Removed Sonicap bypass caps from SDA's

Stew

I just removed the 0.1 uF Sonicap GenII bypass caps from my SDA 2B-TL's and I like what I'm hearing - or rather what I'm not hearing.

When I upgraded my crossovers several years ago, I had all solid state equipment and a smaller room that was less bright and more bass heavy than our new basement. Jeff at Sonicraft recommended the bypass caps for a solid state system but said it may sound better without them in a tube system. I tried it with and without the bypasses and preferred them for that system in that room.

Since then I've added a tube buffer and moved to a new house with a much more reflective basement. I built some acoustic panels for the top corners and they help a great deal. The SDA's still sounded annoyingly bright at times though.

I finally took F1 and Raife's advice and removed the bypasses. In hindsight, I should have done so when I added the tube buffer. The detail is all still there but it sounds more natural. I'm also noticing that I can play them considerably louder without fatigue now.

ben62670

Glad to hear you are liking what you hear. I did away with the bypass in all my Polk's;)

schwarcw

Thanks for sharing your experience Stew!

nspindel

I've Sonicap'ed two pairs of SDA's so far, neither with bypass caps. I'm definitely not feeling like I'm missing anything. I should mention that I run a tube preamp.

Ricardo

Good stuff. My CRS+ have around 40 hours with their new Sonicaps, no bypass, no polyswitches. Sounding gooooood.

zingo

Ricardo wrote: »

Good stuff. My CRS+ have around 40 hours with their new Sonicaps, no bypass, no polyswitches. Sounding gooooood.

I have that combination too, plus RDO-TL, and it does sound goooooood. I'm glad you dropped the bypass Stew.

Stew

Ricardo and Zingo - Agreed! My 2B's are running the TL mod with RD0198-1's, Sonicaps, no bypasses, no polyswitch. I still had the polyswitches in when I first removed the bypass. The sound was more natural but I missed some of the sparkle and detail. Removing the polyswitch brought back the sparkle and detail yet retained the more natural sound. Mids and highs just sound more real now. I've had that "you are there" sound with female voices since I did the TL modification but male voice were never quite right. They are now! Cymbals etc. were kind of "in your face" with the bypass caps but now they're in proper perspective.

On a side note, I measured before I removed the polyswitches and the resistance was only about 0.2 to 0.3 ohms. I doubt that's enough to make much of a difference so there must be another reason. I'm not sure what they're made of but they do muffle the sound. I've only tripped the polyswitches one or two times in their 19 year existence and that was about 19 years ago with a lesser amplifier. I'm not too worried about removing them.

zingo

I removed the polys in my 4.1TLs and Monitor 5Jrs and liked the results of both. I realized that I'm not going to blow up my speakers with an under powered amp or turning it up too loud, so why have another component in the signal path? Thanks for the poly info and enjoy the listening.

Polk_Art

Stew, I just bought a pair of SDA-2Bs and I been reading a number of posts regarding upgrading the tweeters & crossovers. I read a post of yours from a few years ago stating you were going to use a combination of Solen & Sonicap capacitors in the crossovers. Could you tell me how that worked out for you? Going will all Sonicaps is a costly proposition and will nearly double the cost of the upgrade and cost as much as I paid for the speakers. Did you also replace the resistors? Thx in advance.

NJPOLKER

I know I'm not Stew!!
Use Sonic Caps in the high pass and Solens/Aeons/Daytons for the low pass. The high pass is critical and the low pass is not as critical. Buy Mills resistors, they are around $3.00 each so no worries there. Existing chassis wire is satisfactory.

Oh yeah Welcome to Club Polk

NJPOLKER

I always forget something.
Do a forum search because you should find a lot of great info and pictures on the re-build. You may want to consider the TL upgrade as well.

fbm211

You might be better off going with 1% daytons available at parts express.I went with those and mundorf resistors.I didnt think I was qualified yet to do the soldering so I sent them to ben to recap.He did a great job and my 2Bs sound much better.Total cost was less than 100.00.I added some deoxit gold to the order to get the free shipping at PE.The mundorf resistors were about 7.00 from madisound.Here is a link...And you should replace the resistors too.>>http://www.madisound.com/catalog/product_info.php?manufacturers_id=142&products_id=8414

fbm211

fbm211 wrote: »

You might be better off going with 1% daytons available at parts express.I went with those and mundorf resistors.I didnt think I was qualified yet to do the soldering so I sent them to ben to recap.He did a great job and my 2Bs sound much better.Total cost was less than 100.00.I added some deoxit gold to the order to get the free shipping at PE.The mundorf resistors were about 7.00 total for both (and shipping) from madisound.Here is a link...And you should replace the resistors too.>>http://www.madisound.com/catalog/product_info.php?manufacturers_id=142&products_id=8414

Daytons on the low and sonicaps on the high pass.