Capacitor help

[americanlow]

hi guys.

Im looking into building my first amp, im currently copying a fender champ 5E1 schematic, it seems like a nice easy amp to start with. Unfortunately ive already started having trouble sourcing the parts. Looking for capacitors, i cant seem to find the right type. Do i want mica caps? also on the schematic it says 0.02 MFD at 600 volts. Now i found out through an internet MFD is a company, but i think it would be easier just to get the electronics through a site like mouser. What i dont know is if 0.02 is in microfarads? Mouser didnt have any 0.02uF/600V capcitors, it only had 500V or 5000V! what do i do??

thanks very much for the help.

[Blue Strat]

Yes, MFD means microfarads in this case. The voltage rating must exceed the highest possible DC voltage that the cap will "see". Coupling caps in a tweed style amp will never see higher than ~400 volts so 500 Volt coupling or tone caps are fine. The larger electrolytic caps which are used in the power supply may see higher than 400 volts, so 500 or higher volt ratings are required.

Mouser is a fine source of parts, but companies like www.mojotone.com, www.tubesandmore.com and Hoffman Amplification specialize in guitar amp parts and carry specific types of caps that are popular in guitar amps. They also have a much smaller selection than Mouser (who sell electronic parts for everything conceiveable) which makes the selection process much easier.

[americanlow]

thanks for your help. Which are the larger electrolytic caps? are these the ones after the power supply, but before the transformer?

[Blue Strat]

They'd be shown with values such as 20uF @ 450 or 500 volts or similar. They ARE part of the power supply. The way I'd describe them would be AFTER the power transformer (since current flows INTO the amp from your wall socket, not the other way) and the rectifier.

[americanlow]

oh ok. No worries, thanks. one more question ... if i cant find the value i want, say i want 0.02uF, can i wire two 0.01 in parallel ? is this ok praqctice. There just doesnt seem to be every one i need.

[scottl]

You can wire in parallel or even series if you must. But, Mouser has every size you need. My suggestion is Mouser. Prices are usually considerably less than the guitar specific sites. I'd wager many even buy their stock from Mouser!

[TheAmpNerd]

Who did you buy your chassis and other hardware from?
If you can talk to them about buying the whole kit, with
all the componants you'll need, you will save your self
a lot of head aches.

Especially with folks who are new at this, I would always recommend
buying a kit with all the parts to start. That probably doesn't do you
much good now, but in the future when you want to do another amp
buy the whole kit.

[americanlow]

i was gonna make the chassis myself. Mouser didnt have all the capacitors i needed. I cant find a 0.05uF/600V capacitor anywhere. Is 0.047 'close enough' or will this completely not work?

[Blue Strat]

Originally Posted by americanlow

i was gonna make the chassis myself. Mouser didnt have all the capacitors i needed. I cant find a 0.05uF/600V capacitor anywhere. Is 0.047 'close enough' or will this completely not work?

.047 is fine. If you found a .05, it might actually be a .045 or .055 if the cap has a 10% tolerance.

Parallel caps are fine, but every Fender value is available. Mouser IS less expensive, but the other places make chosing the appropriate parts a lot easier for the novice. Time IS money

[americanlow]

haha i have plenty of time, so thats not a problem. thanks for the help guys. Im sure i'll have more questions very soon

[Wicksy]

For that amp, 400V and upwards will work. I used 400V mallorys in my 5F1 champ clone. I had no problems. See if you can hunt down some Sprague Orange drop caps. They can be had on ebay cheaply and sound quite good in Fenders.

[scottl]

tubesandmore.com has the PS series Orange Drops. 600V. .005 size

Fwiw, that is what Dumble used in most of his amps. Nice cap. Smooth tone.

[vibroverbus]

Newark seems to be my current favorite 'big house' alternative when Mouser doesn't have what I need - sometimes a hair more expensive but often have exactly the cap that I can't find from Mouser... both have pretty cool online catalog capabilities, unlike Digi-key which isn't quite as nice...

[hasserl]

For a 5E1 WeberVST will have everything you need: http://www.tedweber.com/

Good prices, easy to negotiate and find the right parts, easy to check out and pay. Hard to go wrong there.

edit: That shoyuld read "easy to negotiate website"

[5992]

Originally Posted by americanlow

i was gonna make the chassis myself. Mouser didnt have all the capacitors i needed. I cant find a 0.05uF/600V capacitor anywhere. Is 0.047 'close enough' or will this completely not work?

Is that the .05uF/600v cap on the fuse connected to the power cord? If so, that is called the "death cap." I would suggest you leave that off and wire the power cord using a modern three-prong plug rather than the two-prong shown in the schematic. I would also suggest that you wire the fuse ahead of the on/off switch on the black (hot) lead of the power cord. Connect the other side of the switch to one primary of the power transformer (usually black). The white wire (neutral) coming from the power cord would then be connected to the other unused lead (usually black) from the primary of the power transformer. The green wire from the power cord gets grounded to the chassis underneath one of the mounting bolts for the power transformer.

HTH,

steve