question regarding electrolytic capacitors

Tallwood13

Tallwood13

New member
So I've got a marshall valvestate which is a fusion of a solid state amp with valves , no idea I'm not much of an amplifier expert I know guitars in and out.

What I'm replacing is the C28 electrolytic capacitor, it's blown and I can't get distortion at all. I'm 90% sure I got the right capacitor I just have two questions
#1 - does it mean anything special when F2 is stamped on a capacitor

#2 - for the guys who mod amplifiers if its possible to switch to other types of capacitors what would you swap the capacitor with for a more dark , aggressive and metal tone out of this amplifier.

The exact amp is a marshall valvestate VS30
the capacitor I've seen is
63v
2.2uf
030 ko series
philips brand
it's this cobalt blue kind like this
http://www.ebay.ca/itm/10pcs-PHILIP...Axial-HiFi-Audio-Capacitors-NOS-/321337094523
 
Re: question regarding electrolytic capacitors

that might be one of the "tone caps"... coupling caps(?) . I'd go with a Mullard 150.. and Sozo for Marshall. For the big E-lytic Filter caps...use Illinois..it makes no difference in tone, they are cheap, and Peavey bulletproof amps use them.Hopefully someone like Crusty or other techs here can elaborate.I'm only a novice.
 
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Re: question regarding electrolytic capacitors

Not to worry I appreciate your input. Yeah I got a mexican fender a few days ago and the guy threw in this amp, a big step up from the 15 watt I use to test wiring mods and so forth but amps are a totally new thing for me. So with the mullard 150 or sozo are they the same 63v and so forth? links are appreciated.
 
Re: question regarding electrolytic capacitors

Tallwood13 said:
Not to worry I appreciate your input. Yeah I got a mexican fender a few days ago and the guy threw in this amp, a big step up from the 15 watt I use to test wiring mods and so forth but amps are a totally new thing for me. So with the mullard 150 or sozo are they the same 63v and so forth? links are appreciated.
Click to expand...

I think so. You can also use Mallory 'PS' "orange drops' ( kind of the best of both world s between the MAllory Metal ( mylar?) Film /Sozo Marshall caps and the Polyester/ Polyproylene type Mallory 'PS' caps . Just generalizing from my notes I have . Weber also sells tone caps, as does Mojo ( Dijon), and Cornell-Dubulier (Wima?) Just scratching the surface. Ive got scores of notes on this stuff, and don't know much though.
 
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Re: question regarding electrolytic capacitors

GoldenVulture said:
Nothing special about the [ F2 ]

That's a lot to pay for a cap like that . Try some where like here. - http://au.mouser.com/Passive-Compon...apacitors/_/N-75hqt?P=1z0wquuZ1yyc4mbZ1z0z819 - Colour and brand do not matter, just the values [ 2.2 ufd/63volt/axial electrolytic ]

For modding these, no idea specifically but you'd be changing resistors as well and maybe chips.
Click to expand...

Wait. Filter capacitors ..the big eletrolytics do not matter in tone. Tone caps are HUGE!You want to weigh your options there. Vulture..do you mean that the 2.2 ufd/63V is a filter capacitor?
 
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Re: question regarding electrolytic capacitors

Tallwood13 said:
this may help solve some questions to help me which kind of capacitor it is. If the F2 doesn't matter on it I've got a match. If so now for the fun part , which kind of capacitor would you guys go with for a more modern metal sound.


View attachment 51806

and the schematic via PDF form
http://www.drtube.com/schematics/marshall/vs30-60-02.pdf
Click to expand...

The cap type won't make a difference for changing the amps characteristics; that's down to circuit design.
 
Re: question regarding electrolytic capacitors

What I'm replacing is the C28 electrolytic capacitor, it's blown and I can't get distortion at all
Click to expand...

Are you saying that the distortion channel works, but it sounds clean, or that the distortion channel does not work at all?
 
Re: question regarding electrolytic capacitors

MetalManiac said:
You look hungry. Hungry for knowledge, so Ima feed'ja.;

http://www.bustedgear.com/faq_Amp_recap.html


http://antiqueradio.org/recap.htm


http://www.chambersamps.com/capacitors.html


http://4sale.sbszoo.com/caps2.htm
Click to expand...

Thanks I appreciate the links I'll check them out now, I saw the inside of this marshall and now all of a sudden I'm interested , so we'll see. I mean Mike fortin is pretty much down the road from me but I figure why waste the mans time with such a simple question. Guitar electronics I'm great with so why not take the plunge.
 
Re: question regarding electrolytic capacitors

@brian
for the clean it's proper functioning, just when i switch to distortion you get a bit of sound at first and then it cuts out as if the cap can't handle it. The only thing I see wrong with the amplifier at this point in time is the blown electrolytic capacitor in the photo so if all else fails I'll see what I can do here as you guys have been very helpful.
 
Re: question regarding electrolytic capacitors

@chris Alright perfect , in this case I've found the exact cap on good old ebay. Thanks for the input.
 
Re: question regarding electrolytic capacitors

Chris of Arabia said:
The cap type won't make a difference for changing the amps characteristics; that's down to circuit design.
Click to expand...

True for the most part I think. Plus you've got to stick to that form factor ( size), so it will fit, otherwise you are going to have to do some modifying the leads.
In that particular circuit, unless you wanted t get invasive and change out all those small blue caps, you'd be better off just replacing the original one and have done with it. Id be more concerned that theres an underlying problem that caused that cap to fry.
I have no idea what I'm talking about, but this is one of the ways I try and get more up to speed on this stuff.And another reason is that TGWIF probably doesn't know much about this stuff, so I can have one thing that I can stay ahead of the curve on him! lolz.
 
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Re: question regarding electrolytic capacitors

MetalManiac said:
Id be more concerned that theres an underlying problem that caused that cap to fry.
Click to expand...

^^ This! Generally speaking, that kind of damage to a cap is the the result of too high a voltage being applied to it. The probable cause would be a resister leading to the HT feed, or one to the ground going short circuit, thereby raising the voltage across the cap itself. I'd get your amp to someone who understands amps better.
 
Re: question regarding electrolytic capacitors

Chris of Arabia said:
^^ This! Generally speaking, that kind of damage to a cap is the the result of too high a voltage being applied to it. The probable cause would be a resister leading to the HT feed, or one to the ground going short circuit, thereby raising the voltage across the cap itself. I'd get your amp to someone who understands amps better.
Click to expand...

Since the amp was made in the late 90s I'm thinking the capacitor just dried up and burned as these caps have a tendency to do that over time I've been told. Didn't do much research other than that on electrolytic capacitors besides that. The guitar it came with was a 1991 mexican fender and how little I paid I got a hardshell case and this amp for free. So honestly I'm hoping for the best.
 
Re: question regarding electrolytic capacitors

MetalManiac said:
Wait. Filter capacitors ..the big eletrolytics do not matter in tone. Tone caps are HUGE!You want to weigh your options there. Vulture..do you mean that the 2.2 ufd/63V is a filter capacitor?
Click to expand...

NO; As he said in the OP, it's C28 in the circuit. It's part of the pre-amp /Fx section of the amp.

The damage to the cap suggests there may be more faulty components but as tallwood13 also suggests , it may have dried out. That can cause the polarity to change and they go Bang! A chip also may be shot. Maybe diodes in the dirt section.

Do you have any understanding/use of a multi meter ?I figure you can use a soldering iron as you say you're going to change the cap yourself.
 
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Re: question regarding electrolytic capacitors

MetalManiac said:
True for the most part I think. Plus you've got to stick to that form factor ( size), so it will fit, otherwise you are going to have to do some modifying the leads.
In that particular circuit, unless you wanted t get invasive and change out all those small blue caps, you'd be better off just replacing the original one and have done with it. Id be more concerned that theres an underlying problem that caused that cap to fry.
I have no idea what I'm talking about, but this is one of the ways I try and get more up to speed on this stuff.And another reason is that TGWIF probably doesn't know much about this stuff, so I can have one thing that I can stay ahead of the curve on him! lolz.
Click to expand...
Dingaling !
 
Re: question regarding electrolytic capacitors

The component numbers on your board don't jive with the component numbers on your schematic...that was confusing. I believe what is C28 on your board, is c36 on the schematic. If that is the case, it looks to be part of the switching circuit. If you can, maybe test that transistor (TR1 on the board & schematic) before you replace the cap. Otherwise, replace the cap and see what happens!
 
Re: question regarding electrolytic capacitors

BrianS. said:
The component numbers on your board don't jive with the component numbers on your schematic...that was confusing. I believe what is C28 on your board, is c36 on the schematic. If that is the case, it looks to be part of the switching circuit. If you can, maybe test that transistor (TR1 on the board & schematic) before you replace the cap. Otherwise, replace the cap and see what happens!
Click to expand...

I was wondering similar or if it was the correct circuit. Then again board layout can be weird at times.
 
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