Bottlehead Forum

Bottlehead Kits => Legacy Kit Products => Topic started by: RPMac on February 09, 2011, 04:33:42 AM

Title: Parabee parafeed cap?
Post by: RPMac on February 09, 2011, 04:33:42 AM

I have check this and the old forum for recommended value for the parafeed cap in the parabee and could find none. Stock is a 3.3 uf Solen...iron is TFA-2004 Ni and EXO-03 plate choke...JJ 300B. I have some 10uf Obbligato caps and 3.3uf Jensen caps. Recommendations?

Title: Re: Parabee parafeed cap?
Post by: Paul Joppa on February 09, 2011, 09:56:47 AM

My measurements - some years ago - indicated the EXO-03 has plenty of inductance, more than the rating. So I would go with the 10uF - I calculated 8.9uF, with a range of 5 to 20 being acceptable.

Title: Re: Parabee parafeed cap?
Post by: RPMac on February 09, 2011, 10:16:08 AM

Thanks, Paul...that's what you recommeneded with my paraglows, but didn't know if the different OPT changed things.

Title: Re: Parabee parafeed cap?
Post by: AudioDave on February 10, 2011, 01:16:28 PM

I still have the 3.3 uF caps in my Parabees and would like to upgrade to the 10 uF 630V caps.  Does anyone have a preference as to brand and where to buy?  I did some checking and it doesn't appear that Auricaps come that large.  I know Parts Connexion has a good selection.  Anywhere else I should shop?
Thanks!
Dave

Title: Re: Parabee parafeed cap?
Post by: 2wo on February 10, 2011, 06:01:25 PM

The Obbligato caps, from DIYHIFI or Parts connection, sound great as parafeed caps. Auracaps are a perennial favorite. I prefer the Obbligatos...John   

Title: Re: Parabee parafeed cap?
Post by: RPMac on February 11, 2011, 04:46:35 AM

I'm not Granger, but I like Obbligato ;>D

I think Obbligatos and Auricaps are similar in that they both bring out 'detail'. I think both are caps you can't go wrong with using.

For ref.>>>squeezebox(apple lossless format)>FP III w/ OB 2.2uf(non-extended...yet)> Parabee w/ Auri coupling and OB parafeed caps...JJ 300b> Klipsch Hersey II w/ Auri's in crossover. Except for the cap changes, everything else stock.

With the 3.3uf Solens, the sound was nice and out in front of the speaker.
With the 10uf OBs, the sound stage became deeper, more bass(cut back on my subs in Sexy speaker arrangement), more detail.
The parafeed cap is between the plate/choke and OPT. I also returned the bottom of the OPT to the cathode(hum pot center terminal) instead of grd.

Title: Re: Parabee parafeed cap?
Post by: AudioDave on February 12, 2011, 03:57:46 AM

Thanks for the recommendation,  Obbligatos it is!  You said that you returned the bottom of the OPT to the hum pot center terminal instead of ground.  What does that do and why is it recommended?
Thanks,  Dave 

Title: Re: Parabee parafeed cap?
Post by: RPMac on February 12, 2011, 04:23:31 AM

Quote from: AudioDave on February 12, 2011, 03:57:46 AM

Thanks for the recommendation,  Obbligatos it is!  You said that you returned the bottom of the OPT to the hum pot center terminal instead of ground.  What does that do and why is it recommended?
Thanks,  Dave 

This is something Paul recommended. As I understand it, it takes artifacts from the cathode bypass cap out of the signal loop. PJ can correct me if I'm wrong and, of course, do a much better job of explaining.

I bought my OB caps from DIYHiFiSupply and there are more 'flavors' now. I don't think they will disappoint.