2. amps-preamps
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Help with Caps if you can

I have purchased a used Sonic Frontiers Line 3, to replace a Sunfire Classic preamp. The line 3 sounds really good in the mids to uppers but lacks bass (seems maybe a few Hz) and also punch and focus, that is compared to the Sunfire.
I have tried replacing tubes (6922) and also a different amp, and still not as much bass.
Under the hood it appears that the output caps have been upgraded to Jensen foil in oil rated at 0.33 uf.
Could the Caps be limiting or rolling the bass?
Would replacing the caps with 0.1 uf fix this problem?
Any help would be appreciated.
Thanks Dave
883dave
audioengr
3,282 posts
 
Make the coupling caps larger and use Chris Venhaus oil-cap V-caps bypassed with smaller V-cap Teflon caps. This is the closest thing to a wire that I have heard.

Steve N
Empirical Audio
Manufacturer/modder
883dave OP
50 posts
 
Thanks for all the help. I jacked in 1.0 uF caps making 1.33 uf and most, but not all the bass reappeared, then tried with 2.0 uf added, which was a little too much, so I think the correct value is 2.00 uF. Am wait for confirmation from Parts Connexion.
Also found that Jensen Oil caps sound a lot better the Solen poly caps
ecclectique
509 posts
 
Hello 883. I would take the parts connextion's recommendations straight to the bank. Chris knows the preamp's voice inside out and backwards. That said: I am a big fan of the V-caps, I use them for couplers in my Vac monos as well as the crossovers in my Tannoy Westminsters.
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