LPguitarman Posted May 6, 2014 Posted May 6, 2014 My son has a Peavey Valve-King 100 Watt amp. His fuse blew and we are trying to replace it. Under the fuse on the back of the amp it says F5A. The fuse is white (assume ceramic) but it says .5A/250V. What kind of fuse should we get? Also explain the .5 vs. 5 if possible. Thanks...
Guest Farnsbarns Posted May 6, 2014 Posted May 6, 2014 My son has a Peavey Valve-King 100 Watt amp. His fuse blew and we are trying to replace it. Under the fuse on the back of the amp it says F5A. The fuse is white (assume ceramic) but it says .5A/250V. What kind of fuse should we get? Also explain the .5 vs. 5 if possible. Thanks... I'm sure it'll be a 5 amp fuse. There is a convension that a component's value will never start with a point (.) As it can be hard to see. Generally the unit will be used to denote a decimal point. I.e 0A5 for 0.5Amp. A half amp fuse seems very unlikely as well. To be truly safe you could start with a 0.5 amp but I think it'll blow as soon as you touch the power and will need a 5 amp fuse. Assuming this fuse is for the main power that is. You could also check the fuse in the plug (do you have fused plugs there?).
LPguitarman Posted May 6, 2014 Author Posted May 6, 2014 I'm sure it'll be a 5 amp fuse. There is a convension that a component's value will never start with a point (.) As it can be hard to see. Generally the unit will be used to denote a decimal point. I.e 0A5 for 0.5Amp. A half amp fuse seems very unlikely as well. To be truly safe you could start with a 0.5 amp but I think it'll blow as soon as you touch the power and will need a 5 amp fuse. Assuming this fuse is for the main power that is. You could also check the fuse in the plug (do you have fused plugs there?). Thanks Farnsbarns... Some plugs have fuses in them here, but I've only seen them in Christmas Lights. I talked to a tech. at Peavey.com also and he said the schematic calls for 5A, so that's what I told my son to get. Thanks for your help.
L5Larry Posted May 6, 2014 Posted May 6, 2014 A fuse seldom blows for simple unexplainable reasons such as power surges, etc, but is usually the sign of a major problem with the amp. If the new good fuse blows, there is problem with the amp. Do not put a higher value fuse in, or even keep trying more 5A's, see your repair tech. Peavey amps are not really built to be repairable, but somewhat disposable. I know one shop in town that won't even take them in for service. Anyway, keep us informed.
Guest Farnsbarns Posted May 6, 2014 Posted May 6, 2014 A fuse seldom blows for simple unexplainable reasons such as power surges, etc, but is usually the sign of a major problem with the amp. I'd have to politely disagree with that. Fuses are, by design, operating at close to their maximum current a lot of the time in most aplications. They degrade and blow, even just the tiny surge from the arc created by plugging in while powered up can do it.. I would say that 99 % of blown fuses fall in to the "simple unexplainable reasons" category. I had a vox ac30 blow the mains fuse once just because the bulb in the power indicator blew. Here in the UK every plug on every apliance has a fuse so we find ourselves replacing them quite often and there is rarely a problem or explanation.
rct Posted May 6, 2014 Posted May 6, 2014 Here in the UK every plug on every apliance has a fuse so we find ourselves replacing them quite often and there is rarely a problem or explanation. Socialism. Yer welcome. rct
Guest Farnsbarns Posted May 6, 2014 Posted May 6, 2014 Socialism. Yer welcome. rct something's gone over my head there.
kidblast Posted May 6, 2014 Posted May 6, 2014 Peavey amps are not really built to be repairable, but somewhat disposable. I know one shop in town that won't even take them in for service. Anyway, keep us informed. Well I don't know if I can agree with you this time Larry, (unusual cuz I think you're always dead nuts on) could be from years past. recently this is not true in my experiences. They have very good customer service, and you will wind up talking with people who are very helpful if you run into anything dicey, and they will be happy to assist repairing, if not, repair it for you and ship it back (of course, you gotta pay the freight so just send what needs to be looked at.. (in other words, if you have a combo, remove the amp, they don't need the speakers.) IMO, they got the "stand behind their products" thing down pretty good.
rct Posted May 6, 2014 Posted May 6, 2014 Ok, so you said... Here in the UK every plug on every apliance has a fuse so we find ourselves replacing them quite often and there is rarely a problem or explanation. With the emphasis on the rarely a problem or(especially) explanation, I said... Socialism. See, here in Americur every difference between Yerup and us is immediately discounted, slagged, and written off as a fail due to "socialism". We have great difficulty with anything that remotely smacks of everyone paying for everyone. So, to the wise and enlightened over here, it was pretty dang funny. Or not, as is more likely. Carry on. rct
Riffster Posted May 6, 2014 Posted May 6, 2014 Well I don't know if I can agree with you this time Larry, (unusual cuz I think you're always dead nuts on) could be from years past. recently this is not true in my experiences. They have very good customer service, and you will wind up talking with people who are very helpful if you run into anything dicey, and they will be happy to assist repairing, if not, repair it for you and ship it back (of course, you gotta pay the freight so just send what needs to be looked at.. (in other words, if you have a combo, remove the amp, they don't need the speakers.) IMO, they got the "stand behind their products" thing down pretty good. I don't think he is knocking down Peavey's customer service but simply saying amp repair shops in general do not want to repair them. And he also must be right that Peavey's are not built to be repaired, I repaired my Classic 30 and the those things are "brittle" inside, working on that PCB is like working on a saltine cracker. I succesfully repaired mine since I only replaced a couple of diodes but I cannot imagine repairing something major.
rct Posted May 6, 2014 Posted May 6, 2014 In the late 70's I used Peavey Classics. Like three, sometimes four a year. They broke, no matter what town we were in you could buy another one. Threw them off trucks, dropped them down steps, whatever, they kept going until they didn't. I'd use them again if it wasn't for the creepy little aliens they used in their ads for a while. Like, 15 years ago now prolly? rct
LPguitarman Posted May 6, 2014 Author Posted May 6, 2014 Hey who stole my thread [biggrin] Well, he got a 5amp fuse, plugged it in and now the clean channel works but the overdrive channel doesn't. Long story short, he took it to a repair shop and is waiting (probably a day or two) for some kind of answer. Hopefully it just some tubes. He bought the amp used several years ago and hasn't had to touch it until this happened. We were changing around some effects pedals and when he plugged it back in, that's when the fuse blew. I'll keep everyone informed when he finds out the problem. BTW, My Peavey Classic VT Series has been a "WORKHORSE" for years. I did change the tubes once and I upgraded the speakers, but other than that no issues.
rct Posted May 6, 2014 Posted May 6, 2014 Well, he got a 5amp fuse, plugged it in and now the clean channel works but the overdrive channel doesn't. Preamp tube went and took the fuse out. rct
LPguitarman Posted May 6, 2014 Author Posted May 6, 2014 Preamp tube went and took the fuse out. rct Ok, so a blown tube will also blow out the fuse... Thanks for the info. Waiting to hear from the tech. Hopefully that's all it is. He doesn't have a lot of money to spend.
deeman Posted May 6, 2014 Posted May 6, 2014 Ok, so a blown tube will also blow out the fuse... Thanks for the info. Waiting to hear from the tech. Hopefully that's all it is. He doesn't have a lot of money to spend. If you have a known good preamp tube, you can replace one by one until you find the valve for the overdrive.
LPguitarman Posted May 6, 2014 Author Posted May 6, 2014 If you have a known good preamp tube, you can replace one by one until you find the valve for the overdrive. Thanks Deeman, the amp is in the repair shop.
Bender 4 Life Posted May 7, 2014 Posted May 7, 2014 A fuse seldom blows for simple unexplainable reasons such as power surges, etc, but is usually the sign of a major problem with the amp. If the new good fuse blows, there is problem with the amp. Do not put a higher value fuse in, or even keep trying more 5A's, see your repair tech. Peavey amps are not really built to be repairable, but somewhat disposable. I know one shop in town that won't even take them in for service. Anyway, keep us informed. this .... fuses serve 1 purpose.....protection from current overload, from either direction..... blown fuse = either bad fuse (not seen one in over 30 yrs) or overload.
retrorod Posted May 7, 2014 Posted May 7, 2014 My son has a Peavey Valve-King 100 Watt amp. His fuse blew and we are trying to replace it. Under the fuse on the back of the amp it says F5A. The fuse is white (assume ceramic) but it says .5A/250V. What kind of fuse should we get? Also explain the .5 vs. 5 if possible. Thanks... Not sure if it was mentioned, but fuses come in amp rating as well as Fast-blow and Slow-blow types. I think the F stands for Fast-blow. Most old Fender amps used Slo-blo types.. I could be wrong....the F may just stand for Fuse in this case.... A shorted power tube could cause the fuse to blow....
Guest Farnsbarns Posted May 7, 2014 Posted May 7, 2014 this .... fuses serve 1 purpose.....protection from current overload, from either direction..... blown fuse = either bad fuse (not seen one in over 30 yrs) or overload. The thing is, when a tube goes, much like a light built, a momentary short can occur, this allows much higher than normal current through the power tranny momentarily. As this is drawn through the fuse it blows. Very occasionally a light bulb blowing can trip the circuit breaker in much the same way. This high current could have damaged other components although the tendency to use much higher rated components than necessary in amps, and the split second nature of the short means this is fairly unusual. In mass produced amps there are often internal fuses that might also blow. There is no perticular reason to think there is an underlying problem here.
Bender 4 Life Posted May 7, 2014 Posted May 7, 2014 from what i've gathered, the underlying problem was a blown tube....so we're both right Farns !!
LPguitarman Posted May 23, 2014 Author Posted May 23, 2014 Got the amp back this week. A lot of electrical "cleaning" $46. and a new "used" pre-amp tube for $5. It works for now. My son doesn't want to sink any more money into this amp. He has GAS for a Marshall JCM2000.
Guest Farnsbarns Posted May 23, 2014 Posted May 23, 2014 Got the amp back this week. A lot of electrical "cleaning" $46. and a new "used" pre-amp tube for $5. It works for now. My son doesn't want to sink any more money into this amp. He has GAS for a Marshall JCM2000. Funny, I'm selling one, albeit I haven't actually listed it anywhere, but the wrong voltage and pricey shipping across the pond will rule mine out.
spacealf Posted May 24, 2014 Posted May 24, 2014 You or your son may want to turn off the amp when messing around with boxes and such plugging in. Volume suppose to be turned down also before turning on a amp. Precautions because like anything they are not in-destructible.
Bender 4 Life Posted May 24, 2014 Posted May 24, 2014 You or your son may want to turn off the amp when messing around with boxes and such plugging in. Volume suppose to be turned down also before turning on a amp. Precautions because like anything they are not in-destructible. also, never turn an amp on w/o a cable/guitar plugged into it.....don't remember exactly why, may be urban myth, but i've heard this many times.
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