Musician Gear & Tech Discussion

Yes Thanks John I am doing some research on those as well. Seems a lot of the cover stuff that Ray is wanting to do now is much more acoustic in tone / feel may be a mute point for the time being. Thats cool though using more and differnt chords and having to play cleaner will only help me in the longrun. May even have to get myself an acoustic guitar. Our Bassest has an acoustic and a stand up type bass. the boys want to do some "unplugged stuff" as well.

I never heard of 6550s in a Marshall.

I have 6550's in one of my 2203's. It became popular with Zakk Wylde as he uses them in all his 2203's and that's what is in his signature Marshall as well. Marshall JCM800 2203ZW (Zakk Model) JCM800 Reissue 2203X (same amp but with EL34's and no Zakk graphics on the face plate and std cloth and logo)
They do give a bit ballsier tone than EL34s but I like both. The sounds blend well together running one head with 6550s and the other EL34s.

Nobody knows what the hell was done to this poor head.

I wish i had a digital camera so i could take a pic and post it!

Literally the rectifier tube??!!?? is 2.5x the size of a 6550. And when i first looked up this head after I bought it, I was sure it took 4 el 34's, not 6550's.

I didn't even know the damn tubes were tung-sol. Pretty damn confusing and when i have to replace something I feel I might be pissing into the fan.

As it is now, I walk softly around that head. The day it blows a tube might be the day I lose probably the most valuable thing I own. (intrinsic value, not monetary)

Thanks for your help, in any case and I mean it. Thank you!

:cry: I want to hear it! Now I am depressed.

When I get all my tubes in, I'll post a clip of the sounds.

I just got some SED 5u4 rectifier tubes in today straight from the Ukraine. It took 2-weeks to get 'em, but they kicked the holy hell out of the Mesas.. My god I'm running across some good tubes!! I have some RCA nos 5u4's on the way as well.. It's gonna be another showdown, 'cause I can't imagine 'em sounding any better than these SEDs.





One thing to note: Coke Bottle 5u4's kick the sh*t out of 5u4gb's (straight tubes)..

JW.. Wanna buy some tubes?? I'll have either some SED or RCA-nos 5u4 tubes leftover when I'm done.

Edit: Nevermind jw.. You have a Triple Rec. I know where you can get some killer matched SEDs, and they're cheap. Takes a while to get 'em, but it's worth the wait. $50 for a matched quad. straight from the Ukraine.

Nobody knows what the hell was done to this poor head.

I wish i had a digital camera so i could take a pic and post it!

Literally the rectifier tube??!!?? is 2.5x the size of a 6550. And when i first looked up this head after I bought it, I was sure it took 4 el 34's, not 6550's.

I didn't even know the damn tubes were tung-sol. Pretty damn confusing and when i have to replace something I feel I might be pissing into the fan.

As it is now, I walk softly around that head. The day it blows a tube might be the day I lose probably the most valuable thing I own. (intrinsic value, not monetary)

Thanks for your help, in any case and I mean it. Thank you!

That's always the way it always is..

You're gonna have to take that leap at some point. That's kinda why I started this thread. 'Cause anytime you can get some good info and insights on good tubes, it's golden information.

Some of the tubes I bought sounded like crap, and a couple were DOA. But the ones that sound good, sound REALLY good!! So I spent the money, and passed on the information of my experience. If it helps someone else, then cool.

That head has to be modded, power tubes usually come in pairs, as somebody already said. I don't know of any amp that only uses 3, some lower wattage amps (below 15 watts) use 1 power tube. My Peavey MX uses 4 - 6L6 power tubes, 130 watts, and the 6550's should do higher wattage. 180-200 watts with 6550's is not out of the ballpark, I don't think, at least for 4 of them. 3 and an oddball though??? A rectifier tube no less???? wierd...

Sounds like a unique amp, 5u4 is the rectifier tube used in my super Reverb, bigger than the 8L6's but I don't think twice as big. But big for sure. In this case it sounds like it's being used as one of the power tubes by some means, which I think would mean some inventive modifications and serious biasing.

Damn, now I'm curious...

Surely it can't be just dumb luck, somebody blew a tube and just plugged in the only extra he had and it happened to work (before you got it, I'm not trying to blame it on you)...I wish you had a digital camera too, now.

Years back, I replaced the rectifier tube in my old Super Reverb with a "new improved solid state " replacement module. I thought it worked great. When I sold the amp to Cesar Diaz, He informed me that the first thing he would do in the restoration process would be to git rid of that damn rectifier an get a proper tube in it! To this day, I'm not convinced that it matters one way or another 'cept to say that the solid state rectifier might make your output transformer operate cooler and possibly more efficiently. I would like to hear more input on this mater, just out of curiosity. One thin I would be cautious of in purchasing foreign vacuum tubes direct from the manufacturer is poor quality control. Sounds like playin' tube Russian roulette to me.

One thin I would be cautious of in purchasing foreign vacuum tubes direct from the manufacturer is poor quality control. Sounds like playin' tube Russian roulette to me.

Well, Howlin.. The tubes I bought aren't straight from the factory. They were made in the early 60's.. NOS tubes will eventually run dry. But before that happens, the prices will increase dramatically.

I had a little doubt myself when I bought my 5u4 Seds from this Ukrainian guy. The price was cheap, And I thought, maybe there's a reason. Maybe they're not very good, or possibly it might be a scam.. But the guy did have 100% feedback, so I thought, oh what the Hell.. What's the worst that can happen? I'd be out $50?. ( I also bought some RCA's from the U.S. just in case something went wrong.)

Man, am I glad that wasn't the case. The tubes are the best I've ever heard in this amp. It's hard for me to describe how good they sound, but I'm extremely amazed by them. It's exactly how I always wanted my amp to sound. I'm stocking up dude. 'Cause when the well runs dry, I don't want to be paying a fortune for these later..

I just bought some more this morning from this guy. I have all the confidence in the world with the seller, and I'm gonna buy even more later. These things are perfect, and I want enough of them to last me a loooong time.

Check it out man..

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... :IT&ih=004

Some 1959 SED NOS 5u4's comin' to papa!!

Now check this out..

http://thetubestore.com/nos-5u3c.html

That price is "per 1 tube" from the U.S. (I'm saving $92 a pair)

Shreddin' Teddy,
I am now convinced that your head is screwed on as tight as your tubes are plugged in. Anyways, the tone of your amp on Burn speaks for itself. You seem pretty damn smart for a git fiddler. This is an interesting topic . Thanks for sharin' the info. Fat tube tone is where it's at! ... later..
Howlin'J

Captain Scott:

Got some info on your amp.

Talked to a local amp builder here yesterday, you're not going to like it most likely. The 5u4 is a rectifier tube, operates on totally different voltages from the power tubes (6550). Can't be modified to work, since they are wired in pairs and the voltage thing kills any possibility they will cooperate.

so if it's working at all, the 5u4 is killing that pair of tubes, you're running only on the other pair.

My guess is someone blew a tube and plugged in the only spare they had lying around hoping to make the night. By some strange stroke of luck it still works, but is only running on 2 cylinders...

And it should be a 100 watt amp, solid state rectifier.

Paleopete, I havent had a Marshall in years but when I did I thought they worked in pairs as far as power tubes, what they call a push pull amp. I had an old plexi and used to pull the outer tubes to quiet it down some. The other day I was reading somewhere about this and it said pulling a pair of tubes will only reduce the overall volume around 3 db, thats not very much, so it could be possible this amp of Scotts is only running on 2 power tubes. 6550s seem to be the most powerful tubes. Ive been using a Scholz power soak on my Sunn head and to get it down to manageble recording levels Ive got it attenuated to -24db and its still probably loud enough to play with a loud drummer. It amazes me cause I used to run a 6x10 and a 4x12 cab with this head and had the gain set at 10 and the master at 8 on this amp, the only reason I didnt run 10 on the master is cause the volume rolled of slightly when I did this. I cant believe that place used to let me run that thing like I did.

I think you're right, you can pull the outer or inner two and use half of each pair, but you can't kill the whole pair, which is what this situation does. I'll have to do some more poking around, but I think it can damage transformers, probably overheats components too.

I ran across an article about pulling power tubes a while back, not sure if I can find it again but I'll look. I do know though, killing the whole pair can cause damage and according to a knowledgeable amp builder here this situation is killing the whole pair, may have already blown the 5u4 long ago.

Hey Howlin,

A bit of Irony here..

The U.S. bought RCA's ????

DEAD ON ARRIVAL!!


Edit: On a good note, they did say they would send me another pair.

Damn man..

Dude overnighted 'em. Now that's what I call customer service!!

I've got a lot of respect for someone who atones for their mistakes, especially as quickly as this. It shows honor and character. Cool sh*t!

So I guess it's a battle of the heavyweights tonight..

A pair of 1960 Svetlana Black plate Nos. 5u4g's. **VS.** A pair of 1964 RCA Black plate Nos 5u4g's.

Should be interesting. Kinda like Rocky VS. Drago. Haha.

Captain:

OK, I can't find the in depth article I was looking for, but did run across a few references in an amp building/repair forum.

Pulling two tubes, either inner two or outer two, will drop the volume level but only about -3db, which is not much. Barely enough to hear. It also doubles the output impedance, so the speakers should be matched accordingly. Marshall transformers seem to be much less forgiving than Fenders in this respect, mismatched speaker loads kill lots more Marshalls than Fenders.

The amp discussed here is just shutting off one side, which is definitely not good, it should be taken to a shop and fixed before it blows a transformer. In addition to the electrical signal going crazy it's probably heating up some of the tubes to the danger level and the impedance I would think is not right either.

The man I talked to locally, good amp builder with a lot of knowledge and experience, said take it in to be fixed before it fries something. The rectifier tube in apower tube position is shutting down that whole tube section and that's not good. So you're only running on half the amp and that half is getting overloaded.

Be glad it's not running EL34's, they seem to have had wide quality variations over the years, 6L6 and 6550 tubes have a reputation among amp techs for being much more reliable.