#1
I have a THD Flexi-50 (Ultimate Tube freedom apparently) and it's gotten noticeably quieter these past few days (so I'm thinking a tube must've died) and now I'm looking to replace all of them. I'm looking for a Randy Rhoads kind of sound while still being able to have chimey clean tones. I know it's kind of broad but I'm not looking for super amounts of gain, just a real rock and roll kind of thing that has punch.

I've looked at a couple of times and EL34's seem to be what Marshall's use, is this for a good reason? Any experienced tube guys know what would seem to "fit" just from the little information I gave?


The other question is what multimeter should I get? One that reads in DC right?

Last is where can I buy a multimeter? Actually, what would be a good site to buy cables, picks, etc. for cheap? I heard Sweetwater was a good place and so was Musicians friend.. I'm just curious as to how you guys end up saving money y'know?


Thanks a lot guys, pretty newbie questions I suppose, I appreciate all the help!
#2
The Flexi will take just about any tube.

Here:

http://www.thdelectronics.com/Flexi-50%20Manual%20080105.pdf
use almost any preamp and power
tubes in any combination, including 6L6, EL-34, 6V6, 6CA7, 8417, 6550, KT-66, KT-77,
KT-88, KT-90, KT-100, EL-84 (with Yellow Jacket adaptor), 6K6, 6F6, 12AX7, 12AY7,
12AU7, 12AT7, 12AZ7, 12DW7, 12BH7, ECC-83, ECC-82, ECC-81

EL34s are pretty popular and known for working really well in 'middy' type amps like Marshalls and the like. To get into it any further may be overkill. I personally really like EL34's and that is what I recommend.

As far as brands I like JJs, old Mullards, and SED Winged =C=.

The multimeter is used to measure volts and current and the digital ones these days have a wide range of parameters they work within. You can also just bias your amp by ear to what sounds right. Your amp has external test points and bias adjustments so that's good.

Fluke makes some of the best meters but they can get expensive. You should be fine with a $20 or $30 meter like you'd find at Radio Shack or Lowes/Home Depot/Walmart.

I recommend these distributors for new valves:

www.dougstubes.com
www.tubedepot.com
www.thevalvequeen.com
www.thetubestore.com
www.kcanostubes.com


mmolteratx owns/owned one of these so he can maybe tell you more about it.
Last edited by 311ZOSOVHJH at Jul 26, 2014,
#3
Thank you so much man, really appreciate all the info and the time ya took to post here! Really couldn't be any happier haha

If anyone else wants to add in anything please do so!
#4
i have the thd bivalve. i keep a bunch of tubes around for it, i used to change tubes in it all the time.

since you have such an amp it's nice to experiment with tubes. i also recommend at EL34, they are readily available. they power tubes aren't going to have much with the amount of gain you get outta the amp though, it can effect how power amp distortion sounds though.
punk isn't dead, it's always smelled that way.

"A perfection of means, and confusion of aims, seems to be our main problem."
-ae
#5
yeah matt has one and he knows way more about tube amps and electronics in general than I do, so hopefully he'll see this thread before too long

randy rhoads used a distortion +, didn't he? might be worth picking one up if you don't have one already since that might be the missing ingredient, and will likely make way more difference than tubes etc. will.
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Quote by K33nbl4d3
I'll have to put the Classic T models on my to-try list. Shame the finish options there are Anachronism Gold, Nuclear Waste and Aged Clown, because in principle the plaintop is right up my alley.

Quote by K33nbl4d3
Presumably because the CCF (Combined Corksniffing Forces) of MLP and Gibson forums would rise up against them, plunging the land into war.

Quote by T00DEEPBLUE
Et tu, br00tz?
#6
What about if I was aiming for a Thin Lizzy Jailbreak esque kind of tone? What kind of tube would be good for that?
#7
thin lizzy just more or less sounds like marshalls to me, but i could be wrong. i guess el34s, but

what speakers are you using?
I'm an idiot and I accidentally clicked the "Remove all subscriptions" button. If it seems like I'm ignoring you, I'm not, I'm just no longer subscribed to the thread. If you quote me or do the @user thing at me, hopefully it'll notify me through my notifications and I'll get back to you.
Quote by K33nbl4d3
I'll have to put the Classic T models on my to-try list. Shame the finish options there are Anachronism Gold, Nuclear Waste and Aged Clown, because in principle the plaintop is right up my alley.

Quote by K33nbl4d3
Presumably because the CCF (Combined Corksniffing Forces) of MLP and Gibson forums would rise up against them, plunging the land into war.

Quote by T00DEEPBLUE
Et tu, br00tz?
#8
Power tubes don't matter. I'll post a clip later comparing EL34s and KT88s in my Flexi with the master and gain dimed. JJ EL34s are cheap and reliable. Go with those. Roll preamp tubes if you want to hear a difference.
E-peen:
Rhodes Gemini
Fryette Ultra Lead
Peavey 6505
THD Flexi 50

Gibson R0 Prototype
EBMM JP13 Rosewood
Fender CS Mary Kaye

WTLT

(512) Audio Engineering - Custom Pedal Builds, Mods and Repairs
#9
^ yeah i was thinking power tubes likely wouldn't make all that much difference, that's why i asked about the speakers. the one i tried (stock, no idea what tubes and just the stock thd cab) did that sort of vintage-ish marshally tone out of the box IIRC.
I'm an idiot and I accidentally clicked the "Remove all subscriptions" button. If it seems like I'm ignoring you, I'm not, I'm just no longer subscribed to the thread. If you quote me or do the @user thing at me, hopefully it'll notify me through my notifications and I'll get back to you.
Quote by K33nbl4d3
I'll have to put the Classic T models on my to-try list. Shame the finish options there are Anachronism Gold, Nuclear Waste and Aged Clown, because in principle the plaintop is right up my alley.

Quote by K33nbl4d3
Presumably because the CCF (Combined Corksniffing Forces) of MLP and Gibson forums would rise up against them, plunging the land into war.

Quote by T00DEEPBLUE
Et tu, br00tz?
#10
I can't find what speakers come stock in the THD Cab

I was looking at tubes and the 6l6 seemed to get a real rocking tone with some Zeppelin thwack (https://www.youtube.com/watch?v=OBSEzX2O0nY). I like how the sovtek 12ax7 really made the 6v6 get more dirty too, would a sovtek 12ax7 tube with a 6l6 give me that hot rodded comprised sound I'm looking after?

I have an input/tone (control) tube slot for a pre-amp tube, a tone control/boost tube pre-amp slot, and a phase splitter driver tube. Does anyone know what combinations sounds good? For tone control it says a 12ax7 is recommended so maybe I'll put a sovtek 12ax7 there but I don't know what to put in the other slots?
#11
12AT7 is recommended for the tone control, IIRC. At least that's what mine (serial #43) says. I'd definitely stick with that, as it tends to sound a bit ratty with a 12AX7, IMO. Though I do know that my particular Flexi is a bit different from later ones.

The speakers in the THD cab were custom made for THD. They called them Longhorns or something like that.

Here's that power tube comparison clip. IIRC, KT88s first then EL34s. Barely any difference, and this is with the amp absolutely cranked.

https://dl.dropboxusercontent.com/u/8021347/t00bz.mp3
E-peen:
Rhodes Gemini
Fryette Ultra Lead
Peavey 6505
THD Flexi 50

Gibson R0 Prototype
EBMM JP13 Rosewood
Fender CS Mary Kaye

WTLT

(512) Audio Engineering - Custom Pedal Builds, Mods and Repairs
#12
i'm guessing the stock thd speakers would be just fine. i know (when they still made them) their cabs were pretty highly-regarded, I think.

i'd probably just go with el34s. they don't make a ton of difference, as matt said, but if you want to get as close as possible to marshall you might as well use the right ones.

sovtek 12ax7s are pretty meh. there's one variant which is meant to be good but i forget which one.

EDIT: ninja'd by matt. listen to him because (a) he owns the amp and (b) he knows more than me regardless.
I'm an idiot and I accidentally clicked the "Remove all subscriptions" button. If it seems like I'm ignoring you, I'm not, I'm just no longer subscribed to the thread. If you quote me or do the @user thing at me, hopefully it'll notify me through my notifications and I'll get back to you.
Quote by K33nbl4d3
I'll have to put the Classic T models on my to-try list. Shame the finish options there are Anachronism Gold, Nuclear Waste and Aged Clown, because in principle the plaintop is right up my alley.

Quote by K33nbl4d3
Presumably because the CCF (Combined Corksniffing Forces) of MLP and Gibson forums would rise up against them, plunging the land into war.

Quote by T00DEEPBLUE
Et tu, br00tz?
#13
I really like the El34 sound in that clip, sounds more like the Guns n' Roses kind of sound that's really hot rodded. You were right, it says 12AT7 instead of the 12AX7, my bad dude. Thanks a lot for the sound comparison, awesome playing man!

So I guess I should get some cool pre-amp tubes, is there any one that's more geared for compressed hot rodded sounds?

Thanks for the help guys, really appreciate everything, with so many of my favorite artists using different settings and speakers it's really hard to nail down a specific sound. Any recs on speakers too? I might not change them for awhile since to my ear they sound great already but just for future reference.
#14
Lizzy is Brit sound so that would be basically what a stock Marshall of the era used, which I think was 12ax7's and EL34s. I like EH as they have a bit more grit, but overall the voicing of the amp would remain the same, you might get some difference with different tubes but I don't think drastic. I did get maybe about say 10-15% tops of difference between stock tubes and a long experimentation that I did on my Fallen Angel FA-60 head which I was trying to tune to be a bit brighter than stock. Ended up trying 3 different kinds of power tubes and preamp tubes until I settled on what I got. It was Shuguans 12ax7s and Mesa EH34s (voiced mid-hot, matched). The Shuguang was a more gainy tube which was actually regarded as subpar due to high distortion which is actually what I wanted in my case as the amp was not as "hot" as I'd like.