CapacitorsReplacing the old with the new. What is acceptable?

[naimgame]

I am faced with replacing some old power smoothing capacitors in a Marantz Model 15 power amplifier, the problem is that the caps are 5450uf@ 50v. The vendor I have contacted has stated that using a 7200uf cap@50v is ok, is this true? safe? as I am doubtful. Also I am looking for two values in axial format 350uf@50v, and 250uf @80v, are there any audiophile grade caps out there? Thanks everyone for your views and help/opinions. Jeff

[tool49]

I'm not so knowledgeable about the Marantz model, but the specs you quote for the replacement part seem ok. As for the "audiophile" grade, I would not worry too much about it, these values are big so they are EDIT: NOT likely to be in the signal path. You can go for above regular brands and will probably get good results.

Sébastien

[Jay]

Small difference in uF (capacitance) is not a problem (in this situation), just keep 50V as the minimum.

Audiophile caps, why it has to be axial? Black Gate is considered audiphile caps IMHO and the standard version has 220uF/50v and 330/50v (the difference must be ok). AFAIK they don't produce the standard version anymore, so you may get them at cheap, or you can hardly find them.

[boholm]

Originally posted by tool49
I would not worry too much about it, these values are big so they are EDIT: NOT likely to be in the signal path.

But they always are, alas.

BTW: Look at this: http://diyparadise.com/cap/dare_to_compare.html

[subwo1]

You may like to look at the option of 63v caps as well.

[priscared]

u should be able to find some alcheapo replacements of this size on ebay, standard size.
Daniel

[naimgame]

I thank everyone who has taken the time to read and also reply to my post; I have in fact taken into consideration the use of a 63v cap as a replacement however the question remains-when going up in uf what is considered safe/wise given the existing equipment(stock). The Marantz equipment is very high performance ( model 15-/model 7t ) and the cap therefore has to be audiophile grade. No matter where inside the amplifier a change of any kind is audible given the euipment. I am primarily concerned that going to a 7200uf cap@50v is perhaps dangerous to the rest of the amp given the original being 5450uf@50v. How high can you go witht he solid stae? Thank You! Jeff

[jcarr]

If I am not mistaken, Marantz's Model 15 was an amazing design for its day - particularly the output stage. I haven't tried to tweak one, but analyzing the design concepts, I suspect that with some judicious component replacements and alterations of operating points, it could be made to sound quite nice indeed. An underrated design that is well worth taking care of, IMHO.

hth, jonathan carr

[john curl]

It should not matter that you use a bigger cap. Bigger capacitance is better. I had the mono version of this design in 1969. I went back to designing my own power amps after owning this design. Measured well, however.

[naimgame]

Essentially what I am wondering is, is there a limit or rule to follow when installing new capacitors. What is unsafe? Thanks! Jeff