New caps for my phono stage

[colinB]

Hi everyone, im very intregued by a mod on offer from Icon Audio for their Ps1 phono stage which i own.
They can replace the polypropelane caps for JENSEN oil paper caps at a cost of £200. Now im not that knowledgeable about electronics but i can use a soldering iron and im thinking about having a go myself.
If anyone has an opinion or advice on the matter before i blow up the amp or myself id appreciate it.

[Ali Tait]

If you are happy working on the amp you could save yourself a lot of money.Bear in mind that valve equipment has dangerous voltages in it.

I think the change from polypropylene to paper in oil will be a difference rather than a wholesale improvement,the two types of cap giving quite different sonic flavours.I'd suggest trying these-

http://www.hificollective.co.uk/components/claritycap_esa.html

They are very good for not much wonga,and will likely be a good step up from what's already in there.

[colinB]

Thanks for that Ali ( noticed your from my home town ) the prices on those claritys are cheap as chips , a tenth of the price of jensens. On the issue of safety, the amp is point to point wiring and the big 1uf supply caps are buried deep inside and not easily accessible.
Is it just a case of sniping the cable making sure the - and + dont short or is it a bit more involved than that?

[Dave Hewitt]

Hi
Hifi collective are selling off Jensen pio for 4 quid each.
Regards Dave.

[colinB]

mazing prices. Unfortunately the values are to low. I need 1.0 uf and 0.1 uf , all 630v

[Ali Tait]

Some folk don't like pio's in any case.If you like the sound as it is but just want more,try the clarity caps.

[colinB]

I have read that jensens can leak over time which doesnt sound to good.
Im still unsure as to safety when handling caps. Ive seen 200v caps bridged with a screwdriver and it was pretty scarey!

[Ali Tait]

Use a resistor with leads attached and croc clips at the ends to drain the caps.

[colinB]

Im guessing a descent sized resistor with one clip on the hot lead and the other on a good earth?

[Ali Tait]

Just connect across both terminals of the cap.Use insulated croc clips.

[colinB]

Cheers, if im still alive ill post my findings

[Ali Tait]

Good practice is to keep one hand in your pocket while doing stuff like this.Stops any shock you may get from passing across your chest.

[goraman]

A good substitute for Jensens is this one.They come in different values and are not to expencive.
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=027-700

I used to like a cap called ALCAP if you can find some if space becomes an issue.
They tend to out last the Jensens and sound great doing it.
Paper in oil are a great choice and can be found on ebay mostly from the Ukraine and Russia.http://www.pedalhackermods.com/servlet/the-Russian-Mil-Spec-PIO-Capacitors/Categories

Also look here if you need something small that sounds good.http://www2.cricklewoodelectronics.com/Cricklewood/home.php?printable=Y&cat=139&sort=productcode&sort_direction=0

If room is not an issue.
http://www.madisound.com/manufacturers/mundorf/capacitors.php

[dowser]

Good practice is to keep one hand in your pocket while doing stuff like this.Stops any shock you may get from passing across your chest.

Left hand in pocket, not right hand - shock to your left hand will see the current through your heart...

Richard

[Ali Tait]

Nope,what you don't want is the current passing from one hand to the other and going across your chest.Either hand in your pocket will prevent this.It's an old wives tale about the left hand.A shock to either will kill you just as dead!

[dowser]

Thanks - it was passed to me by my physics teacher at school. To be honest I have received mains burns on both hands and TV EHT belts to both hands/arms and am still here to tell the tale.

Although EHT arcing to my sweaty forehead while trying to diagnose a TV in the field was probably my worst experience - I scared the customer as much as myself when I knocked the TV off it's stand from the shock. A definite uplift to workshop :)

Richard

[Ali Tait]

Ouch! worst that happened to me was being thrown off a pair of step ladders by some 240.That didn't hurt as much as hitting the floor did!

[leo]

I used to repair TV's, I learned the hard way to make sure the thing had discharged before probing around inside after it had been unplugged.
Also had a few good belts off some of the old big valve PA amps at one of the service departments I worked at :lol:

[Marco]

They say it's good for your heart!!

...If not your hairstyle :lol:

Marco.

[dowser]

You definitely get used to it, and feel energised after you have recovered from initial shock (I was [badly] hung over when I got the EHT blast to the forehead, those kV worked better than tomato juice and egg as a cure...) - I remember my local doctors surgery when I was a kid had a wind up machine that you dropped a coin, turned the brass handle while holding the other and it delivered a shock to you...that you paid for :D

I used to discharge EHT before working on the damned things, but diagnosing needed to be done live. I hated TVs, trained in a video manufacturing factory where the only danger was a slight buzz if you rested your arm over the (45v?) fluorescent display pins, and a quick retraction if over the mains wires at the back of PSU (JVC/Ferguson late 80s models for those in the trade - dangerous buggers) - I then moved to the repair company for Lasky's, and suddenly had to repair these things people watched and learned quickly they had nasty surprises once you had removed the back cover! Was the same story with smoothing caps in SMPSs - I knew nothing when I first started working on them, I still have a few burn scars on the back of my fingers that represent my learning ;)

Ali - I sympathise; but at least it was only step ladders, LOL!

Richard

[Ali Tait]

:)