Tube Talk

[ChadVanHalen]

So a friend of mine finally got into the world of big amplifiers when he bought a DSL50 and 1960A in preparation for an audition he's got. As his only guitar playing friend and gear geek he knows he called me asking what to plug where and why it wasn't working and with the power of FaceTime I was able to help him get his tubes in and feel the roar of his first Marshall (When I consider you become a man)

I had my Splawn open for reference and looking at my insides again, taking note of what tubes I have, etc and I realize while all 4 my power tubes are Mullard EL34 each preamp tube was a different brand of 12AX7's... I had a Ruby, Solvtek, JJ and one other one I can't remember off the top of my head but I thought that was really weird the previous owner did that, and seeing as it was 4 different companies I think maybe it was intentional? Does anyone know if there's a thought process behind this like each company's tube sounds good in that particular position or does it matter? I know the ins and outs about pretty much everything in my rig except tubes so please, school me!

 

[Deleted member 21113]

After the Power Tubes, the gain stage slots V1-V3 have the greatest effect on your tone. The first slot (V1) will define much of your tone for both channels and is very noise sensitive. V2 is the least noise sensitive of the gain stage slots. Of the gain stages, V3 has the least effect on the tone. However, a tube with lots of gain is still needed for a full-bodied tone. The V4 slot drives the Effects Loop. It has a small effect on the tone and can still affect the noise level. The Phase Inverter has the least effect on the tone and noise of any preamp slot.
Note, some places offer a "balanced" tube for the phase inverter slot. The idea behind this is due to the nature of how an AB push-pull amp works. The Phase Inverter splits the signal into two parts and sends one part to the right power tube(s) and the other to the left power tube(s). A "balanced" preamp tube supposedly sends the signal evenly to each power tube, or pair of power tubes. Even if this were true, which looks unlikely, it doesn't matter with a guitar amp, I always use balanced.

Each amp is different but this is a basic layout.

You can use different tubes in any slot you want, depends on the gain and tone you desire, I use NOS RFT's in V1 and high gain JJ'S in V2 and V3, balanced JJ in V4, all in my Mesa triple and dual rectifiers. JJ KT88's for power.

 

[ChadVanHalen]

After the Power Tubes, the gain stage slots V1-V3 have the greatest effect on your tone. The first slot (V1) will define much of your tone for both channels and is very noise sensitive. V2 is the least noise sensitive of the gain stage slots. Of the gain stages, V3 has the least effect on the tone. However, a tube with lots of gain is still needed for a full-bodied tone. The V4 slot drives the Effects Loop and Reverb. It has a small effect on the tone and can still affect the noise level. The Phase Inverter has the least effect on the tone and noise of any preamp slot.
Note, some places offer a "balanced" tube for the phase inverter slot. The idea behind this is due to the nature of how an AB push-pull amp works. The Phase Inverter splits the signal into two parts and sends one part to the right power tube(s) and the other to the left power tube(s). A "balanced" preamp tube supposedly sends the signal evenly to each power tube, or pair of power tubes. Even if this were true, which looks unlikely, it doesn't matter with a guitar amp.

Each amp is different but this is a basic layout.

Ok, so does a particular company's 12AX7 make that much of a difference in the spots that it would require him to tube it that way or is it more he just used whatever he had?

 

[Deleted member 21113]

Yes it depends on taste, one player might like one tube, while another may not like the same tube.

 

[Deleted member 21113]

A process called "tube rolling" is when you choose a preamp tube for a certain slot, play and listen to the tone, then swap out a different tube and compare the tone, then decide which one is the better choice.

I know many players that don't really care about what they put in, I'm not one of those players.

 

[MrDowntown]

I'm quite new on this board and at the risk of sheer blasphemy.....there is nice thread :cough: (on another forum), where a group has done extensive tube rolls on various heads, and report there findings.

I've often thought of getting something like a vox nighttrain 15 for rolling; fairly inexpensive tube amps, that are cathode bias (I believe).

 

[ChadVanHalen]

A process called "tube rolling" is when you choose a preamp tube for a certain slot, play and listen to the tone, then swap out a different tube and compare the tone, then decide which one is the better choice.

I know many players that don't really care about what they put in, I'm not one of those players.

Haha of course, just like with everything with the guitar, should have figured... With this mixing and matching in the preamp I'm guessing (or hoping) that there would be no need to re bias which is left for only power tubes. I'll have to do my share of testing once I stop buying new guitars for a load of tubes and listen for the differences and see what I like. I'm asking so I can know what to buy for this amp when I decide to bulk up on tubes

As for the Mullard EL34's I can replace them with Mullard EL34's without a need to bias right? And would I need to replace all of them if one went out or can I change them one at a time? I've never bothered to learn about tubes, might as well ask all the questions I have about em now

 

[OUTLAW1969]

One of the biggest favors that I ever did for myself was to find out everything that I could about tubes, especially the particular ones that my amps utilized. Mainly 12AX7's, EL34's and 6L6's.

Most modern preamp tubes are merely re-branded tubes from a few different manufacturers, so your 12AX7's could even be the same variety of tube (ex: Chinese 9th Gen), but just have different company names stamped on them.

Another generic example is that some people prefer an RFT in V1, an EI in V2, and then Chinese 8th generation tubes in all of the other slots.

Don't even get me started on NOS (new old stock) tubes, which can get expensive if you get too wrapped up into it

 

[Deleted member 21113]

Yes MrDowntown, I'm a member of said board.

No need for bias with pre's, for power, as long as you use the same type and rating power tube you will be fine, but some will say bias with every retube to be on the safe side. Power tubes are sold in matched pairs, so it would be advised to change the pair if one went out.

 

[ChadVanHalen]

Yes MrDowntown, I'm a member of said board.

No need for bias with pre's, for power, as long as you use the same type and rating power tube you will be fine, but some will say bias with every retube to be on the safe side. Power tubes are sold in matched pairs, so it would be advised to change the pair if one went out.

I'll trust the guy with a tube type in his name that he knows what he is talking about... I've always read about the different types of tubes and their tonal qualities, etc but as I know everything about my guitars and board and cab I figure I should be able to operate around my amp at least. So while on tour having an extra set of Mullard EL34's and replacing all 4 when one goes out is what you should do, got it. Preamp tubes don't need to be rebiased as long as I'm putting 12AX7's in and the debate is out as to how they effect the tone, just something you have to get into yourself... Is there anything else I need to know/worry about regarding the maintenance of my tubes? I don't wanna be on the road and ruin my Splawn (very expensive mistake) by doing something incredibly stupid while in a pickle

 

[OUTLAW1969]

As for the Mullard EL34's I can replace them with Mullard EL34's without a need to bias right?

Not necessarily.
You might be alright for the most part, as HOPEFULLY they would be around the same rating. The same company's tubes can vary a great deal, so a lot of companies sell them in graded or rated sets, even if they are re-branding them.
BUT I would really recommend a re-bias with every power tube change, because power tubes are RATED for a very good reason.

And would I need to replace all of them if one went out or can I change them one at a time?

Definitely, I would change them all, if you can afford it.
But in an emergency, you could have "extras" on hand with the same rating to throw in there, if needed. In other words, if you aren't broke buy a sextet instead of a quad, so that you would have 2 extras with the same rating, for an emergency. That way you CAN actually replace it without a re-bias.
Power tube sets are also MATCHED for a reason.

 

[Deleted member 21113]

The power tubes SELL in matched DUETS, usually match up like this, A BB A , A is a pair and B is a pair, so the 2 tubes on the end are pairs and the 2 in the middle are pairs. If one of the A's go out, just replace that pair, same thing with the B pair. If one tube goes out, you don't need to replace all 4, just the pair that is faulty, that will get you through you set without having to change them all, this would be an emergency situation, you would need to replace the quad for best reliability.

Yes OUTLAW1969, is spot on!

 

[ChadVanHalen]

The power tubes SELL in matched DUETS, usually match up like this, A BB A , A is a pair and B is a pair, so the 2 tubes on the end are pairs and the 2 in the middle are pairs. If one of the A's go out, just replace that pair, same thing with the B pair. If one tube goes out, you don't need to replace all 4, just the pair that is faulty.

And you can tell which one(s) are out due to them not being lit up correct?

As for the Mullard EL34's I can replace them with Mullard EL34's without a need to bias right?

Not necessarily.
You might be alright for the most part, as HOPEFULLY they would be around the same rating. The same company's tubes can vary a great deal, so they sell them in graded or rated sets.
BUT I would really recommend a re-bias with every power tube change, because power tubes are RATED for a very good reason.

And would I need to replace all of them if one went out or can I change them one at a time?

Definitely, I would change them all, if you can afford it.
But in an emergency, you could have "extras" on hand with the same rating to throw in there, if needed. In other words, if you aren't broke buy a sextet instead of a quad, so that you would have 2 extras with the same rating, for an emergency. That way you CAN actually replace it without a re-bias.
Power tube sets are also MATCHED for a reason.

Is there a way to know what the rating on the ones I have are now and where to find similarly rated ones? I'm so anal about preparing for stuff relating to gear and performances (I got my Eagle award, I guess that whole "Be Prepared" thing really stuck with me haha)

 

[Deleted member 21113]

When a power tube is failing, it will glow red hot, your amp will hum and not sound good at all, if the power tube fails, the fuse will blow with it, saving your transformer from frying as well, which is the whole purpose of the fuse, of course your amp will not have power until you replace the tube and fuse. If you catch it in time before the tube fries, you can replace the pair and get through your set. Even if it does fry, as long as you have an extra fuse, which you should, you can replace the tube and fuse and be ok.

Usually the rating is written on the tube with numbers or letters, depends on the manufacturer.

You can contact a reputable seller and tell them what tube and rating you have, and they should be able to match it up.

On a side note, in some amps it's still possible to run your amp with just 2 tubes safely, ( the matched pair), until you can replace them all

 

[ChadVanHalen]

Ok... So my preamps from 1-4 are Ruby 7025SS, Sovtek 7025, Tung-Sol 0807 and JJ ECC83S. All 12AX7s, so that should be fine right?

My power tubes, however, make me a bit nervous based on your ABBA tip. They are Mullard EL34 and under the "Made in Russia" type the numbers read from left to right 06 12, 06 12, 06 11, 07 01... Am I looking in the wrong place or is the amp tubed wrong?

 

[Deleted member 21113]

Pres sound right, not sure about splawn amps, and not too sure about those numbers, they could be dates, I buy JJ tubes from Eurotubes, they put the number on the box to match the fixed bias on my Mesa amps, like a matched pair of KT88 is #45, KT66 is #56, not totally sure what it refers to though, (milliamps?) I could find out. As long as you aren't having problems then don't worry.

You can do research on the web, it's full of helpful info, the guys at eurotubes answer ALL my stupid questions with no problems, they know their tubes no doubt.

The ABBA is for Mesa amps, that I know is correct, not sure about splawn, you can contact them for more help if need be.

 

[ChadVanHalen]

Pres sound right, not sure about splawn amps, and not too sure about those numbers, they could be dates, I buy JJ tubes from Eurotubes, they put the number on the box to match the fixed bias on my Mesa amps, like a matched pair of KT88 is #45, KT66 is #56, not totally sure what it refers to though, (milliamps?) I could find out. As long as you aren't having problems then don't worry,

I'm not sure if any of the tubes were changed between when Scott made it and when it arrived to me (and however many owners it had between) but nothing too wrong, just normal gain noise. So before I head out on a long stretch of dates (We're supposedly doing a few weeks with Last In Line whenever Viv is done touring with his other band... Dead Leopard or some nobodies ) I should buy myself some new tubes and have it biased to them so I'll know from then on what they are, but until then I should be good.

So looking at Eurotubes I see I can buy single tubes and matched 2/4/6/8 tubes. I'd buy a matched quad or sextet (depending on my bank account at the time) and I get the tubes that I get. Every order of pairs after that do I specify the rating or will they always send me ones that are rated close enough to themselves?

I also noticed Splawn sell their own 12AX7's and matched pairs and quads of EL34 for really cheap... Would it be advantageous to use the ones Scott picked out over elsewhere?

 

[xXDaveyJonesXx]

On a side note, in some amps it's still possible to run your amp with just 2 tubes safely, ( the matched pair), until you can replace them all

You'd have to drop your OHMs by half respectively though, correct? Say, from 4 functioning tubes at 16 OHMs to 8 OHMs for your remaining matched pair.

 

[OUTLAW1969]

Ok... So my preamps from 1-4 are Ruby 7025SS, Sovtek 7025, Tung-Sol 0807 and JJ ECC83S. All 12AX7s, so that should be fine right?

My power tubes, however, make me a bit nervous based on your ABBA tip. They are Mullard EL34 and under the "Made in Russia" type the numbers read from left to right 06 12, 06 12, 06 11, 07 01... Am I looking in the wrong place or is the amp tubed wrong?

No, probably not tubed wrong at all.
Those particular numbers are more than likely manufacture dates / codes (or something), and have nothing to do with the rating.

Tubes are not manufactured "matched", and have to be rated and then matched together at a later time, from bulk quantities.

Just buy replacement power tubes from a reputable dealer or seller, when the time comes to re-tube.
The safest and easiest way to do that is to request the matched quantity that you want, after researching that particular company or manufacturer's rating system.
Knowing their rating system will help you decide what rating to request for your matched power tubes (example: early breakup, average breakup, late breakup, etc).

Hint: If you know what to ask for, then you will get it.......as opposed to merely requesting "a quad of Mullard EL-34's", because that is exactly what they might send you!

 

[ChadVanHalen]

Ok... So my preamps from 1-4 are Ruby 7025SS, Sovtek 7025, Tung-Sol 0807 and JJ ECC83S. All 12AX7s, so that should be fine right?

My power tubes, however, make me a bit nervous based on your ABBA tip. They are Mullard EL34 and under the "Made in Russia" type the numbers read from left to right 06 12, 06 12, 06 11, 07 01... Am I looking in the wrong place or is the amp tubed wrong?

No, probably not tubed wrong at all.
Those particular numbers are more than likely manufacture dates / codes (or something), and have nothing to do with the rating.

Tubes are not manufactured "matched", and have to be rated and then matched together at a later time, from bulk quantities.

Just buy replacement power tubes from a reputable dealer or seller, when the time comes to re-tube.
The safest and easiest way to do that is to request the matched quantity that you want, after researching that particular company or manufacturer's rating system.
Knowing their rating system will help you decide what rating to request for your matched power tubes (example: early breakup, average breakup, late breakup, etc).

Hint: If you know what to ask for, then you will get it.......as opposed to merely requesting "a quad of Mullard EL-34's", because that is exactly what they might send you!

Ok... So what I get for early/normal/late break up is head room. My amp is 100w that I turn to half power and even then I don't think I've ever needed it anywhere near noon live. I play pretty high gain, mid-rangey 80's sounding stuff with my cleans only being used for my cover band when we play a few Bon Jovi/Def Leppard songs. Early/Normal/Late or does it matter?... Just so I know what to ask

It's been a while since I've known this little about my gear, thanks a lot again for the responses