JCM800s are awesome. (Also, use the knobs on your guitar!)

xscaramanga

As some of you know I recently bought @HHWarner's JCM800 2204. It sounded great anyway but I decided to take it to my tech for a once over. He found it was running very cold. 

This morning I got a chance to plug it in for the first time since he biased it up. I plugged it in and I couldn't work out what was going on...

There was far less gain than there used to be. I couldn't figure it out at all. How could making the amp hotter give you less distortion? And even if it could, why would that reduce the amount of preamp gain?

I didn't really care, though, because I was getting one of the best just-breaking-up tones I've ever had. 

Then I realised I was plugged into the low input. 

It still took me a while to bring myself to switch over to the high input because it was just sounding so cool. Before, the low input was a pointless thing with a thin and lifeless clean tone and no real breakup even when cranked. Now it's awesome. So what was the high input going to do?

Just sound epic. 

At first, I really hated the bright cap on this amp. When I was trying to get a mild AC/DC crunch with the master cranked and the preamp volume low, it was too shrill. By the time I cranked the preamp up enough to lose the harsh high end, I had far too much gain for the Angus tone.

I don't know why it took until today for me to think of using the knobs on my guitar.

Well anyway, this morning I finally noticed that the four knobs on my Les Paul are not on/off switches. spent forty minutes having an awesome time experimenting with different volume and tone levels. And now I can get every sound I want out of the amp. I know I'm not the only rock guitarist who forgets to use the guitar knobs. Why are we such idiots? There are killer sounds in there. It's really fun setting up an old school amp with the maximum amount of gain and treble you're going to need and controlling everything else from the guitar. I'd been sitting around of forums thinking of gassing on low gain pedals or even a different amp to get the sound I wanted, and actually I just needed to use my gear properly.

Only downside of the morning is that I was reminded how "Brit Hi" is the most unconvincing emulation in a Yamaha THR10. Doesn't come close to a real JCM800.

ThePrettyDamned

Jcm 800s are epic sounding things. Some folk think they're a bit fizzy to be truly Marshall, but they sound huge.

Chuck an sd-1 in front and thank me later

fretmeister

SD-1 to boost

and a Homebrew Detox EQ to back it off if you don't want to fiddle with guitar volume controls mid song.

HHwarner

How cold was it Jonny, I biased it to 60%

xscaramanga

Yeah, I've got an SD-1 and haven't got round to using it with the 800 yet. After I posted this I messed around with the TC Spark Booster I just bought in the classifieds. Sounds good, but I'm not blown away. At some point I'll get out the SHO and A/B them. I own a few pedals that will probably sound great with this amp that I want to try—SD-1, Guv'nor, SHO, two different TS clones...

xscaramanga

HHwarner said:

How cold was it Jonny, I biased it to 60%

He said it was running at about 20 and it should have been 30 or 32. 

HHwarner

Mmmm odd. I set it in the lower 30's. About 15W per tube

HHwarner

Angus tone should be easily achieved with that amp. Although the man himself has been quoted as saying he never used MV Marshall Amps, you study any live shots from late 70s onwards he is deffo using 2 hole 2203/2204 JMP's. Earlier was 4 hole Non MV super leads. As far as I know the JCM 800 2203/2204 are basically the same as the last run of JMP's

xscaramanga

fretmeister said:

and a Homebrew Detox EQ to back it off if you don't want to fiddle with guitar volume controls mid song.

Out of interest, apart from a better-smelling cork, what will the HBE EQ offer me that I can't get from my cheap-but-effective Danelectro and Joyo EQ pedals?

ICBM

HHwarner said:

As far as I know the JCM 800 2203/2204 are basically the same as the last run of JMP's

It's slightly more complicated - yes, the earlier vertical-input JCM800s are the same as the last JMPs, both for the 2203s and 2204s. Later horizontal-input 2203s are different, but the 2204s didn't change other than the jacks.

But the 2204s *did* change earlier in the JMP period - the very first ones in '75 and '76 have a totally different circuit with the input stages in parallel and sound poor (in my opinion). After the 2203 was introduced in '76 with the cascaded input stages, the 2204 was changed to this circuit (in early '77 I think). Then later, just before the end of the JMPs, the power supply was changed slightly, I think at about the time the voltage and impedance selectors were upgraded to the modern rotary switches.

So there are three 2204 versions: early JMP, mid JMP, and later JMP/JCM800; and two 2203 versions: JMP/vertical-input JCM800, and horizontal-input JCM800. The best-sounding seem to be the mid-JMP 2204s and the JMP/vertical 2203s.

I still think the earlier 2203s are the best and some of the most under-rated amps Marshall ever made. To me they're the absolute definition of the sound of rock guitar, more even than the non-MV ones are.

HHwarner

Nothing ever straight forward with Marshall ha ha

Evildurka

I have a fish and chips 7 band eq which never fails to sound great through an fx loop. It also sounds good infront of the amp with my kramer 5150 copy to emulate a neck pickup.

SidNewton

I have a 2204 dating from 1984. Still going strong after 30 years, I gigged it this weekend. I use the low input all the time. I them use a Gigrig Loopy 2 with a Fulltone OCD in one loop for crunch rhythm and a Suhr Riot/Mad Professor Deep blue Delay in the other for lead. This makes it surprisingly flexible.

Just out of interest Jonny what cab/speakers are you using and what do you have it valved with? I currently use a Marshall 1936 2x12 and have it valve with Svetlana 'Winged C' EL34's and Tungsol ECC83 (12AX7's). Putting the Tungsols in made the biggest difference. I know ICBM questions their reliability in the middle position but I've never had a problem and they are a huge improvement over the JJ's that I had in there before. They were harsh and muddy in comparison.

fretmeister

jonnyscaramanga said:

fretmeister said:

and a Homebrew Detox EQ to back it off if you don't want to fiddle with guitar volume controls mid song.

Out of interest, apart from a better-smelling cork, what will the HBE EQ offer me that I can't get from my cheap-but-effective Danelectro and Joyo EQ pedals?

It's really really really quiet. Way quieter than the awful Boss EQ.

Other than that I don't know!

I've got one and I loved it with single channel amps, but then I bought a Dual Rec and it now lives in the cupboard!

Borrow it if you like. I won't be using it for a bit.