Parafeed cap value experiences

[Alonzo]

So I've been climbing the value ladder on parafeed caps in my amps.  Searching the old posts didn't yield much info on high values so I'm asking everyone to pitch in there experience for those who come along behind us (and to help me in the next steps).

I've worked my way up to 30uF Obligatto Oilers in the Stereomour 2A3.  Lots of bass in my full range horns, still got 50 hours or so to finish break in.  This amp went from 4.7 to 8, to 10, to 15 now at 30.  Haven't lost any midrange at all, just more fullness in the bass, more depth as I've went up the ladder.  Some of the brightness (well that's my description, probably I lost some of the upper registers of treble) has decreased.  That's not an issue for me for this amp because I have a separate amp for the highs.  Oh, my Opts are 3K with Dowdy (125H) plate chokes.  If these don't do something drastically bad in the next month or so I'll upgrade to Supremes.

On the tweeter amp, I'm at 15uF Mundorf in a Stereomour 45 (Dowdy and 5K Opts).  It started way down at .068 uF and has been changed slowly up.  This one is still a experiment, I'm going to let this play awhile longer to break in the caps and then go lower and add/remove caps on the speakers.  I was happy at 4.7 but I can't say that the sound is bad now, just more midrange than before.

Up to 22uF now in the Mainline.  As these break in they get better and better.  Went from 3.3 to 4.7 to 10 to 18's in and upgraded to a better cap at 22.  Seems perfect for HD-800's and TL-404's.

What cap value is the sweet spot for your system?

[tsingle999]

Thats really interesting! I just did a bit of that with the sr-45's. Tried 3.3 4.7 and 6.8. There was just subtle improvements in the bass as you went up the range. I tried to strap the 3 and 6 together but it sounded terrible.

[Paul Joppa]

Just a caution here - don't over-interpret what you hear. The effect will depend on the speaker's impedance curve, so results are not easily extrapolated to a different speaker or amp.

Headphones are usually less extreme in their bass impedance variations, but those variations are usually still there so the same caution applies.

[Alonzo]

Ok Paul, I'll try to keep a calm and scientific demeanor .  I realize this is totally system dependent.  I'm not measuring anything but just going on hearing, I have a couple of tracks that I've heard live and I try to compare the amps to the sound and feeling that I remember.  I know it's very fallible since I'm going on memory and that is "rose colored" at best.  So I may be masking a loss area with over emphasis in another.

I think a good experiment would be to see how far my enjoyable sound is from a good response curve. Everyone seems to have settled on the standard values of caps, I just want to see if anyone ventured out and what happened when they did.  I like my horns more now, put the sub in the garage because I have enough bass.  If I can experiment and get my tweeters the same I can move on to some other money pit like speaker wires or interconnects