P.S. question...

rtate · 17th March 2009, 11:59 PM

Are there any disadvantages in using 1 PS cap inplace of 2??

I have an Adcom GFA-555 with old caps and I am not having much luck finding replacements at the same or slightly higher value.
Each channel uses 2 15,000uf caps rated at 80v.
I have 2 33,000uf 100v caps that I could use but I thought I read somewhere that it is better to use multiple caps for the power supply.

Opinions??

Lumba Ogir · 18th March 2009, 12:36 AM

rtate,
the outcome chiefly depends on their quality

rtate · 18th March 2009, 12:42 AM

all things being equal quality of coarse...

Ragnwald · 18th March 2009, 12:47 AM

This amp has two powersupplys sharing one transformer.
Each supply neads at least two caps, one for + and one for - rail.

lgreen · 18th March 2009, 03:38 AM

It depends on how they are connected. If in parallel it likely won't matter. Here though they are not, so you need 2 caps, one for the + supply and one for the - supply. Yours are bigger and should work.

Multiple caps are preferred because if you put multiple caps in parallel they have lower ESR (resistance) than a single cap, but that is beyond what you are dealing with here.

Lumba Ogir · 18th March 2009, 03:50 AM

tate,

Quote:

all things being equal quality of coarse...

Of course...

rtate · 18th March 2009, 10:54 AM

sorry if I wasn't clear enough...

There are 2 caps connected in parallel for each channel...
2 x15000uf for 30,000uf per channel.

I would like to use one-- 33,000uf cap for each channel...
Is there a problem with this??

Ragnwald · 18th March 2009, 11:34 AM

Quote:

Originally posted by rtate

I would like to use one-- 33,000uf cap for each channel...
Is there a problem with this??

Scroll to the bottom of the
schematic .

AndrewT · 18th March 2009, 11:40 AM

the PDF schematic clearly shows +-15mF 100V on each channel.

Is your's the same?

rtate · 18th March 2009, 02:21 PM

Mine is not the MK-II however it is the same configuration..

I have now seen the light

Please excuse my ignorance....

I now see that I do need 2 pieces for each channel...

Now if I could only find some suitable replacements that don't cost as much as I paid for the amp...

17th March 2009, 11:59 PM	#1
rtate diyAudio Member Join Date: Jan 2002 Location: Burlington, Ontario, Canada	P.S. question... Are there any disadvantages in using 1 PS cap inplace of 2?? I have an Adcom GFA-555 with old caps and I am not having much luck finding replacements at the same or slightly higher value. Each channel uses 2 15,000uf caps rated at 80v. I have 2 33,000uf 100v caps that I could use but I thought I read somewhere that it is better to use multiple caps for the power supply. Opinions??

18th March 2009, 03:38 AM	#5
lgreen diyAudio Member Join Date: May 2003 Location: San Diego, USA	need 2 It depends on how they are connected. If in parallel it likely won't matter. Here though they are not, so you need 2 caps, one for the + supply and one for the - supply. Yours are bigger and should work. Multiple caps are preferred because if you put multiple caps in parallel they have lower ESR (resistance) than a single cap, but that is beyond what you are dealing with here. __________________ My DIY audio projects- PartTimeProjects.com.

18th March 2009, 11:40 AM	#9
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	the PDF schematic clearly shows +-15mF 100V on each channel. Is your's the same? __________________ regards Andrew T.

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18th March 2009, 12:36 AM	#2
Lumba Ogir Banned Join Date: Apr 2005 Location: Stockholm	rtate, the outcome chiefly depends on their quality

18th March 2009, 12:42 AM	#3
rtate diyAudio Member Join Date: Jan 2002 Location: Burlington, Ontario, Canada	all things being equal quality of coarse...

18th March 2009, 12:47 AM	#4
Ragnwald diyAudio Member Join Date: Feb 2008 Location: Gotland	This amp has two powersupplys sharing one transformer. Each supply neads at least two caps, one for + and one for - rail.

18th March 2009, 10:54 AM	#7
rtate diyAudio Member Join Date: Jan 2002 Location: Burlington, Ontario, Canada	sorry if I wasn't clear enough... There are 2 caps connected in parallel for each channel... 2 x15000uf for 30,000uf per channel. I would like to use one-- 33,000uf cap for each channel... Is there a problem with this??

18th March 2009, 02:21 PM	#10
rtate diyAudio Member Join Date: Jan 2002 Location: Burlington, Ontario, Canada	Mine is not the MK-II however it is the same configuration.. I have now seen the light Please excuse my ignorance.... I now see that I do need 2 pieces for each channel... Now if I could only find some suitable replacements that don't cost as much as I paid for the amp...

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