Threshold S 300/II Main Caps Replace

jpetek · 2nd April 2010, 03:24 PM

Hi,

I want to replace my Mallory 29.000y / 100V with other Caps.

What is the best choice? Do you heard any difference if you use a different type of Caps?

Thanks for help.

Josef

analog_sa · 2nd April 2010, 03:54 PM

No idea what is the best choice but i used Rifa PEH169 33mF/100v. At the same time also replaced the 10uF nfb decoupling polyester with a polyprop, the input jacks and binding posts with Vampire and shorted all the fuses apart from the mains fuse. Did not expect much but the improvement really startled me. It is just an amazingly good amp now. Future upgrades include a separate, possibly shunt regulated PS for the input. And of course not using a heatsink as a ground bus.

The Stasis circuit is so simple and easy that i wonder why are there no diy designs around it. As the output is a completely separate entity it will be easy to use any type of voltage amplification and also easily build a tube hybrid. Even if one retains the original input circuit there must be some possibilities to enhance its performance. Higher quality CCS are one option and probably replacing the VAS transistor with something better is another.

Sorry if this appears as threadjacking, i'll probably start a new thread devoted to improvements of the Stasis amps.

jpetek · 12th April 2010, 03:01 PM

Thanks for the Message. Do you know if I can change the Voltage from 100 V to 63V without any Problem?

regards

Josef

BrianEno · 12th April 2010, 09:03 PM

The railvoltage of the S/300 is 63 Volt. So I would take at least the next voltage range 75 or 100 Volts and buy the same casedimension. You will probably get a much higher uF value as a bonus.
Try Cornell Dubilier (They also market Mallory as a brand name) and see at resellers what's in stock. If they don't have stock in your value you have to buy at least 24 to place an order. If you buy NOS (much cheaper) you have to reform them first.

2nd April 2010, 03:24 PM	#1
jpetek diyAudio Member Join Date: Feb 2008	Threshold S 300/II Main Caps Replace Hi, I want to replace my Mallory 29.000y / 100V with other Caps. What is the best choice? Do you heard any difference if you use a different type of Caps? Thanks for help. Josef

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2nd April 2010, 03:54 PM	#2
analog_sa diyAudio Member Join Date: Aug 2002 Location: Sofia	No idea what is the best choice but i used Rifa PEH169 33mF/100v. At the same time also replaced the 10uF nfb decoupling polyester with a polyprop, the input jacks and binding posts with Vampire and shorted all the fuses apart from the mains fuse. Did not expect much but the improvement really startled me. It is just an amazingly good amp now. Future upgrades include a separate, possibly shunt regulated PS for the input. And of course not using a heatsink as a ground bus. The Stasis circuit is so simple and easy that i wonder why are there no diy designs around it. As the output is a completely separate entity it will be easy to use any type of voltage amplification and also easily build a tube hybrid. Even if one retains the original input circuit there must be some possibilities to enhance its performance. Higher quality CCS are one option and probably replacing the VAS transistor with something better is another. Sorry if this appears as threadjacking, i'll probably start a new thread devoted to improvements of the Stasis amps.

12th April 2010, 03:01 PM	#3
jpetek diyAudio Member Join Date: Feb 2008	Thanks for the Message. Do you know if I can change the Voltage from 100 V to 63V without any Problem? regards Josef

12th April 2010, 09:03 PM	#4
BrianEno diyAudio Member Join Date: Jul 2007	The railvoltage of the S/300 is 63 Volt. So I would take at least the next voltage range 75 or 100 Volts and buy the same casedimension. You will probably get a much higher uF value as a bonus. Try Cornell Dubilier (They also market Mallory as a brand name) and see at resellers what's in stock. If they don't have stock in your value you have to buy at least 24 to place an order. If you buy NOS (much cheaper) you have to reform them first.

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