Help to id the capacitors in my preamp

[Eugenehifi]

I like to recap my 20 years old preamp. However there are some capacitors I never see them before. Can someone tell me what they are so that I can get the proper replacement capacitors?

[Eugenehifi]

I mean the capacitors in orange color.

[Elvee]

Originally Posted by Eugenehifi

I mean the capacitors in orange color.

They are Al Elko's in a thermosetting case. Excellent quality, should be in pristine condition after 20years

[Jay]

1000uF/6V. It might be difficult to find a 6V cap (small size), especially at the same quality as the ROE.

[PChi]

Just adding a little detail to the post by Elvee.
They look like Siemens Aluminium Electrolytic capacitors, 1000 uF, 6 V. The parts that I have are marked with an S instead of EK.
I believe that the Siemens range became EPCOS which is now TDK EPCOS. I don't think that they list that type any more.
I have been told that they did have a nasty habit of firing the orange plastic case upwards if they were abused. Convential types fail a little less dangerously.

[Eugenehifi]

The preamp is about 25 years old and the audio sound coming out is very good and sweet. Should I still bother to replace them or not? If I should, what brand of replacement caps should I get to keep up with the high quality?

[jacco vermeulen]

Originally Posted by PChi

They look like

PChi,

they're Roederstein EK series (5mm pitch, -10% to +50% , -40C to +85C)

(yellows are Philips KS445 series polystyrene)

[sreten]

Originally Posted by Eugenehifi

The preamp is about 25 years old and the audio sound coming out is very
good and sweet. Should I still bother to replace them or not? If I should,
what brand of replacement caps should I get to keep up with the high quality?

Hi,

Replace all electrolytics with decent modern versions, which
are a lot better, and leave everything else as is capacitor wise.

Film/foil capacitors have got smaller over the years, but not better.

rgds, sreten.

[indianajo]

Your 68 nf etc are film which should not deteriorate based on time alone. The 1000 uf @ 6 and the 100 uf @ 40 have plus's on them and are patently electrolytic. Without the datasheets one doesn't know what these were sealed with, as late quality caps could have been sealed with silicon rubber (good) or epoxy (better). However, 99.99% of electrolytic caps in the equipment I have ever owned have service lives of less than 20 years, so I do not own a $150 ESR indicating electrolytic capacitor meter. I just replace the **** things based on the calander and overall lack of performance of a piece of old electronic gear, leading in most cases to better sound or performance with each cap I install. I sound check after every 2 caps to make sure I made it better and not worse.
Brand is not the best indicator of quality, as Panasonic, Nichicon, Rubicon, United Chemicon, Epcos, Illinois, Vishay Sprague and Cornell Dublier all sell short life caps lines sealed with **** to the the majority of customers that want those for replacement. I find reading the datasheets that United Chemicon and CD have worse ripple specs for their end of life specification, so I prefer to buy something else. I like sprague initial quality but nobody seems to stock long life versions of e-caps from them. So I mostly buy long life Panasonic, Rubicon, or Nichicon caps. I buy nothing under 3000 hours rated service life unless I make a mistake. Some vendors have the service life in the selector table, others make you download the datasheet to use this quality indicator.
I find lead spacing to be not very important where there is vertical room above the cap. However, in higher values you have to watch diameter and height to not exceed the amount of room you have on the PCB. Where my equipment has 3 volt or 6 volt caps I tend to install 12V or 25 V caps to limit the number of lines I have to purchase. Also some people say the higher voltage caps tend to last longer.

[jacco vermeulen]

Originally Posted by indianajo

The 1000 uf @ 6 and the 100 uf @ 40

The GPF print on the electrolytic caps is a DIN code, the EK series are switch tolerant types (what German lytic cap manufacturers commonly refer to as "schaltfest")
Capacitance of these caps doesn't deteriorate at switch-offs, comes in handy at phono board locations.
Replacements are smps suitable lytics, or if it's supposed to remain something German, a Frolyt : FROLYT Radial Lead Type

Next quiz : name the brand and model number of the amp.
(hints : ILP transformer, the steel plate shielding, and in particular the red-painted bolts/nuts/washers)