5150 Question - What Tubes are you using?

guitarguru777

guitarguru777

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Nov 13, 2003
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I have been researching this subject for the last 2 weeks since I picked up my 5150 and I have seen a shitload of options.

After doing some research I found my amp has whats called an "Integrated Quad" setup. This comes from EuroTubes and consists of 5 ECC83 High Gain Tubes, 2 KT88 Output Tubes and 2 6L6 Tubes. The KT88s are used in the 2 outer sockets and they are all JJ Tubes.

I did a test today with my 5150 and the results really surprised me.

I ran the amp as purchased with the "Integrated Quad" setup and did some recording. Then I popped in 2 of the other JJ 6L6 tubes from my Valve King and did some recording.

The tone between the 2 was virtually identical. I even did some frequency analysis on the signals and the differences were negligible.

Integrated_Quads_Test.jpg


(Full Size Image http://picasaweb.google.com/lh/photo/9boTVSvpF7I0sStw5wv21g?feat=directlink)

Now I attribute some of this to that fact that the amps volume is only on 2 and the power section really isn't working that hard (that's just a guess) but I am in an apartment and anything over that volume the neighbors start banging on walls.

Then again it could be my noob ears ...lol

So what tubes are you using in your 5150 and what do you prefer. I am not talking so much about brand as I love my JJ's and will probably never switch, I am talking more type as far as 6L6 vs KT88, Integrated Quad setup vs Stock Setup.

Thanks
(I can post sound clips later if you are interested to see if you can hear the difference)
 
stay away from those "integrated quads"...I know that Bob (or whatever his name is) says it's perfectily fine to use them....it's not!
You can't just drop any tube you want into any amp (without changing parts) and call it a day....and even if you change grid resistors and adjust the bias circuit...does the tranny deliver enough juice to run the KT88 (heatercurrent)? what about OT and impedances etc?

also about those ecc83.....I guess you bought at eurotubes...those are just JJ 12ax7, not a bad tube, but IMO too muddy for the 6505 unless they're combined with tighter/brighter tubes (like chinese etc)....

all that said...in an amp like the 6505 the preamp tubes don't make a major difference (in more straight forward amps they do), neither do the powertubes (this amp is getting its tone from the preamp anyways)....

my advice would be to get some chinese/tungsol/jj for the preamp and put high quality 6L6 in the poweramp (=C= are awesome).
bin those tubes you bought as an "integrated quad"..they should be called "integrated nonsense" anyways.


EDIT:

here's what Roger Crimm (Peavey) says about the topic:

Roger Crimm said:
Integrated Quad

Sorry, but this has to be one of the wackiest ideas I have ever seen. I know there are a lot of guys who are doing this, and there is at least one tube supplier who seems to think this is a good idea. I tried to stay silent on this one, after all it's your money.

The theory here is that they pick a set of EL34 and a set of 6L6, which draw the same exact amount of natural plate current. The danger here is in the implied assumption that plate current is the only spec that matters, and that the tubes will not drift from these specs as they age.
Two other real differences you have to deal with is available heater current (the EL34 draws twice the current, 1.5 amps as opposed to .9 amps for the 6L6), and that 6L6s and EL34s have different reflected plate impedances. Not taking specs like these into account might get you into real trouble with some amplifiers.

This sounds like a good way to move some tubes which you otherwise couldn’t sell to me.

Using an "Integrated Quad", you start out with two sets of tubes, which are already at the extremes of their designed specs. That is my primary objection to this idea. I consider the sonic benefits dubious, considering the potential problems you may run into.
Once these tubes are subjected to wear and tear anything can happen. I prefer tubes falling into the middle range of spec for that particular tube. That way, you are still ok as they age and slide one way or another.

Every engineer (Including the guys where I work who design the stuff), and every master level tech that I have approached with this idea either thought it was the stupidest idea they had ever heard of (a quote), or simply just laughed out loud. This is especially silly if you have an amp designed to get most of it's tone from the preamp anyway.

I have had a few guys come through the service center where I work, who fell for this particular sales pitch. Everything is ok at first, then you run into problems when the tubes drift too far away from spec or just fail outright.
I was recently involved with servicing a Peavey Triple XXX, which had suffered from this particular bit of foolishness. The complaint was noise, low gain/output, and overall crappy sound. The owner had put an integrated quad in a few months back. All was well for a month or so, but then the amp just lost it.

He brings it in, and sure enough, the only thing wrong with the amp was the tubes. The bias measured WAY off, and couldn’t be brought to spec with the tubes that were in there. The two EL34s I pulled out of that amp have to rank among the worst set of tubes I have ever seen that would still actually function. They aren’t even close to a current match, they rattle worse than any EL84 I have ever heard, and are microphonic as all get out.
Compounding the problem, the preamp tubes he had in there were no better. They were low in gain and the amp sounded muffled and flat even after we cured the other stuff.
I replaced the crappy tubes, and the amp came back to life. The guy left with a big smile on his face, and promised me he wouldn’t make that mistake again. He got lucky this time, no other damage done (other than to his pocket book).

Yes, I know some of you are doing this with no problems. If you like the way it sounds, and you are in the studio or at band practice where a failure would not be a serious problem or embarrassment, go for it. If you doing this in a live situation and ESPECIALLY if you have no equivilent or reliable backup available, you are pushing your luck I say. Remember who told ya so.
Click to expand...
 
@lasse: he's talking about running 2 6l6 and 2 el34 though, but the integrated quads are actually 6l6 and kt88 tubes.

anyways, winged C all the way. i'm loving mine :)
 
Fragle said:
@lasse: he's talking about running 2 6l6 and 2 el34 though, but the integrated quads are actually 6l6 and kt88 tubes.
Click to expand...

doesn't matter "intergrated quad" just means 4 tubes of different kind...the problem with KT88 is the same as with el34


=C= FTW
fucking up your amp by believing some "expert" who's only trying to sell tubes FTL
 
Running kt88's and 6L6's is actually worse than running 6l6's and el34's.

But bottom line is, the transformer can't handle those kt88's.(heater current too high. Pray they don't go wacky and pull more current).

And if those KT88's drift out of spec, things will start to fry quick(OT,PT, Fuses, Tubes, Resistors, etc.) Just stick with 4 SED 6L6's and you are golden!

Edit- Ah the guy from Peavey said it all. Damn.
 
And from my experience, stay away from Eurotubes. Only place I've bought tubes from and they came to me bad. And this happened more than once.

TubeDepot has never done me wrong. All tubes are always what they say they are!
 
Ya I made that decision today based on some shit I been hearing like this for the past 2 weeks. Im just going to go straight up with the 6L6's. How are the winged C tone wise comparable to the JJ. I have JJ's now and really like them.
 
guitarguru777 said:
Ya I made that decision today based on some shit I been hearing like this for the past 2 weeks. Im just going to go straight up with the 6L6's. How are the winged C tone wise comparable to the JJ. I have JJ's now and really like them.
Click to expand...

not a major difference in that amp (changing the bias makes a bigger difference)...the =C= are a bit more definied with a tighter lowend and more sparkle..the JJ have thick and juicy mids, but as I said, not a major difference.
the Quality of the =C= is better though, so I'm buying them for reliability
 
I shall also try these "winged C"'s. I've been using the Eurotubes Standard Gain full retube once a year after moving off of the ridiculous High Gain kit. I don't think it's anything like "integrated" quads - since they're just 4 matched tubes of the same type (6L6GC) - in terms of dangerousness. However I am looking to tighten up the lows a bit more and these intrigue me.
 
Let me come in burst a lot of bubbles to some degree, but just about everything coming out of both Bob's and Rodger's mouth is pure garbage, neither one of them are credible in terms of reliable information. The only real issue with running an amp designed for 6L6's with other types of tubes is the obvious, 6L6 amps were not built strong enough to handle the heater currents of the tubes and you have to assume that the maximum SAFEST output power dissipation that a OT can handle is the standard 150 watts granted the oversize of the older 75 watt OT's that Marshall used to run 2 OT's on when they believed there could not be an OT big enough to handle more than some 60-75 watts, with a quad set of KT88's you are getting close to near 200 watts in class A and about 180 watts in AB, which means your OT could get hot if you crank it too hard.

Honestly though if the Power tranny and OT were beefed up enough to handle EL34s or KT88's there would be no issue whatsoever if the tubes are biased correctly at their properly set impedance loads, but in a stock 6L6 amp, things could overheat real quick. Maybe you should throw some 88's in a 6534+? :D
 
Oh im definitely not interested in running the 88s especially after doing research and "tone tests". I dont see any advantages of swapping out the transformers and moving up to 88's in a 5150.

There is just so much contradictory info in response to this "Integrated Quad" deal. Supposedly the guy that had the amp before me has been running it this way for the last 4 years with no issues. The amp works fine, i dont see any "mods" done to it other then a logo removal and some "cosmetic" changes.

I just thought it was real interesting that there was no difference in the tone. Funny thing is even when I asked the guy from EuroTubes about it he said at the volume I am running the amp I wont notice the difference. I really need to crank it up.

When I asked him how high he said about half way. I get this amp on 3.5 / 4 on volume I am already drowning out the drummer ....lol

I dont think I would ever run the amp hot enough to notice a difference if there was one, and if I did I risk losing a transformer. So whats the benefit exactly? :lol:
 
guitarguru777 said:
Oh im definitely not interested in running the 88s especially after doing research and "tone tests". I dont see any advantages of swapping out the transformers and moving up to 88's in a 5150.

There is just so much contradictory info in response to this "Integrated Quad" deal. Supposedly the guy that had the amp before me has been running it this way for the last 4 years with no issues. The amp works fine, i dont see any "mods" done to it other then a logo removal and some "cosmetic" changes.

I just thought it was real interesting that there was no difference in the tone. Funny thing is even when I asked the guy from EuroTubes about it he said at the volume I am running the amp I wont notice the difference. I really need to crank it up.

When I asked him how high he said about half way. I get this amp on 3.5 / 4 on volume I am already drowning out the drummer ....lol

I dont think I would ever run the amp hot enough to notice a difference if there was one, and if I did I risk losing a transformer. So whats the benefit exactly? :lol:
Click to expand...

you hit the nail with the hammer in a discovery. Tubes, do not color the sound until they begin to distort. A KT88 will not take out a tranny if your not cranking that hard, because the failure will result from tranny overheating and since you are not cranking it hard to saturate you are not overheating anything. Problem is, as soon as you begin to turn up, that is when you will pull both trannys.
 
I used to pull out two of the tubes in order to cut the power to 60 watts. Outside pair or inside pair, either one.

Not sure if it has a negative impact, my old Tech told me that it wasn't a big deal. I stopped doing it for other reasons.
 
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