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Old 8th December 2006, 07:11 AM   #1
aroS3 is offline aroS3  Greece
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Unhappy New Jensen caps has no bass in..Simple EL84PP

I changed recently in my Simple EL84 PP the SCR 0.22uF MKP coupling caps to Jensen 0.22uF copper foil - paper in oil ones.
I was hoping for a total better image and reproduction. Instead of this the bass became week and rolled off. The only improvement is the mids which are more warm and maybe a slight better image.
The amp has already 60 hours run in time with the new caps and the result remains the same.
As for the driver or the output circuit no other change is made. I'm using EL84 in triode mode as a driver while using the Yeo's CCS circuit in the output stage.
The amp in the previus stage with the SCR caps was outstanding.
Any idea why the Jensens performed worse than the MKP 's ?
Thanks
George
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Old 8th December 2006, 07:28 AM   #2
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While i have no experience with Jensen caps there may be many reasons for your disappointment. You probably achieved a better synergy in you system using the SCR caps. So, what if they're cheaper?

Oil caps always sound a bit overdamped to my ears and while in some systems it means 'tight bass' in yours it doesn't seem to work.

IMO boutique components are often difficult to use. You may have to replace other caps or resistors in order to return the synergy.
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Old 8th December 2006, 01:54 PM   #3
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200hours minimum run in time needed. Hope nothing else gone wrong when replacing the caps. IMHO, They're excellent caps as I swear by them in my DIY Mullard 5-20 and Leak TL12+. They did not sound right somewhat sluggish and veiled when new. Be patient please.
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Old 8th December 2006, 03:56 PM   #4
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I have always wondered if break-in improves the sound or if my ears just get used to the changed sound. I am not questioning the value of quality components. Rather, after years of playing in bands, do my ears have the sensitivity to really tell a difference. Maybe someone should offer pre-burned in parts.

Kevin
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Old 8th December 2006, 04:11 PM   #5
rdf is offline rdf  Canada
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Have you checked for DC leakage? I vaguely recall a discussion about defective Jensens. Worth metering.
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Old 8th December 2006, 04:29 PM   #6
Zibi is offline Zibi  Poland
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Polypropylene is better dielectric than paper in oil or beeswax.
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