What Input cap for amp3

I don't know which input cap to choose for the amp3, as Jan himself seems undecided and provided us choice of ceramic and electrolytic.
Based on you experience which one should I choose?
Or should I go for another electro like BG or polyster or polypro.
Jan also suggested 0.1uf parallel for the input to improve HF. Has anyone tried this to good results.
I have read somewhere that electro should not be used as input cap, same with ceramic. What should I do then?
Thanks.
 

BWRX

diyAudio Moderator Emeritus
2005-01-17 5:29 am
Pennsylvania
i used the 2.2uF ceramic and have no complaints regarding the sound. i haven't tried the electrolytic and don't plan to :)

a lot of people have tried other caps. i think i remember reading about it in some pretty recent threads too. i would look for them but i'm off to finish up recasing my amp3!
 
AMP3 caps

So far I've tried the supplied ceramic, a 2.2uf tantalum, a russian 1.5uF PIO and now have a 4.7uf Taurus polypro bypasses with a .33uF Vitamin Q. All I can say is there are many options. The PIO bypasses I recently installed added a bit of body and took away a bit of the plastic sound of the polypro caps.....it's a nice mix of smooth, detailed sound that has great bass.

Here's a pix inside my Amp3 just before adding in the VitQ bypasses.

BTW, I love the sound of this thing. It really gets my toes a tappin'.
 

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TommyTube,
Wow, I'ver never even heard about the caps you are mentioning.
... on the other side I'm a noob so maybe this explains that.
They must be pretty rare and/or expensive exotic caps. Where you get these? I'm pretty impressed with the parts you used inside your amp. What's that big black cap?
Anyone using the more common Black Gates (?!) or anything, who thinks its worth the cost compared to the supplied ceramic?
 
cap choices

Most of the ones I mentioned are on ebay commonly. The green PIO russians are around a lot. I bought a dozen of the lesser known Tauras polypros from a guy in England off ebay. Never heard of them either and wanted to try them. Very cheap in price, pretty good sonics.

BG's some like for coupling, I believe there are better choices. But most of the choices I like won't fit on the board so you need to put these off board. I put the input coupling caps directly on the input RCA's and then wire the output onto the Amp3 board at the normal input. Just jumper over the caps on the board so the signal gets into the SMD resistor and onto the tripath's input.

The large black cap is part of my capacitor board in the power supply. Jan mentions using up to 20,000uF capacitance for a 12V SLA battery supply. I just put a bunch of Nichicon Muse KZ's in parallel as well as the big black one (a larger value Solen), these are all between the +12V input and ground. I used both polypros and electrolytics on the cap board to try and get the benefits from both types of caps.

If you wanted a good quality input coupling caps, I'd go either plastic/polypro type or paper in oil. Getting a large enough PIO is not as easy as finding a larger plastic caps. Use Audience, Relcaps, Kimber, Cardas, Sonic....all these are commonly available and nice caps. What you need to realize is many of the best couplers are rated much higher than 50V and but can still be used in your amp.

If you want a path of least resistance, get the audience and try that. Most love it's sound and it's price is reasonble....but good poly's are still at least 5 to 15 dollars a piece. Some much more.

Have fun with it. Ebay is a good source of many exotic caps...especially if you don't mind dealing with the Ukrainian guys.