what jcm 900 model is this? - any good?
- Thread starter Sune
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ErikH
Well-known member
Re: what jcm 900 model is this? - any good?
Hey Sune. Unfortunately I don't have any sound clips of mine. I'm hoping to at some point but it will be a while and you'll probably have yours before I get to it.
I'm going to share with you a few tips on playing with the gain and pre-amp levels to get the most out of it.
First, the pre-amp level (1-10) adjusts the primary gain. The gain level (11-20) adjusts the secondary gain. (Yes, they are two different controls on these). Now, the gain level can take you from JCM800 mild crunch to completely insane overdrive. It really does kick it in to high gear. The way I run it is I set the pre-amp gain at 10, gain about half-way. This is a really nice middle ground for good 'ol rock-n-roll. I then use a booster to slam the front end harder. Granted, that booster doesn't boost the volume any really but it sends a higher level signal in to the pre-amp which makes it overdrive some more. Sometimes I'll play with the pre-amp still on 10 but the gain at zero and use an overdrive like the Wylde OD or Boss SD-1 and slam it that way. There's my clean (sorta clean anyway) or dirty. Play with it, you'll find the right settings for you. Heck, yours may be pre-amp on 10 and gain on 20.
Just so you know, there are diodes in the gain stage of this amp but the clipping diodes are in the secondary gain stage (gain level control). But to be totally honest, the way they did it, you can't really tell. It is very warm sounding and the tone doesn't thin out at all like it does on other amps. In all actuality, it gets fatter as you turn the gain level up.
Now, for the footswitch, like mentioned, all that will do is switch between two different volumes (Master A and Master B). Master B is perfect for soloing in a band situation. I use Master A mostly so I rarely switch over but it's there if I need it. Also, without the footswitch plugged in, the red light will be on meaning it is on Master Volume B. If you want to always use Master A, just take a 1/4" plug without a cable, connect the tip and sleeve connections together within the fitting and plug it in. The light will go out and you are now able to use Master A. If you want to switch between them, then by all means get a single button footswitch. Just sharing an option with you.
It looks like everything else was covered by Zerb and Imp. If you want a manual that will help explain the controls, you can get one from the Marshall web site. Unfortunately they don't have one for the Mk III models but the one for the SL-X will do since the controls are the same.
Oh yeah, you asked the difference between the Mk III and the SL-X. One pre-amp tube, that's it. In all honesty, I think that additional pre-amp tube hurt the sound of the amp and made it too buzzy. It's not as warm sound as the Mk III. Plus, many more of the SL-X (or Mk IV) came with 5881's as opposed to the Mk III models which came only with EL34's.
My speaker cab is an old Music Man 4x12 and to be honest, I have no idea what speakers are in it. They aren't labeled and I can't find any info on it. All I know is that it has been able to handle everything I've thrown at it, and that includes my Marshall at full blast and before that, a 5150 at full blast. Those speakers have held up so well I don't wanna change them. If you can't get a 4x12, look at a 2x12.
Something I forgot to add. These amps, the JCM900 2100/2500 Mk III were the next evolution of the JCM800 2203/2204 Master Volumes. The JCM900 4100/4500 were based of the JCM800 2205/2210.
Hey Sune. Unfortunately I don't have any sound clips of mine. I'm hoping to at some point but it will be a while and you'll probably have yours before I get to it.
I'm going to share with you a few tips on playing with the gain and pre-amp levels to get the most out of it.
First, the pre-amp level (1-10) adjusts the primary gain. The gain level (11-20) adjusts the secondary gain. (Yes, they are two different controls on these). Now, the gain level can take you from JCM800 mild crunch to completely insane overdrive. It really does kick it in to high gear. The way I run it is I set the pre-amp gain at 10, gain about half-way. This is a really nice middle ground for good 'ol rock-n-roll. I then use a booster to slam the front end harder. Granted, that booster doesn't boost the volume any really but it sends a higher level signal in to the pre-amp which makes it overdrive some more. Sometimes I'll play with the pre-amp still on 10 but the gain at zero and use an overdrive like the Wylde OD or Boss SD-1 and slam it that way. There's my clean (sorta clean anyway) or dirty. Play with it, you'll find the right settings for you. Heck, yours may be pre-amp on 10 and gain on 20.
Just so you know, there are diodes in the gain stage of this amp but the clipping diodes are in the secondary gain stage (gain level control). But to be totally honest, the way they did it, you can't really tell. It is very warm sounding and the tone doesn't thin out at all like it does on other amps. In all actuality, it gets fatter as you turn the gain level up.
Now, for the footswitch, like mentioned, all that will do is switch between two different volumes (Master A and Master B). Master B is perfect for soloing in a band situation. I use Master A mostly so I rarely switch over but it's there if I need it. Also, without the footswitch plugged in, the red light will be on meaning it is on Master Volume B. If you want to always use Master A, just take a 1/4" plug without a cable, connect the tip and sleeve connections together within the fitting and plug it in. The light will go out and you are now able to use Master A. If you want to switch between them, then by all means get a single button footswitch. Just sharing an option with you.
It looks like everything else was covered by Zerb and Imp. If you want a manual that will help explain the controls, you can get one from the Marshall web site. Unfortunately they don't have one for the Mk III models but the one for the SL-X will do since the controls are the same.
Oh yeah, you asked the difference between the Mk III and the SL-X. One pre-amp tube, that's it. In all honesty, I think that additional pre-amp tube hurt the sound of the amp and made it too buzzy. It's not as warm sound as the Mk III. Plus, many more of the SL-X (or Mk IV) came with 5881's as opposed to the Mk III models which came only with EL34's.
My speaker cab is an old Music Man 4x12 and to be honest, I have no idea what speakers are in it. They aren't labeled and I can't find any info on it. All I know is that it has been able to handle everything I've thrown at it, and that includes my Marshall at full blast and before that, a 5150 at full blast. Those speakers have held up so well I don't wanna change them. If you can't get a 4x12, look at a 2x12.
Something I forgot to add. These amps, the JCM900 2100/2500 Mk III were the next evolution of the JCM800 2203/2204 Master Volumes. The JCM900 4100/4500 were based of the JCM800 2205/2210.
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greendy123
New member
Re: what jcm 900 model is this? - any good?
I think actually not much of a buzzy tone to sl-x with the experience of mine. It's probably more on how you setup the amp. Oh, by the way for my sl-x the pre-amp volume is for thicker distortion, while the gain sensitivity is for thinner distortion. Make sure you have a trusted working speaker cable connected between your speaker cabinet and jcm900 before turning the amp on or you could blow something.ErikH said:
JeffB
Let it B
Re: what jcm 900 model is this? - any good?
Lotsa good info here on the 900s...I may hafta go check one out for grins...been awhile since I've played one..
I forgot they had a pentode/triode switch...that and an attentuator MAY just be the ticket for me (though I know..it will sound diff at 25 watts vs. 50)
Lotsa good info here on the 900s...I may hafta go check one out for grins...been awhile since I've played one..
I forgot they had a pentode/triode switch...that and an attentuator MAY just be the ticket for me (though I know..it will sound diff at 25 watts vs. 50)
greendy123
New member
Re: what jcm 900 model is this? - any good?
Oh, didn't know that, so how do the pre-amp and gain sensitivity knobs work tonally on the mk III's.
ErikH said:
Oh, didn't know that, so how do the pre-amp and gain sensitivity knobs work tonally on the mk III's.
ErikH
Well-known member
Re: what jcm 900 model is this? - any good?
On the MkIII, with the gain sensitivity knob all the way down and the pre-amp all the way up, it sounds really smooth, very JCM800 Master Volume like. As the gain knob gets turned up, it gets fatter and fatter. That's one of the things that sold me on it, high gain but still very fat sounding.
When I use the Zakk Wylde OD in front, I leave the gain sensitivity all the way down and the pre-amp all the way up. When I kick the Wylde OD on, wow, all I'm missing is his Les Paul. It sounds really really good.
EDIT: Or do what Zerb said.... :laugh2:
greendy123 said:
On the MkIII, with the gain sensitivity knob all the way down and the pre-amp all the way up, it sounds really smooth, very JCM800 Master Volume like. As the gain knob gets turned up, it gets fatter and fatter. That's one of the things that sold me on it, high gain but still very fat sounding.
When I use the Zakk Wylde OD in front, I leave the gain sensitivity all the way down and the pre-amp all the way up. When I kick the Wylde OD on, wow, all I'm missing is his Les Paul. It sounds really really good.
EDIT: Or do what Zerb said.... :laugh2:
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T
theodie
Guest
Re: what jcm 900 model is this? - any good?
Sune, I use mine with a Marshall 1960AV cabinet! I used to have a 1960B cab with the 75W speakers in it and it sounds a tad better with the Vintage 30's in the 1960AV. It was tad more warmer! I really recomend Sovtek WXT EL'34's and Sovtek LPS 12AX7's in that thing! I have used JJ's, Electro Harmonix's, etc, the Sovteks I mentioned are the real deal!!!! If I remember correctly, they are Gearjonesers tube of choice also. I do not have any clips of it, though it would not do the amp justice if I had sound clips!!!!!!!
Zerb, Soldano Hot mod huh???? You think it would be the real deal in my 2100?
Erik, it is a killer sounding amp with anything but a JB played thorugh it!!! LOL!!!!!!!!!!! :laugh2: :laugh2: :laugh2: :laugh2:
Sune, I use mine with a Marshall 1960AV cabinet! I used to have a 1960B cab with the 75W speakers in it and it sounds a tad better with the Vintage 30's in the 1960AV. It was tad more warmer! I really recomend Sovtek WXT EL'34's and Sovtek LPS 12AX7's in that thing! I have used JJ's, Electro Harmonix's, etc, the Sovteks I mentioned are the real deal!!!! If I remember correctly, they are Gearjonesers tube of choice also. I do not have any clips of it, though it would not do the amp justice if I had sound clips!!!!!!!
Zerb, Soldano Hot mod huh???? You think it would be the real deal in my 2100?
Erik, it is a killer sounding amp with anything but a JB played thorugh it!!! LOL!!!!!!!!!!! :laugh2: :laugh2: :laugh2: :laugh2:
T
theodie
Guest
Re: what jcm 900 model is this? - any good?
LOL!!!!!! Maybe your right but, I cant think of anything right with it either!!! LOL!!!!!!!!!!
Sune said:
LOL!!!!!! Maybe your right but, I cant think of anything right with it either!!! LOL!!!!!!!!!!
ErikH
Well-known member
Re: what jcm 900 model is this? - any good?
If I had the cash to get a 2500, I would so I'd have the set.
The funny thing is theodie knows I'm a JB fan and I know he's not so we constantly stab at each other about it. But yes, the amp sounds great with everything I've thrown at it.Sune said:
If I had the cash to get a 2500, I would so I'd have the set.
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Sune
New member
Re: what jcm 900 model is this? - any good?
Cool, I think the 2500 might be alot better for use at home, since it's half the wattage, and can get down to even 25 watts. But basically the 2100 and the 2500 are the same amps, with different output power, isn't it?
By the way, I asked Zerb about this too, but didn't get an answer (yet, at least). Would I need to get it re-biased if I put in the tubes that Odie recommended ? And can you explain for me what "bias" even means? Sorry..you gotta start somewhere, with some amp. :laugh2:
Cool, I think the 2500 might be alot better for use at home, since it's half the wattage, and can get down to even 25 watts. But basically the 2100 and the 2500 are the same amps, with different output power, isn't it?
By the way, I asked Zerb about this too, but didn't get an answer (yet, at least). Would I need to get it re-biased if I put in the tubes that Odie recommended ? And can you explain for me what "bias" even means? Sorry..you gotta start somewhere, with some amp. :laugh2:
ErikH
Well-known member
Re: what jcm 900 model is this? - any good?
Yes, the 2100 and 2500 are the same amp, in the pre-amp. The only difference is the 2500 has half the power-amp of the 2100. Same basic design though.
Yes, if you change tubes, even the same type, always get the bias checked and adjusted. The tubes take a certain amount of voltage across their plates. Biasing means adjusting this voltage to the recommended operating range for the amp and tubes. Different amps have different recommendations. The power tubes are the ones that need it. Pre-amp tubes are just a swap and go.
Jeff, the JCM900 reissues are the Dual Reverbs, 4100/4500. Why, I have no clue. And they still put 5881's in it. :smack:
Sune said:
Yes, the 2100 and 2500 are the same amp, in the pre-amp. The only difference is the 2500 has half the power-amp of the 2100. Same basic design though.
Yes, if you change tubes, even the same type, always get the bias checked and adjusted. The tubes take a certain amount of voltage across their plates. Biasing means adjusting this voltage to the recommended operating range for the amp and tubes. Different amps have different recommendations. The power tubes are the ones that need it. Pre-amp tubes are just a swap and go.
Jeff, the JCM900 reissues are the Dual Reverbs, 4100/4500. Why, I have no clue.
And they still put 5881's in it. :smack:
Sune
New member
Re: what jcm 900 model is this? - any good?
Well, since there's no tech's here where I live, how could you bias-adjust it?
And does the fact that it only has 2 power amp tubes instead of 4, like the bigger version, affect the sound compared to the bigger version? Or will it sound similar?
Well, since there's no tech's here where I live, how could you bias-adjust it?
And does the fact that it only has 2 power amp tubes instead of 4, like the bigger version, affect the sound compared to the bigger version? Or will it sound similar?
Sune
New member
Re: what jcm 900 model is this? - any good?
Would this amp also be able to give a crunch like you hear in some of "The Darkness" songs..?? I don't listen that much to them, but they've got some good songs, with a nice full and warm crunch going on.. Like if you listen to "I believe in a thing called love". I know they use Marshalls too.
Would this amp also be able to give a crunch like you hear in some of "The Darkness" songs..?? I don't listen that much to them, but they've got some good songs, with a nice full and warm crunch going on.. Like if you listen to "I believe in a thing called love". I know they use Marshalls too.
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