Tubes

[Hsb]

So Ive had my Jubilee since about 1992, had the Groove Tubes, EL34s and 12AX7s, changed when I bought it. I thinking it may soon be time to change tubes in the amp. I play at home and since Ive had it its only been used on stage maybe 2-3 times by my room mate at the time. I play a few hours a week with family obligations, etc. Was playing it the other day and thought it may be time to change the 28 yr old tubes.

For preamp tubes I know its a pure swap and its done, and I have to bias the amp when I change the power tubes. I am 99% sure this has been discussed before on here but I dont have enough coffee in me this morn to do a search, any recommendations for tubes?

 

[Lake Placid Blues]

Re: Tubes

They originally came with Siemens EL34s. You can still get them for a price. So if can swing it, Siemens NOS would be first choice.

Likewise, if you can afford it, a set of =C= might be a possibility.

Among current production, I would go with the Russian Mullard RI EL34.

I'm currently running old 80's groove tubes 12AX7 in the preamp positions and the PI, so I don't know about what CP tubes to recommend there. You don't have to worry about a cathode follower killing a spiral filament Russian 12AX7 tube in the Jubilee, though.

The original Jubilees did't have 1 ohm resistors between cathode and ground on the power tubes to measure current flow like modern 50 watt and 100 watt Marshalls do. I added some to mine to make biasing it easy.

 

[JMP/HBE]

Re: Tubes

Matched quad of Tungsol EL-34B's

https://www.ebay.com/itm/New-4x-Tun...548975?hash=item1eb2aaadef:g:HNwAAOSwwbdWKSal

 

[dystrust]

Re: Tubes

Matched quad of Tungsol EL-34B's

https://www.ebay.com/itm/New-4x-Tun...548975?hash=item1eb2aaadef:g:HNwAAOSwwbdWKSal

I didn't care for those in my Mini Jubilee; they gave the rhythm channel a nice Fender-y chime for clean tones, but were painfully bright on the lead channel.

So Ive had my Jubilee since about 1992, had the Groove Tubes, EL34s and 12AX7s, changed when I bought it. I thinking it may soon be time to change tubes in the amp. I play at home and since Ive had it its only been used on stage maybe 2-3 times by my room mate at the time. I play a few hours a week with family obligations, etc. Was playing it the other day and thought it may be time to change the 28 yr old tubes.

For preamp tubes I know its a pure swap and its done, and I have to bias the amp when I change the power tubes. I am 99% sure this has been discussed before on here but I dont have enough coffee in me this morn to do a search, any recommendations for tubes?

They originally came with Siemens EL34s. You can still get them for a price. So if can swing it, Siemens NOS would be first choice.

Likewise, if you can afford it, a set of =C= might be a possibility.

Among current production, I would go with the Russian Mullard RI EL34.

I'm currently running old 80's groove tubes 12AX7 in the preamp positions and the PI, so I don't know about what CP tubes to recommend there. You don't have to worry about a cathode follower killing a spiral filament Russian 12AX7 tube in the Jubilee, though.

The original Jubilees did't have 1 ohm resistors between cathode and ground on the power tubes to measure current flow like modern 50 watt and 100 watt Marshalls do. I added some to mine to make biasing it easy.

I've owned my 2555 since June 2001, and 2525H since May 2017. When I bought the 2555 it was loaded with Groove Tubes 12AX7s & EL-34s and it sounded pretty weak and anemic. I honestly believe the tubes were shot, and can't say how GTs sound in general. I replaced them with EH 12AX7s & EL-34s, and they sounded great and lasted really well until the EH design change in 2008-ish. Post-2008 the tone stayed similar, but tube reliability was pretty poor. At Lake Placid Blues's recommendation I had Savage Audio check it out in early 2017, and they gave my 2555 a clean bill of health. Jeff at Savage recommended JJ EL-34s, and I've been using them ever since. IMO they sound great; like a best-case compromise of a typical EL-34 with the thickness of a good 6550. Lots of trial and error lead me to a bias preference of 36ma per tube; below 35 gets really bright and thin, while higher than 38 made my 2555 overly bass-y and loud. I run the same complement in the 2525H, but it's cathode bias so no worries there.

For current production preamp tubes, I've been running a Tung-Sol in V1, a Shuguang in V2, and a Sovtek 12AX7LPS in V3. I've tried a few different V2 tubes, but they don't seem to have much effect on the overall tone. I found Shuguangs too bright for V1, while JJ ECC83s sounded good on the lead mode but resulted in dull and flat clean tones. JJs may be a good option if you use the rhythm clip and set the amp up as dirty rhythm / boosted lead. I use my rhythm mode for JTM-like clean tones, so the brighter Tung Sol works better for me.

I don't have the disposable income for an NOS habit, so I choose to avoid them.

 

[JMP/HBE]

Re: Tubes

I didn't care for those in my Mini Jubilee; they gave the rhythm channel a nice Fender-y chime for clean tones, but were painfully bright on the lead channel.





I've owned my 2555 since June 2001, and 2525H since May 2017. When I bought the 2555 it was loaded with Groove Tubes 12AX7s & EL-34s and it sounded pretty weak and anemic. I honestly believe the tubes were shot, and can't say how GTs sound in general. I replaced them with EH 12AX7s & EL-34s, and they sounded great and lasted really well until the EH design change in 2008-ish. Post-2008 the tone stayed similar, but tube reliability was pretty poor. At Lake Placid Blues's recommendation I had Savage Audio check it out in early 2017, and they gave my 2555 a clean bill of health. Jeff at Savage recommended JJ EL-34s, and I've been using them ever since. IMO they sound great; like a best-case compromise of a typical EL-34 with the thickness of a good 6550. Lots of trial and error lead me to a bias preference of 36ma per tube; below 35 gets really bright and thin, while higher than 38 made my 2555 overly bass-y and loud. I run the same complement in the 2525H, but it's cathode bias so no worries there.

For current production preamp tubes, I've been running a Tung-Sol in V1, a Shuguang in V2, and a Sovtek 12AX7LPS in V3. I've tried a few different V2 tubes, but they don't seem to have much effect on the overall tone. I found Shuguangs too bright for V1, while JJ ECC83s sounded good on the lead mode but resulted in dull and flat clean tones. JJs may be a good option if you use the rhythm clip and set the amp up as dirty rhythm / boosted lead. I use my rhythm mode for JTM-like clean tones, so the brighter Tung Sol works better for me.

I don't have the disposable income for an NOS habit, so I choose to avoid them.

Marshalls are brite amps by nature but the brightness likely had to do more with your preamp tubes than anything else. Jubes are typically darker sounding in my experience.
Speakers/tone woods/fretboards/pickups/strings/pedals/cables and other things either in concert or alone all contribute to tone.









I know what you mean tho as i used the Tungsol's for 10+ years and felt it was great tone until i scored a matched quad of NOS Amperex/Blackburn XF-2's and Holy F*ck is that some great tone.

 

[dystrust]

Re: Tubes

Marshalls are brite amps by nature but the brightness likely had to do more with your preamp tubes than anything else. Jubes are typically darker sounding in my experience.
Speakers/tone woods/fretboards/pickups/strings/pedals/cables and other things either in concert or alone all contribute to tone.

Absolutely concur about Marshalls generally and original Jubilees more specifically. If I were going to describe the tone of a Jubilee to someone who'd never heard one, I'd say it's like a JCM800 but with more gain, a fatter tone, and a much more powerful EQ.

I didn't care for the Tung-Sol EL-34Bs in my Mini Jube, but that amp is a special case in terms of power tubes. I have no idea why, but power tubes influence the tone of that amp more than any other amp I own. My 2555 doesn't seem to have much of a preference in regards to power tubes unless you're playing wall-shaking loud, then you might be able to discern a difference. I even tried a quad of KT-88s in the summer of 2009 and was shocked at how little difference it made to the overall tone. The amp was louder, less bright, and maybe the slightest bit less compressed. Conversely swapping the same quad of KT-88s into my brother's JMP2203 was a night and day difference.

 

[JMP/HBE]

Re: Tubes

Absolutely concur about Marshalls generally and original Jubilees more specifically. If I were going to describe the tone of a Jubilee to someone who'd never heard one, I'd say it's like a JCM800 but with more gain, a fatter tone, and a much more powerful EQ.

I didn't care for the Tung-Sol EL-34Bs in my Mini Jube, but that amp is a special case in terms of power tubes. I have no idea why, but power tubes influence the tone of that amp more than any other amp I own. My 2555 doesn't seem to have much of a preference in regards to power tubes unless you're playing wall-shaking loud, then you might be able to discern a difference. I even tried a quad of KT-88s in the summer of 2009 and was shocked at how little difference it made to the overall tone. The amp was louder, less bright, and maybe the slightest bit less compressed. Conversely swapping the same quad of KT-88s into my brother's JMP2203 was a night and day difference.

A 100 watt Mashall on "6" is going to sound a helluva lot different than on 1 or 2. That goes for the Jube too.

 

[Hsb]

Re: Tubes

So characteristically, what is the difference between brands?

Funny some days my Jub sounds like a fire breatherand others its just spitting smoke.

 

[Lake Placid Blues]

Re: Tubes

Funny some days my Jub sounds like a fire breather and others its just spitting smoke.

When amps get this old such inconsistency can get complicated.

It could just be the tubes, but it could also be other things or a combination of things. It could be tubes and electrolytic caps. Switches could be intermittently not functioning correctly. Switching jacks could be making poor contact. I have had all such problems with my 87 Jubilee in recent years. Fortunately, I think I got it sorted out and it's consistently sounding great again. It would be worth to take it to a good tech if you can find one. It is not an easy amp to work on and do it properly.

One thing you can do yourself right now is make sure that the jacks are clean, especially the loop jacks.

So characteristically, what is the difference between brands?

Mullard: warm musical
Tung Sol: a bit of 6L6 (crisper top end and more bass).
EH (EL34 not 6CA7) midrangey
Shuguang: raw rock attitude.
JJ: I haven't used them in recent years.

 

[dystrust]

Re: Tubes

When amps get this old such inconsistency can get complicated.

It could just be the tubes, but it could also be other things or a combination of things. It could be tubes and electrolytic caps. Switches could be intermittently not functioning correctly. Switching jacks could be making poor contact. I have had all such problems with my 87 Jubilee in recent years. Fortunately, I think I got it sorted out and it's consistently sounding great again. It would be worth to take it to a good tech if you can find one. It is not an easy amp to work on and do it properly.

One thing you can do yourself right now is make sure that the jacks are clean, especially the loop jacks.

Can't second this one enough. In my case I was lucky and had a couple tubes that needed to be replaced.

Mullard: warm musical
Tung Sol: a bit of 6L6 (crisper top end and more bass).
EH (EL34 not 6CA7) midrangey
Shuguang: raw rock attitude.
JJ: I haven't used them in recent years.

I'm a recent convert to JJ EL-34s, and IMO they sound very similar to pre-2008 EHs if maybe slightly thicker sounding and less bright.

 

[Hsb]

Re: Tubes

Thanks guys, it definitely needs a good once over, have a couple pots that no matter how much I clean them, they are still scratchy and now that I think about it, that may be some of the issue, may have a bad pot or two. Or it could be I need a better contact cleaner and since there isnt a port to spray cleaner into, its kind of hit or miss how much cleaner gets inside the pots.

But I definitely think Im also gonna change tubes, they are almost 30 yrs old, although I dont play for hours on end, Im sure they have gotten tire and good chance out of bias. Luckily preamp tubes are cheap and easily changed, power tubes take a lil bit more work.

I appreciate the help guys, now time to get it back and running properly and sounding its best.

 

[Hsb]

Re: Tubes

Took some time to learn and bias the amp, when I checked the amp it was at approximately 39 ma, 448 ÷ 25 x .07 = .0039, tweaked it down to 38 ma and sounds a bit better. Surprised it hasnt been biased since I had the tubes changed when I got it in 92-93.

I did notice the tube in V2 wasnt burning as bright as the other two, so may order up a set of 12ax7s for it

 

[JMP/HBE]

Re: Tubes

Took some time to learn and bias the amp, when I checked the amp it was at approximately 39 ma, 448 ÷ 25 x .07 = .0039, tweaked it down to 38 ma and sounds a bit better. Surprised it hasnt been biased since I had the tubes changed when I got it in 92-93.

I did notice the tube in V2 wasnt burning as bright as the other two, so may order up a set of 12ax7s for it

Brite/not brite doesn't mean anything for preamp tubes, different makes to different things. If it aint broke don't fix it. But having spare tubes is a good thing. You want all 4 EL-34's to light up the same tho.

 

[Gtrjunior]

Re: Tubes

Brite not brite doesn't mean anything for preamp tubes, different makes to different things. If it aint broke don't fix it. But having spare tubes is a good thing. You want all 4 EL-34's to light up the same tho.

+1 here.
There are a few tubes out there that you won’t see a glow coming from (one of the Sovtek, iirc).

Plus preamp tubes don’t need to be replaced as sets. They often last years and years (ie. decades) before they stop functioning.
If the amp sounds good, roll with it.

 

[JMP/HBE]

Re: Tubes

Some old stock Blackburn Mullards & Amperex from the 50's/60's/70's emit a brite flash of light upon power up of the heater filament just for a second which is completely normal. But during normal operation its almost impossible in daylight to see them glow.
First time i saw the flash i thought something was on the way out but thanks to the internet found out not the case.

 

[Hsb]

Re: Tubes

Ok, so Ill ignore the fact one preamp tube isnt as bright as the other two. Still may buy a few for spares and to swap around a bit. Was happy to see the bias was still in a good place.

But all thimgs considered for 28 yr old tubes the old Groove Tubes are chugging along quite well.

Thanks for a the help guys appreciate it

 

[Hsb]

So pulling back up my old dead thread, finally got around to ordering new tubes and wanted to see what you guys thought of my selection. I ordered 2 Mullard EL34 power tubes, 1 Tung-Sol 12AX7 new production, 1 Mullard 12AX7 new production and 1 Sovtek 12AX7LPS, should arrive on Friday. I also requested the 2 EL34s to be matched.

Ended up ordering them from Tube Depot, found a 5% off coupon and with upgraded shipping still came in just over $100, seems TD has pretty decent prices compared to other vendors.

 

[Gtrjunior]

I like Tube depot as well. They are my go to.
As far as the tube selection, tough to say....you’ll have to be the final judge once you get them installed and biased.
I find the Mullard EL34 to have a LOT of midrange. Not necessarily a bad thing.
The Sovtek is a common choice for the PI and the other 2 routinely get good reviews.

 

[Hsb]

Im off from after Friday till the first of the year, so Ill have time to put them in and get it biased as needed. Id read a few posts about the LPS, think it was even mentioned in here as a good choice for the PI.

Def can hear my poor old tubes starting to get tired esp as of recently. Starts getting muffled esp going from clean channel with a pedal back to the dirty channel.

 

[STRATDELUXER97]

After watching quite a few of the Tone Talk youtube videos....Dave Friedman mentions that the EH EL34s have been the most reliable. He said because he deals with many tubes,he needs something that will be reliable...Having owned many tube amps(still do) there is not as much tonal change we hear in the output section compared to the heart of the overall tone via the preamp.These days I also go for reliable and Friedman and some of the other amp guru guys mentioned that the JJ EL34s have been a problem.So my next set of Marshall EL34s will probably be the EH based on their recommendation.