Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: worth on January 17, 2011, 08:55:43 am
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Can someone describe the tonal difference between a 6L6 and a 5881.... I've always used 6L6s' , and I'm thinking about trying 5881s' in a AB763 Super Reverb.
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I don't know, the ones I have say 5881/6l6GC on them from Mesa. They sound good but don't know the difference. I would say that MFG would play the largest part in what they sound like. I bet the same MFG may even have better days of the week that the tubes sound better.
Tony
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Can you describe the taste difference between Skippy creamy peanut butter and Peter Pan peanut butter?
The difference you'll hear will probably be very subjective (meaning every person hears a different "difference"), and you may not hear any real change at all.
Modern tubes marked "6L6" and "5881" may have little or no internal difference; they have been used as distinguishing marks for marketing purposes for at least 20 years. If we were talking tubes from the 40's through the 60's, there would be very real voltage and power capability differences between tubes with these markings (and all the other letter suffixes added to "6L6"). I would the difference of ratings to be a bigger change than a tonal change.
Some amp circuits seem to have a big sound-change with a tube change, and other seem to have no sound-change at all. Based on my hearing and experience, I'd say that changing output tubes in an amp with output stage feedback (from the OT secondary to the phase inverter) will result in little, if any, difference. The change you're likely to hear is the transition from clean to distortion and/or the distortion quality. Feedback is used (among other things) to reduce how much the circuit's performance changes with a change in tube characteristics. So it would be less likely for you to hear a change when swapping tubes.
I'll also say that I've always heard a bigger tonal change when changing preamp tubes (although more effect in some amps over others), but comments regarding feedback still apply.
But everybody hears things differently, so your experiences may differ.
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Can you describe the taste difference between Skippy creamy peanut butter and Peter Pan peanut butter?
Peter Pan tastes more peanutty. Crunchy is preferred by early rockers. Younger players may like the taste of Great Value though. But really, it's the brand of jelly that makes the difference. :grin:
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So what you're telling me is switching picks is where it's at... :laugh:
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This is a really good peanut butter forum.. thanks.
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Can you describe the taste difference between Skippy creamy peanut butter and Peter Pan peanut butter?
The difference you'll hear will probably be very subjective (meaning every person hears a different "difference"), and you may not hear any real change at all.
Modern tubes marked "6L6" and "5881" may have little or no internal difference; they have been used as distinguishing marks for marketing purposes for at least 20 years. If we were talking tubes from the 40's through the 60's, there would be very real voltage and power capability differences between tubes with these markings (and all the other letter suffixes added to "6L6"). I would the difference of ratings to be a bigger change than a tonal change.
Some amp circuits seem to have a big sound-change with a tube change, and other seem to have no sound-change at all. Based on my hearing and experience, I'd say that changing output tubes in an amp with output stage feedback (from the OT secondary to the phase inverter) will result in little, if any, difference. The change you're likely to hear is the transition from clean to distortion and/or the distortion quality. Feedback is used (among other things) to reduce how much the circuit's performance changes with a change in tube characteristics. So it would be less likely for you to hear a change when swapping tubes.
I'll also say that I've always heard a bigger tonal change when changing preamp tubes (although more effect in some amps over others), but comments regarding feedback still apply.
But everybody hears things differently, so your experiences may differ.
Ditto
In my limited experience I get the biggest tonal changes from preamp tubes.
It's been my understanding that tubes with a 4 digit name like 6550 or 5881 were industrial tubes. and tubes like 6L6 and 12AX7 were called consumer tubes. The industrial tubes were (again to my understanding) ruggedized. Extra Mica's were used and other such engineering features so that they could withstand high vibrations and misuse, making them great candidates for use in a gigging musicians amp.
Ray
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:laugh: I agree any peanut butter is good with smuckers strawberry jam. So it's all in the JAM
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FWIW if you're looking for a cheap '5881' variant, the Russkie 6P3Se is a rugged 20W tube with good crunchiness
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FWIW if you're looking for a cheap '5881' variant, the Russkie 6P3Se is a rugged 20W tube with good crunchiness
The same tube is resold under various brands/references, such as Sovtek 5881...
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i like PB and honey... i don't do jam & i like the crunchy stuff.
that reminds me of a tune....
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Reminds me of a tune too...
&feature=related
See what you did HBP? :laugh:
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FWIW if you're looking for a cheap '5881' variant, the Russkie 6P3Se is a rugged 20W tube with good crunchiness
The same tube is resold under various brands/references, such as Sovtek 5881...
that is also my favorite russian 6l6 variant. it seems to be the only tube to hold up reliably to the 450V B+ of fender amps.
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"6L6" _is_ a lot like peanut butter.
They change the formula every decade.
(http://www.radiomuseum.org/images/tubephoto_klein/807_syl.jpg)
There was the 807, it was good, but expensive.
(http://www.radiomuseum.org/images/tubephoto_klein/6l6_rca_n.jpg)
There was the Metal 6L6, 24.Mar.1936, supposedly a cheaper 807.
The 6L6 had many fathers and enemies. Someone else had a patent on Power Pentode, so the 6L6 had to work as good as a pentode yet appear to not be a pentode. A combination of spacing and side-bars do what G3 does in a pentode. A straight pentode is a pig for G2 current, RCA bought a patent that was deemed too expensive for production and invented a machine to make it practical, and got G2 current way down. Great tube, but a lot of hype around it.
(http://www.radiomuseum.org/images/tubephoto_klein/6l6g.jpg)
The metal 6L6 was expensive, RCA also registered a glass 6L6G on 08.Jun.1936.
(http://www.radiomuseum.org/images/tubephoto_klein/kt66.jpg)
6L6 was so popular, Osram made something like it for the european market, the KT66. This does not seem to be a copy but a work-alike. If you don't strain it, you may hardly know a difference. In fact the original spec shows the same performace. But the original KT66 lacks the G2/G3 kinks of original 6L6 and may sound different when slammed. It could also make more power in amps designed for KT66.
(http://www.radiomuseum.org/images/tubephoto_klein/6l6ga_r.jpg)
The 6L6GA of 1943.
(http://www.radiomuseum.org/images/tubephoto_klein/6l6gb_1.jpg)
Coke-bottle went out of style, cylindrical was in, so 6L6GB.
(http://www.radiomuseum.org/images/tubephoto_klein/5881_tungsol_1.jpg)
Tung-Sol was tired of making good headlights, went into tubes, niche was extra-tough tubes for applications which were killing standard tubes. Their 5881 works in nearly any 6L6 socket but will take more abuse.
Tube major-improvement peaked in the mid-1930s, then developers rested or worked on getting costs down. Then a war with a few fabulous developments and a lot of old-warhorses.
Close examination of these tubes shows that the electrode structures varied from 1936 onward. Improvements, short-cuts, many different makers doing things a little different. Also the Power Pentode patents either expired, wer captured, or were cross-licensed, and pentode-like structures crept in.
(http://www.radiomuseum.org/images/tubephoto_klein/6l6gc_rcb.jpg)
But then came TV. Cost a LOT of money. If costs could be brought down total sales would rise. So the tube designers really changed things up. The 2nd biggest and costliest tube in a TV set is the H-Sweep tube. And that's kinda an Audio tube with some adaptations. Someone took the 6L6 cathode, re-thought all the rest, and made a great sweep tube. When that was in production they omitted the high-voltage cap and offered it as an audio tube. Because the 6L6 family was still SO popular, they called this nearly-new tube 6L6GC. But it's really a different tube than original 6L6.
Meanwhile the transistor was eating the tube's breakfast and going for the tube's lunch. Tube development mostly stopped. The people making them kept on for a couple decades, but also yard-saled their excess machinery to eastern europe where the Russians studied it (but they had their own good production, self-designed types and US/EUR work-alikes), then on to the Chinese.
(http://i.imgur.com/GSrss.gif)
6P3P is the Chinese 6L6 and may be made on some old USA machinery.
(http://www.radiomuseum.org/images/tubephoto_klein/6p3s_o.jpg)(http://www.radiomuseum.org/images/tubephoto_klein/6p3se.jpg)
The Russians had several tubes like 6L6. 6p3s was in production a long time with many variations.
(http://upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Jif-01.jpg/220px-Jif-01.jpg)(http://upload.wikimedia.org/wikipedia/en/thumb/6/63/Skippy_jars.jpg/220px-Skippy_jars.jpg)
So which Jif are we picking? The original from 1958? The updated Jif of the 1990s when even dads picked Jif? How about Skippy, which fell into the claws of the Corn Products Refining Co. after stealing the name and stashing a cartoonist in a nut-hatch?
Use your ears.
Don't expect a tube to make music FOR you. It's just a tool, like a peanut crusher.
(http://www.madehow.com/images/hpm_0000_0001_0_img0145.jpg)
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PRR, That was a nice history lesson on the 6L6. Thanks for sharing that. Punky
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PRR that was entertaining and informative as well :laugh:
Rock On
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~>Prefers Laura Scudders old tyme chunky.
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THX, PRR......You's da MAN!
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i think it is worth noting here that the tung sol reissue 5881 has more low end and high end definition as compared to the midrange heavy jj 6l6 i compared it to. I don't know how this compares to nos stuff but but the grit and sparkle of the reissue tungsol is where its at for me. i use it in a blackface pro reverb style amp. (hoffman board of course)
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:laugh: It reminds me of a song too
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I used to have my own peanut butter maker as a kid...and leave it eBay to have them available still.
Then in 2nd photo found "Mr Peanutbutter" - check out the (young) factory women too :wink:
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The way I understand it M-OV created the Kinkless Tetrode, figured it too expensive, and RCA bought rights to it and produced the 6L6 and variants (ie 6v6) Once they seen how well it was selling through RCA they of course brought the KT66 to market under their Genelex name. Of course the Beam power Tetrodes were a way to get around the Phillips Pentode patents, providing near pentode performance, but still keeping it technically a tetrode.
Of course this info, as I understood it has one caveat, the source is Wikipedia, so there is always a chance for errors. (Apparently if you got a KT63 someplace, you got a 6V6 equivelant)
As far as PB goes, I'm not too fussy as long as it isn't cheap tasting and is Crunchy.
Marmalades/Jams/Jellies/Preserves/Fruit Spreads/Honey: Honey is good, Raspberry or blackberry is super, Grape is the ol' standby, and Strawberry isn't bad either. :) I'm not much on Marmalades.
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But, you all know the definitive peanut butter song is Skippy (http://www.youtube.com/watch?v=ABEH5SMf3B4), right?