Author Topic: Bypassing PSU caps  (Read 2557 times)

Offline ozcal

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Bypassing PSU caps
« on: October 29, 2010, 02:30:12 PM »
Hi guys , my Supratek has a large 10000uf cap in the psu. I have read that bypassing this with a 2.2uf film cap may improve hf performance.
What are your thoughts on using bypass caps?
I have a 2.2uf Obligatto film cap I can use.
Gordon
Listening with my ears :)

tuyen

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Re: Bypassing PSU caps
« Reply #1 on: October 29, 2010, 05:47:30 PM »
Give it a go Gordon and let us know how it is.

I've tried some Jensen copper 0.01uf bypass caps on my 220uF Jensens in the powersupply for the dac.

Added more air and highs in the sound, but took away some body in the mids too.  It was exciting at first, but after I while I realised I preferred having more texture and body in the midrange so I removed them. :)


Offline ozcal

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Re: Bypassing PSU caps
« Reply #2 on: October 29, 2010, 07:36:44 PM »
Ta T,.
Tried it this arvo , sound has more weight and solidity in the mids but the upper mid and treble is thinned and the bass is now boomy.
I don't think I like the Nichicon FG ST so I might try putting the original cap back in until I can afford a 10 000UF Jensen to compare.
Gordon
Listening with my ears :)

tuyen

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Re: Bypassing PSU caps
« Reply #3 on: October 29, 2010, 07:49:42 PM »
Try different values mate. 0.1uf  and 0.01uf :)

I can lend you some vintage 0.01uf  jensens next time  :)

Offline stevenvalve

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Re: Bypassing PSU caps
« Reply #4 on: October 29, 2010, 11:05:33 PM »
Hi guys , my Supratek has a large 10000uf cap in the psu. I have read that bypassing this with a 2.2uf film cap may improve hf performance.
What are your thoughts on using bypass caps?
I have a 2.2uf Obligatto film cap I can use.
Gordon
I have never liked bypass caps. In the old days when caps where slow and rolled off it was Ok. gives the sound a high frequency boost almost peaky. The best of todays caps don't need it.
« Last Edit: October 30, 2010, 12:43:32 PM by stevenvalve »

tuyen

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Re: Bypassing PSU caps
« Reply #5 on: October 30, 2010, 09:47:28 AM »
Mirrors my experiences (very limited though compared to gurus like Steve)..  as now I remember I also tried bypassing the 4x 500uF jensens in my valve power amp with 0.01uf jensens and boosted treble response up   and detracted the balance of the low-mid range.    Some people might enjoy that sound though.. very 'airy'.

Although in saying that, using a bypass caps may be good when the base cap is of average quality and you bypass it with a decent quality cap. The qualities of the bypass cap could possibly work in favour of the base cap.   Never know if you never give it a go!

Offline ozcal

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Re: Bypassing PSU caps
« Reply #6 on: October 30, 2010, 04:56:34 PM »
Put the original cap back in ,without bypass , and removed the Nichicon , much more coherent and fun to listen to.
The other caps are Jensen electro and obbligato film in oil and the combination sounds great  and better than the all original cap config.
I will get another Jensen to try replacing the single remaining original cap and see how that goes.
Thanks for all the help guys.
Gordon
Listening with my ears :)

Offline zenelectro

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Re: Bypassing PSU caps
« Reply #7 on: October 30, 2010, 10:59:02 PM »
Hi guys , my Supratek has a large 10000uf cap in the psu. I have read that bypassing this with a 2.2uf film cap may improve hf performance.
What are your thoughts on using bypass caps?
I have a 2.2uf Obligatto film cap I can use.
Gordon

Bypassing electro with film cap creates a tank circuit that peaks at some very high frequency.
As SV says - not a good idea.

If the original cap needs bypassing, change the original cap or try using a small resistor in series
with the bypass cap, say 1 to 5 ohms to damp it.

Terry