So im retubing my preamp now and power amp later.

Ive been recommended JJ and especially Tung Sol 12ax7 reissues but im going to put a 12AT7 in the V1 or V2 to reduce the fizziness of this amp. I dont know which brand to go with as the person who recommended said JJ's were great but went microphonic and other issues fast and that tung sols were just more reliable.

Which one is the V1 and V2 of the XXX as i heard its in a wierd order in the 5150 and wondering what it is in mine.

Which Brand should i go for and do any of them need to be a balanced triode?

See Tech Tricks / Faqs by Roger Crimm. First post at top. Select and page down to JSX/XXX.

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http://profile.ultimate-guitar.com/Cap4 ... lay1083925

Yeah i noticed that later, thanks.

Triode issue?

BUMP

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PAF Classic Series Tube Kit.......Created By Classic30inCincy
Majic Mojo Tradename..........Created By Classic30inCincy
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_________________

PAF Classic Series Tube Kit.......Created By Classic30inCincy
Majic Mojo Tradename..........Created By Classic30inCincy
Graduate Of Joe Friday / Dragnet School Of Correspondence
Doctorate Degree Diplomacy From Royal Order Possum Lodge

You really shouldn't get a fizzy sound from the XXX with any tubes unless the amp is not set up properly. First of all, make sure the master is cranked and use the channel volume to control overall volume. Dampening switch should be set to loose and the effects loop controls set at 12 o'clock to start. This is not set in stone by any means, if nothing else the sound level with the effects loop on and off should be about the same. For more information on setting the effects loop controls do a search on unity gain or just turn them until you get a sound you like. I'd tell you what mine are set at, but I can't remember. Finally, set all the EQ controls at 12 o'clock and adjust as needed.

I've had my XXX for over two years and have read all the threads here and on harmony central and have spent a lot more on preamp tubes than I care to admit. Most of which are sitting in a box unused. I think that the preamp tube obsession is overstated, as it is with many amps.

Here's how I hear it: Some tubes are high gain, some tubes are low gain, and others are neither here nor there but work well in V4 and V5 to keep things quiet.

In a high gain amp like the XXX I like to use EH 12Ax7s in V1-3 and a JJ 803s in V4. Other JJs work well in V4 also. I recently changed out the 7 year old Sovtek LPS in V4 with the JJ 803s and was surprised that the amp became brighter and louder....in other words I think the Sovtek must have been close to dead as I've never heard such a difference from a change in V4.

I run my 6505s the same way, starting with EH and ending with JJs. The 6505 tube layout is a bit different than the XXX, as it has an extra preamp tube and I think the order is different. Both of my 6505s came from the factory with three EH and two JJs. Probably not a coincidence.

A lot of the harmony central guys disagree with me, but a few do agree: Low gain preamp tubes are like a vasectomy for the XXX. If you want a low gain amp, don't buy a XXX in the first place. Buzz and fizz aren't from the preamp tubes, they are from the way the amp is set up.

I'm sure I will be told where I am going wrong!

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Amps
VTM 60
Ultra 60
6505
XXX Super 40

Preamp
Rockmaster

Cabs
Butcher 4x12
MC 2x12

Well i was speaking to another XXX owner/tech who said that the AT7 would work great and that the fizz is from the preamp stage. So eh ill try it and see how it goes. My question was more on teh balanced triode but that def helped

I have an AT7 and have tried it in V1 and V2. It reduced the gain quite a bit and seemed to take away a lot of the punch that the XXX is known for. I had to crank the gain to get a passable sound out of the amp with this tube. I ended up returning the EHs to V1 and V2 and turning the gain back to 12 o' clock.

I'll hold onto the AT7 as a backup for the V4 slot.

As far as balanced triodes, I don't buy it and wouldn't worry about it

I would consider using KT77 power tubes if you aren't already. I've always been a 6L6 guy but the KT77s really open up the sound on the XXX.

Good luck, and let us know how things work out for you.

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Amps
VTM 60
Ultra 60
6505
XXX Super 40

Preamp
Rockmaster

Cabs
Butcher 4x12
MC 2x12

I've experimented with diff pre tubes. I have been successful at getting either cruch or ultra where I would like it but never both. I just want a more useable gain control.

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Creativity is doing something weird and finding out others like it!

Well ive ordered a mullard AT7 and ill let you know how it goes. as well as the new tung sols. And with the KT77's ill let rip with the E34L's first and then move on.

Ive been trying to find for ages but which tube is what in terms of V1/2/3/4

_________________

PAF Classic Series Tube Kit.......Created By Classic30inCincy
Majic Mojo Tradename..........Created By Classic30inCincy
Graduate Of Joe Friday / Dragnet School Of Correspondence
Doctorate Degree Diplomacy From Royal Order Possum Lodge

Triple XXX/JSX

In terms of the circuit, the tubes are numbered V1 thru V4 starting at the end nearest the input jack. V4 is the phase splitter and is part of the power amp.

V1 is the input tube and is shared by all channels.
V2 is only used in the ultra/crunch channel
V3A is the active EQ section for the ultra/crunch only
V3B is the preamp output tube.

Clean signal path is:
V1A - EQ/Pre - V1B - (loop) V3B - Master - power amp

Ultra/Crunch signal path is:
V1A - Pre - V1B - V2 - V3A (active eq)- (loop) V3B - Master - power amp.

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Roger Crimm
Peavey Customer Service