As some of you already know my Blue Voodoo 120H (old blue model) is lacking in volume and gain and tone.. clean sounds nice though. I can sit right in front of it with full volume and a 4x12 cab and its not that loud so I'm going to try some new tubes. I've never done this before, this is my first tube amp. Which tubes are preamp tubes and which are the power tubes? Should I change them all or just the pre's? Which brand should I get? I want the clearest, heaviest gain possible with this amp. After I sort out the tubes I'll be running a 4x12 cab with Celestion V30's or Hellatones or a 2x12 cab with Eminence Swamp Things. Not sure which yet. Reccomendations on tube/speaker combinations are welcome. I currently use guitars with EMG 85 bridge pups and SD JB bridge pups.

Can I bias this amp myself with a relatively cheap biasing device? I hear they produce these with a cold bias and its best to turn it up for high gain stuff. How much do shops usually charge to do this? Thanks

get svetlana tubes or groove tubes.
the bigger ones in the back are your power tubes.

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Crate blue voodoo amps other than the 300 are self biasing amps.

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Bigger ones are power tubes, k thanks. I'd like to know what people think I should get specifically for pre and power tubes, also I was thinking JJ's. Groove tubes are whats in there now so I don't know if I want to get more of those..

they are not self biasing they are fixed bias. they can handle any standard el34 or 6l6. i reccomend jj tubes in the power and sovtek in the pre.

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if you want more volume, pop in some 6l6's (theyre 30 watts instead of 25 like el34's)... SED winged "c"'s are the bomb, almost nonexistant microphonics, lots of harmonics, and super clear. I'm not sure about el34's though, my amp only takes 6l6's...

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I second that, Winged C's are probably the best production 6L6 made right now. I would avoid Groove Tubes though, never really had a good experience and there are far better alternatives. You cant go wrong with JJ's for the pre, the Sovtek LPS' are a good choice as well.

EDIT: In case you bought the amp used, you might wat to check and make sure that all the pre's are 12AX7's. If a 12AU7 slipped in there somehow that would seriously cut down your gain and volume.

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Thanks for the info guys. I was reading at www.eurotubes.com and when talking about blue voodoo amps the owner said..

"These are one of my least favorite amps. I remember years ago when the first one came in for tubes. I fired it up and played the amp and I thought wow, these tubes must have really been hammered on, so with delusions of grandeur and great expectations, I pulled the sovtek power tubes and chinese pre's, biased up a quad of the JJ 6L6GC's to about 40mA per tube, stuffed in some good preamp tubes and let it rip! At first listen I was floored... There was no difference in tone what so ever... The clean was still sterol and mediocre at best and the drive tone was just as thin as it was before. I threw some of my best NOS pre's at it and there was no real difference. I tried a quad of EL34's and it only proceeded to get thinner sounding."

Well, that's got me kind of scared. Dont want to throw $100 or more on tubes when it wont make it much better. Anyone here swap tubes in a blue voodoo and get good results?

6L6GC's have more lowend and balls than your average EL34. They come stock in Engl Fireballs/Powerballs as well as Peavey 5150's and XXX's. Get JJ/Tesla's though, because some of the cheaper 6l6's sound a bit thin with excess treble, JJ's are more rounded and have tons of warm midrange and plenty of gain..

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JJ 6L6's are what i would associate with a crunchy hardrock type tone. They have decent low end, very prominent mids and are dark and smooth in the top end. They cut through really well and don't mud up. Very "thick" and punchy sound. Very fast attack.

Now the SED "Winged C" (=C=) 6L6 type - really deep, huge and tight bottom end, little more relaxed in the mids and somewhat more sparkle in the top. Never ever harsh, fluid sustain, notes lead into one another. They cut good, never go muddy and the harmonics are incredible. Very punchy More headroom than most other 6L6's, a little louder, very nice break-up.

If i played death metal tuned D or lower I'd go with the SED. I think they work better for a tight and focused rhythm tone in that genre, and they are incredible for fluid, smooth leads as well. JJ has the edge on leads for me though, a little looser and not as deep in the bottom, very prominent midrange, less top (very round lead tone). SED is probably the most versatile.

However, you can't really go wrong with either one, the sound difference is actually not that big as most descriptions would have you believe, rather, they're pretty subtle and if you're good with EQ and presence / depth controls you'll have a really hard time telling the difference.

For the preamp i would use JJ ECC83's, and if that is a little too dark for you I'd might get a Sino (same as Mesa, Ruby etc, chinese type) or EH in the very first stage (the tube closest to the input jack, also called "V1" as they're a little brighter (chinese the brightest, EH a little less). JJ ECC83's are very good tubes, strong low end, nice brown mids and a little sparke up top without going harsh (more lower mids than high mids makes it sound a little darker than most). Great "liquid" sustain.

Anyway here's some links that may / may not be interesting:

http://www.thetubestore.com/6l6templeton.html
http://www.thetubestore.com/6l6costello.html
http://www.tubedepot.com/6l6reviews.html
http://www.tube-town.de/info/doc/tt-tubemap.pdf ("Extreme" metal here is more like a thin black metal type sound AFAIK).

Also give 5881's a shot(they're interchangeable with 6l6's), they're a common choice with people who demand tons of gain and clarity.

Btw if swapping powertubes doesn't change the tone substantially on the Blue Voodoo it's because it's self biasing, so naturally it will run the powertube bias a bit "colder" than most other amps. Amps that need to run the tube bias "hotter" to sound good will undoubtedly need a bias every time you swap powertubes(ie: most Marshalls), but amps that have a fixed or automatic bias will take powertubes without the need for taking it to a tech, BUT will not sound substantially different with different powertubes.

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So I took my amp to a amp tech today and told him I wanted JJ 6L6GC's and JJ ECC83's. He showed me some tubes that look like JJ's and have those model numbers but say Groove... I said I didn't want Groove but he assured me they were JJ's just rebadged as Grooves because Groove is only a rebadging comany and that they don't actually make tubes. Is he bullshitting me?

One more question.. Are JJ ECC803's better than JJ ECC83's? Anyone tried them?

From the tubedepot website..
"The new JJ/Tesla ECC803s is a hi-gain 12AX7 that has a spiral wound filament to reduce noise and hum. The construction is different from the JJ ECC83 in that the plates are more conventional, but have a special heat dissipating fin that serves to improve efficiency and gain. If you want that great JJ tone in a hi-gain package, then these are for you."

Also, on the tube depot website when u order tubes you have the options of high-gain, matching, balanced triodes, matched and balanced triodes, low noise and microphonics.. all for extra money. Should I order any of these options? I think I'm gonna get tubes from tubedepot rather than from the local amp guy because I know for sure they will be JJ's and they cost less.

i wanna make some corrections.

the 5150 takes 6550's

5881 is british for 6l6 (just like ecc83 is british for 12ax7, and 'valve' is british for 'tube')

if you want more balls in that puppeh, bias the 6l6's to 50 ma. =)

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Yes, groove tubes relabel JJ's. What GT does is buy huge piles of tubes, test the tubes, and throw out the bad ones. They also sell other 6L6's, make SURE you get the GT-6L6-S if you buy groove tubes.

You want one preamp tube to be "balanced triodes". This is the tube that's closest to the power tubes (it's called a phase inverter). Plus, you want one "low noise and microphonics" for the tube closest to the input jack (this will kill most unwanted noise). For the other preamp tubes you can just order standard without any options.

You want matched power tubes too, else they'll bias up quite diffrently. Matching ensures they won't differ too much in bias current draw.

I thought the Blue Voodoo's used 6L6GC's not S's? Because the GC's are the ones JJ/Tesla make(I have a pair of em).

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A few things here. First, 5881's should, in most cases, NOT be used as a substitution for 6L6's. They are much lower power and would noot work well in an amp designed for 6L6's. The other is 50ma is a little much. The hotter you bias an amp, the looser it gets and the colder you bias an amp, the tighter it gets, so you need to find a happy medium.

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matched tubes = sweet clean signal
slightly unmatched tubes = distortion.

Trust me, you dont NEED to match your tubes, sure its nice, but thats what they've been doing since they invented the tube amp to get the CLEANEST sound possible. If you keep them slightly unmatched, you'll get your poweramp to breakup faster, and some cool harmonic content popping up here and there. Mind you, dont go off and get two entirely different rated powertubes and throw them in expecting your amp to come through it unscathed. Keep their ratings close, but not the same (unless you're tubing up a fender twin reverb to have the loudest clean ever possible without micing )

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If you don't match the tubes and fail to bias an amp properly, you're tubes won't last for shit. Improperly biased tubes will be eaten away a lot faster due to the irregular voltage draw they're being submitted to.

Marshall reccomends a 90-90 setting for their 100 watters, look at the instructional biasing video at www.eurotubes.com . The guy suggests even 90-90 is a bit too hot, he suggests 85-85 for a JCM2000TSL. 40-40 or 45-45 is ideal in dual powertube amps like combos and 50W heads and such.

Actually Valtiel, I've read on many sites that 5881's have more output than the regular 6L6GC. You're the only one I've heard saying the contrary. :?:

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Here's what I'm getting. But have a few more q's..

(4)Matched quad of JJ 6L6GC's
2 JJ EC803's/High-Gain 12ax7 Standards
1 JJ EC803's/High-Gain 12ax7 with Balanced Triodes (for phase inverter slot)
1 JJ EC803's/High-Gain 12ax7 with Low Noise and Microphonics (for tube closest to input jack)

Bias the 6L6's to 45mA?
Bias the ECC803's to _____?

I think I want a loose sound because I played a Peavey XXX and really liked it with the loose knob on! On tight and middle it did not sound as good to me.

Well, 6L6GC / 6L6 / 6L6RAPMASTERHIPHOP or whatever are all the same nowadays. I think 6L6GC's were a version of the 6L6 that could take higher plate voltage originally. The "S" part in GT-6L6-S is just a model name, not a tube type (Like the JJ ECC803S / ECC83S, even though it doesn't say ECC83 it actually is an ECC83, they just added an "S" and a "0" )

You don't "bias" preamp tubes yourself, the bias on these is fixed and is a large factor in how the amp sounds. You just pop them in. The bias on the 6L6's have to be determined by plate voltage and maximum ratings, i.e. if plate voltage is 450 volts and max dispassion is 30w, and you wanted the bias set to 70% of max dispassion (21 watts) you would set the bias to roughly 46mA (Disspassion / Plate voltage = 21W / 450V = 0,046 amperes).

Taken from thegearpage.com.

The main point is, if the amp is designed for 6L6's, thats what you should use.

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Thanks for that info Jopop. Have you played the JJ ECC803S? Do you think it's worth the extra few bucks over the JJ ECC83S? I guess I want a sound similar to the Peavey XXX.

I have not tried that tube. Read what this guy says:
http://eurotubes.com/euro-e.htm

From what he says, the "regular" ECC83S would be your best bet.
He's really good on JJ tubes, too. Best prices you'll find i guess.

Edit: Check out https://ssl.eurotubes.com/cart/inde..._category_id=87

- You want the "Crate Red or Blue Voodoo120 High Gain Retube Kit with 6L6GC's"

Thanks man, didn't realize his prices were that low and he had a kit.

Now, since my amp is not here with me, I don't know if it's like the Marshall that Bob biases in the video on his site. Do Blue Voodoo 120w amps have a trim pot? Can I adjust the bias like the Marshalls or do I need to put a trim pot in place of the simple resistor? If I have to do that is there a writeup on the web? I will buy a bias probe and I already have a multimeter. Thanks

I own the exact model, and I highly reccomend Sovtek KT66s. You will have to take off the tube retainers, but other than that they sound great, and have low microphonic noise too.

The ECC83's have more gain (have these in my amp)than the ECC803's