Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: TerryD on April 10, 2017, 06:34:08 am
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I got two used "seemingly" small sized RCA 6l6s to go with two other slightly larger RCAs that I had on hand to go into my Fender PA 100 project. Can smaller 6L6s make an amp sound "compressed" . This amp is too "compressed" Any ideas what to do??
Thanks,
Terry
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I got two used
physical size should not effect physical characteristics, physical age might
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Also tube mismatch can have effect on sound
Franco
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Some of RCA Tubes, the early 6L6GB were made by Tung-sol. The RCA Cleartop 6L6GC is a larger tube with a more rounded top and a pair will produce 60 watts. If you smaller ones have a getter flash on the side and a brown base, probably Tung-sol. Great tube, but shouldn't sound different until running them hard. The Tung-sol tubes are smoother and RCA tubes have a warmth that is different than any tube. The Holy Grail RCA is supposed to be the 6L6GC clear top and the glass is taller. I still like the RCA 6l6GB, Black Base for most things and run Tung-sol 5881 in all older fenders.
None should sound compressed as a 6L6 is a very open and piano sounding tube.
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That tube has been around since, what, the late 30's? As the years have gone by, ratings have crept up. Is it possible he might have an older set with lesser ratings and they are now being pushed hard? Has the amp ever sounded not compressed? If not, you need to look at the amp.
Ed, I've got a bunch of coke bottle 6L6's. I looked up the ratings a while back and they were pretty anemic. As I cant stand 6L6's anyway, I've never done anything with them. Since you are the guru, are these things worth doing anything with? Or worth selling? Or gifting to a Hoffman friend?
Jim
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Ed, I've got a bunch of coke bottle 6L6's. I looked up the ratings a while back and they were pretty anemic. As I cant stand 6L6's anyway, I've never done anything with them. Since you are the guru, are these things worth doing anything with? Or worth selling? Or gifting to a Hoffman friend?
A pair would look purdy in my 1954 RockOla conversion. It had one coke bottle in it when I got it but it was cracked. I have a coke bottle recto to match.
http://sluckeyamps.com/rocky/rocky.htm (http://sluckeyamps.com/rocky/rocky.htm)
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Coke btl sixes! Love those purdy stingers. I agree that sixes can sound sterile in some builds but I found a cure for that. It is called the Klon Centaur Klone pedal. I built one using a well laid out pcb from GGG and I wouldn't hardly play without it ever again. It is called a "distortion" effect but when you keep the gain low on it it adds a wonderful tone to the amp. With that setting it behaves like a booster/OD. The only drawback is that a true clone uses several uncommon parts values.
I guess I strayed from the gentleman's topic so perdona mi. With today's PA setups you can crank a 15 watt amp and mic it or use a DI box. Makes it sound like a thousand watts if you have the setup. I would match up the sixes and then play them for a while. If you like the sound keep them whether they are 'strong' or 'weak'. Hey but that's just one man's opinion. If you don't have a tube matcher in your tool bin, there are a few really easy to build layouts for a tube matcher on the web that require only a metal box, an unusable 6L6 or 6V6 tube, an octal socket, one or two Rs and Cs, and about 20 ft. of hookup wire cut to 4 ft. lengths. Of course there are several commercially sold tube matching gizmos on the market too. :icon_biggrin:
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That tube has been around since, what, the late 30's? As the years have gone by, ratings have crept up. Is it possible he might have an older set with lesser ratings and they are now being pushed hard? Has the amp ever sounded not compressed? If not, you need to look at the amp.
Ed, I've got a bunch of coke bottle 6L6's. I looked up the ratings a while back and they were pretty anemic. As I cant stand 6L6's anyway, I've never done anything with them. Since you are the guru, are these things worth doing anything with? Or worth selling? Or gifting to a Hoffman friend?
Jim
From the guru. Grasshopper, ah yes, ST bottles have value and you are correct they are low on the totem. However, if you have a way to match them you have some value.
See, you already have a couple wanting them. Yes, they have value.
Tone? Really nice, but all the old ones are, but excel in the cleaner chewy side of things. I like them and have quite a few. Others may want first dibs.
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https://www.youtube.com/watch?v=l91ISfcuzDw (https://www.youtube.com/watch?v=l91ISfcuzDw)
Jim :dontknow:
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https://www.youtube.com/watch?v=1ytCEuuW2_A (https://www.youtube.com/watch?v=1ytCEuuW2_A)