Some valve/tube questions

[benjaturner]

My local tech called round my house earlier today as he's fixing up two of my amps and he wanted to bring me up to speed on his progress, as well as find out what I wanted him to do next.

He said a few things that contradict everything I thought I'd learnt about valves. Firstly, that the vast majority of modern valves are designed to look pretty and don't perform at the premium temperature for sound. He says he always uses NOS for everything and can get some 1964 EL34 Mullards for £30 each (about $55 each) for my Marshall. For the Fender he said he would use some RCA(?) 6L6's for about the same price.

The brands he says I should never buy from are; Groove Tubes, Electro-Harmonix, JJ Tubes, Sovtek and Mesa/Boogie

The second thing he said was that matched valves are a big con. He says that because very few amps have a matched transformer anyway there's no point in bothering with matching the valves. He explained about the wrappings of a transformer and how the central point(?) in never in the middle.

I just wanted to know what others here thought about this stuff. I'm a little concerned the guy's taking me for a ride.

-Benja

 

[shreder75]

Re: Some valve/tube questions

um, Groovetubes and JJ are two of the premier tube manufacturers in the world according to what I've been told..lol...I don't think any of those tubes are actually 'bad'...

 

[greendy123]

Re: Some valve/tube questions

I would just ask to for whatever tubes you like. Those nos ones seem a bit expensive, I would stick with cheaper one's JJ's, Svetlana, or any present day production ones. It'll save you alot money and their quality are better these days. For tube matching I would ask for that, I think it would be best for amp if they are matched.

 

[SlyFoxx]

Re: Some valve/tube questions

Well if you can get NOS Mullards and RCA's that would be a good thing as those are the tubes many classic Marshall and Fender amps were designed to take. And $55 bucks a pop does not seem like an unreasonable price considering how scarce they are. But I'm a little suspisious that he just happens to have access to the "correct" tubes for a good price. Then again he might be on the up and up.

I should never buy from are; Groove Tubes, Electro-Harmonix, JJ Tubes, Sovtek and Mesa/Boogie

Since 95% of the guitar playing public does get tubes from said sources I think THAT'S an interesting statement. Lemme guess...he does not sell them!? Hummmm.

As for matched power valves...I'n not sure how the output transformer has anything to do with it since it does it's job AFTER the phase inverter and the power valves. Every book and tube manual I've ever come across stresses the importance of matched valves in a push pull design.

I'm no amp guru but something tells me that something fishy is going on in the local service shop.

 

[benjaturner]

Re: Some valve/tube questions

Since 95% of the guitar playing public does get tubes from said sources I think THAT'S an interesting statement. Lemme guess...he does not sell them!? Hummmm.

He said he'll put any valves in I want. He called to ask if I had any spares so I wouldn't even have to buy any at all. I do believe he's genuine and honest, I'm just concerned he's not that well informed himself. He's not actually a guitar specialist, he's a P.A. guy. He's very well respected right across the U.K. and a lot of the bigger companies consider him to be a guru as far as P.A. valve amps are concerned. I want to stress that I in no way think he might be lying to me.

What about the matched valves issue? That really was a new one on me, but it does make sense to my very limited understanding of valve circuitry. I'd like to hear some more thoughts on this.

As for matched power valves...I'n not sure how the output transformer has anything to do with it since it does it's job AFTER the phase inverter and the power valves. Every book and tube manual I've ever come across stresses the importance of matched valves in a push pull design.

I think the matching is in volts, and as for the push/pull thing, the matching is neccessary to equal the positive and negitive flow of the AC current. I think the transformer is then split to power each valve seperately. If the split does not occur in the middle of the coil wrappings then a different amount of juice is going to each valve. In these circumstances the valves being matched is irrelevent, as they are bing powered by different currents.

Sorry about my lack of correct terminology, but I think this is kind of how it works. Atleast I guess this is what the guy is thinking with his theory. Does this sound plausible to the better informed amongst us?

Thanks for all help,
-Bemja

 

[benjaturner]

Re: Some valve/tube questions

I spelt my own name wrong, how embarrassing! Er... I hope no one noticed.

 

[wixedmords]

Re: Some valve/tube questions

Benja,

Your tech has a certain point of view, a view shared by many. He seems to like NOS tubes. NOS tubes are thought to be built better and last longer than modern tubes. That being said, a majority of modern tubes are built well, but there have been some lemons.

I generally use modern tubes, but am not against using any tube that you feel sounds good. For me it is about the sound, and as long as there has reasonable reliability, I am fine with most any tube.

My concern is it appears as though your tech has a fairly closed mind.
It is kinda like telling someone to stay away from Ibanez, at all cost. There are some good models from Ibanez, and I am sure some not so good models, so closing off an option isn't generally a good thing. You could miss the boat on a fantastic thing if you don't leave yourself open to certain brands. I am not a big fan of GT tubes, but I will leave myself open for that one GT tube that may come along that just rocks.

Matched power tubes aren't a con, but they don't need to be matched perfectly, just close. Power tubes perform better if they are closely matched.

Balanced pre-amp tubes aren't always important, but if you are searching for the 9th degree of sound a balanced pre-amp tube is an option. I can't hear the difference myself.

 

[wixedmords]

Re: Some valve/tube questions

I am guessing english isn't Benja's first language.

 

[Pink Unicorn Horsey]

Re: Some valve/tube questions

I am guessing english isn't Benja's first language.

Good point. Thank you!

Sorry 'bout that, Benja. I will say this: For someone whose first language isn't English, you sure write well, Benja.

 

[The Golden Boy]

Re: Some valve/tube questions

um, Groovetubes and JJ are two of the premier tube manufacturers in the world according to what I've been told..lol...I don't think any of those tubes are actually 'bad'...

It's where companies "rebrand" tubes. In other words, companies like Groovetubes and Mesa don't manufacture (or manufacture very few) tubes, just procure tubes and put their own label on.

Think of this as you won't buy "Ching Wa" brand Chinese tubes, but not only will you buy- but you'll fork out good dough if they say "Mesa/Boogie" on them.

 

[mind_transplant]

Re: Some valve/tube questions

As far as NOS tubes are concerned, I think this is a case of voodoo toneology, where people assume vintage is always better (the "only '54 strats sound good" syndrome :banghead: ). While NOS tubes do sound different, it's due to variances between batches and manafacturers of tubes, much like Sovteks sound different from JJs. Not all NOS tubes sound the same either (I've had some ratty ones) and all in all it's just personal preference, like strings and picks and everything else.

I find the concept that tubes in general were of higher quality in the 60s and 70s to be ridiculous. Your tech may be great, but he (and many others) are sometimes a bit confused in terms of history. Back in the 60s tubes were not made to some immensely high standard of quality, in fact the opposite was true. Tubes were built to be inexpensive, and this notion of some 'golden age' of tubes seems a little odd to people who lived through it...

As far as matched tubes, your tech is a bit closer to the mark there. Matching a circuit in general will result in it being cleaner and more powerful, and matched tubes are a factor in doing so. However in effectively any tube guitar amp, the rest of the circuit isn't matched anyways. The driver components were never perfectly matched to start and then drift with time, and as your tech noted the output transformer's primary is almost never exactly perfectly matched either.

However, jumping to the conclusion that matched tubes are useless is a touch misguided. :33: Yes, everything else is never perefectly matched in a guitar amp, but having grossly mismatched tubes isn't going to help the situation either. I think perhaps matched tubes are less important than some tube manafacturers make them seem in guitar amps (class B audipohile amps are another story...) but they're by no means a "big con".

:soapbox:

 

[aleclee]

Re: Some valve/tube questions

The point with matched power tubes isn't like the tripe surrounding matched PIs. The reasons you match power tubes are to have both tubes operating in roughly the same region (so you don't have one way too hot and the other way too cold) and to help equalize wear since hotter bias = shorter life. Unless the amp has separate bias adjustment for each tube, I'd go for a matched set.

um, Groovetubes and JJ are two of the premier tube manufacturers in the world according to what I've been told..lol...I don't think any of those tubes are actually 'bad'...

Actually, GT does very little manufacturing and has traditionally just tested and stamped a logo on tubes made by other companies. Same goes for Mesa.

Those nos ones seem a bit expensive, I would stick with cheaper one's JJ's, Svetlana, or any present day production ones. It'll save you alot money

Given that NOS tubes can last 5-10 times longer than their current production counterparts, you can save a lot of money over the long run by going NOS.

their quality are better these days.

Better than what? Even though the very best NOS tubes got picked over a couple decades ago, most NOS tubes are closer to spec than anything made today. The reason a lot of amps don't have adjustable bias is because they didn't need it. Tubes back then were so consistent that letting someone adjust the bias was more likely to throw things off than the minimal variance between tubes.

Personally, I use NOS in some places and current prod in others. My Two Rock has a mix of NOS & current tubes while my Rivera is pretty much all current.

 

[aleclee]

Re: Some valve/tube questions

I find the concept that tubes in general were of higher quality in the 60s and 70s to be ridiculous. Your tech may be great, but he (and many others) are sometimes a bit confused in terms of history. Back in the 60s tubes were not made to some immensely high standard of quality, in fact the opposite was true. Tubes were built to be inexpensive, and this notion of some 'golden age' of tubes seems a little odd to people who lived through it...

Yeah, tubes were definitely a commodity item back in the day but they were a lot tighter on specs (some absurdly small percentage of today's 12AX7s are even within 5% spec on gain). Also keep in mind that the old tubes were used in automotive and military applications where the environment was a heckuvalot more harsh than that of the typical guitar amp or audiophile stereo. The military ones in particular were definitely designed and built for reliability.

In short, there were plenty of very high quality tubes made back in the day. They were cheap because, as with integrated circuits today, they were embedded in so many devices and volumes were huge. Even the consumer grade tubes of the past were of much higher quality (in terms of spec and MTBF) than the vast majority of modern tubes. Maybe that reflects more on the QC in today's tubes than the exceptional quality of the NOS stuff.

Note that I didn't say anything about whether NOS sounds better than current prod. That's a matter of taste but the argument that old tubes are more consistent electrically and have a greater life expectancy is pretty hard to dispute.

 

[mind_transplant]

Re: Some valve/tube questions

In short, there were plenty of very high quality tubes made back in the day. They were cheap because, as with integrated circuits today, they were embedded in so many devices and volumes were huge. Even the consumer grade tubes of the past were of much higher quality (in terms of spec and MTBF) than the vast majority of modern tubes. Maybe that reflects more on the QC in today's tubes than the exceptional quality of the NOS stuff.

I agree QC today certainly isn't what it should be. While plenty of high quality tubes were available in the 60s and 70s, I can also attest to the fact that plenty of low quality tubes were available too. But you're certainly right that old RCAs, Mullards and Telefunkens were closer to spec than what we see today. I'm just thinking back to some real **** quality tubes I saw from RTC and Tung-Sol (among others) back in the day as well.

Note that I didn't say anything about whether NOS sounds better than current prod. That's a matter of taste but the argument that old tubes are more consistent electrically and have a greater life expectancy is pretty hard to dispute.

I guess we probably agree for the most part, I just find that a lot of NOS enthusiasts like Benja's aforementioned tech fall prey to the 'vintage is always better' syndrome, which I find questionable. Some NOS tubes are great (again Telefunken and Mullard for me) but others (some JAN GE, Sylvania) are IMHO junk.

 

[PUCKBOY99]

Re: Some valve/tube questions

Unless the amp has separate bias adjustment for each tube, I'd go for a matched set.

That's my understanding.

Given that NOS tubes can last 5-10 times longer than their current production counterparts, you can save a lot of money over the long run by going NOS.

....and that's my understanding.....

Personally, I use NOS in some places and current prod in others. My Two Rock has a mix of NOS & current tubes while my Rivera is pretty much all current.

.....and that's me: NOS Mullard EL84s/ECC83s in one, current production in the others.

 

[benjaturner]

Re: Some valve/tube questions

I am guessing english isn't Benja's first language.

Erm... Yeah, it is actually. HA HA. Born and bred in Ol' England herself.

Wow! And I thought spelling my name wrong was embarrassing, that really cuts deep. LOL. The worst part is I read through my post and I can't find an example of what made people think English wasn't my first language. I'm sorry for my bad typing/spelling.

Perhaps the funniest thing in all of this is that I've actually been offered a place to study English at two top ten U.K. Universities, lets hope they're not into their pickups! If they see this then I've missed that boat. LOL!

Would anyone mind posting what KGMESSIER actually said in his deleted post? I'd love to find out.

As for the the 'vintage is better' theology, I'm not a subscriber myself. My main concern with getting into NOS is whether I'll be able to find the same valves again when the time comes to replace them.

Thanks for everyones input, it is appreicated.
-Benja

 

[benjaturner]

Re: Some valve/tube questions

I've just read through my last post. I hope I didn't come across as being too 'snotty'. Sorry if any offence was caused.

-Benja

 

[jeremy]

Re: Some valve/tube questions

not at all. grammer is for sallys anyway

 

[aleclee]

Re: Some valve/tube questions

not at all. grammer is for sallys anyway

What about "grammAr"?

 

[wixedmords]

Re: Some valve/tube questions

My apologioes to KG and Benja, I thought Benja was of a different language.

Anyway, wasn't Larry Johnson Grandma-ma ?