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power supply filter cap replacement question

#21
BassmanPaul said:
Most people don't know how to access the extended character set from their keyboards including me. ;(

Paul
Click to expand...

Paul, use Character map which is in Accessories / System utils on most XP boxes. Find the character you need and use the copy function to copy it to clipboard and then paste it here as there's no keyboard shortcut The default font here is Arial. The ° symbol is ALT + 0176 and © is ALT + 0169

Hope this helps.
 
#22
FYI: the lower-case mu symbol, µ, is Alt+0181.

When I first got into electronics in the late 60s/early 70s, most schematics, books, etc., abbreviated microfarad as "mfd" instead of µF. Now the proper use of "m" would be for "milli," or 1/1000, but no one uses "millifarad."
 
#27
Best idea is to stay "at" the same voltage, although a bit above is OK too.

Most amps (except original Crown DC300) have a cap voltage rating somewhat above actual voltage in use. Some of that allowance is for the 10% up normal variance allowed for mains voltage, the rest as "margin".

Going too far above actual voltage can cause trouble if the cap "un-forms" a bit due to the low voltage. That normally is for more extreme situations like 2 or 3 x voltage however.

Most of the time you just pay a penalty of cost and size for excessive voltage rating.

BTW, common voltage ratings are 25, 35, 50, 63, (80) and 100. The 80 isn't totally common, but is available. Higher common ones 160, 200, 250, 400, and 450.
 
#29
okabass said:
HI

I have never understanded why you americans use "u" or "m" instead the correct µ.
Click to expand...

We can never remember alt-230. :D

Also, old habits die hard. Many of us go back to days when µ was not in any computer font, and if it was, we could not trust two display devices or printers to have the same character table.

I don't even know today how µ will display on a Mac. :eek:
 
#31
SB100 said:
Paul, use Character map which is in Accessories / System utils on most XP boxes. Find the character you need and use the copy function to copy it to clipboard and then paste it here as there's no keyboard shortcut The default font here is Arial. The ° symbol is ALT + 0176 and © is ALT + 0169

Hope this helps.
Click to expand...

What!!!!!! --- Windows?????? Arrrgggghhhh!

Seriously though, thank you for posting this information. It will help others and gave me a kick to find out how to do the same on the Mac. It is all built in, as I expected, and the extended characters are available using the option key and a letter. Example µ is option m (from mu). ∑ option w (it looks like a sideways w). They're all there.

Hope this helps other Mac users.

Paul
 
#32
BassmanPaul said:
What!!!!!! --- Windows?????? Arrrgggghhhh!

Seriously though, thank you for posting this information. It will help others and gave me a kick to find out how to do the same on the Mac. It is all built in, as I expected, and the extended characters are available using the option key and a letter. Example µ is option m (from mu). ∑ option w (it looks like a sideways w). They're all there.

Hope this helps other Mac users.

Paul
Click to expand...

Hey Paul, your welcome mate.
 
#35
NationwideBass said:
Found a lot of 10, Hitano 3300μF (see, I learn :) ) 100V 105˚C on Ebay for 6.99. After shipping it was still less than buying just the number I needed from a place like Digikey. Now, hopefully they get here soon. I'm quite an impatient person ;)
Click to expand...

Good stuff.

While you're servicing the head a few more chores worth doing. (make sure you discharge the HT supply properly first).

Pull all the bottles (valves) and hide them in a safe kid and wife free zone so they won't get smashed.

Check every single valve base for cracks on both sides of the chassis. Use a magnifying glass.

Check for fraying of leads on the heaters and HT leads.

Check all soldered joints for dry joints.

Check all gromits for perishing.

Replace all other electrolytic caps you find in the amp, it's a pain in the backside but do it now and you'll save a lot of downtime in coming months and years. Electro's in older valve gear usually fail in batches.

Clean all the pots .. might as well do the job right hey!

Viola one fully serviced and reconditioned head, fit for another couple of decades of work.

Don't forget you'll probably need to check the valve biasing after replacing the caps.
 
#36
SB100 said:
Good stuff.

While you're servicing the head a few more chores worth doing. (make sure you discharge the HT supply properly first).

Pull all the bottles (valves) and hide them in a safe kid and wife free zone so they won't get smashed.

Check every single valve base for cracks on both sides of the chassis. Use a magnifying glass.

Check for fraying of leads on the heaters and HT leads.

Replace all other electrolytic caps you find in the amp, it's a pain in the backside but do it now and you'll save a lot of downtime in coming months and years. Electro's in older valve gear usually fail in batches.

Don't forget you'll probably need to check the valve biasing after replacing the caps.
Click to expand...

Pssstttt.... his amp is solid state! ;)
 
#40
NationwideBass said:
I agree the parts seem easier to find, but it seems like with biasing, and what sounds like a greater chance of electrocution, why are they easier to work on? I ask seriously, not sarcastically.
Click to expand...
Old tube amps are like old cars, with carburetors and such. Not many parts, everything is easy to get at. SS is more like modern fuel injected computer controlled cars, where changing a sparkplug can require removing half the engine. I used to enjoy working on old tube stuff, and dreaded every encounter with SS.
 

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