Lucid_Lunatic
Rebelyellologist
Can someone school me on the different 900 models? I'm talking only the heads. I have heard good and bad things about them. How many different models did they make?
Marshall JCM 900's
- Thread starter Lucid_Lunatic
- Start date
Ascension
Well-known member
Re: Marshall JCM 900's
There were two main variants. The Dual Reverbs and the Dual Master volumes.
Because I needed a clean channel I played the Dual reverbs through most of the 90's.
The Dual Master volumes IMO were the real tone machines though and are some of my favorite Marshalls of all time.
There were two main variants. The Dual Reverbs and the Dual Master volumes.
Because I needed a clean channel I played the Dual reverbs through most of the 90's.
The Dual Master volumes IMO were the real tone machines though and are some of my favorite Marshalls of all time.
Reckless Abandon
New member
Re: Marshall JCM 900's
Not sure on years made.
Dual Reverb-2 channels with reverb 3 preamp tubes with diode
MKIII-Single channel 3 preamp tubes w/diode
SLX-single channel 4 preamp tubes no diode
Not sure on years made.
Dual Reverb-2 channels with reverb 3 preamp tubes with diode
MKIII-Single channel 3 preamp tubes w/diode
SLX-single channel 4 preamp tubes no diode
dystrust
Well-known member
Re: Marshall JCM 900's
Dual Reverbs are a love it or hate it thing. I really like them for the 90s alt-rock sound, but I can't say I find it useful for much else. I don't currently own one, but I'd buy one if the price were right. I never really liked the SL-X, but I own a 2555 and have access to a really good 2203. I guess maybe I just have different taste in Marshall tones.
Dual Reverbs are a love it or hate it thing. I really like them for the 90s alt-rock sound, but I can't say I find it useful for much else. I don't currently own one, but I'd buy one if the price were right. I never really liked the SL-X, but I own a 2555 and have access to a really good 2203. I guess maybe I just have different taste in Marshall tones.
ErikH
Well-known member
Re: Marshall JCM 900's
http://www.erikhansen.net/?page_id=8
All about the MkIII Model but some mention of the MkIV (SL-X) and Dual Reverbs.
Yes, that is my site (just in case anyone asks).
http://www.erikhansen.net/?page_id=8
All about the MkIII Model but some mention of the MkIV (SL-X) and Dual Reverbs.
Yes, that is my site (just in case anyone asks).
ErikH
Well-known member
Re: Marshall JCM 900's
Here's the years.
Dual Reverb-2 channels with reverb 3 preamp tubes with diode - 1990-1999
MKIII-Single channel 3 preamp tubes w/diode rectifier - 1990-1992
SLX-single channel 4 preamp tubes no diode - 1993-1999
Correction on the MkIII diode - it's a diode rectifier which sounds different from typical clipping diode arrangements like found in tube screamers and distortion pedals. It's more natural sounding.
Here's the years.
Dual Reverb-2 channels with reverb 3 preamp tubes with diode - 1990-1999
MKIII-Single channel 3 preamp tubes w/diode rectifier - 1990-1992
SLX-single channel 4 preamp tubes no diode - 1993-1999
Correction on the MkIII diode - it's a diode rectifier which sounds different from typical clipping diode arrangements like found in tube screamers and distortion pedals. It's more natural sounding.
Lake Placid Blues
New member
Re: Marshall JCM 900's
What about the 5881's in place of the EL34's? The early models came with EL34's but they switched to 5881's in about 93 or 94. Many feel that they were much better with EL34's.
What about the 5881's in place of the EL34's? The early models came with EL34's but they switched to 5881's in about 93 or 94. Many feel that they were much better with EL34's.
ErikH
Well-known member
Re: Marshall JCM 900's
The Dual Reverbs and SL-X are the only ones that came with EL34's first and then 5881's. The MkIII's were replaced with the SL-X by the time the changeover happened.
IMO, the EL34 models are far better sounding. When the change to 5881's happened, they got too stuff, lost a lot of that Marshall mojo that we all go nuts over. I remember A/Bing a couple Dual Reverb 50 watt heads, one with El34's and one with 5881's. The obvious choice was the EL34's. The only thing the amp benefited from the 5881's is the clean channel got a bit cleaner.
They're not bad amps, just a bad choice in power tubes throughout a majority of their production lifespan, IMO.
The Dual Reverbs and SL-X are the only ones that came with EL34's first and then 5881's. The MkIII's were replaced with the SL-X by the time the changeover happened.
IMO, the EL34 models are far better sounding. When the change to 5881's happened, they got too stuff, lost a lot of that Marshall mojo that we all go nuts over. I remember A/Bing a couple Dual Reverb 50 watt heads, one with El34's and one with 5881's. The obvious choice was the EL34's. The only thing the amp benefited from the 5881's is the clean channel got a bit cleaner.
They're not bad amps, just a bad choice in power tubes throughout a majority of their production lifespan, IMO.
the guy who invented fire
Fuzzy. Guitars
Re: Marshall JCM 900's
What?! Is it a clipper or is it the rectifier???
Marshall amps have used non tube (diode) rectifiers for years starting in the late 60's but there are some Marshalls that have diode clippers to add gain/distortion...I know the MK III's have a diode rectifier but do they also use diode clipping???
What?! Is it a clipper or is it the rectifier???
Marshall amps have used non tube (diode) rectifiers for years starting in the late 60's but there are some Marshalls that have diode clippers to add gain/distortion...I know the MK III's have a diode rectifier but do they also use diode clipping???
ErikH
Well-known member
Re: Marshall JCM 900's
A diode bridge rectifier is used for the additional clipping in the MkIII's (adjusted via the Gain Sensitivity control) and looks like this: LINK. The actual part number in the MkIII is W005F. Here's the preamp schematic on how it's used: LINK. As you can see, the arrangement is a bit different than what you'd find in a typical overdrive or distortion pedal.
With the Gain Sensitivity all the way down, any preamp breakup is all tube. Turning up the Gain Senstivity adds in more distortion by way of the diode bridge rectifier.
So yes, they do use diode clipping, as long as you turn up the Gain Sensitivity.
A diode bridge rectifier is used for the additional clipping in the MkIII's (adjusted via the Gain Sensitivity control) and looks like this: LINK. The actual part number in the MkIII is W005F. Here's the preamp schematic on how it's used: LINK. As you can see, the arrangement is a bit different than what you'd find in a typical overdrive or distortion pedal.
With the Gain Sensitivity all the way down, any preamp breakup is all tube. Turning up the Gain Senstivity adds in more distortion by way of the diode bridge rectifier.
So yes, they do use diode clipping, as long as you turn up the Gain Sensitivity.
Bludave
New member
Re: Marshall JCM 900's
I have a 50W Combo that I bought used about 15 years ago. I use it pretty regularly with my band due to the channel switching and MV I can get some good tones out of it. I just used it Saturday at a GIG and had it retubed with Svetlana EL34's. I turned it on on Friday to test it before the GIG and I blew a fuse. My amp tech told me the tubes were in there since 1997:fing2:, up until then the amp has been rock solid. I like it quite a lot.
I have a 50W Combo that I bought used about 15 years ago. I use it pretty regularly with my band due to the channel switching and MV I can get some good tones out of it. I just used it Saturday at a GIG and had it retubed with Svetlana EL34's. I turned it on on Friday to test it before the GIG and I blew a fuse. My amp tech told me the tubes were in there since 1997:fing2:, up until then the amp has been rock solid. I like it quite a lot.
