Should I replace the Chinese tubes in my TH30?

[ardilla]

Hello all,

I ended up picking up a TH30 with the Music123 sale. I think the sound is good and I'm happy with it, but I heard that the Chinese tubes are crap. So now I'm wondering what it could sound like if I picked up a set of new tubes for it. A new set of JJ's (seems like almost everybody likes these) will only run about $100.

Like I said, I'm happy with it now but I don't really know what I'm missing if I change tubes. Am I $100 away from turning this into a better sounding amp or am I splitting hairs? How bad are the Chinese tubes vs JJ's and such?

For reference, the TH30 uses 4 ECC83's and 4 EL84's. It also uses a ECC81 for the FX loop but I'm not sure if that's worth changing or not (input welcome).

And yes, I'm a tube newbee so please forgive me if I'm asking something silly...

[Randy Bass]

If the Chinese tubes sound good and function properly, they are not crap. Sino/Shuguang has had quality issues in the past but have noticeably improved in both sound quality and durability in the last couple of years. It is not really a simple good/bad question with tubes. Some people (like me) actually prefer the sound of Sinos (especially 12AX7s) over Sovteks and some other brands. You will probably get a slightly different sound if you swap the stock tubes out with JJs, but "better" is up to your ears. I would suggest getting them so that you have spares on hand. You can swap them to see which you like better. I would first swap the EL84s to see how the tone changes. Then switch preamp tubes one at a time so that you can tell what difference each one makes individually. The Effects Loop driver tube won't make a noticeable difference as long as you don't swap it with a different type.

[jpmcclan]

I've also have a TH30 ... I thought the stock tubes (valves) were OK, but 2 of them went bad pretty quickly (Orange immediately sent 2 free replacement tubes ... under warranty). I put in Mullard 12AX7s in the dirty channel gain stages and Tung-sol gold pin 12AX7s for the clean channel and PI, with a JJ gold pin 12AT7 for the EL. As for the power tubes, I've tried Mullard el84s (had a late break-up, but great all around sound), JJs (I'm going to try these again), and TADs (early break-up). I really liked the TADs for the early break-up, but, the TADs seem to have a slight mid scoop though.

Question - Has anyone used the Harma Tubes from Watford Valves? Specifically, the high gain ECC83/7025s?

PS - My amp tech is now in love with the TH30 (he liked the Tung-sols all around) ...

[ardilla]

Randy Bass: You make some good points. I will do as you recommend and buy a set for tryout/backup. The Chinese tubes sound good to me and I guess one idea would be to use them until they fail or need replacement. Buying another set both lets me experiment and have backups at the same time. Thanks!

jpmcclan: I know this is all subjective, but did the tube changes make a marked improvement? Which set did you like the best? Reading online I've seen a lot of +1's for the Tung-Sol's. What do they sound like on the TH30?

By the way, I take it there's minimal danger to damage the amp/tubes while swapping. Is there something I should watch out for?

Also, what does the FX Loop Tube do?

Thanks for the feedback so far.

[jamison162]

Is the TH30 cathode biased, fixed biased or adjustable?

If you didn't bias the amp and just popped in different tubes, you can't correlate breakup with a specific brand name. Set A may have been a matched set of low current draw whereas the next set may have draw more and would naturally breakup sooner. This could be the case regardless of name brand. Remember how Groove Tubes had a rating system. And Tube Depot puts the #'s on the boxes of their matched set.

Just thought I would mention this. I like the JJ EL84's myself and Mullard reissue 12ax7's in every position, esp. the PI and drive stages.

[OrangePaul]

I thought that 4x EL84 30 watters were generally cathode biased (correct me if i'm wrong), similar to the lower wattage 2x EL34 amps in that respect.
I may be generalising here though, but if thats the case with the thunder 30 i dont think re-biasing is as critical as it is with fixed bias amp designs (ie Rockerverbs etc)

[Randy Bass]

I think that the TH30 is largely based on the (cathode-biased) Dual Terror power section with preamp voicing inspired by the Rocker 30 and TV50.

[jpmcclan]

I check the current rating for the TADs, JJs and the Mullards. You were right, The TADs were rated at 31.2 (actually listed on the box as the plate current in mamps), the Mullards have a 31, and the JJs a 21 (I'm assuming these numbers, listed on the box for the JJs and Mullards, are the plate current in mamps). Again, you were right, I did not have the amp rebiased, I just exchange the tubes.

By the way, the gains for the Tung-sol GPs are 110/110, the Mullards are 120/123, and the JJ GP is 65/70 (12AT7). I'll also try sovtek LPSs and JJ 803S GPs ...

Obviously, I'm still playing around with the pre-amp and power tube selections ...

[addisj]

I check the current rating for the TADs, JJs and the Mullards. You were right, The TADs were rated at 31.2 (actually listed on the box as the plate current in mamps), the Mullards have a 31, and the JJs a 21 (I'm assuming these numbers, listed on the box for the JJs and Mullards, are the plate current in mamps). Again, you were right, I did not have the amp rebiased, I just exchange the tubes.

By the way, the gains for the Tung-sol GPs are 110/110, the Mullards are 120/123, and the JJ GP is 65/70 (12AT7). I'll also try sovtek LPSs and JJ 803S GPs ...

Obviously, I'm still playing around with the pre-amp and power tube selections ...

Let us know how you get on, Im interested what you end up with

[jpmcclan]

All

I'm still swapping preamp tubes, but have actually been using an Orange/Ruby HG/JJ ECC83 (a replacement tube sent from Orange and in an Orange box) in the V1 position and a JJ ECC83 gold-pin in the V2 position (for the dirty channel) and the same set-up for the clean channel, phase inverter (Tung Sol 12AX7 GPs), and power section (TAD STRs). The combination has a lot of gain and crunch.

I was looking at my preamp tubes that I have purchased and noticed that what I thought was the gain of the tube, listed on the box, is actually the Gm, I hadn't noticed this before. I had just glanced at the side of the box and thought the gain was listed. The only tubes I have with the gain listed are 2 Sovtek 12AX7LPSs (95/95).

jpmcclan

[Unadan]

I contacted Orange about the re-biasing question on the TH30 head after power tube replacement. Here is the answer:

"Nope, Class A cathode biased, no re-biasing required.
Just as long as you replace in matched quad, you're fine."

[jpmcclan]

All

I saw 2 different messages pertaining to tubes for the TH30, so I thought I would drop a line ... Now given that I'm an amateur rhythm guitarist at best and I play heavy rock, some metal, and heavy alt ... this is my tube set-up at this time ...

Dirty Channel - TAD RT080 -> Ruby 12AX7AC7 HG+
Clean Channel - Genalex
Effects Loop - JJ 12AT7 Gold Pin
Phase Inverter - JJ 12AX7 Gold Pin
Power Tubes - TAD EL84-STRs

The 12AX7s in the dirty channel and PI positions are high gain and low noise ,,, The others are average gain and low noise. I know they're high gain and/or low noise because I have a Maxi Preamp tube tester.

Gibson Les Paul Traditional or R8 -> MI Audio Boost'n'Buff -> T-Rex Squeezer -> MXR 10-Band EQ -> Effects Loop (BBE Sonic Stomp) -> TH30 -> PPC112C

[clund]

Bump of an old thread... I am looking to change tubes in my TH30 and would like suggestions as well. I sent an e-mail to Dougstubes.com - Here was my e-mail....

I am looking at putting new tubes in my Orange TH30 Head that still has the stock Chinese Tubes (not sure brand). I think the Clean channel needs more headroom and the Gain channel has TOO much gain

I am looking for a 90's style rock / alternative rock type sound – think Pearl Jam, Soundgarden, Alice in Chains

I’m looking for more of 3 dimensional Open sound with Good Crunch and cleaner cleans

I really like this Orange TH30 Amp... But would like to swap tubes in it to maybe better the tone. The clean channel is GREAT, but it does start to break up early and would like a little more clean headroom.

The Gain channel has TONS of gain available and I think it's too much gain. I usually run the gain setting of this channel at around 10 - 11 o'clock on the dial. I would like to smooth out this channel a little bit and make it a bit more of a Crunch than searing high gain.
What tubes should I be looking at to do this... Also, will changing out the 4 EL84's in the power section help at all?

Thanks for any advice....
- Corey



-- and got this response:

You could get a little more headroom out of Sovtek EL84M's, for the 2 x ECC83/12AX7 you can do a Tung-Sol in the first spot then a Sovtek LPS in the other spot. The 12AT7 in the loop should be fine.


----------
Anyone tried the Sovtek EL84M? From what I hear they are VERY clean tubes, I want a little more headroom, but not a WHOLE lot that it starts to sound sterile. And any good luck with the Tung-Sol out there?

Thanks!

[addisj]

Funny... I am after a simular sound to you and this was my reply;

Go with the Sovtek EL84M's or the TAD EL84's.

For the 2 x ECC83/12AX7's go with a Ruby 12AX7AC5 HG+ in V1,
then a Sovtek 12AX7WC in the other spot.

For the 12AT7, the JAN Philips 12AT7WC is great.

Doug
http://www.dougstubes.com" onclick="window.open(this.href);return false;

>
> What kind of amp do you have? ORANGE TH30 COMBO
> What tubes are in there now? STOCK
> What do you like/not like about your sound? LACKING CRUNCH
> What kind of music do you play? REASONABLY HIGH GAIN ROCK
> What do you want to improve? I WOULD LIKE MORE CRUNCH AND LESS
> FIZZ FOR THE DIRTY CHANNEL AND A LATER BREAKUP ON THE CLEAN CHANNEL.

[clund]

Funny... I am after a simular sound to you and this was my reply;

Go with the Sovtek EL84M's or the TAD EL84's.

For the 2 x ECC83/12AX7's go with a Ruby 12AX7AC5 HG+ in V1,
then a Sovtek 12AX7WC in the other spot.

For the 12AT7, the JAN Philips 12AT7WC is great.

Doug
http://www.dougstubes.com" onclick="window.open(this.href);return false;

>
> What kind of amp do you have? ORANGE TH30 COMBO
> What tubes are in there now? STOCK
> What do you like/not like about your sound? LACKING CRUNCH
> What kind of music do you play? REASONABLY HIGH GAIN ROCK
> What do you want to improve? I WOULD LIKE MORE CRUNCH AND LESS
> FIZZ FOR THE DIRTY CHANNEL AND A LATER BREAKUP ON THE CLEAN CHANNEL.

WOW! That is very interesting! Anyone else replace tubes in the TH30? Can you post results, favorites, etc?