Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: hesamadman on September 14, 2014, 04:42:34 pm

Title: Are there differences in these caps?
Post by: hesamadman on September 14, 2014, 04:42:34 pm
I've been building some of these 5watt amps. The first one I used some larger (physical size)caps in the power supply. I bought some mini radial caps (same Value and voltage) to use in the future. These things are about $9 cheaper than the first ones. Are there any differences in the sound or reliability?
Title: Re: Are there differences in these caps?
Post by: shooter on September 14, 2014, 08:06:16 pm
there have been a few threads on small caps n it seems they work the same, think Sluckey did some autopsies and found the big ones inside are smallish.  I've used a few without issue, but I'm a visual artist trying to get my ears tuned for musical art.
Title: Re: Are there differences in these caps?
Post by: HotBluePlates on September 14, 2014, 08:29:15 pm
I've been building some of these 5watt amps. The first one I used some larger (physical size)caps in the power supply. I bought some mini radial caps (same Value and voltage) to use in the future. These things are about $9 cheaper than the first ones.

Are the radials Illinois, Rubycon, Nichicon or the like? If so, they're probably every bit as good as the big electrolytic caps.
Title: Re: Are there differences in these caps?
Post by: hesamadman on September 14, 2014, 10:47:53 pm
I've been building some of these 5watt amps. The first one I used some larger (physical size)caps in the power supply. I bought some mini radial caps (same Value and voltage) to use in the future. These things are about $9 cheaper than the first ones.

Are the radials Illinois, Rubycon, Nichicon or the like? If so, they're probably every bit as good as the big electrolytic caps.

They will be now that you said so. Thanks HBP
Title: Re: Are there differences in these caps?
Post by: HotBluePlates on September 15, 2014, 04:10:23 pm
Those aren't the only brands. Most modern radials are better in every way compared to old-style large axial caps. A good data sheet will tell the tale.

If you're worried for how well they'll hold up, spring for the 105 C rated caps (though you should never come close to that temperature inside your chassis). There are also details buried in the data sheets about ripple current ratings, which are important in a filter cap, especially the one right after the rectifier.
Title: Re: Are there differences in these caps?
Post by: PRR on September 16, 2014, 09:47:40 pm
> spring for the 105 C rated caps (though you should never come close to that temperature inside your chassis).

You should never be boiling spit on your chassis, true.

But if you did work them at full voltage and right at 105 deg C all day and all night, the expected life is about a month. Maybe a year or so of gigging a few hours a night.

If you expect to run the amp many years, and don't want to go back in for expired caps, the 105 rating is well worth having.

Flip-side... experimental amps that will be re-re-built frequently and used rarely can use the low-temp caps. 
Title: Re: Are there differences in these caps?
Post by: G._Hoffman on September 17, 2014, 02:02:51 pm
Just don't buy the super cheap made in China caps.  The normal priced made in China should be fine, just avoid anything that seems improbably cheap. 


Gabriel
Title: Re: Are there differences in these caps?
Post by: HotBluePlates on September 17, 2014, 03:56:12 pm
What about those ones I saw at 15 for a dollar? You mean I shouldn't get them? Come to think of it they might have been cigarette butts rolled up in a blue wrapper with a couple leads sticking out...  :l2:
Title: Re: Are there differences in these caps?
Post by: Willabe on September 17, 2014, 06:46:11 pm
Come to think of it they might have been cigarette butts rolled up in a blue wrapper with a couple leads sticking out...  :l2:

Now those are 'smoking hot' caps!!!!!!!

 
                      Brad     :l2: