Conference napalm::guitar

    
    I read in the Marshall Amp book that if a marshall head keeps blowing
    the HD fuse (standy fuse), then its a sign that you need new output
    tubes.  I don't know what it means if you are blowing the mains
    fuse and/or both of them.

    SOLUTIONS:
    
        1. You tried "other cabs". Didi you check your speaker cord
     for shorts? 
    
         2. A tube could be causing the fuse to blow. Get a good one
    and go thru the head replacing it with existing tubes one at a time.
    Don't limit yourself to power tubes, in some cases pre-amp tubes
    can cause this.
    
        3. Get rid of the Marshall and buy a Boogie. :^) .......
    
    

    BOY, is this common ground or what?
      I played a friends Marshall 100 lead head and switched the 
    impedance selector to match my cabinet (4 ohm), then put it back 
    to 16 ohms for the 4-12" cabinet. Trouble was that the selector 
    switch never quite made properly, so it blew fuse after fuse until 
    it dawned on me that that switch was the only thing I changed all 
    night! duh... real smart dude  ;^)
    I flipped the impedance selector back and forth a few times, then 
    switched it to it's normal 16 ohm output. {This was done with the
    power OFF, btw}. It worked fine from that point on. 
    No matter what happens, NEVER put anything besides the recommended 
    fuse, because my Major 200 (back in college), did a smoke show because
    I didn't put the correct fuse in after it blew the first time.
    Sorry folks - One smoke show per night! 
    
               I've learned to never ever...
    
    
    
    
    
    
    
    
    
    
                                                    ...ever
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    buy / touch / use / recommend another Marshall!   
    
    JMO, but I hope that switch does the trick for you.
    
    Have fun,
    Fred (who LOVES that Marshall sound, but can do without the headaches)

    Forget the boogie. I think they sound muffled and cute.
    Is this the amp oyu got from Buck with two tubes yanked?
    I really like the sound of my 100 as a 100, tried the 50 thing but
    didn't have the nearly instantaneous high current capability
    for those delicate sounds after the thrash I dig.
     Man, I HATE it when these things go to lunch...
    Andrw

>1. You tried "other cabs". Didi you check your speaker cord for shorts? 

Yes, I used different chords each time also...

>         2. A tube could be causing the fuse to blow. Get a good one
>    and go thru the head replacing it with existing tubes one at a time.
>    Don't limit yourself to power tubes, in some cases pre-amp tubes
>    can cause this.

Good idea - I have extra power tubes at home, so maybe I'll try that first 
(after I pick up a bunch of extra fuses....). 

> 3. Get rid of the Marshall and buy a Boogie. :^) .......

agagagagaga!!!! Actually, I already have a Boogie also. BTW, just as a 
sidenote, I used my .22 Calibre Boogie through a 4x12 cab, and had absolutely
no problems being heard at this past weekend's gig (even with the other 
guitarist playing a 100 watt head and 4x12 cab, and the bass player pumping out 
200 watts). What a great investment that Boogie was!

Alan S.

    
    
    
    	I recently fixed an amp for the son of a friend of mine that
    had this problem... I'm no tech but I have friends who are and after
    checking to make sure that the impedance for the speaker cab was
    correct... too low causes trouble... too high just sounds crummy.
     I found that one whole side of the output stage was going to ground.
     Replacing the output tube worked fine and stopped the fuse blowing...
    I agree strongly with who ever said not to use a higher rated fuse..
    Every time I've been tempted to do this I've created smoke, very
    impressive with old ham radio transmitters ;^)
    
    Steve

re: impedance

Both the output and the cabs are 8 ohms, I was very careful to check that out,
so that's one thing that can be ruled out.

>     I found that one whole side of the output stage was going to ground.
>     Replacing the output tube worked fine and stopped the fuse blowing...

Again, that seems to be the consensus to try, so I'll let you know how it goes
tonight....

>    I agree strongly with who ever said not to use a higher rated fuse..

Yeah, I agree there! With the amount of knowledge I possess, I would *never* 
go against the recommended specs - I don't feel like using it a large 
paperweight!

Thanks again to all the suggestions so far - feel free to continue to comment.
I'm glad I have at least one avenue to try before spending the big bucks for a 
repair shop...

Alan S.

Hey, whaddya know!

I replaced both the power tubes with two extras I had, and tried it out. It
works fine now! I can't tell from looking at them which of the two (or both)
old ones are bad, one of them does have a rattling sound to it, like a burnt
out light bulb does. 

I figure that I'll keep them as a spare (all four are matched Groove Tubes),
and keep the spare set in there for good.

Thanks again to those who made suggestions - you saved me a bunch of money, 
time, and hassle!!!

BTW - yes, Capt. Toenail, the Marshall is the same 50/100 watter that I 
had bought from Buck....

Alan S.

    RE: .3 AND .4 ......
    
         You know, you guys are hooked on Marshalls like a motorhead
    hooked on a '57 Chevy. I just want to rub-it-in a little, that
    
       1. My suggestions worked.
    
       2. He already HAS a Boogie (one of the smallest made) that has
    tha capability of regularly EATING MARSHALLS FOR LUNCH.
    
    And, although I do kinda like Boogies, I continue to LOVE a great
    Marshall tone which I'll admit is VERY hard to get out of a Boogie....
    it has its OWN sound which I like as much. The Boogie does give
    me a WIDER RANGE of instantly switchable USEFULL sounds, which is
    why I use one on stage (the band I'm with doen't just play METAL
    all night).
    
    -BAP    ;^) ......

    Well, after owning two Marshalls for over 6 months, I must sya I
    agree.  My GK (Which I've had for six years) sounds more like a
    "Marshall" than my Marshalls do !
    
    I still want something better though... So I'm gonna buy a rack,
    not some tube-drive low tech bug zapper.
    
    JMO...
    
    jc

    But Coop, you have to remember, your Marshalls are mighty sick puppies.
    Maybe with some new tubes they'll sound like they should instead
    of sounding like high tide ....
    
    
    
    				Scary
    	         (who's into solid state Marshalls ...)

    I dunno...  The ones I played up at Express (jubilee series, 25/50)
    sounded about the same...like poop...
    
    I think I don't like stock marshalls...
    
    jc

Well, I finally figured out what the initial problem seemed to be. The 
Marshall worked for about 24 hours, so I figured it was fine. So I re-hooked
up the Power Soak I have (it was connected when it originally blew), and
guess what? Yup, it broke again.....

Its fairly obvious to me that my Marhsall and my Power Soak are not gonna
be best friends, so the Power Soak is gonna have to go.....Too bad, because
up until this point, they had worked fine and sounded great together!

I guess you can't have everything....

Alan S.

    Do you think that maybe the stress produced by having the Power Soak on
    with the amp cranked all the way up is bringing on the failures in the
    amp rather than an actual problem with the Power Soak itself?  I kind
    of wonder if the amp would have fared any better if you'd not used the
    PS, but had the thing set on 11 for the same amount of time.
    
    I use a Power Soak with my HiWatt and haven't had any problems so far
    (picture fingers crossed here).  But I don't leave the amp cranked all
    the way for long periods at a time.  We play songs where I want a
    clean sound and I set the PS for no reduction of power and pull down
    the volume on the amp.  Perhaps this helps.
    
    Greg

>    Do you think that maybe the stress produced by having the Power Soak on
>    with the amp cranked all the way up is bringing on the failures in the
>    amp rather than an actual problem with the Power Soak itself?  

Possibly. The amp worked fine without the Power Soak, because the volume was
only set at 1� or maybe 2. With the Power Soak, however, it was turned up
to 11 (what else?).

I'm gonna take the Marshall in to Daddy's and have them take a look at it,
along with the Power Soak.

BTW - it only took about 3 minutes after I hooked up the Power Soak for the
amp to blow...

Alan S.

    Power soaks have a reputation of causing problems like this. Get
    a master volume installed instead.
    
    dbii

    Do you own a car with a standard transmission ?? Try driving from
    LA to NY in first gear (average around 55mph) and see how the engine 
    likes it. This is comparable to driving the marshall on 10 all the 
    time with a power soak in the circuit. Eventually, something has got 
    to give. I suggest you use the power soak as a space heater.
           
    Save the Marshall for colliseums and get something smaller for
    practice. My Fender "The Twin" is hard on tubes, so I generally
    practice with a Pignose, and only use the tube amps when it's 
    needed.
    
    Mark

	Marshall clearly states in there warranty that using power
attenuating devices will immediately void the amp warranty. Not only
will you wear out power tubes quickly,but I suspect it will also
contribute to the insulation breakdown in the impedeance matching
transformer. This is your output transformer after the power tubes.
	I once bought a Marshall which had been soaked by it's previous
owner,and I went through alot of power tubes. Before I realized that
there was something seriously wrong. :^(   It was a nice amp and
sounded great when it worked....but I always had a backup amp.
	There are several people who do Marshall mods,plus plenty of
preamps with a "soaked" sound I'd suggest you look into. There was
even a company listed in the back of GP who sold plug in Mod's which
were pretty cheap.Or use your Mesa Boogie slaved into a power amp. 
	
	Save your money I really doubt Daddy's will do anything other than 
tell you not to use a power soak or sell you some more tubes and/or
    a transformer..... :^(  
		

    I'm interested in how fast and well Daddy's does service here. Union
    Music rebuilt my head ( Xformer, changed valves from 6550 to el34,
    new preamp tubes and el34) took 3 weeks and I'm happy ( although 
    it cost me almost as much as the thing itself).
     
     The way I play it is usually with the pre-amp on 6-10, and the master
    volume around 1.  I like the sound of 100 watts. But I don't play it
    loud, it sounds different and better to me than 50 watters at the same
    volume.
    
     What I am wondering is why do you have to drive the thing at high
    volumes? If it's distortion you want, run the thing as a 100 watt
    with 4 tubes and use a Guv'nor box.  >That'll distort like George
    Bushes face when he wakes up in the morning and sees ole Mrs.
    President.   The Toenail whose on the verge of trading a Kramer for a
    Les.

I think what I'll end up doing is putting new tubes in to get the amp to
run correctly, and run it at 100 watts. Then I'll have to examine the cost of 
either getting a Master Volume installed or buying a good distortion effect 
(i.e. Chandler rack-mount of something similiar - not just a stomp box).

Or maybe I'll just save my money and invest on one of those ART SGEs......
someday....

Alan S.

    Do it, Alan. That 100 watt sound don't come any other way, even at 1 or
    2. But check out the Guv'nor, it surprized me. 

> But check out the Guv'nor, it surprized me. 

Never heard of a Guv'nor - can ya give me some more info? What it is? What it
does? $$$? Where to get one? etc, etc, etc....

Alan S.

    
    It's an FET stomp box distortion from Marshall.  Two cool features:
    
    1. Three band EQ, bass, mid and treble.
    
    2. Effects loop!  You can patch ina an extra effect (like a delay
    or chorus) and when you kick in the Guv'nor, the other effect is
    on too.
    
    

    Go down to Mr C.s, at 100$ this thing goes like wasaid, between the
    guitar cord and amp or in the special effects loop in that I bet you don't
    have. If the repair'll run some bucks I'd check in a trade in;
    maybe the 400 Watt Boogie Power Amp and a Marshall rackmount preamp 
    or a 100 watt Custom might look closer than you think...  
    
    does any body want to trade a surfboard for my Baretta? 

    re:.9; meaning no disrespect, but I would think that if you didn't
    put the wrong fuse in your marshall; you wouldn't have had any 
    problems with it. I've played for 10+ years, mostly with maniac
    guitarists who have to have a marshall forget it---I personally
    like the sound of a twin w/ a Les Paul most of all. I don't own
    a marshall nor am I ever likely to (bass player).But I am a true
    believer in giving credit where credit is due! The honors for  
    BEST SUPPORTING ROLE IN A MARSHALL HORROR STORY go exclusively
    to you!
    -Bill who loves his gear and ALWAYS CARRIES THE CORRECT FUSES(nyaah!!!)
    

>                       <<< Note 1333.25 by HAMER::KRON >>>
>                -< PUT WRONG FUSE IN YER BOOGIE IF IT BLOWS! >-

	I Had an EMC Transistor Amp (125 watts, Taurus Bass Head) back
	in the 1970's. It output stage was fuse protected. I have to agree,
	every time the output was dead shorted, the output stage transistors
	burned out (actually the Base/Collector went open on all 4 power
	transistors), thereby protecting the 10 cent fuse. I ended up putting
	a 50 watt 4 ohm resistor in series with the output speakers, so that
	the fuse no longer needed protection & output transistors would 
	survive some idiot unplugging the speaker cabinet at random times.
	I always had the right fuse in the Amp, but it did no good.

								Jens