2. amps-preamps
  3. 1120164146

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

Showing 1 response by herman

herman
2,212 posts
 
Jeffrey is right that going to a .1 will only make it worse. The impedance of a .33uF cap is 24,000 ohms at 20Hz. That means even with a relatively high amp input impedance of 100,000 ohms the response will be down about 2dB at 20Hz. That's quite a bit. It will be worse if the input impedance of your amp is lower.

That compares to only about - .3dB for a 2.2 uF cap.

I think your caps are too small if those are the output caps. Are you sure they aren't the caps between stages?
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