most amps are noisy with the high gain maxxed out so really its no issue. This is a killer preamp but the effects are a joke. The delay isn't terrible to tell the truth. This thing isn't about effects anyway. It would be better if it didnt have any. i never use them. Its all about the preamp.
This sounds very, very good either clean or with distortion. It burns like a blowtorch for hard rock or metal. Its the bomb. It gives the sweetest cleans. Everything in between is perfect. I tried out newer units in my time but I never moved ahead. This is still one of the best sounding preamps around. Until somebody comes up with a better preamp Im sticking with the GFX1.
My sound path is this: Guitar - BBE wah wah - GFX1 - Fender Bassman 50 - Peavey 4x12 cab with vintage 30s.
This gets a 10.

Built to take it. Tough as hell.

You can't beat this for true tube tone. Nothing else comes close. For a unit made so long ago it still has the goods and beats the crap out of modern preamps with all the useless bells and whistles.

Some of the presets were okay, most were crappy. It wasn't that hard to figure out how to change and save the presets to something better. One drawback about the editing process, you have to scroll through the different parameters in order to change anything. (whereas, my ADA preamp has a button for each one - I guess that's the tradeoff - the GFX-1 has less buttons to monkey with) I was able to find the manual online by simply Googling for it.

I don't know if these came with Mesa tubes inside, but that's what mine has. Oddly, they're not 12ax7 tubes...I forget what they are, but definitely not 12ax7, so I'd say they've been changed.

I was using strictly my single coiled Telecaster initially, and have since tried my full Hollowbody Ibanez with Super 58 humbuckers. It sounds really impressive with either guitar. It's a bit noisy on high gain settings, but most preamps are, so I don't see that as a drawback. Further, the noise gate works well to keep that noise in check. I'm running out of the GFX-1 into a Quadraverb, then into a Solid State ADA B200s poweramp. I only use the compressor and tube gain in the GFX-1 and use the Quadraverb for all chorus, reverb, or delay.

I have also plugged the preamp directly into my tube combo amp, so that I don't have to lug around my speakers. Because every combo amp's tone varies, the speaker emulator feature is a definite plus here (see the Overall Rating section below for what I'm talking about)

The sound out of this thing is very rich and tube-like. It rivals my ADA MP-2, which is impressive. A lot of bang for the buck in this little thing. Two tubes really bring out the yummy saturation for high gain stuff, and the warmth of a tube amp on cleans. Very nice unit and a suitable backup for the ADA, should it need one. The thing is, I'm playing with the Digitech a LOT. It's really a good sounding preamp.

I don't know about the reliability, but it's over 15 years old and it still works. I just bought it used, so I don't really know how many hours this thing has on it. I will say this though, the paint is wearing off one of the parameter buttons, so somebody has been hitting that button over the years.

I bought it as a backup, so I guess I have a backup in place should I need one. I usually have some sort of backup at every gig, because if it's gonna break, it'll be on stage (never at practice :)

Well, I found the owner's manual on Digitech's web site very easily, so they get points for that. I doubt I'll be able to get much support for an item this old, but who knows.

I play a wide variety of styles. The only exceptions to "everything" are death metal (complete with alternate tunings) and country (with all that twangy stuff). I think this preamp could handle either of those styles and everything in between without a problem.

What I typically play is Alt rock, Jazz, Funk, Blues, and occasionally some pop. Hey, I play whatever I get paid to play :) I've been playing for over 25 years, and I'm really glad I hung on to my rack gear while I tried boutique tube amps & other options. The rack rules, simple to set up, only one button to change your entire tone, flexible and expandable.

I think this unit really shines on clean sounds, with the compression pretty high. I get a nice spanky sound out of the Tele and really nice Jazz tones from the Hollowbody. That is not to take away from the crunch tones though, it's very nice for that too. I can get some solid distortion from this thing that doesn't fizzle out, or I can set an overdrive that is very responsive to picking attack...perfect for blues.

If it were stolen, I would not hesitate to look for another one...they're pretty reasonably priced. It holds it's own against my ADA, and it's a fraction of the cost. I can use my existing MIDI pedal to change patches, so it's even more affordable if you're not buy the proprietary Digitech foot controller.

The only drawback that I can see is the scrolling through parameters to get to the one you want to edit. Other than that, it's pretty easy to make edits on the fly. One very nice feature is the "speaker emulator" which is really just a global EQ. You can set individual EQs for each patch, but when you use the "emulator" it affects all the patches...very handy if you're plugging into somebody else's cabinet or (as I've done) into a combo amp that has a distinctly different tone than my rackmount power amp.

Okay so I lifted this from the guy before me. Sue me. It's the best description of the features that's on this post.
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1. Great Compressor.
2. Preamp. Versatile, good sounding preamp, especially using the tubes. Good gain and saturation settings and controls.
3. EQ. Good EQ section. Each 1dB up or down step in the bands makes a difference you can actually hear, except for the 16k band. Seven bands of EQ..
4. Volume. Plus or minus 12dB of volume. Plenty of room to equalize your volumes for different gain amounts.
5. Noise gate present, but not the best.
6. Effects. Very limited digital effects. Chorus, flanger and delay is all you get. You can only use one at a time. Sound quality is okay.
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Hey. this is very good preamp but a stone age box 4 effects. 7 FootController. Uses any MIDI pedal out there or the dedicated Digitech one.
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This is very easy to use and it gives you tone that's out of this world.

Let's face it. This is a damned good preamp but it's a crap effects processor. Use it for the preamp functions and you'll be happy as hell. It will give you good cleans, overdrives and distortions. Good compressor, overdrive and distortion. Good EQ section. This is one of the best tube preamps ever made.

Anybody who knows anything about tube preamps knows that the GFX 1 is still considered to be one of the best preamps ever made that's still around. It was made back in a period of time when the analog overdrive circuits still behaved like the ones in REAL tube amps. That's why it sound just like a tube amp. IT IS A TUBE AMP!!! Duh.
If you get one that doesn't sound good then you need to swap the tubes. If it still sounds bad to your ears, sell it to me! LOL

1. Great Compressor. Best I ever used.
2. Preamp. Versatile, good sounding preamp, especially using the tubes (two 12AX7 tubes holy shit!) Good gain and saturation settings and controls.
3. EQ. Good EQ section. Each 1dB up or down step in the bands makes a difference you can actually hear, except for the 16k band. You have to make a drastic change at 16K cuz it's too high to hear. plus or minus 12dB per band. seven bands.
4. Volume. Plus or minus 12dB of volume. Plenty of room to equalize your volumes for different gain amounts.
5. Noise gate. Limited noise gate. For high gain with lots of compression it is great when set to the lowest value. For anything else it will chop your notes off. Not shit, but not the best.
6. Effects. Very limited digital effects. Chorus, flanger and delay is all you get. You can only use one at a time. Sound quality is okay.
Hey. this is old shit people. It's a very good preamp but a stone age box 4 effects. This is easy as hell to work cuz it is so simple. Very easy to get ass kicking killer tone from it.
7 FootController. Simple to use and it is made 4 the twintube. Goez in a special jack on the back.

For using it to do rhythme or leads it will do anything and does everything very good. Just use the compressor the preamp and the EQ and you will find too many ass kicking sounds to even count. The clean sound is fat and sweet. Don't use the compressor for clean stuff. Clear as hell. Rings like a bell.
The distortion goes from blues overdrive all the way to pretty heavy distortion. Use the eq and the compressor to tighten up the distortion tone. Super high gain presets are what the noise gate is for. Works like a charm but keep it set real low. Twintube kicks MAJOR serious ass 4 the high gain stuff. I still shit myself even after years of using it.
I owned it for about 7 years and I still find new ways to get even more great shit out of it. Never fails to get people telling me my tone is great. Even with my shitty peavey bandits I still get compliments all the time on my sound.
I use it with two peavey transtube bandits. Keep them on clean with the volume up and the master volumes up and the T dynamics on 7. Plenty of power and punch.
My guitarz are Ibanez RG 350 and JEM 6 string. I have a few cheap guitarz 2...but the Ibanez ones are what I play the most.
For my style of hard, ass kicking rock and 80s shred and metal the twintube is the bomb. I used other preamps but this is the best 4 me. tried peaveys and other digiteks. This is the best.

I dropped mine 2 many times to count. It never broke and never let me down once. I never changed tubes yet. Just keeps going, man. It was made in the 90s so it is OLD. I was like 10 or 11 when this came out.

Play hard ass rock and early metal like Crue, Metallica, Def Lep, Scorpions and some oldies like Led Z, Deep Purple, Santana, Stones, and other shit from the old days. Play clean and mostly distorted styles. I'm hard on equipment so I use solid state amps so I need tubes somewhere in my chain. I love how this sounds and I will never get rid of it. Now they are cheap cuz people want the new shit. I need good loud clean tone and distortion and thats all I need so the twintube is all I need.

I'll start by saying that until now I have resisted purchasing rack mount gear. I avoided it like the plague in the 80s and 90s, preferring to use older BOSS pedals like the ME 5. Maybe that's not entirely accurate; I actually did buy a BOSS SE 70 processor, but it never left the home and wound up being a high-priced headphone / practice amp. Although it was a pretty cool unit for noodling around, I could never seem to coax a really desireable live performance tone out of that box with the amps I used, which are 112 combo amps for the most part.
Enter the Twin Tube. A friend was getting rid of his and I almost passed but the price was good and so I figured what the hey...I owe it to myself to demo this box. Boy am I glad I did!
The best feature is the lack of unnecessary features. This unit has an excellent analog compressor, analog preamp with tubes, great EQ section for every patch (plus tone-curve global presets), decent delay /chorus /flange digital algorythms and handy front panel master input / output levels. It's very easy to operate. Mine came with a Rolls RFX MIDI Buddy foot controller-again, a simple, no frills unit.
There is a pair of 12AX7A tubes in the Twin Tube, which you can insert into the signal path-either one (clean) or two (overdrive/distortion.) The clean tube setting seems to deliver a nice "output tube section" kind of vibe, and the dirty tube setting adds distortion. As mentioned, the EQ is really good with 12dB of boost or cut in the guitar frequency bands. Very effective. There is a noise gate, which would probably be good for the ultra high gain stuff but it cuts notes off abruptly in the clean, light crunch and moderate distortion settings I use...so I don't use it. At the low settings I use, it's quiet as a mouse without the noise gate. Using the noise gate makes it TOTALLY silent when you're not playing.
MIDI in /out-through(shared). Separate connection for the proprietary Digitech foot controller. Nice big fat AC cord. Internal transformers. No phantom power js available from the Twin Tube for the Rolls MIDI Buddy so I use a 9 volt wal wart. Mine runs software rev. 1.01 and it has the RIGHT features so I'll give it a 9, cause I wish it had reverb.

I'm using a Gibson Les Paul with 490R and 498T PUPS; a Jay Turser Chalice (older headstock inlay) Serpent LP knockoff with GFS Dream 180 PUPs; A Jay Turser LT deluxe (Telecaster knockoff with humbucker at the neck) with GFS hot rail bridge humbucker and GFS Alnico boutique PAF in the neck; a Jay Turser Moon ("NEW" headstock inlay) JT 200 Les Paul knockoff (Goldtop with mahogany back/sides-beautiful guitar!) loaded with LACE Hemi-humbuckers (KILLER set of pups!) and upgraded control pots&caps, and an Ibanez SA 160 QT-stock.
The Twin Tube allows the character of each of these very different sounding guitars shine through. It's an analog unit so no digital artifacts and it's touch sensitive. WOO HOO!
This unit is stupidly perfect for anyone who wants a nice clean, gritty clean, bluesy overdrive, perfect rock tone that is FAT and loaded with sweet harmonic content. It may not have enough hair for metal but it will do anything else and do it very, very well-tonewise. Any old stomp box can give your amp a boost or add distortion; this box will give you the perfect Fender clean tube tone, perfect Marshall tube tone, (almost) perfect VOX (class A) tube tone and a nice (almost perfect) early Boogie, saturated tube tone.
As for amps I'm using it with, all of this great stuff is going into a Roland BC 30 or BC 60, in my case. These are two very nice SS amps from Roland so the Twin Tube simply makes their circuits all the better with a tube-rich audio signal going into them. The clarity and glassy, juicy tone of this unit justs cuts through the Rolands right through to the speaker cone and drips with true-tube tone like no other unit I've ever used before. I like the Blues Cubes for their "Almost Tube Tone, but now they NAIL it with the Twin Tube!
I only have 4 patches that I use, a nice rich, warm Fender tube clean that has just a tiny bit of hair when I dig in; a slightly bluesy version of the Fender clean with a bit more tubey, spongy overdrive; a jangly AC type VOX class A tube sound with a little overdrive and harmonics and a Marshall JCM 800 "in your face" C_R_U_N_C_H tube tone that allows for tons of sustain and harmonic feedback. Each patch includes a tiny amount of delay-that's it.
All the tone knobs on the Rolands are set to 12 o'clock so I can boost / cut the lows, mids and highs at the amp, according to the room I'm in. This is a good working system, folks. I could never return to floor pedals after using this. It is a MONSTER tube tone box. The MIDI Buddy makes patch changes a noiseless, instant breeze and there's another 116 patch locations so I'll probably not have to worry aboout running out of program space, ya think?
I leave it on 100% of the time, switching patches for the type of sound I need for a particular song. That's it for me. One box full of righteous tube tone, a respectable amp and a couple of cords. All I need to get what I want.
The compressor and the EQ section work together to produce a fantastic clear signal. The tubes add richness, body and harmonically rich balance & clarity. This is one righteous box, folks. It is "THE KIND!" It will improve whatever you're using for an amp-SS or tubes.

N/A Hey, this was made in 1993 so it's done the job for 14 years without a hiccup. My guess is that I'll have it forever.

The user manual is still available for downloading at the digitech site. God bless those guys, huh?

I'm a big Les Paul fan but I also like the strat and tele tones so i have them, too. I've been a serious electric player since the mid 80s. I played bass and a little guitar back in the 70s but my real gigging career with the electric guitar started in the 80s and 90s. I play in band that does a blend of rock, surf, hard rock, jazz and blues these days. We have a steady monthly gig (that's all I'm looking for) and play for a local surf shop at their events-we're the house band. We also play private parties and for a local church youth group from time to time. I'mm 55 this year and extremely grateful to be gigging at this stage in life. I know what good tone looks, feels and sounds like so I'm very pleased to have acquired this unit to augment my rig. I highly recommend this unit and I believe it will become one of those classic pieces of essential gear like the TS 9 or Univibe. You won't be disappointed with one if you are looking for authentic tube tone. Dude...IT'S IN THERE! A fantastic value at current eBay prices.

i aquired the unit second hand, so guess what NO MANUAL. however once i figured out how everything works on it(after like a week, seemingly endless parameters) its all rather up front after you get to know it. if i would have had a manual it would have been easier though.

ive given it an 7 simply because it is an absolute neccesity to use an external eq. unless your running through a sound board. if you try to run it into a power amp(strait power amp, no controls other than master volume) using only the built in eq. it sounds like absolutely useless garbage. but if you already have, or purchace an external eq., like say, a crate audio cq31(what i use, in my opinion one of the best if not the, but well leave that for a separate review)than this pre amp has almost endless potential. my gfx1 currently is tuned in somewhere between boss metal zone and randall rh200(with the help of the eq. of course). FREAKIN SWEET!!!

seems reliable to me. ill definently be hurt when it dies(godd willing that day come after i die 70 years from now). as far as a backup, rule of thumb is if its got tubes, bring a backup.

never dealt with them

overall, if used with the right equipment, i.e. external eq. and decent power amp, if givin the oportunity to make the decision regarding the purchase again, i wouldnt hesitate to pusrchase it again. ive been playin for 8 yrs. i play metal and this things great for it. my setup is as follows: digitech gfx1 w/crate audio cq31 in the effects loop, which is run into a somewhat vintage crown d150a which powers 1 412 marshall cab loaded w/celestions and 1 4x8 custom built cab(my frankenstein built from a guitar research cab)with diamond plate grill and loaded again with celestions. with the unit as a whole is a heavy metal weapon.

very easy to program good sounds outta this thing but then i used to own a digitech dsp256xl and the menus and button configuration are virtually the same so i was used to it. Got a manual with it but never needed it.

I only use the preamp on the twin tube, I come out of the fx send into my PODxt (bypassing the twintubes crap digital effects)then out of the PODxt in stereo into a Marshall 9005 all valve 50/50 power amp then into 2 2x12 celestion loaded cabs. Both units are controlled by a FCB1010 midi foot controller. I only use the fx on the PODxt because I HATE the crap digital fizzy sounding amp sims on the POD.
This setup works really well, i have the best of both, real tube overdrives and tone and very high quality digital effects. I can get any sound i want.
When I first got this unit it was loaded with a pair of groove tubes, probably the original ones and the sound was harsh and a bit tinny and lifeless so i changed them for a pair of jj's and that did the trick, a lot warmer and natural sounding.
I use this setup with an ibanez 1570 loaded with custom made active pickups, 2 humbuckers and 1 single coil, the single coil does create a bit of hum with this unit.
the compressor is really very good but the noise gate is a bit too good cutting the sound before you want it to. I leave the noise gate off and use the one on the PODxt.
The digital effects on this unit are not really very good and the lack of reverb is just crimminal, for this reason I give sound quality a 9 and not 10

super reliable, I have dropped this thing a few times, bent the front etc and it just keeps going

I have had no need to contact digitech

I've been playing 26 years and over that time I have owned a lot of equipment, I play rock and blues and this unit (with the PODxt)does it all for me, from lovely warm compressed cleans to blistering super overdrives and everything in between with the push of a button on my foot controller, what more could you ask for :-)

Typical pages and scrolling for programming sounds. It's a little more simple than stuff that's out these days, but's certainly not a problem child.

Digital effects are OK, but not excellent, however the analog preamp is awesome. I have had this unit for about 10 years now and I still find new and awesome sounds. The trick as stated in an earlier review is to use the tube clean sound for Marshallesque stuff with less saturation. I tend to think of the Saturation as "preamp tube distortion" and the Gain as Power tube distortion. Both are impoirtant, but the balance between the two is critical for programming great sounds.

My chain is guitar> GFX1 (with volume pedal in effects loop)> Alesis Quadraverb> ADA power amp> Celestion 1x12 cab.

I have used it for 10 years and it's never failed me on a gig.

I had a problem with the cable to the foot controller and had to order another one. Their customer service stinks. It 5 weeks and about 15 phone calls to get my cable 'cuz they were out of stock, even though they took my $$$ on the first phone call.

Great sound with a Yamaha Pacifica 912 (late 80's) and a ADA power amp to a 1x12 Celestion cab. I've changed bands and styles a lot in 10 years since buying this thing and it's the one thing in my rig that has not changed during that time.

I have been using one of these for several years. I've owned two of them. They are pretty simple, but with the manual you have more info to work from, and there are some things that you'll never know without it. I find it easy to use, but then I'm used to it. My current unit has software v. 1.02. The software in these is somewhat buggy; my old one would boot up in a strange high gain mode if it was initially set on a tube patch but booting with it set to a solid state patch was fine. My current unit does not have this peculiarity but it is subject to "forgetting" all of its digital effects settings, although so far they have come back after shutting the unit down and letting it sit for a few minutes. Luckily, it does not do this often. I recommending backing up the memory!

As for getting a good sound...that depends on what you want. IMO this unit is best when the tubes are disengaged; in this, I seem to be totally counter to most of the people here. I really like the clean (solid state) sounds this thing has and I hate the tube sounds. The tube distortion the GFX produces comes from diode induced clipping rather than real tube overdrive. I build tube amps and think I have a fair handle on what I'm talking about.

The unit is limited with respect to effects, having only digital delay (no reverb, just delay), chorus and flange. There's not even a tremolo, although the compression sounds better than you would expect. The output is mono although there are left and right outputs so you can use a stero fx unit in the fx loop. The very high gain tube settings are pretty noisy and the noise gate isn't very adjustable, having too few paramaters for my taste.

Both of mine have been reliable with the exception of the already mentioned memory glitch one of them has.

I have dealt with Digitech and found them helpful once you get past the phone menu. I was able to get a printed copy of the manual from them for this but I gather from the other reviews you can now also get it online.

I love the GFX-1 for its clean tones but I never use the tubes. Because the unit is so old now you can someitimes find them pretty cheap. If you want true tube tone buy a real tube amp with an output section, but if you want GREAT clean tones this unit can be very helpful.

Editing this thing is a bit of a hassle, as you have to use buttons to navigate through parameters. I typically just set it up with presets and then go.

What knobs exist on the unit are easy to use. Input and output volume levels (separate) are handy and easily accessible.

Don't have the manual.

Using this with a variety of solidbodies. I typically use this thing as a recording preamp or practice amp. I run it into a 31 band graphic eq, then into a lexicon MPX 100, from which I run a pair of headphones. Sometimes I dump the MPX to my computer or zoom hard disk recorder.

The unit is a bit noisy, but I don't know how old the tubes are. I haven't bothered to replace them.

The unit sounds quite good considering its vintage. THe cleans are a bit bland, but serviceable. It certainly beats out some of my other gear. Medium gain settings are acceptable, and you can get a decent crunch out of it. I've only tried out the high gain settings once (i'm a jazz guy and not into high gain stuff anymore)... ironically, I ran it through a roland ac100 acoustic amp at a jam session, and the result was something jawdroppingly close to a marshall. Very odd...

My particular unit has no effects, so I can't comment on that. I simply set the FX to be 'out' on every patch. tHe noise gate works well, and the onboard graphic EQ is VERY handy.

This thing is solidly built. My own unit has seen a lot of abuse. However, teh FX portion is gone. No idea why, but i'm not inclined to fix it either. I have a lexicon for that purpose.

never dealt with em.

I'm mostly a jazz guy, although I have a lot of good rock gear. Jackson USA solidbodies, tube amps. I've been playing a while.. long enough to become acquainted with a variety of gear.

THis is an under-rated unit that you can pick up for cheap. It provides decent sounds at a rock bottom used price. I use it for recording ideas and for getting better electric sounds out of amplifiers that don't have a lot of natural dirt or grit.

My own unit generates a lot of heat though. If you stick it in a rack, provide some space around it. ONe nice feature of the unit is that it is reasonably compact... short depth.

If someone stole it, I'd find another on ebay. It's a good deal more for a mesa formula preamp. This thing provides 60% of the sound quality for 1/10th of the price.