Twin Tube GFX-1

[AxeHarmony]

Twin Tube GFX-1  always wanted one as I had a GSP-21 back in the 80's.
my old gsp-21 foot controller works perfect with this unit...

i really think Digitech checked out the MP-1 before making this pre... ??? lots of similar parts and I basically did the same noise mod to it and some other obvious stuff ...  and quite an impressive pre, really - real fun to play with as it has a full array of effects, the flanger is awesome while the delay and reverbs need to be subtle ...

matbe some mods to this one ?  ... ...

[Dante]

I bought one of those for a backup when my MP-2 was at a local shop, and used it with my ol' B200s. It was a very good preamp, but I remember it being a pain to program (something about scrolling through all the settings to get to save? - I can't remember specifically)

That said, if I see another one pop up on Criagslist, I'll probably grab it ;)

BTW: I sold mine to pay for my MP-1 Classic 

[AxeHarmony]

neat how things come together, Dante did you notice how much cleaner this unit is than the ADA's ?? sure a little less organic sound than the ADA's but damn it's a clean low noise/hum compared to the ADA's  !!!

[Dante]

Yes, I did. It's a very quiet unit on the dirty stuff fo sho.

However, as you state, the 'organic' feel of it left a bit to be desired in a live situation. Many of the gear I try sounds fantastic by itself, but the true test is the BAND. How does it fit in the mix? How does it cut through the mix (or not)? Those are the questions that determine actual functionality of gear.

That said, I love Love LOVE my MP-2. I have for years. The MP-1 Classic still cuts through better to my ears, but the MP-2 has a LOT more bells & whistles.

I like ringing bells and blowing whistles

[sebastien]

i had one some months ago, i found it was "old date" sound, with nuch such gain as ADA mp1 or 2
but quite good preamp.

[Sparker]

Just got one of these, super-cheap from EB, ... but super high gain squealing as well (probably why super-cheap!!! Gotta love EB). Anyway, changed the 'hooting' tubes out and I'm really pleased with it, to my ears sounds like rich organic overdrive plus super high gain as well. Totally agree Digitech must have been checking out the ADA MP's when pushing this one out (weird with 2 transformers eh?). Strange none of their subsequent rack tube preamps sounded as good. Axe - I would like to hear more about your mods to this pre (I see the twisted wires to the tube board and the changed out caps), have you got any more mods in there? Got any schematics as well? I've emailed Digitech for some, but won't hold my breath.

Cheers

Mike

[Sparker]

Digitech came good!! Got schematics if anyone needs them. Still loving this thing btw.

[rnolan]

Go Sparker, good to hear, I've always had a soft spot for Digitech and my IPS33 has always been solid and still going strong 20+ years later...

[Dante]

Whelp, here's an OLD bump...

I just picked up one of these GFX-1 units for less than $100. I figured, why not? It does not disappoint. I don't remember it sounding this good when I had one before.

When I brought it home, I could hear something inside rattling around....hmm... I opened up the case (each screw a new experience - lol) Man, it was dusty inside...and many loose screws. The tube board had three screws, one of which actually had a nut. DOH! I tightened that up as much as I could and it's much more solid now. The tubes were covered in dust and gunk - I wiped them off with a clean rag and found out they are Groove Tube GT 7025 tubes. Not particularly great in my Microtube power amp, but (from what I hear from Harley), they are good preamp toobs. Circa 1993-5 (I think - correct me if I'm wrong), they sound great.

I'm loving this thing and I'm gonna keep it as an emergency backup rig or a fly rig. Does it have what I NEED for a gig? Yes. Does it have everything I WANT for a gig? no...almost...

[rnolan]

  :whoohoo!:

[Iperfungus]

Hi guys!

Could any owner of this unit, please, let me know where battery is located and what's battery type?
Does the Twin Tube have some reverb effects inside or just flanger/chorus/delay?

Thanks a lot! 

[Dante]

I'll have to find it (in the garage) and open it up for you. I just moved, so everything is in disarray right now.

I'm not sure if there's a reverb, I only used it for distortion/gains and had another FX unit for that. I didn't want to be limited by only ONE effect at a time in the GFX-1

[vansinn]

It has at least reverb, delay, chorus, flange..

EDIT: oh well, clips I heard sounded like reverb..

[Dante]

I found the manual - no Reverb :( Just a Digital Delay (quite the rage back then)

Like I said, I would really only use it as a programmable dirt box, then use something else for FX. It is limiting in the effects arena, I believe it was Digitech's first attempt at a rack mount tube preamp. 

[Iperfungus]

Hi gents!

Thanks for hints and information.
I found a Twin Tube for 60 euros and this could be a very good deal.
Looks in good shape and fully functional.

It's not close to home and the owner doesn't ship it...but, lucky me, the unit is for sale in the same town where my brother in law works...so I will ask him to get it for me.

It has a GT and a Marshall tubes inside...curious combination.
The battery looks like a normal 1.5V battery, even if it should be a 4.5V one, and it should be possible to remove it and replace it in a very easy way.

I think I'll give the thing a try: I can use the Intellifex as FX and reverb unit.