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Bottlehead Kits => S.E.X. Kit => Topic started by: coca on January 17, 2011, 05:11:43 PM

Title: .1uf630V COUPLING CAPACITOR IN S.E.X. AMPLIFIER
Post by: coca on January 17, 2011, 05:11:43 PM

Good day all!  In looking at the schematic of the S.E.X. amp, there is a .1uf 630v cap that couples the first stage of the audio circut to the second stage. Can anyone tell me how critical the "quality" of that is in that position in the schematic?
Thanks in advance.

Bernie.

Title: Re: .1uf630V COUPLING CAPACITOR IN S.E.X. AMPLIFIER
Post by: dobbykins on January 17, 2011, 11:14:06 PM

In general, from what I've read and experienced, that 0.1 uF cap, and the 1.0 uF cap, are the most vital to the sound of the amp.  Changing these to any high quality audio cap should be one of the first and most beneficial mods done.  I found their contributions to be comparable to one another, and greater than changing the 1000 uF or 47 uF PS caps, or changing the bias resistor to a resistor + LED, though all of these had some measure of impact.

Of course, I am something of a newbie to all of this, but you can read my impressions about the Obbligato golds and Russian FT-3 teflons in a thread I started about caps below.

It's also a simple matter to find a number of reviews with comparisons between audio grade caps - just search for "capacitor shootout" or something similar.

Best of luck,
Guy

Title: Re: .1uf630V COUPLING CAPACITOR IN S.E.X. AMPLIFIER
Post by: corndog71 on January 18, 2011, 04:13:14 AM

Any caps in the signal path should be as high in quality as you can comfortably afford in my opinion.

I had some low cost Erse caps for the .1uF and 1uF which were a slight improvement over the stock caps.  But being the curious experimenter that I am, I ended up trying a pair of .47uF TFTF V-Caps in the .1uF spot and Clarity Cap ESA 1uF for the output caps.  I also swapped out the output wiring with Homegrownaudio cotton-insulated pure silver wire.  The last thing I did was add the C4S boards.  

My Sex Amp is now the best sounding amp I have!  It seriously sounds better than some multi-thousand dollar gear I've heard over the years.  It even makes my $25 Philips ear buds sound fantastic.  I've fallen asleep to this amp several times - it's just so darn seductive.  I have to tear myself away from it!

While the V-Caps are expensive, the ESA Clarity Caps are reasonably priced and still sound terrific.  Just give them around 100-200 hours to sound their best.

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi576.photobucket.com%2Falbums%2Fss207%2Fcorndog642%2FBottlehead%2520Sex%2520Amp%2Fe21d80c3.jpg&hash=32d4c75e088d203c5b9e9eb5b27069ae9b4cca67)

Title: Re: .1uf630V COUPLING CAPACITOR IN S.E.X. AMPLIFIER
Post by: Maxwell_E on January 18, 2011, 04:45:41 AM

I agree with Rob, I have ESA Clarity Caps and the C4S boards and I couldn't be happier.