So I was doing some recording today and my amp just went dead. I was playing on the Ultra Gain channel and I lost the input sound. There still some hiss etc going on though. (The preamp tubes were a bit noisy). The Clean channel still seems to work ok and all the tubes are still lighting up, albeit the V1 preamp tube seems brighter than the rest. Is it some internal failure rather than tube related? I'm going to take it to a tech, but I can't get it there until Monday, any ideas?

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Yeah, get yourself some new tubes. If it was an input jack failure you would get no sound at all on either channel.

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Sorry I meant the guitar isn't coming through on the Ultra channel, not input jack faults. I thought if a preamp tube went then it wouldn't light up and neither channel would work? I have been reading your previous posts though regarding tubes so I'll probably order a set anyway.

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Not necessarily. I had this same thing happen to my old ENGL E530, no output on the lead channel but the clean channel was fine. Just a bad tube, id swap em. But then again, thats my answer for everything.

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Cool well, I might just do that to start with. I find tube shopping a bit annoying as you always get conflicting advice but I was thinking about 12ax7EH (Electro Harmonix) in V1 and JJ's in V2+3, as its a nice mix of bright and dark, plus the EH has incredible clarity. Should I change the PI as well? It looks like its been swapped at some point anyway as its currently a Winged C in there. I know the power tubes were changed just before I bought it so is it usual to change the PI then as well? Oh and is it worth buying a 'gold' version of x tube for V1, i.e. does it make a real difference?

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Don't buy EH's... cheap tubes.

Right now I have all JJ's and it's kicking ass, I used to think it was muddy but it's not at all really, I was simply not letting it warm up enough, it really makes a bit of a difference when you let the amp warm up a good minute instead of 20 seconds like the manual says.

BUT another good suggestion for the V1 would be a Tung Sol 12AX7. They have some upper mid/treble cut and are pretty high gain so they do give some balls to any amp's crunch. A lot of people use them in the V1 in Rectifiers. It'll probably make the amp scream a bit more. Sovtek 12AX7LPS is also good for V1 for the same reason(treble + high gain).

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Tung Sols are just rebranded EH's though, exact same tube just slightly different getter, whatever the hell a 'getter' is... I was just looking at Tube reviews on watfordvalves.com and they just love the EH too, more so than JJ's. I've also heard that a NOS RFT 12ax7 works really well in ENGL's but I'm not prepared to pay £30 for one tube. Man, now I remember why I sold the Thunder instead of changing tubes!

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A lot of the time, lower gain channels uses less tubes.
So, yeah, blow tube I guess.
That would be the first thing to check.

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EH's are definitely not the same tubes as TS's, they might be built in the same series factories but the construction and sound on them is a lot better, but you can see that in the price.

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Well the cool thing is that you can chop and change without much outlay, so if I don't like the sound I'll give the TS a go or maybe try and find a RFT to go in V1.

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It seriously matters a lot less than you might think.. the internets seem to think you can totally transform your amp by changing a tube, which you mostly can't.

OTOH i run this:
V1: Chinese 12AX7
V2: Mullard RI 12AX7
V3: EH 12AX7
V4: Sovek 12AX7LPS

Power tubes JJ

The V2 tube is the latest tube from the EH/Tung-sol/Sovtek guys.. i used to have a JJ in there but this tube makes the ultra gain channel a bit grittier and dirtier i think, the distortion became a little less Hi-Fi.. Was actually quite noticable IMO. I guess this is the 2nd generation Sovtek LPS, very long plates on this one.

Also the EH and Tung-sol tubes indeed look identical inside save for the getter.. i have both here at home. The TS is more expensive due to the fees they paid to aquire the name i think.

The getter is the piece in the very top of the tube, it looks like a ring or square or whatever (depends on the tube) connected by a rod to the lower part of the tube, almost like the halo on certain biblical figures.

I've tried both in V1 and the difference was very small, the TS was a tad (and i mean a very slight tad) smoother maybe.. The China tube is similar but it is a little warmer IMO. I like the EH tube in the FX loop slot since it's very bright and clear sounding, some effects can suck a lot of treble and the EH tube can remedy that to a degree. Tung-sol works too but my TS tubes have gone microphonic (i had two).

I've tried nearly anything in the V4 slot and it just doesn't make that big a difference, but teh internets seem to think the LPS works best so i stuck with that. Balanced / unbalanced doesn't matter.

I love the sound of my amp right now with the new duncan blackouts. I also have an Ibanez RG7421 with stock pickups and it's pretty clear sounding for a 7 through this amp. Funny, i don't think it sounds so good in E standard, you need to tune down a little for this beast to wake up

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