In good condition, picking it up tomorrow. Anything I should know about these amps? From what I hear, the ones with EL34s don't sound bad, while the ones with 5881s are gainy and crappy. I'm very excited!

What a score! For $150, if you can't use it, you'll make money on a sale.

There's lots of mods and tweaks for this amp that make it growl a little more and sound less 'eighties.'

AFAIK, JCM-800's never came with 5881's, US and Japanese versions came with 6550's until 1985 or 86, when they reverted back to EL34's. JCM-900's OTOH came with 5881's starting around late '93 until about '96 or so.

If you got a JCM-800, you got a great deal, if you got a JCM-900, you still got a deal, but not as good as the former. --The 900 series was when Marshall's build quality really started to suffer.

JCM 800s of the first year or two had a different distortion circuit in the preamp and sound dramatically better in overdrive than later ones. The "good 800s" can be identified by having their input jacks one above the other rather than beside each other.

We have a JCM 800 and it sucks balls, but people still use it. That's all I got.

Where are all the "prove it's" and finger pointer's?

The earlier ones sound more like the 'JMP' Marshalls when you turn the gain up, the later ones have this bizarre thing where it sounds pretty good distorted when you play on your own but they just disappear when you play with a band. Someone more knowledgable than me could explain this with frequencies somehow but it seems like the later ones' distortion is voiced really oddly like there is no presence to the sound at all.
I just sold a really nice early JCM800 Lead Series with reverb and switchable channels and it sounded grand.

MrFood wrote:

Atlantis wrote:Where are all the "prove it's" and finger pointer's?

You really are a first rate little cock aren't you?

Just doin my part to hold people to there own bullshit

Sorry, but in my excitement I made a typo. Its actually a JCM-900.

Atlantis wrote:

MrFood wrote:

Atlantis wrote:Where are all the "prove it's" and finger pointer's?

You really are a first rate little cock aren't you?

Just doin my part to hold people to there own bullshit

"Their."

steve wrote:JCM 800s of the first year or two had a different distortion circuit in the preamp and sound dramatically better in overdrive than later ones. The "good 800s" can be identified by having their input jacks one above the other rather than beside each other.

We have a JCM 800 and it sucks balls, but people still use it. That's all I got.

AFAIK, the circuit in the JCM 800 (4)2203/04 series amps utilised the same preamp as the JMP series amps. The ones that were differant were the channel switching amps which utilised clipping diodes in the gain stage. The main differance between the vertical input amps and the horizontal input amps that I've noticed is that the vertical input amps have a PTP wired input/control pot assembly, and nearly all the horizontal input amps have PCB mounted inputs and pots. Also, Marshall started using a less robust PSU in their 100 watt amps around 1986.

I may be talking out of my ass here, however I understand that when high levels of gain are involved, circuit design, componentry choices, and layout play a crucial part in the sound of an amp, and any changes in the layout and componentry will affect the sound of an amp for better or for worse. --If this is so, then it's probable that moving the pots/inputs to the PCB changed the sound of their amps for worse, as doing so changed the circuit layout slightly.

Also, another factor in this is also the fact that around the same time that Marshall moved the inputs and controls to the PCB, they were also using Celestion G12M-70's, which in my opinion are not a good sounding speaker.

Then again, I'm sure that you've used your JCM 800 with differant speaker/cab, and tube combinations with it as well, and still been rewarded with ass tone despite your efforts. One thing that I've noticed with a lot of older Marshall amps is that there is some variance in sound from amp to amp. A lot of them sound consistant enough, though occaisionally you'll come across one that sounds amazing, while another will sound like complete shit. That being said, I tend to generally agree that most of the late 80's JCM 800's that I've played through sounded like complete ass.