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Topic: Tube question |
Rick Winfield
From:
Pickin' beneath the Palmettos
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Posted 28 Jun 2007 12:07 pm |
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I have a Marshall JCM 800 100 watt tube head and a Marshall 4x12 celestion 70 cab.(circa 1980) I used it for my Les Paul. I use it for my steel now a days but....
Here's the question.
If I change the EL34's to 6L6's will the amp still work? and if so, will I get a warmer Fender-ish type of sound ? |
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John Dahms
From:
Perkasie, Pennsylvania, USA
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Posted 28 Jun 2007 1:51 pm
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As I recall, going from EL34 to 6l6s doesn't require rewiring the tube sockets but the bias adjustment won't have enough range and needs reworking. The response will change some but it will not sound like a Fender because the tone stack arangement is different and the output transformer, speakers, and other components are not Fender in origin.
_________________
Time flies like an eagle
Fruit flies like a banana. |
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William Matthews
From:
New York, USA
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Posted 28 Jun 2007 8:39 pm
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You'll need to change out your screen resistors, and re-bias.. It is not just a plug and play type of thing. The job should be done by someone who knows their way around a Marshall ( like me  I have 23 of em ) If you need more info, please feel free to contact me, even phone me if you need. I am in NY if you need any help. |
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Jim Sliff
From:
Lawndale California, USA
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Posted 28 Jun 2007 9:12 pm
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Do what William said - it's not a job for a non-tech, and even those whit basic soldering skills can get messed up by printed circuit boards.
Rick - did you buy your amp new or get it used? The reason I ask is most US JCM800's from that era came with 6550's and a couple of different methods of converting them to run with EL434's were used (in fact, are you SURE you have EL34's?)...some better than others. If it was a conversion you absolutely want it looked at my a tech, and the "quick and dirty" one-resistor-replacement conversion method (which simply allows the EL34's to be biased somewhat correctly) is almost guaranteed to cook your 6L6's even with new screen resistors.
_________________
No chops, but great tone
1930's/40's Rickenbacher/Rickenbacker 6&8 string lap steels
1921 Weissenborn Style 2; Hilo&Schireson hollownecks
Appalachian, Regal & Dobro squarenecks
1959 Fender 400 9+2 B6;1960's Fender 800 3+3+2; 1948 Fender Dual-8 Professional |
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Rick Winfield
From:
Pickin' beneath the Palmettos
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Posted 29 Jun 2007 7:42 am tubes
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Thanks to all who replied.
you have 23 Marshalls? Whoa !!
As usual I'm in over my head!!
I was hoping for a simple "plug 'n'play",maybe a little biasing, and now I see the light. !!
I guess the real decision I have to make at this point is whether or not I want to alter the amp, or get something else.
I purchased it 2nd hand from a local music store in the mid 80's. At that time I was working 2/3 nites a week, so the first thing I did was get "groove tubes". I used them for about a year,(too much high end for what I needed) and them had a tech replace them with Sovtek EL334 and bias them. I don't remember what originally was used.
SAD TALE:
Around this time, I sold a 1965 Fender Vibrolux black face(2x10, I think) to help with the costs.
SOMEBODY SHOOT ME PLEASE !!! |
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Papa Joe Pollick
From:
Swanton, Ohio
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Posted 29 Jun 2007 9:17 am
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| BANG |
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