Need some replacement reservoir caps for a power amp. Nothing special -
just 10,000uF at 63v. RS have them from about 4 quid to about 50.

Old amp so not PCB mounted - just wires to them and plenty space so not
restricted to an identical part - which isn't made now anyway.

Best make to go for? Is a 50 quid one really worth it?

--
*24 hours in a day ... 24 beers in a case ... coincidence? *

Dave Plowman London SW
To e-mail, change noise into sound.

On Sat, 14 Apr 2018 16:00:49 +0100, "Dave Plowman (News)"
wrote:

Need some replacement reservoir caps for a power amp. Nothing special -
just 10,000uF at 63v. RS have them from about 4 quid to about 50.

Old amp so not PCB mounted - just wires to them and plenty space so not
restricted to an identical part - which isn't made now anyway.

Best make to go for? Is a 50 quid one really worth it?

No.

Go for the cheapest.

In the days before deoxygenated silver topped constant impedance pilot
lights, the only parameters to electrolytics that were of concern were
the inductance and ripple current.

A small additional cap was often added across the biggy to take care
of the first problem and the second parameter was usually stamped on
the case of a reputable cap.

The existing electrolytics probably lost performance for years before
the motor boating set in, I would be willing to bet that until crunch
time, there was little warning.

Personally I would go to Ebay and buy the cheapest, if you have
goldfish, then they could worry about the ripple :-)

If you are into gold bonded speaker cables, green CD restoring pens
and satin lined willy warmers, you may want to read up on reforming
capacitors before soldering your investments in.

AB

Dave Plowman (News) wrote:
Need some replacement reservoir caps for a power amp. Nothing special -
just 10,000uF at 63v. RS have them from about 4 quid to about 50.

Old amp so not PCB mounted - just wires to them and plenty space so not
restricted to an identical part - which isn't made now anyway.

Best make to go for? Is a 50 quid one really worth it?

The two parameters to look at that tend to impact on price are
1)ripple current (@ 100Hz in your application I expect) which relates to
ESR
and
2) life expectancy at whatever temperature you will be running at.

I tend to stick to mid price known brands -Epcos - (ex Siemens) have not
knowingly given problems - never had one back in equipment that I've
used them in and sold on to others.
hth
Bob

On 14/04/2018 16:30, Archibald Tarquin Blenkinsopp wrote:

Personally I would go to Ebay and buy the cheapest, if you have
goldfish, then they could worry about the ripple :-)


http://www.discovercircuits.com/dc-m...Capacitor1.jpg


--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

I would suspect that it wasn't the hum that led to the dissection.
Electrolytics are made to a wide tolerance anyway.

From experience with overloads and RCD's, the pirate versions with
hardly any innards are almost always the better known brands.

AB



On Sat, 14 Apr 2018 17:53:43 +0100, alan_m
wrote:

On 14/04/2018 16:30, Archibald Tarquin Blenkinsopp wrote:

Personally I would go to Ebay and buy the cheapest, if you have
goldfish, then they could worry about the ripple :-)


http://www.discovercircuits.com/dc-m...Capacitor1.jpg

Archibald Tarquin Blenkinsopp wrote:

On Sat, 14 Apr 2018 16:00:49 +0100, "Dave Plowman (News)"
wrote:

Need some replacement reservoir caps for a power amp. Nothing special -
just 10,000uF at 63v. RS have them from about 4 quid to about 50.

Old amp so not PCB mounted - just wires to them and plenty space so not
restricted to an identical part - which isn't made now anyway.

Best make to go for? Is a 50 quid one really worth it?

No.

Go for the cheapest.

In the days before deoxygenated silver topped constant impedance pilot
lights, the only parameters to electrolytics that were of concern were
the inductance and ripple current.

A small additional cap was often added across the biggy to take care
of the first problem and the second parameter was usually stamped on
the case of a reputable cap.

The existing electrolytics probably lost performance for years before
the motor boating set in, I would be willing to bet that until crunch
time, there was little warning.

Personally I would go to Ebay and buy the cheapest, if you have
goldfish, then they could worry about the ripple :-)

If you are into gold bonded speaker cables, green CD restoring pens
and satin lined willy warmers, you may want to read up on reforming
capacitors before soldering your investments in.

AB

ESR may also be important, but not so much in a reservoir capacitor at
50Hz. This may account for some of the range in prices. Also working
temperature.


--

Roger Hayter

Not convinced, some of these el cheapo ones have a tendency to leak and dry
out.
However 50 quid sounds almost like Russ Andrews fodder.
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"Archibald Tarquin Blenkinsopp" wrote in
message ...
On Sat, 14 Apr 2018 16:00:49 +0100, "Dave Plowman (News)"
wrote:

Need some replacement reservoir caps for a power amp. Nothing special -
just 10,000uF at 63v. RS have them from about 4 quid to about 50.

Old amp so not PCB mounted - just wires to them and plenty space so not
restricted to an identical part - which isn't made now anyway.

Best make to go for? Is a 50 quid one really worth it?

No.

Go for the cheapest.

In the days before deoxygenated silver topped constant impedance pilot
lights, the only parameters to electrolytics that were of concern were
the inductance and ripple current.

A small additional cap was often added across the biggy to take care
of the first problem and the second parameter was usually stamped on
the case of a reputable cap.

The existing electrolytics probably lost performance for years before
the motor boating set in, I would be willing to bet that until crunch
time, there was little warning.

Personally I would go to Ebay and buy the cheapest, if you have
goldfish, then they could worry about the ripple :-)

If you are into gold bonded speaker cables, green CD restoring pens
and satin lined willy warmers, you may want to read up on reforming
capacitors before soldering your investments in.

AB

On Sat, 14 Apr 2018 18:26:59 +0100, (Roger Hayter)
wrote:

Archibald Tarquin Blenkinsopp wrote:

On Sat, 14 Apr 2018 16:00:49 +0100, "Dave Plowman (News)"
wrote:

Need some replacement reservoir caps for a power amp. Nothing special -
just 10,000uF at 63v. RS have them from about 4 quid to about 50.

Old amp so not PCB mounted - just wires to them and plenty space so not
restricted to an identical part - which isn't made now anyway.

Best make to go for? Is a 50 quid one really worth it?

No.

Go for the cheapest.

In the days before deoxygenated silver topped constant impedance pilot
lights, the only parameters to electrolytics that were of concern were
the inductance and ripple current.

A small additional cap was often added across the biggy to take care
of the first problem and the second parameter was usually stamped on
the case of a reputable cap.

The existing electrolytics probably lost performance for years before
the motor boating set in, I would be willing to bet that until crunch
time, there was little warning.

Personally I would go to Ebay and buy the cheapest, if you have
goldfish, then they could worry about the ripple :-)

If you are into gold bonded speaker cables, green CD restoring pens
and satin lined willy warmers, you may want to read up on reforming
capacitors before soldering your investments in.

AB

ESR may also be important, but not so much in a reservoir capacitor at
50Hz. This may account for some of the range in prices. Also working
temperature.
As I pointed out, it is normally catered for using smaller caps across
the big one.

None inductive electrolytics were available, I think the foil/
insulator was doubled and rolled from the center, these cannot have
been commonly used though, I certainly never, ever ordered one.

The reactance at the frequency of use, wasn't the problem, it was
harmonics and the other garbage that hit VCC and ground that made the
need to decouple using smaller caps necessary.


AB

On Saturday, 14 April 2018 16:07:40 UTC+1, Dave Plowman (News) wrote:
Need some replacement reservoir caps for a power amp. Nothing special -
just 10,000uF at 63v. RS have them from about 4 quid to about 50.

Old amp so not PCB mounted - just wires to them and plenty space so not
restricted to an identical part - which isn't made now anyway.

Best make to go for? Is a 50 quid one really worth it?

SMPSUS run reservoir caps hard, ESR, temp rating & life expectancy matter. But for a 50Hz psu as yours surely is, it doesn't matter at all.


NT

On Sat, 14 Apr 2018 12:06:06 -0700 (PDT), wrote:

On Saturday, 14 April 2018 16:07:40 UTC+1, Dave Plowman (News) wrote:
Need some replacement reservoir caps for a power amp. Nothing special -
just 10,000uF at 63v. RS have them from about 4 quid to about 50.

Old amp so not PCB mounted - just wires to them and plenty space so not
restricted to an identical part - which isn't made now anyway.

Best make to go for? Is a 50 quid one really worth it?

SMPSUS run reservoir caps hard, ESR, temp rating & life expectancy matter. But for a 50Hz psu as yours surely is, it doesn't matter at all.


NT
Precisely!

I would hazard a guess that a CRO would provide an interesting set of
traces, because all those little interstage coupling caps and the
decouplers across the emitter resistors will be drying out too.

Not to mention the speaker coupling electrolytics.

Mind you, he probably uses a Shure V15 for his 78's ;-)


AB

"Dave Plowman (News)" wrote in message
...
Need some replacement reservoir caps for a power amp. Nothing special -
just 10,000uF at 63v. RS have them from about 4 quid to about 50.

Old amp so not PCB mounted - just wires to them and plenty space so not
restricted to an identical part - which isn't made now anyway.

Best make to go for? Is a 50 quid one really worth it?

If you apply the RS product filters to select max temperature of 85C and
reject screw terminals, you are left with only three choices: £4.13, £4.28
and £6.15, all equally suitable.
--
Dave W

On 15/04/2018 00:19, Dave W wrote:
"Dave Plowman (News)" wrote in message
...
Need some replacement reservoir caps for a power amp. Nothing special -
just 10,000uF at 63v. RS have them from about 4 quid to about 50.

Old amp so not PCB mounted - just wires to them and plenty space so not
restricted to an identical part - which isn't made now anyway.

Best make to go for? Is a 50 quid one really worth it?

If you apply the RS product filters to select max temperature of 85C and
reject screw terminals, you are left with only three choices: £4.13, £4.28
and £6.15, all equally suitable.

Did you mean to say "reject max temperature of 85C"?

Otherwise there are some for as little as £2.40

I thought this was for resale, so a 85C would be suitable, otherwise I
would generally go for 105C if any semblance of reliability is required.

On 15/04/2018 00:43, Fredxx wrote:
On 15/04/2018 00:19, Dave W wrote:
"Dave Plowman (News)" wrote in message
...
Need some replacement reservoir caps for a power amp. Nothing special -
just 10,000uF at 63v. RS have them from about 4 quid to about 50.

Old amp so not PCB mounted - just wires to them and plenty space so not
restricted to an identical part - which isn't made now anyway.

Best make to go for? Is a 50 quid one really worth it?

If you apply the RS product filters to select max temperature of 85C and
reject screw terminals, you are left with only three choices: £4.13,
£4.28
and £6.15, all equally suitable.

Did you mean to say "reject max temperature of 85C"?

Otherwise there are some for as little as £2.40

I thought this was for resale, so a 85C would be suitable, otherwise I
would generally go for 105C if any semblance of reliability is required.

No I meant reject 105C as I see no necessity for it. I don't believe
that 85C capacitors from a reputable make lack "any semblance of
reliability".

The £2.40 ones are for bulk buys.
--
Dave W

On 15/04/2018 08:22, Dave W wrote:
On 15/04/2018 00:43, Fredxx wrote:
On 15/04/2018 00:19, Dave W wrote:
"Dave Plowman (News)" wrote in message
...
Need some replacement reservoir caps for a power amp. Nothing special -
just 10,000uF at 63v. RS have them from about 4 quid to about 50.

Old amp so not PCB mounted - just wires to them and plenty space so not
restricted to an identical part - which isn't made now anyway.

Best make to go for? Is a 50 quid one really worth it?

If you apply the RS product filters to select max temperature of 85C and
reject screw terminals, you are left with only three choices: £4.13,
£4.28
and £6.15, all equally suitable.

Did you mean to say "reject max temperature of 85C"?

Otherwise there are some for as little as £2.40

I thought this was for resale, so a 85C would be suitable, otherwise I
would generally go for 105C if any semblance of reliability is required.

No I meant reject 105C as I see no necessity for it. I don't believe
that 85C capacitors from a reputable make lack "any semblance of
reliability".

The £2.40 ones are for bulk buys.

I didn't spot some were bulk buys. I can't see an option, like DigiKey,
where you can specify the required number.

I tend to design equipment that has a long life expectancy and have only
ever been caught out in the Japanese capacitor fiasco a couple of
decades ago. As a result I would choose a 105C capacitor and one with
long hours of endurance.

If a capacitor is worked hard in a warm enclosure, I would prefer the
cap to last longer than 3 months of usage as per the ones you suggest.
Raising the operating temperature to 105C, using rules of thumb, should
mean it would last 4 times longer given the same endurance hours.

In article , Dave Plowman (News)
scribeth thus
Need some replacement reservoir caps for a power amp. Nothing special -
just 10,000uF at 63v. RS have them from about 4 quid to about 50.

Old amp so not PCB mounted - just wires to them and plenty space so not
restricted to an identical part - which isn't made now anyway.

Best make to go for? Is a 50 quid one really worth it?


What amp is it not a 405 perchance;?..
--
Tony Sayer