Recommend new tubes?... If necessary

[itamar101]

Hey Guys, long time no speak!
Anyway, i have a problem and i was hoping for some help here.

I have a Orange TH30 which I absolutely love but recently it seems like something has changed with the tone, and it is more noticable when distorted.
On the gain channel the amp sounds very fuzzy and undefined and has very little sustain of high end, which is not how the amp used to be. In general it just sounds a little flat, all of a sudden. This is also noticeable on the clean channel.

Other than that the amp works perfectly and is in great condition.

Do I need new tubes? If so would i need to replace the pre-amp tubes or power-amp tubes?
And what would you guys suggest out of my available options - JJ, Mullard and Tung-Sol?

[richard]

How long have you had the amp ? It sounds like it could be worn out tubes. Pre-amp tubes generally last a lot longer than output tubes and some amps are know to eat EL84s. Have you had a good look to see what the tubes are up to ? Do you have a tech that could check it out for you ? It could be a component other than the tubes so I'd have it looked at first.

[itamar101]

I've had it for about two and a half years.
I haven't taken it to a tech because, to be honest I don't really have any techs in the area at all and I figured i should ask before doing anything. changing tubes is also something that i was planning on doing anyway so I dont think another component being the issue changes anything about getting new tubes - and i figure its worth a try.

With that said, surely these symptoms suggest a problem with the pre-amp tubes rather than the power amp tubes? Of course, i could be totally wrong - I'm obviously not much of an amp wiz.

[Telerocker]

Could be one of the preamptubes. You can replace them yourself.
If it's the powertubes, look if they all have the same glow. If they are too blueish, tubes are not vacuum (enough).  Tungsol and JJ's make good EL84's. Buy a matched set and have your amp biased by a tech. If your amp was biased quite hot and you played the TH30 a lot since new, then a swap could be needed. A hot bias eats your powertubes fast.
Inspect also your cables, inputs, and effectsloopjacks.

[itamar101]

Thanks.
The power tubes all glow the same reddish orange, which is normal as far as i know.
The amp is cathode biased... doesn't that mean that I don't need to bias them as long as I get a matched set?

As far as pre-amp tubes go, is there anybrand or combination you'd suggest?
If i replace one I'm gonna replace them all so I'd be working with a combination of 4 new pre-amp tubes.

[Telerocker]

If cathode biased you don't need to rebias after a tubeswap.

TAD 7025 HighGrade: transparant and balanced without sharpness
Tungsol 12AX7: about the same, with a little bright peak.
TAD 12AX7C: transparant with a touch of sharpness compared to the 7025
Electro Harmonix 12AX7: emphasis on the low frequencies, good for metal
JJ ECC83S: more emphasis on the mids, less highs and lows than the others mentioned here.
JJ ECC81 / 12AT7 tube is a low noise and low microphonic preamp tube. A good choice for phase inverters and reverb circuits calling for 12AT7 tubes.

In general JJ's are fine for a lot of tubeamps.

[itamar101]

Great, thanks!

If I wanted to have a combo of JJ and Tungsol 12AX7s, is there any particular order that you'd suggest?

I'm looking for something that is pretty tight with high gain, and balances out the low mids that tend to come with an orange, but also works well with low/med gain and clean, without sounding harsh.

[Telerocker]

The V3 is the preamptube for the clean channel, the V1 and 2 for the dirty channel. You can mix different brands preamptubes. You have to experiment a bit what sounds best.

Another preamptube that does the highgain-thing very well is the Sovtek 12AX7 LPS.
The JJ ECC83S will do also a very good job in the V1-position. It's pretty tight and sounds a bit like a Telefunken NOS, but for a tenth of the price.

[itamar101]

The V3 is the preamptube for the clean channel, the V1 and 2 for the dirty channel. You can mix different brands preamptubes. You have to experiment a bit what sounds best.

Another preamptube that does the highgain-thing very well is the Sovtek 12AX7 LPS.
The JJ ECC83S will do also a very good job in the V1-position. It's pretty tight and sounds a bit like a Telefunken NOS, but for a tenth of the price.

So would V4 be for the effects loop?
What would you suggest there?

At the moment I'm thinking:
V1 - JJ
V2 - Tungsol
V3 - JJ
V4 - JJ

Would that be a logical choice?

[Telerocker]

V1 & 2 = leadchannel
V3 = cleanchannel
V4 = effectsloop (12 AT7/ECC81)
V5 = phase inverter

I would just experiment if you are mixing different brands.

[itamar101]

Ok thanks.

So I should be getting three 12AX7s and one 12AT7?

[Telerocker]

Ok thanks.

So I should be getting three 12AX7s and one 12AT7?

Yes, if you want to replace all five preamptubes.

[Slartibartfarst42]

I don't want to hijack the thread but I have a similar problem. I have a Blackstar HT60 Soloist and the valves have just given up completely. I noticed a week or so ago that it was starting to squeal a bit but now there's virtually nothing coming from it even when it's cranked. The thing is, I've never changed valves before so I have no idea what to buy or where to buy it. Could anyone help me out here please?

[FRockStar]

Slarti, HotRox UK or Watford Valves are a good place to start. Both do revalve kits for HT60. I have used both with no problems.

[Telerocker]

Ok thanks.

So I should be getting three 12AX7s and one 12AT7?

I didn't read ccareful enough: 5 if you want to replace the preamptube for the phaseinverter too, but that's not really necessary.