JumpMarine
18 watts of Mayhemologist
I was reading about Bob at Eurotubes doing this to both a JCM 800 and 900 with good results, especially on the 900. Would it be safe if I tried this on my JCM 600 combo?
Anyone ever swapped out EL34's for 6L6's in a JCM series amp?
- Thread starter JumpMarine
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JumpMarine
18 watts of Mayhemologist
Re: Anyone ever swapped out 6V6's for EL34's in a JCM series amp?
Re: Anyone ever swapped out 6V6's for EL34's in a JCM series amp?
Re: Anyone ever swapped out 6V6's for EL34's in a JCM series amp?
Yep, already corrected that in my question. Good catch! LOL!mrid said:
Duke of Metal
New member
Re: Anyone ever swapped out EL34's for 6L6's in a JCM series amp?
Hmm.. I thought the JCM900 series came stock with 6L6s?? or am I wrong??
I know that there is a person who Harmony Central (JerryP) who has modded his JCM800 to use 6L6 and he added an extra 3rd 12ax7 to it. I listened to some clips and it sounded pretty good I gotta say.
Duke
Hmm.. I thought the JCM900 series came stock with 6L6s?? or am I wrong??
I know that there is a person who Harmony Central (JerryP) who has modded his JCM800 to use 6L6 and he added an extra 3rd 12ax7 to it. I listened to some clips and it sounded pretty good I gotta say.
Duke
STRATDELUXER97
Stratoblaster Tone Meister
Re: Anyone ever swapped out EL34's for 6L6's in a JCM series amp?
Hello Duke....The SLX series came with 5881 tubes because at the time of this amp's release no one made a decent EL34....Marshall was forced to go with the best or most relaible tube at that time and that was the Sovtek 5881 tube...
JM...If you want a rounder clean tone with more headroom,the 6L6 is a nice tube....If you want the whole Marshall crunch and compression that these amps are known for then stay with the EL34s....If you switch over to the 6L6 tube you more than likely will have to have your bias resistors changed to meet the new bias requirements of the 6L6 tube....In a Marshall...I always love EL34s....
John
Duke of Metal said:
Hello Duke....The SLX series came with 5881 tubes because at the time of this amp's release no one made a decent EL34....Marshall was forced to go with the best or most relaible tube at that time and that was the Sovtek 5881 tube...
JM...If you want a rounder clean tone with more headroom,the 6L6 is a nice tube....If you want the whole Marshall crunch and compression that these amps are known for then stay with the EL34s....If you switch over to the 6L6 tube you more than likely will have to have your bias resistors changed to meet the new bias requirements of the 6L6 tube....In a Marshall...I always love EL34s....
John
STRATDELUXER97
Stratoblaster Tone Meister
Re: Anyone ever swapped out EL34's for 6L6's in a JCM series amp?
Basically the 6L6 is the American tube...Think Fender,Boogie,Ampeg....The British amps favored the EL34s,EL84's,KT66,KT77,KT88....
The 6L6 is a great tube,warm,round,sustainful,and has more clean headroom than the EL34....I wouldn't say they sound sterile to me,but they sound very full and lush in my BF Fender amps...Depends alot on the tubes you use,especially today's tubes...I still keep plenty of N.O.S. 6L6,5881,EL34s,and 12AX7s on hand because I feel the tone is better and the reliability...Finally we are seeing some great tubes coming our way,but the mid to late 80s was just dismal...The 12AX7s of that era and up until recently were awful also,but this is now changing....Finally! :dance:
yes-fan said:
Basically the 6L6 is the American tube...Think Fender,Boogie,Ampeg....The British amps favored the EL34s,EL84's,KT66,KT77,KT88....
The 6L6 is a great tube,warm,round,sustainful,and has more clean headroom than the EL34....I wouldn't say they sound sterile to me,but they sound very full and lush in my BF Fender amps...Depends alot on the tubes you use,especially today's tubes...I still keep plenty of N.O.S. 6L6,5881,EL34s,and 12AX7s on hand because I feel the tone is better and the reliability...Finally we are seeing some great tubes coming our way,but the mid to late 80s was just dismal...The 12AX7s of that era and up until recently were awful also,but this is now changing....Finally! :dance:
Jeff Seal
New member
Re: Anyone ever swapped out EL34's for 6L6's in a JCM series amp?
Putting 6L6GC's in a JCM800 is not particularly recommended....or any amp that didn't come with them.
First off, a 6L6 is not the same as a 6L6GC...No one i know of actually makes true 6L6's anymore, and for the most part it's generally assumed the GC version is implied....the point of this little clarification is simple..
An actual 6L6 in a JCM800 will work for approximately 30 seconds before it burns up....wheeee, fun...sparks!
A 6L6GC will last considerably longer, but depending on exactly which 800 it goes in, it really is not advisable....Why, thou do ask?
JCM800 plate voltages are usually around 460v for the EL34 versions and closer to 485v for the 6550 versions.
The EL34 has a maximum plate voltage of 800v...no problem here
The 6550's plate maximum is 600v..again no problem
The 6L6GC plate maximum is 500v......bad idea
The 6L6 plate maximum is 360v....poof!
Although again, it's a rare ocassion to find actual 6L6's...but NOS 6L6's are still available...so be forwarned to use the GC versions...
It's usually easy to spot the JCM800's and Super Leads (although not mentioned as a choice here) that have been improperly converted to run 6L6GC's. The main filter caps always have the outer heatshrink wrap melted off (the plastic looking outer cover that says LCR, Daly..etc.). Pushing any output tube to it's maximum is asking for trouble, so unless you really know what you're doing and change the rectifier circuit to lower the plate voltage, I would highly advise against it!
Jeff Seal
Putting 6L6GC's in a JCM800 is not particularly recommended....or any amp that didn't come with them.
First off, a 6L6 is not the same as a 6L6GC...No one i know of actually makes true 6L6's anymore, and for the most part it's generally assumed the GC version is implied....the point of this little clarification is simple..
An actual 6L6 in a JCM800 will work for approximately 30 seconds before it burns up....wheeee, fun...sparks!
A 6L6GC will last considerably longer, but depending on exactly which 800 it goes in, it really is not advisable....Why, thou do ask?
JCM800 plate voltages are usually around 460v for the EL34 versions and closer to 485v for the 6550 versions.
The EL34 has a maximum plate voltage of 800v...no problem here
The 6550's plate maximum is 600v..again no problem
The 6L6GC plate maximum is 500v......bad idea
The 6L6 plate maximum is 360v....poof!
Although again, it's a rare ocassion to find actual 6L6's...but NOS 6L6's are still available...so be forwarned to use the GC versions...
It's usually easy to spot the JCM800's and Super Leads (although not mentioned as a choice here) that have been improperly converted to run 6L6GC's. The main filter caps always have the outer heatshrink wrap melted off (the plastic looking outer cover that says LCR, Daly..etc.). Pushing any output tube to it's maximum is asking for trouble, so unless you really know what you're doing and change the rectifier circuit to lower the plate voltage, I would highly advise against it!
Jeff Seal
D
DeadSkinSlayer3
Guest
Re: Anyone ever swapped out EL34's for 6L6's in a JCM series amp?
Woah...Slayer's head's were really modded then...as were Zakk Wylde's.
Woah...Slayer's head's were really modded then...as were Zakk Wylde's.
msplines
New member
Re: Anyone ever swapped out EL34's for 6L6's in a JCM series amp?
Depending on what you are looking for, you could try yellow jackets running class A with EL84s and no rebiasing. This gives chime and crunch in abundance when warmed up (class A, see ) with some good quality EL84s, but at a lower overall volume.
This simple plug and play conversion not everyone's cup of tea and does not sound like EL34s at full chat (think rather AC30), but it won't make your ears bleed either!
Depending on what you are looking for, you could try yellow jackets running class A with EL84s and no rebiasing. This gives chime and crunch in abundance when warmed up (class A, see ) with some good quality EL84s, but at a lower overall volume.
This simple plug and play conversion not everyone's cup of tea and does not sound like EL34s at full chat (think rather AC30), but it won't make your ears bleed either!
JumpMarine
18 watts of Mayhemologist
Re: Anyone ever swapped out EL34's for 6L6's in a JCM series amp?
Thanks John and Jeff, great info! I myself am quite happy with my Svet EL34's but just wondered what the reality was after reading this on the Eurotube website.
Thanks John and Jeff, great info! I myself am quite happy with my Svet EL34's but just wondered what the reality was after reading this on the Eurotube website.
willeubanks
Whitewater Toneologist
Re: Anyone ever swapped out EL34's for 6L6's in a JCM series amp?
i don't think the SL-X has 6L6's but i could be wrong. the MkIII does though, and i thought that other than the tubes, the SL-X and MkIII were identical...i'm pretty sure that's the only difference which is why i think the SL-X is EL34. i've gota MkIII and i like it. it has a more raw tone than the EL34 versions of the 900's. the treble is a bit much at full, but if you think it's too much trouble to turn a knob down, you've got problems.
i don't think the SL-X has 6L6's but i could be wrong. the MkIII does though, and i thought that other than the tubes, the SL-X and MkIII were identical...i'm pretty sure that's the only difference which is why i think the SL-X is EL34. i've gota MkIII and i like it. it has a more raw tone than the EL34 versions of the 900's. the treble is a bit much at full, but if you think it's too much trouble to turn a knob down, you've got problems.
STRATDELUXER97
Stratoblaster Tone Meister
Re: Anyone ever swapped out EL34's for 6L6's in a JCM series amp?
The SLX came with Sovtek 5881 tubes because Marshall had no other choice at the time.There just simply wasn't a reliable EL34 being made when the higher gain SLX head was issued...Marshall wasn't in a position to buy hundreds or maybe thousands of EL34s and then have reliability issues with inferior EL34s....Marshall bought tons of Sovtek 5881 tubes from the New Sensor/Sovtek company out of New York....This company is now ElectroHarmonix....
John
willeubanks said:
The SLX came with Sovtek 5881 tubes because Marshall had no other choice at the time.There just simply wasn't a reliable EL34 being made when the higher gain SLX head was issued...Marshall wasn't in a position to buy hundreds or maybe thousands of EL34s and then have reliability issues with inferior EL34s....Marshall bought tons of Sovtek 5881 tubes from the New Sensor/Sovtek company out of New York....This company is now ElectroHarmonix....
John
willeubanks
Whitewater Toneologist
Re: Anyone ever swapped out EL34's for 6L6's in a JCM series amp?
ohhhh. my bad. the difference in them is an extra preamp tube. the MkIII uses a diode instead of a tube. haha. i knew there was a slight difference in tubes. just couldn't remember it.
STRATDELUXER97 said:
ohhhh. my bad. the difference in them is an extra preamp tube. the MkIII uses a diode instead of a tube. haha. i knew there was a slight difference in tubes. just couldn't remember it.
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