I also just bought a new amp

[Malmsteen's accomplice]

I just bought a Marshall JCM 800 half-stack and I cant really get any overdrive out of the tubes at lower volumes, I really have to crank it to blaring before I get the Marshall distortion. I have the pre amp on 10 and its sopposed to be able to get good gain at lower volumes. So is there something Im doing wrong or is that just the way it is?

Thanks for your Help

nate

[westhemann]

alot of the gain comes from the volume in that amp i think.but you can get it hot rodded.i am not sure how though.i will move it to the electronics section

[Drak]

Are you trying to play that thing in your bedroom?

When you say 'lower volumes', where are you on the dial, are you even on, say, 1.5? Less? More?

[jbkim]

Hmm... my knowledge of things is from the 80's so there might be newer technologies . There used to be things called "Power Attenuators." The "Sholz Power Soak" comes to mind (there might be newer modern equivalents.) You'd use one of these between your power out and your speakers so there's no modification of the head. This'd allow you to crank the power amp section of your amp without being too loud.

I should also ask, what kind of guitar are you plugging into it? Humbuckers, single coils? You might need hotter pickups to overdrive the pre-amp.

[Biblical]

a marshall powerbreak is what you need. $120 i think, they let you turn it all the way up and stil have it working at a low volume.

also is it second hand, if so the tubes might be a little knackered and might stop it overdriving as much

[ansil]

hmm u know if you have a basic grasp on electronics. u can go to the weber site and use there free schematic they have up and make a weber mass attenuator

or u can use a light bulb..

hmm think about it

[Malmsteen's accomplice]

Its brand new and I play it in my 12'' by 9'' bedroom with the pre-amp on 10 and the master volume on 1.5. I think mabe I should save up for a power brake and I play a strat with single coils through the High sensitivity input.

[Jivin]

Thats quite a big bedroom amp

not that i can talk.

- Dan

[Malmsteen's accomplice]

Yea it is but I bought it for gigs and my room only place in my house that I can put it.

( just kidding)

[BLS]

To play my 5150 at lower volumes i took two tubes out. This made the amp act like a 60w instead of a 120w. I know you can also do this with a Mesa Boogie Dual Rect (even says so in the manual) but before you do that i would ask around and make sure it would work with the 800. Harmony-central has alot of amp freaks in the forums.

[ansil]

hey there malmsteens acomplice.. can you not afford a light bulb.. man they are like four for a dollar at the dollar store.

[jbkim]

hey there malmsteens acomplice.. can you not afford a light bulb.. man they are like four for a dollar at the dollar store.

Wire it in series to the speakers?

[ansil]

weber mass antenuator has the schematic of there antenuator on there site with a little riggin, you can use the light bulb to soak up power.

it is used to soak up excess current in pa equipment..

we are talking about this on the diy forum over at arons

there has been one person say it wouldn't wokr.. however i have personally seen it done for over 8 years with no effects on the amp

[jefm]

Well I guess you wouldn't want to lower the power when you play live....but it'd be a bummer if the light went out when you were playing...

How would you decide what rating to use...is it trial and error or say for a 100 watt amp would a 60 watt bulb bring it to a 40??? and do you use the lightbulb in the weber circuit or on it's own... just a little lost

[ansil]

well u can use it to bring down the wattage, but i always put in a reisostor there also to keep acidents from happening..

[jefm]

Yeah but does it cut the wattage by that amount or has nobody tried measuring it yet???

[lovekraft]

I really have to crank it to blaring before I get the Marshall distortion.

Yeah, a JCM800 makes a lousy bedroom practice amp - if you want it to sound like a Marshall, turn the preamp gain down and turn up the power amp! It'll be really, really loud, but it'll give you that creamy goodness (a Weber MASS or a Powerbrake will help, but it's still gonna have to be cranked enough to push some air).

Its brand new and I play it in my 12'' by 9'' bedroom  with the pre-amp on 10 and the master volume on 1.5.

Who spends that kind of money to play in his bedroom? Dude, get an 18 watt - you'll still need earplugs!

[Malmsteen's accomplice]

Dude, I really bought it for gigs and normally I wouldent play it in the house but even playing it clean sounds way better than my 15 watt fender practice amp.

[lovekraft]

Dude, I really bought it for gigs and normally I wouldent play it in the house but even playing it clean sounds way better than my 15 watt fender practice amp.

First of all, I mean no disrespect, but where are you gigging that you need a 100 watt half-stack? I mean, seriously, about the only place you're going to be able to crank that puppy up to a good level is the Metrodome!

Classic Marshall distortion is about a mix of preamp distortion and power amp saturation - if you don't crank it up enough to saturate both the preamp and power amp stages, you might as well be playing a Fender (all power amp clipping) or a Mesa/Boogie (all preamp distortion). The Weber MASS-100 should tame it for home use (or recording) for about $200. A light bulb in series will soak up some power, but if it blows, your amp is without a load and it will start destroying its output stages almost immediately, so be careful. Good luck with it.

[ansil]

but i always put in a reisostor there also to keep acidents from happening..

[westhemann]

keep in mind lovekraft that unless you are using all the gain the amp has then you are only getting a portion of what the amp can produce

i prefer to have some headroom myself.and all the rock bands around austin use the 100 watt marshall amps...

[ansil]

Dude, I really bought it for gigs and normally I wouldent play it in the house but even playing it clean sounds way better than my 15 watt fender practice amp.

question there m. a.

if you play the high gain rock sounding stuff, and need something to bedroom play it that sounds like a HG marshal whynot build a firefly. it can all be stuffed into a hammond C size box, and well depending on your parts box it can be done for like 20-100 dollars and can easily rock your 4*12 at saturated levels, and still not be ear piercing bleeding volumes and at decent hours of the night will not even get you yelled at by roomates.

its a two tube, plexi based preamp that slams a 12au7 to give more of a poweramp saturation, cause it uses the 12au7 in self split mode as its poweramp section.. also if you drop the b+ down to 180-200 u get a killer high gain metal sustaining sound.

if you want i can draw up a jcm800 type version for ya.

its fairly easy to acomplish. and can be done inside a few hours depending on your skill level in electronics

[ansil]

also to let you know its a 1.5 watt at 240 + voltage so i am guessing around 1 watt tube power output, at 180-200v b+

which basically will sound 1/4 as loud as your 100 watt amplifer due to the non linear hearing response we have for watts and decibels

for those who dont' know its aproximately 10 times the wattage to sound twice as loud to the human ear.

ie a 1watt amp is only half as loud as a 10 watt amp. there for a 100 watt amp sounds like it is twice as loud as a ten watt amp.

also keep in mind we are talkin about tube here which always sound louder than the wattage ratings.

and marshalls which are never even close to there wattage ratings

usually way over.

and we are dealing with aproximation

but i can tell you this, i have played boogies bogners marshalls peaveys fenders randalls and well basically any amp you can think off good to bad to excellent to total crap, and when i plugged this thing in, [my first one was done in an old 1*10 peavey backstage 30 combo amp chasis with line out.] i could belive how close in sound to my 50 watt marshall it was, i mean the 50 watt would keep up with drums nicely, but the drummer couldn't hear me, and well i could still here myself with the drummer all though not as well as with the 50 watt, but i cut through more and just miced up this thing and have been pleased till someon offered to buy it at a show in atlanta, and well i am a money spam so i tend to sell stuff after i make it.. lol

[lovekraft]

keep in mind lovekraft that unless you are using all the gain the amp has then you are only getting a portion of what the amp can produce

Wes, I think we're talking about two different things here - in general, when a guitarist talks about gain, he means preamp clipping. That's a good sound, IMO, but it isn't classic Marshall distortion, which involves power amp saturation as well. I guess what I'm trying to say is that a JCM800 only sounds like a Marshall if it's cranked, and if you want preamp distortion, Engl, Bogner, Soldano, MezzaBoggie and Peavey are all better, more versatile choices.

and all the rock bands around austin use the 100 watt marshall amps...

Yeah, I know, around here it's Tripple Rectumfriers - face it, we guitar players aren't a progressive lot. And most manufacturers don't make 50 watt heads in their top of the line models, because they can't charge as much for 'em. But we gotta face it - if you don't ever turn the master above 3, you don't know what your amp sounds like. YMMV, my too sense, no offense intended - and yes, Kerry King rules!

[westhemann]

i just spent about an hour playing with my mode 4(off the subject i know),and this thing makes the jcm 800 look like a chump as far as preamp gain goes...but it has that master volume so you can run the gain up,then run the preamp volume 100%,and control the master volume for decibal level.

but i guess what i am trying to say is don't write off marshall versatility until you try this amp...anything you want,you got,pretty much.

i hear good things about bogner,soldano,etc....but peavey makes my skin crawl.i doubt i will ever get over that line of amps they put out all through the 80s...i STILL see those damn things everywhere and they are completely toneless!

i know they are putting out better stuff now...but i am hardheaded