@TOM50518 yes most filter cap values are still availble & this may cure part of your problem .... think of it like a 30 year old car ... you are going to renew a number of things
before you solve all the problems ... you ust have to be methodical
Hi wicked video!! I have a selmer zodiac mk2. It blew the main fuse and I took the valves out and replaced them one by one and all exept the rectifier seem good. (Fuse only goes when rectifier valve is in). Am I right in thinking the tube just blew ( I've had it 15 years with the same valves and i think the Mullards are from new lol) or is there anything underlying I should look for?
Fantastic videos. I have a Marshall Super100JH signature reissue stack. IM a vintage tone nut, as a billion others are too. Id Love advice on having vintage NOS mustard caps put into my amp to replace the current reissue ones. Your advice would be great. The amp is "amazing" as it is - superb. Its a 2006 reissue. You know, a real great amp, but just thinking of "going that little bit further than Marshall did" with it, and getting new old stock mustards for it. Any advice will be fantastic!
@nznaturopath tough call ... I don't know if it would be that easy to hear the difference ... I use mallory 150's for all repairs and have lots of Traynors and Marshalls with mustards either cap sounds great.
The Super JH is a great amp I don't know if Id suggest you do much to it ... FWIW I also own an early Park 45/100 and have played the JH many times
I have a Crate XT65R that i just bought as a practice amp. I was playing it and the sound just cut out. i have power but no sound. the only noise i get is a very quiet but high pitch noise that can only be heard on the Solo channel. Ive done as much research as i could for this problem and it seems like the caps are the problem. at least from what ive been reading. think you can help me out? id appreciate it greatly.
@patfurlan yea i was thinking about that until they said 75 an hr on top of charging me just to look at it. but if i must i must. but before i do that do you have any ideas at all?
@pumpkinfan283 its a solid state disposable amp ... typically these types of amps rattle apart over time since solder does not hold the components properly to the board ... unless you know how to find cold solder joints
and broken mechanical connections you will need a professional ... IMHO you may want to save your dough and invest in a garage sale vintage Traynor
@patfurlan Hi pat, i have a jcm 900 head. Its had 2 unmatched valves for around 10 years, it still has the original caps-all was fine. My friend pluged my 9v powered acoustic guitar into my amp, since then i feel the tone is off. Is this a coincidence or damage, and what whould you check or change first? Maybe change both valves and caps? anything else to check?? circuits maybe? many thanks
What are the signs that your filter caps need replacing?
I've got a solid state amp and i've recently opened it up to have a nose about inside as my main problem is that it's never had alot of gain on tap. According to other these amps are known for their gain. So would the filter caps need replacing seen as the amp is 24 years old now also would this help with the gain issues.
As far as i can tell nothing is wrong with the amp nothing loose everything is clean and works just lacks the gain.
@kingdarko if you dont mind me asking, what amp do u have? the amp i just bought is also 24 years lol, and its also lackin the gain that its said to have and be famous for
@MVLINEMAN The only thing i ended up doing to mine was open it up and tighten the screws that hold down the PCB board. It seamed to sure the lack of gain but it's still not enough for me at the moment.
Give that a try and see if it helps you any.
Also i am not sure a solid state amp can be biased like a tube amp.
@kingdarko i did that, it helped a lil bit, my randall really has a bias adjustment on the PCB.
i dont know why???? If its not too much to ask could you please take some pics of the board on your randall and top of it, where the box thing is...idk if this sounds kinda odd to you, i asked another guy who has this amp and his has a TREMENDOUS amount of gain, i asked him the same thing about the pictures but he is on tour right now and his randall is at home. could u plz??? really appreciate it.
@MVLINEMAN Yeah i can take a picture mate, maybe not today but i can get around to it, just explain a bit more of what part you want me to take a picture of ? I never knew solid state amps could be biased but do they need doing only the once or do they need it every now and then like tube amps ?
Send me a Private message mate and we'll get chatting on this cos it's something i want to sort with mine too.
Oh man! thanks so much for answering all my questions patfurlan, I wish I understood amp circuitry, I know alot about electricity & control wiring ( I am an HVAC service tech.) so I think I could probably learn amp circuit's, any advice on learning material?
there are lots of good books out there dave funks amp book out of print was great there are a few good websites
& otherwise pick a simple vintage amp design and study it to death ... then build a kit also look at how common amps like the classic fenders and marshalls have evolved over the years and look at common mods & see what
Hi, I was just wondering if I could have caused any damage to my amp. I cleaned all of the tone & volume controlls on the amp without discharging the capacitors, is this bad? could I get zapped?
no, discharging the caps is strictly about safety ... whenever you open an amp chassis there is always a danger of getting Zapped ... the power supply runs through the amp and one wrong poke and you can get hit
I once got a vicious jolt from a 100 watt marshall when it slipped and I had to change my grip to catch it .. put my thumb right onto the main filter ... almost threw the chassis across the room zeee--yow
Sorry for this noob question, but I need to replace a 60uf - 20uf @ 450 - 2uf @350 filter cap, And such a cap doesn't exist. how could I make a different cap work, and why will it work?
What happens if you just try and whip the caps out of the amp without discharging them first? I have a Marshall Valvestate amp which had a filter cap which was shorting out, one side had a dry joint and I re-soldered it. I turned the amp back on and it played fine for about ten minutes and then the sound just turned to a solid buzz and no other sound...
yes if those connections are grounds the amp does not care where they are connected.... unless you great a ground loop ... a poor connection or some other kind of mess... whole books have been written on grounding
yes the amp is quieter and more musical. When filter caps age and wear out they allow hum to exist mixed in with the audio signal robbing your amp of punch and clarity.
No ... good ones last much longer in fact the ones being replace in this video were fine and would be good for another 10 years or so... however I use these amps
to gig with and prefer everything to be in perfect shape...
I change guitar strings before every gig... most people change guitar strings
every 6 months to a year or longer ... same Idea... but if you played my guitar the strings would be fresh ... both guitars would "play"
I have a Fender Deville 410 and after one jam session it all but stopped working.. The sound coming out of all speakers is quiet and muddled.. almost with a phase variance as if someone was constantly moving every dial back and forth.. I confirmed its not blown speakers by connecting it to another speaker cabinet seperately and the same sound. All tubes appear to be fine and glowing normal. No capacitors appear to be blown or extended on top. What is the likely cause?
Do you know of any sound clip / video that's demonstrating how under-/over filtering sounds? I don't work with amps because of the high voltage but I have built stompboxes.
For experimenting, do you know if I would hear differences in overdrive stompboxes as well, when changing the electrolytics?
Experimentation is still the most valuable tool when it comes to audio and that is the only one that counts.
Why could less ripple harm the feel? Could that be because you don't change the resistors in the chain (If it is the first capacitor, inner resistance of tranny and/or additional rectifier output resistance) and your filter's cut frequency goes lower and because of that amp's guitar signal modulating the B+ supply?
I think it simply adds too much bottom end, like too big of coupling cap would ... resulting in a lot of lows the speaker can't control.
Secondly added filtering reduces certain distortion harmonics some people call the "Brown sound" ie power brown out. Too much filtering expands the bandwidth too much, adding hi's and lows people don't want to hear in a guitar tone ....
In a non master amp this midrange eq emphasis is critcal to the distortion tone.
This is one of the biggest mistakes people make! Don't change your caps unless the amp is humming, or just plain sounds bad. If you like the way the amps sounds as it is - take readings off your caps, and replace them with a value close to the that reading. If you change the caps with stock value caps, you may find that you prefer the sound the way it was. I have a 72 Marshall, with original caps... I love the tone - and wouldn't change a thing!
Adding extra filtering is a very common bad idea ...
since it destroys the sound and feel of the amp, while providing the illusion of added bottom end
Don't get me wrong it works for certain amps, like master volume marshalls, and a number of modern hi gain amps
If you've played most non-master volume re-issues of classic amps and noticed they don't sound like the old recordings, you will also notice they are grossly over-filtered
Once the new caps are installed - do you need to leave the amp in standby mode for a certain amount of time before using & is there a break in period for new caps? Very helpful video - Thank You
I HAVE A HAMMOND CONCORDE ORGAN..IT HAS A POP AND CRACK AND HUMM.
SOME 1 TOLD ME TO REPLACE THE FILTER CAPS.IN THE MAIN AMP.IS THIS TRUE.
IT HAS 4 IN IT.. IF I CAN BUY THEM ??/ STILL.IT'S OLD LIKE ME....LET ME NO IF YOU CAN THANK'S...TOM50518
TOM50518 1 month ago
@TOM50518 yes most filter cap values are still availble & this may cure part of your problem .... think of it like a 30 year old car ... you are going to renew a number of things
before you solve all the problems ... you ust have to be methodical
patfurlan 1 month ago
@TOM50518 THANK'S FOR THE INFO...
TOM50518 1 month ago
@TOM50518 ps stop yelling YELLING
patfurlan 1 month ago
Hi wicked video!! I have a selmer zodiac mk2. It blew the main fuse and I took the valves out and replaced them one by one and all exept the rectifier seem good. (Fuse only goes when rectifier valve is in). Am I right in thinking the tube just blew ( I've had it 15 years with the same valves and i think the Mullards are from new lol) or is there anything underlying I should look for?
Fourqmofo 5 months ago
@Fourqmofo sounds like you have a bad rectifier tube
patfurlan 4 months ago
Fantastic videos. I have a Marshall Super100JH signature reissue stack. IM a vintage tone nut, as a billion others are too. Id Love advice on having vintage NOS mustard caps put into my amp to replace the current reissue ones. Your advice would be great. The amp is "amazing" as it is - superb. Its a 2006 reissue. You know, a real great amp, but just thinking of "going that little bit further than Marshall did" with it, and getting new old stock mustards for it. Any advice will be fantastic!
nznaturopath 5 months ago
@nznaturopath tough call ... I don't know if it would be that easy to hear the difference ... I use mallory 150's for all repairs and have lots of Traynors and Marshalls with mustards either cap sounds great.
The Super JH is a great amp I don't know if Id suggest you do much to it ... FWIW I also own an early Park 45/100 and have played the JH many times
patfurlan 5 months ago
I have a Crate XT65R that i just bought as a practice amp. I was playing it and the sound just cut out. i have power but no sound. the only noise i get is a very quiet but high pitch noise that can only be heard on the Solo channel. Ive done as much research as i could for this problem and it seems like the caps are the problem. at least from what ive been reading. think you can help me out? id appreciate it greatly.
pumpkinfan283 5 months ago
@pumpkinfan283 take it to a tech ... caps have little to do with sudden amp failure
patfurlan 5 months ago
@patfurlan yea i was thinking about that until they said 75 an hr on top of charging me just to look at it. but if i must i must. but before i do that do you have any ideas at all?
pumpkinfan283 5 months ago
@pumpkinfan283 its a solid state disposable amp ... typically these types of amps rattle apart over time since solder does not hold the components properly to the board ... unless you know how to find cold solder joints
and broken mechanical connections you will need a professional ... IMHO you may want to save your dough and invest in a garage sale vintage Traynor
patfurlan 5 months ago
@patfurlan alright. thanks for the advice
pumpkinfan283 5 months ago
@pumpkinfan283 Im not trying to be harsh... its probably a cold solder joint or loose part ... very simple to fix
if you have the detective skills to find the problem ... with electronics repairs 99% of the work is finding the probelm
patfurlan 5 months ago
@patfurlan Hi pat, i have a jcm 900 head. Its had 2 unmatched valves for around 10 years, it still has the original caps-all was fine. My friend pluged my 9v powered acoustic guitar into my amp, since then i feel the tone is off. Is this a coincidence or damage, and what whould you check or change first? Maybe change both valves and caps? anything else to check?? circuits maybe? many thanks
modernrocks 5 months ago
Thanks for posting! lots of good info there...
smashedg 7 months ago
Electrosonic, the Tube store, Long & McQuade & swap meets
patfurlan 8 months ago
Do you source your parts in Toronto or do mail order?
rousejeremy 8 months ago
What are the signs that your filter caps need replacing?
I've got a solid state amp and i've recently opened it up to have a nose about inside as my main problem is that it's never had alot of gain on tap. According to other these amps are known for their gain. So would the filter caps need replacing seen as the amp is 24 years old now also would this help with the gain issues.
As far as i can tell nothing is wrong with the amp nothing loose everything is clean and works just lacks the gain.
kingdarko 9 months ago
@kingdarko Filters have little to do with gain you have another problem
patfurlan 9 months ago
@kingdarko if you dont mind me asking, what amp do u have? the amp i just bought is also 24 years lol, and its also lackin the gain that its said to have and be famous for
MVLINEMAN 6 months ago
@MVLINEMAN randall rg100es
kingdarko 6 months ago
@kingdarko oh no shiz, i have the same exact amp with the same exact problem, so could you please help me out if you can?
does your randall have a bias adjustment? idk what to and not to mess with so any information on it would be greatly appreciated.
Thank you,
Tony
MVLINEMAN 6 months ago
@MVLINEMAN The only thing i ended up doing to mine was open it up and tighten the screws that hold down the PCB board. It seamed to sure the lack of gain but it's still not enough for me at the moment.
Give that a try and see if it helps you any.
Also i am not sure a solid state amp can be biased like a tube amp.
kingdarko 6 months ago
@kingdarko i did that, it helped a lil bit, my randall really has a bias adjustment on the PCB.
i dont know why???? If its not too much to ask could you please take some pics of the board on your randall and top of it, where the box thing is...idk if this sounds kinda odd to you, i asked another guy who has this amp and his has a TREMENDOUS amount of gain, i asked him the same thing about the pictures but he is on tour right now and his randall is at home. could u plz??? really appreciate it.
MVLINEMAN 6 months ago
@MVLINEMAN Yeah i can take a picture mate, maybe not today but i can get around to it, just explain a bit more of what part you want me to take a picture of ? I never knew solid state amps could be biased but do they need doing only the once or do they need it every now and then like tube amps ?
Send me a Private message mate and we'll get chatting on this cos it's something i want to sort with mine too.
kingdarko 6 months ago
What wattage rating soldering iron do you recommend?
vatonaught 9 months ago
@vatonaught The higher the better, just make sure it's got a temp control on it so you can lower it down of more delicate jobs
kingdarko 9 months ago
anything 35 or 40 watts for most work. I use a pair of cheap hardware store 80 watt irons for big filters like these.
patfurlan 9 months ago
Oh man! thanks so much for answering all my questions patfurlan, I wish I understood amp circuitry, I know alot about electricity & control wiring ( I am an HVAC service tech.) so I think I could probably learn amp circuit's, any advice on learning material?
fuzzfreak1967 11 months ago
there are lots of good books out there dave funks amp book out of print was great there are a few good websites
& otherwise pick a simple vintage amp design and study it to death ... then build a kit also look at how common amps like the classic fenders and marshalls have evolved over the years and look at common mods & see what
can apply to other designs
patfurlan 10 months ago
Hi, I was just wondering if I could have caused any damage to my amp. I cleaned all of the tone & volume controlls on the amp without discharging the capacitors, is this bad? could I get zapped?
fuzzfreak1967 11 months ago
no, discharging the caps is strictly about safety ... whenever you open an amp chassis there is always a danger of getting Zapped ... the power supply runs through the amp and one wrong poke and you can get hit
I once got a vicious jolt from a 100 watt marshall when it slipped and I had to change my grip to catch it .. put my thumb right onto the main filter ... almost threw the chassis across the room zeee--yow
patfurlan 11 months ago
@patfurlan . i got quiet a jolt from a digital camera . i can only imagine what an amp would feel like
tomodrive 9 months ago
Sorry for this noob question, but I need to replace a 60uf - 20uf @ 450 - 2uf @350 filter cap, And such a cap doesn't exist. how could I make a different cap work, and why will it work?
trentger1 11 months ago
I assume you are talking about a Can cap with three sections ....
Match or exceed the voltage & be close on the mfd rating
you may have to use a more common can cap and mount the 2 uf at 350 in another place
patfurlan 11 months ago
What happens if you just try and whip the caps out of the amp without discharging them first? I have a Marshall Valvestate amp which had a filter cap which was shorting out, one side had a dry joint and I re-soldered it. I turned the amp back on and it played fine for about ten minutes and then the sound just turned to a solid buzz and no other sound...
DarkMedievalTimes1 1 year ago
What happens if you just try and whip the caps out of the amp without discharging them first?
DarkMedievalTimes1 1 year ago
what if you used men's clear nail polish?
mattlittler89 1 year ago
men's black nail polish perhaps
patfurlan 1 year ago
This is very helpful to me for changing caps in amps and radios!
Thermionman1970 1 year ago
yes if those connections are grounds the amp does not care where they are connected.... unless you great a ground loop ... a poor connection or some other kind of mess... whole books have been written on grounding
patfurlan 1 year ago
@patfurlan
THANKS! Ihave done perfect.
keroyonoflove 1 year ago
Hi, my ampeg has an aluminum filter cap that have 4 pins on circumference are connected to ground cables.
Now I'm going to replace to new mundorf filter cap(I have found same capasitance one). Can I connect the ground cables together to the minus terminal?
"Substitute" is my favorite THE WHO song.
keroyonoflove 1 year ago
Is there a sound diffrerence when You replaced the old caps for new ones?
coin777 1 year ago
yes the amp is quieter and more musical. When filter caps age and wear out they allow hum to exist mixed in with the audio signal robbing your amp of punch and clarity.
patfurlan 1 year ago
You may not be a tech, but you certainly play one on TV!! :)
Very informative videos and comments. Top notch.
Funnily (??) enough, I AM one of those who does NOT change strings very often!! :)
PeterPug007 1 year ago
Do the filter caps ALWAYS need to be replaced every 10 years or so??
PeterPug007 1 year ago
No ... good ones last much longer in fact the ones being replace in this video were fine and would be good for another 10 years or so... however I use these amps
to gig with and prefer everything to be in perfect shape...
I change guitar strings before every gig... most people change guitar strings
every 6 months to a year or longer ... same Idea... but if you played my guitar the strings would be fresh ... both guitars would "play"
patfurlan 1 year ago
I have a Fender Deville 410 and after one jam session it all but stopped working.. The sound coming out of all speakers is quiet and muddled.. almost with a phase variance as if someone was constantly moving every dial back and forth.. I confirmed its not blown speakers by connecting it to another speaker cabinet seperately and the same sound. All tubes appear to be fine and glowing normal. No capacitors appear to be blown or extended on top. What is the likely cause?
FletcherHabit 1 year ago
whoa... I am not an amp technician ... and any tech would want to examine your amp in person rather than guess based ona description ...
#1 just because tubes Light Up does not mean they are passing audio properly
so check your tubes first
#2 if you were just playing normally and it cut out it could be one of two things
a bad tube, or a cold solder joint (a common problem in modern amps)
so substitue your tubes till you find a bad one ... if that fails take it to a proper tech
patfurlan 1 year ago
I'm confused by the polarity and how you determine which lugs translate to which. Is the cap marked to show you that?
guitarcapo 1 year ago
yes polarized caps are CLEARLY marked
patfurlan 1 year ago
Do you know of any sound clip / video that's demonstrating how under-/over filtering sounds? I don't work with amps because of the high voltage but I have built stompboxes.
For experimenting, do you know if I would hear differences in overdrive stompboxes as well, when changing the electrolytics?
ericohman 1 year ago
Most Reissue amps are overfiltered .. and a Fuzz face should have no power filtering & should be used with a carbon zinc battery ...
most people & engineers cannot resist the temptation to "improve" vintage power supplies ... real vintage powersupplies were very crude
patfurlan 1 year ago
Why doesn't anyone ever show how to replace a CAN CAP?
guitarcapo 1 year ago
did you watch the video past 4.38 ....
the reason you never see anyone remove one is because desoldering is a big pain
cutting the tabs with a dremel is a big pain & once the cursing and swearing is edited out you don't have much left for a video
patfurlan 1 year ago 2
Regarding filtering, I would hope the audio/video
clips speak for themselves ...
The only drive effect used in any of the clips is a clean booster sometimes used for solos ...
The guitars are also set up with the same attention to detail
patfurlan 2 years ago
Thanks for the reply...
Experimentation is still the most valuable tool when it comes to audio and that is the only one that counts.
Why could less ripple harm the feel? Could that be because you don't change the resistors in the chain (If it is the first capacitor, inner resistance of tranny and/or additional rectifier output resistance) and your filter's cut frequency goes lower and because of that amp's guitar signal modulating the B+ supply?
cloudydandy 2 years ago
I think it simply adds too much bottom end, like too big of coupling cap would ... resulting in a lot of lows the speaker can't control.
Secondly added filtering reduces certain distortion harmonics some people call the "Brown sound" ie power brown out. Too much filtering expands the bandwidth too much, adding hi's and lows people don't want to hear in a guitar tone ....
In a non master amp this midrange eq emphasis is critcal to the distortion tone.
patfurlan 2 years ago
Nice and solid work. Better than I saw in some amp shops...
Is there any electronic text/book supporting your info about powersupply overfiltering destroying tone and feel or is it from your experience?
cloudydandy 2 years ago
Nice and solid work... Better than I saw on some amp shops.
Is there some electronic book/text that supports your info about over filtering destroying feel and tone or it comes from your experience?
cloudydandy 2 years ago
its from hours of experimentation where I have
raised and lowered values to alter the feel
of the amp
patfurlan 2 years ago
This is one of the biggest mistakes people make! Don't change your caps unless the amp is humming, or just plain sounds bad. If you like the way the amps sounds as it is - take readings off your caps, and replace them with a value close to the that reading. If you change the caps with stock value caps, you may find that you prefer the sound the way it was. I have a 72 Marshall, with original caps... I love the tone - and wouldn't change a thing!
jcoopercam 2 years ago
Does anyone know the tolerance limit on MFD?
kevykev38 2 years ago
as in how much filtering you can add ?
patfurlan 2 years ago
Exactly.
kevykev38 2 years ago
60 mfd first stage on a tube rectifier...
Adding extra filtering is a very common bad idea ...
since it destroys the sound and feel of the amp, while providing the illusion of added bottom end
Don't get me wrong it works for certain amps, like master volume marshalls, and a number of modern hi gain amps
If you've played most non-master volume re-issues of classic amps and noticed they don't sound like the old recordings, you will also notice they are grossly over-filtered
patfurlan 2 years ago
I'd add that I would filter the same amp two different ways for stage vs. low volume use.
For a "live amp" I do add filtering at the first filter stage... but tend to reduce filtering in all pre amp stages whenever possible
added Filtering can add add headroom at the expense of tone
patfurlan 2 years ago
Once the new caps are installed - do you need to leave the amp in standby mode for a certain amount of time before using & is there a break in period for new caps? Very helpful video - Thank You
Diary81 2 years ago
Great vid
ojgibbins 2 years ago
Where did you get the new filter caps ??
BigFishingShop 2 years ago
places like the tubestore and various online
parts suppliers have them.
patfurlan 2 years ago
Thanks, just to be sure, does uf and mfd mean the same ?
BigFishingShop 2 years ago
Yes you want 32 mfd caps / 32uf
Don't overfilter
patfurlan 2 years ago
Sounds awesome!
bobob13131 2 years ago