Threshold S/300

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Good morning all,

I am brand new to this forum and am pleased to be able to confer with so many intelligent and great people. In particular, I am pleased to meet so many individuals who don't mind sharing.

I purchased a Threshold S/300 not long ago which appears to be in really great shape. As a matter of fact, the gentleman (previous owner) would not ship the amp but delivered it from Philidelphia which I throught was great. I have had no problems with the amp and am pleased with the great sound.

I had heard that some high powered amps have troubles with their turn on/off switches after a while so I use a high grade power strip for this purpose.

All this the long way round to ask, how can I tell if the large caps in the power supply have been upgraded? What would I look for? Otherwise, I will send the amp off to Jon Solderburg in CA. Actually, I hate to send this heavy amp all the way there. However, I don't know of a repair place or person with Jon's rep and experience here on the east coast.

Finally, is there anyone on this forum still using this fine power amp in their music system? I would appreciate all input. Thank you all for your time and responses.

Bob :)
The one and only
Joined 2001
Paid Member
You can run the amp until it gets noisy, and then you'll know.

The original capacitors are likely blue Mallory, and I don't think
they are still available. In any case, replacing the caps with
like type is not a problem. If you can purchase some of the
same size, similar value and same or higher voltage, you
should be able to do it locally, as it's just a mechanical

I do know a guy in NYC (email me), or you can ship it off to Jon.

I to, am in the same situation, just purchased a S300. In fact I don't even have the amp yet and am already looking to update. I was told you could change out the main power caps with a slighty higher uf and higher voltage and still be safe. Is this true, I am new to this type of DIY , but trying to learn. By the way what is the orginal value of the main caps in the S300
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.