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August 24, 2019, 04:48:38 AM

Author Topic: Upgraded Output Capacitors  (Read 719 times)

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Offline brightcity

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Upgraded Output Capacitors
« on: January 20, 2018, 09:23:12 AM »
Hello, I have recently upgraded the output capacitors in my Quicksand to 4700uF 35V Nichicon Gold Tune bypassed with 1MOhm 2W carbon film resistors. The difference is night and day. Bass is more impactful as well along with notes end when they are supposed to.

The Quickie can really overdrive it now!!
« Last Edit: January 20, 2018, 09:28:55 AM by brightcity »

Offline Paul Birkeland

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Re: Upgraded Output Capacitors
« Reply #1 on: January 22, 2018, 06:26:27 AM »
Putting resistors across the output capacitors is not a great idea, I would suggest removing them to prevent any unpredictable damage.  You're also putting a standing DC current across the inductors at the output; this is a detriment to performance.

The capacitor and inductor in the output stage of the Quicksand form a tuned filter.  Changing the value of the cap changes the value of the filter (also not necessarily a great plan).

The Nichicon KA capacitors that we provide with the kit are their current state of the art capacitor purpose made for audio.  The Gold Tune (KG) caps are an older design and less expensive than what we already provide. 

Changing the 1uF caps at the input is, however, a good mod to do to the circuit.  One can put a wire jumper in where the current 1uF caps are and place 1uF film caps between the center solder wells of each RCA jack and the PC board input.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline brightcity

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Re: Upgraded Output Capacitors
« Reply #2 on: January 25, 2018, 12:13:57 PM »
Thanks, I will definitely be doing the input mod. Edit: This is a significant mod. Much more clarity, I really did like the FW on the input though. Gave it a bodied sound.

Good to know about the resistors, I will keep them as I prefer the sound and don't mind damaging my 30 dollar pair of bookshelf speakers. Also prefer KG over KA but that's just personal preference.

Also put a 0.47uF film cap on between Vcc and Gnd. Also placed 0.47uF caps to bypass the output coupling caps.
« Last Edit: January 27, 2018, 11:55:25 AM by brightcity »

Offline brightcity

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Re: Upgraded Output Capacitors
« Reply #3 on: January 25, 2018, 12:30:29 PM »
Replaced the inductors for a 47uH toroidal inductor. It did not help the hash noise yet it did make midbass more present. I like the note so I'm going to keep them in.