Should I replace the Chinese tubes in my TH30?

[baytamusic]

Try an RCA or GE in the first gain stage of each channel. That'll clean her up and add some clarity in the overdrive channel.

[OrangeFox]

I just tried replacing my Chinese, power tubes with JJ's. From all I'd read I thought this was going to be awesome. It was so bright and had so much treble on both channels that it was unusable. Put the chinese tubes back in and it sounds way better. In the pre-amp section I have a gold pin jj in v1 regular jj v2 and (i think) a sovtek in v3 don't remember v4. Any thoughts?

JC

[a.hun]

I just tried replacing my Chinese, power tubes with JJ's. From all I'd read I thought this was going to be awesome. It was so bright and had so much treble on both channels that it was unusable. Put the chinese tubes back in and it sounds way better. In the pre-amp section I have a gold pin jj in v1 regular jj v2 and (i think) a sovtek in v3 don't remember v4. Any thoughts?

JC

Hi JC. Welcome!

Odd. JJs aren't usually the very brightest power valves around. They are usually fairly full and fat sounding in fact so that doesn't sound normal to me. Did you get the valves from a supplier with a limited period return warranty? Might be worth trying them in another EL84 amp to see if the valves themselves are duff. (That's what I'd be doing anyway.)


Andy.

[sizzlingbadger]

I like Tung Sols as they are bright and have reasonably high gain. They work well in clean channels to add a bit of sparkle. I find JJ's are a bit warmer in the dirty channel and if you want to reduce the gain of the dirty channel then I would recommend JAN Philips 5751. These reduce the gain to about 70%.

I'm not keen on the cheap WA Sovteks at all. The LPS is a better tube but may not suit combo's as it a long plate and could get microphonic.

JAN Philips 12AT7WC's are great for FX & Reverb, nice and neutral and low noise.

[OrangeFox]

I just tried replacing my Chinese, power tubes with JJ's. From all I'd read I thought this was going to be awesome. It was so bright and had so much treble on both channels that it was unusable. Put the chinese tubes back in and it sounds way better. In the pre-amp section I have a gold pin jj in v1 regular jj v2 and (i think) a sovtek in v3 don't remember v4. Any thoughts?

JC

Hi JC. Welcome!

Odd. JJs aren't usually the very brightest power valves around. They are usually fairly full and fat sounding in fact so that doesn't sound normal to me. Did you get the valves from a supplier with a limited period return warranty? Might be worth trying them in another EL84 amp to see if the valves themselves are duff. (That's what I'd be doing anyway.)


Andy.

Full and fat is exactly what I was hoping for, I've been thinking something has to be wrong with them. I should have put them into my Pro Junior but I just took them back before going into it further. The JJ 12ax7's I put in v1 and v2 tamed the high end fizz on the distortion channel and warmed it up nicely. Every single thing I've read on the net speaks very well of the JJ's. Perhaps I'll try them again some time, but for now I'm actually pretty happy with the no names. Thanks for the reply, and the welcome Andy!

JC

[clund]

Wanted to re-hash an old thread. I like my amp, but the Dirt channel always seemed a bit dark and way too much gain. Wanted to give it a little more classic Orange/Brit flavor. So I put some GE 5751 tubes in V1 and V2 of the gain stage of my TH30 after trying a bunch of different 12ax7 tubes with no real change. These 5751's made a HUGE difference! Sounded like someone lifted a blanket off the cab. Gave it a bit more harmonic character, gave it more pick response and slightly focused the mid/highs. I'm really liking the change.

[Randy Bass]

5751s are better at Blanket-Lifting than Michael Jackson.

[Phlowen]

5751s are better at Blanket-Lifting than Michael Jackson.

WOW! RB FTW!

[johnnyblues]

Wanted to re-hash an old thread. I like my amp, but the Dirt channel always seemed a bit dark and way too much gain. Wanted to give it a little more classic Orange/Brit flavor. So I put some GE 5751 tubes in V1 and V2 of the gain stage of my TH30 after trying a bunch of different 12ax7 tubes with no real change. These 5751's made a HUGE difference! Sounded like someone lifted a blanket off the cab. Gave it a bit more harmonic character, gave it more pick response and slightly focused the mid/highs. I'm really liking the change.

Sorry if this is a stupid/silly question: I'm looking at the TH30 schematic and it doesn't tell me which preamp slot is V1 and V2.

Any help please?

[Les Paul Lover]

If you have the schematic, you will see that each valve is separated in 2, with each triode labelled as V1A & V1B or something similar.

In any case, V1 is usually located nearest the guitar input as it simplifies the circuit design and lay out.

[johnnyblues]

If you have the schematic, you will see that each valve is separated in 2, with each triode labelled as V1A & V1B or something similar.

In any case, V1 is usually located nearest the guitar input as it simplifies the circuit design and lay out.

This is what I'm looking at right now --> https://global.rakuten.com/en/store/ontai/item/th30h/

So, I assume V1 is the dirty channel stage 1 and 2, while V2 is the dirty channel stage 3 and 4... correct?

[Les Paul Lover]

V1 is probably the clean channel valve, V2 the dirty channel 1st valve.

It makes sense, as it means the valves changes he made have impacted both channels.

[johnnyblues]

Got it. Thanks for the assist LP-Lover!