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Other Stuff => Archived Manufacturer Circles => Ellis Audio => Topic started by: David Ellis on 26 Apr 2007, 10:35 am

Title: .1uf bypass testing and the 1801C
Post by: David Ellis on 26 Apr 2007, 10:35 am
These comments will cover a recent experiment I performed with .1uf bypass capacitors in the 1801C.  I do realize this commentary may be controversial, and I certainly do accept there will be some naysayer's.  I was certainly a member of this group until this test was accomplished.  Hence, I am compelled to offer my comments.  The first point that needs to be addressed is the 1801C.  I will then describe the testing arrangement, provide a summary of the results, and specific comments regarding the capacitors.

The 1801C is a 2-way speaker in development using the Accuton C95 and the OW1.  The initial results are very favorable, and this product will eventually be found on my web page.  The typology of the crossover is similar to the 1801 and several other designs using a 7" stiff cone midwoofer.  The crossover components included Goertz 14ga Inductors (in series), plain air-core inductors in parallel, Sonicap Gen I capacitors, and Mills Resistors.  The test box for the 1801C used in the bypass experiment was & is quite crude.  It's simple plywood with an MDF baffle.  It doesn't have significant mass, and the cabinet was placed on a non-spiked stand during testing.  Nonetheless, the 1801C performed admirably when compared to the 1801B and the ACI Jaguar in the system used for testing.  Despite the humble cabinet, the 1801C sounded very good.  After completion, the 1801C will easily displace the 1801B in my home.

The source gear used was extremely good.  The amplifier was a 60wpc Atma-Sphere unit, and the other associated pieces were commensurate.  This is Ralph's system, and Ralph was the test-subject. 

I presented 4 pairs of .1uf bypass capacitors for testing.  Each capacitor was covered with Blue Masking tape to conceal it's identity.  Ralph isn't keen on the various flavors of capacitors, and did NOT know what flavor capacitor was being tested.

Ralph preferred a slightly older female vocal track for testing.  He was very familiar with this track.

I installed/inserted the coupling capacitors into the circuit using copper alligator clips.  I clamped the bypass and primary capacitor wires together to make a connection. 

I was very careful not to prompt Ralph or create any bias. He didn't touch or handle the capacitors prior to testing.  He didn't know what capacitors were being tested.  I did not present the capacitors in hierarchical manner.  Hence, the most expensive capacitor was not tested last, and the least expensive capacitor was not tested first.  I did my very best to ensure that Ralph didn't know what was being tested.  I was only interested in his comments.

There were 4 bypass capacitors tested.  I will first provide a summary of the findings, and then describe their individual sonic character.

Overall, I was extremely surprised at the impact of the .1uf bypass capacitors.  I really thought the impact would be very mild and that Ralph would have to spend hours with the capacitors to discern a very mild difference.  This wasn't the case.  The impact was immediate and obvious.  Subjectively, the impact was less significant than bypass capacitors in coupling circuits, but only because the region of impact for this test was the tweeter.  In this regard, the sonic impact was prevalent.  I didn't expect this, but it did happen.

Sonicap Gen1 – I don't recommend this.  The impact was extremely detailed, but quite harsh and not very pleasant.  As a bypass capacitor it provided a very clear example of why folks don't like using bypass capacitors in the signal path.  It just sounded wrong.

Sonicap Gen2 – This was quite pleasant, and much better overall.  The impact was slightly more detailed, while remaining reasonable harmonic character in the tweeter.  However, it created a sonic separation between the tweeter and woofer, that some folks may not deem desirable.  The cost of these capacitors is very minimal.  As such, experimentation purchasing them for experimentation is very worthwhile IMO.  I sincerely hope others test these capacitors and provide feedback herein.

Sonicap Gen5 (prototype) – This capacitor is obviously not available for open purchase, but did sound fairly decent behind the tweeter.  The impact was slightly more detailed, but a slight edge was also present.  Overall, Ralph and I preferred the character of the Sonicap Gen 2 and the next capacitor.

Sonicap Platinum – Darn!  Darn!  Darn!  Why does the best performer also have to be the most expensive?!!  The Sonicap Platinum had wonderful separation, and a very pleasant tonal character without any nasty edge.  I can't explain why this happened, but it did.  For the guy willing to spend solid money $$ on a product that is the very best, using Sonicap Platinum bypass capacitors is wise.  Their quality is commensurate with this cost.  I will be using them in my home speakers. 

I also performed a test using a .1uf bypass capacitor in the trap circuit in the crossover.  Much to my chagrin, there was audible impact here too.  Although the impact was slightly different (and lesser) than bypassing the tweeter capacitors, the impact was audible.

My short summary is the Sonicap Platinum (yes, again) proved superior and the Sonicap Gen 5 came in 2nd place.  The Sonicap Gen 1 and Sonicap Gen 2 were not desirable in this component location.  I really don't know why, but this is how we heard it.

Oh, I almost forgot, we also tried a .22uf Audio Note capacitor in the trap circuit.  It sounded inferior to the Sonicap Platinum and Gen 5.

Unfortunately, the .1uf Sonicap Platinum is temporarily out of stock.  When more arrive, I will complete the prototype of the 1801C.  While these capacitors add about $185 to the cost of the speaker, I believe they are fully essential when offering the best possible product.

A question that is will likely be asked is… what about other capacitors.  Well, in other areas in my source gear I used Mundorf Gold and Mundorf Silver and Oil.  I have also experimented with Auricap.  I do intend to accomplish some further experiments in the realm of bypass capacitors, but I have learned over the years to trust Jeff Glowacki at Soniccraft.  While his public press might lag behind more popular capacitors, his honest and product quality do not.  Jeff has sold me a very competitive product for many years.  Some experiments will follow, but I won't be testing every .1uf capacitor available.  Solen and Bennic need not apply.  However, if anyone is willing to share a pair of .1uf capacitors, I will gladly entertain them.  Heck, you can even send them with blue masking tape and your initials covering the seal/seam. 

Update - Nov 07.  I implemented .1uf Sonicap bypass capacitors in the 1801B (using the Seas W18 driver) at the Rocky Mountain Audio Fest on Friday evening of the show without telling Hugh Dean (AKSA) that I planned to accomplish this.  The next morning Hugh Dean entered our listening room and within 1 minute of listening he affirmatively commented, "you installed the Sonicap Platinum's... didn't you?".  Hugh is familiar with the positive impact of the Sonicap Platinum and was able to easily discern the change.

So, the impact of installing Sonicap Plaintum bypass capacitors in the 1801B and 1801C is the same.  In this case there aren't any issues of driver and capacitor synergy affecting a disparity.  Both speaker's responded in the same fashion.  I suspect this would not be true in other situations.

My general hunch is that a very lush sounding capacitor (i.e. Audio Cap Theta or any Paper/Oil) would sound very good behind a harsh metal come or planar tweeter.  I actually read a very good example of this last week.  The designer used an Audio Cap Theta behind a HiVi planar tweeter.  This is a very wise decision - IMO.
Title: Re: .1uf bypass testing and the 1801C
Post by: David Ellis on 26 Apr 2007, 10:58 am
I don't have a scientific explanation for the post above, but I would like to offer the following comments.  I feel compelled to mention that I fully disagree with this comment:

Quote
Bypassing

Do not use bypass capacitors in the signal path. A single capacitor for DC blocking/AC coupling creates a simple path with one time constant. The signal quality will be compromised if a bypass or multiple bypass capacitors are added to a signal path capacitor. Bypass capacitors were used in the past to bypass low quality film capacitors or electrolytic capacitors. The bypass was the lesser of two evils. With the advent of better quality film capacitors the need for a bypass capacitor was eliminated. Bypass capacitors create multiple signal paths with multiple time constants. These time constants are very short but they can still be heard as a smear or overall loss of focus.

It can be viewed in on the original web page here:

http://www.jacmusic.com/auricap/htm/auricap_application_notes.htm (http://www.jacmusic.com/auricap/htm/auricap_application_notes.htm)

Candidly I believe the words time-constant are abused and eschewed by many folks, and it really makes me wonder if there is an understanding of this very simple issue.  Time constant is the measure of how completely a capacitor will discharge in a given impedance circuit.  Smaller value (i.e. uf) capacitors discharge faster.  Lower impedance circuits also create a faster discharge.  Small capacitors in low impedance circuits discharge faster.  Large capacitors in high impedance circuits tend to discharge slowly. 

A while ago I bypassed a Sonicap Gen I with a smaller Sonicap Gen I in my CD player.  It worked well, and the results were positive. I believe this is because the more "faithful" smaller bypass capacitor restored some of the information lost by the larger capacitor.

Also important is the assumption in the Auricap note concerning the better quality film capacitors. They seem to infer that ALL better quality metalized capacitors are identical.  Hence the comment, "With the advent of better quality film capacitors" .

For the record, I do not believe all better quality film capacitors are the same. There are differences in film composition, thickness, porosity, winding tension, and tension.  I also believe there are differences in the metal chemistry, and how the crystallization process happens after the metal is deposited.  Oh, and the end spray also varies.  Please understand these are guesses from an capacitor outsider.  I have not spent the $30k + necessary to have a capacitor constructed, and don't intimately understand the process.

Dave
Title: Re: .1uf bypass testing and the 1801C
Post by: jeffreybehr on 26 Apr 2007, 04:30 pm
Mr. Ellis--
1.  'Ralph' is the Wonder Dog?  Or?
2.  What's the value of the original tweeter cap?
Title: Re: .1uf bypass testing and the 1801C
Post by: David Ellis on 26 Apr 2007, 07:31 pm
Quote
1.  'Ralph' is the Wonder Dog?[/

Nope. Ralph is a local hifi nut living here in Bellevue (Omaha) Nebraska.  This test was accomplished in his listenging room with his system.


Quote
2.  What's the value of the original tweeter cap?

Both of the tweeters capacitors were between 4uf and 7uf. 

Dave

Title: Re: .1uf bypass testing and the 1801C
Post by: David Ellis on 26 Apr 2007, 07:42 pm
Also, Ralph provided these slighlty more specific comments about the comparative character of the 1801B and 1801C.  At the bottom of these comments is his system information:

Quote
Dave,

1801B - I found to be extremely detailed with a soundstage on plane or slightly forward of the speakers. It was excellent from the upper midrange though the mid-bass. It became slightly less distinct in the dilineation of bass notes as it moved lower in the scale of the bass range. Decay is superb, particularly notable when hearing the dying resonances of instruments in the fade out at the end of songs.  In some music coherence of the overall presentation is lessened due to the sharp relief of the detail presented. Instruments can seem more forward from the whole of the music than usual because of an aggressive attack. It walks very close to "edgy" but never gets there.  Realistic and accurate reproduction of the input signal with minimal colorations are the hallmarks of this speaker.

1801C - This version sounds very natural in its delivery of musical tones sacrificing only the smallest bit of detail to the 1801B. I was more impressed with the smooth presentation of difficult to reproduce piano  notes and female vocals with the "C" than the 1801B. Again superb through the upper mids, mids and upper bass and having a better tonal quality in the lower bass region though not going much deeper. The decay is wonderful like the 1801B revealing instrument and vocal nuance. The attack is much smoother. The layering and texture of music is better to my ear than the 1801B because it suits my preference of coherence and musicality in speakers. There is accuracy in the presentation a more refined delivery.

Associated gear:
Meridian 508.24 CD player
Reference Line 1A Passive Preamp
Atma-Sphere M60MkII.3 OTL amps
JPS labs Superconductor FX interconnects and speaker wire

Ralph
Title: Re: .1uf bypass testing and the 1801C
Post by: DSK on 27 Apr 2007, 01:36 am
Interesting experiment, David. I've been thinking about bypassing the Sonicap Gen I's in my own XO's with the Platinums for a while but haven't gotten around to it.

Most people seem to bypass tweeter caps with a smaller 0.01uF cap. Do you feel there is any benefit or downside to using the larger 0.1uF cap instead (other than being more expensive)?

Also, where multiple smaller caps are used to make up the required uF value, do you advocate bypassing each cap with its own bypass cap, or just one bypass cap for the group of caps?
Title: Re: .1uf bypass testing and the 1801C
Post by: rez on 27 Apr 2007, 05:03 am
Hi Dave,
Any advantage to retrofitting the XO components in the 1801b with the ones listed for the 1801c?  What is the cost of 2 Accuton C95's if one was to upgrade an existing 1801b?
Thanks
Roman

pacific beach last summer
Title: Re: .1uf bypass testing and the 1801C
Post by: David Ellis on 27 Apr 2007, 06:12 am
Quote
Interesting experiment, David. I've been thinking about bypassing the Sonicap Gen I's in my own XO's with the Platinum's for a while but haven't gotten around to it.

And unfortunately, it's fairly expensive  :roll: .

Quote
Most people seem to bypass tweeter caps with a smaller 0.01uF cap. Do you feel there is any benefit or downside to using the larger 0.1uF cap instead (other than being more expensive)?

This is very new territory for me.  Jeff told me that .1uf is what I should try.  Since he makes a living providing the best possible sonic impact from his products, this advice came with a very good base of testing.  However, from an impedance and time constant perspective, a .47 should work better.  Years ago I tried a .47uf capacitor around a 5uf sonicap and couldn't hear any impact.  However, my source gear back then was unmodified Stereopile grade "B" stuff.  The gear used in the current test is much better.  There are probably other issues extant that I don't understand.  The 10% step-down cascade bypass seems to make the most sense objectively, and is certainly present in better source gear power supplies.

Quote
Also, where multiple smaller caps are used to make up the required uF value, do you advocate bypassing each cap with its own bypass cap, or just one bypass cap for the group of caps?

This is a bag of worms having many possible outcomes and explanations. I have never experimented with this, but suggest using a cascade setup and bypassing the smallest capacitor with the .1uf.  Aside from this, the multiple capacitors (if the same size) should be electrically "one".  As such, they are effectively a multi-cap.  As such, using a single bypass should be fine.  However, this advice is a could be a "mixed bag".  There is probably some shard of truth to time constant smear when using various size capacitors in the signal path.  I really don't have a good answer for you.  Based on my experiment, I can easily suggest using a single .1uf bypass around the correct size larger capacitor. 

Quote
Any advantage to retrofitting the XO components in the 1801b with the ones listed for the 1801c?  What is the cost of 2 Accuton C95's if one was to upgrade an existing 1801b?

I stilll have some prototype work to accomplish before the 1801C arrives on my web page.  The initial answer regarding the Accuton C95s is... they are expensive.  I don't have any sneaky/special way to buy them cheap.  Additionally, most of the crossover is different, but there are a few salvageable parts.  The 1801B inductors could easily be unwound in my workshop.

But..., the cost to upgrade the 1801B to 1801C is much more than the sonic impact warrants IMO.  The drivers ($550) plus crossover (perhaps $100 if the inductors are re-used), and Platinum Bypass (if desired - about $185) make this a very painful proposition.

If you have an itch, I highly suggest installing 4 very inexpensive Sonicap Gen 2 (not Gen 1) capacitors around the tweeter capacitors in the 1801B.  If you like what you hear, and still have an itch, take the plunge for 6 Sonicap Platinums and bypass all the capacitors in the 1801B crossover.  Please let me know what you find/hear if you do this experiment.

Guys, I really have to admit that suggesting the purchase of $185 in bypass capacitors is very difficult for me.  It's uncomfortable!  This is because 2 weeks ago I would have thought it completely ludicrous.  Spending $185 on 6 small value capacitors seems absolutely insane. It makes minimal objective sense and I have very little explanation for the phenomena.  Those little capacitors really shouldn't have any impact, and they really should be so darn expensive.  But, I don't understand the issues.  I am still emotionally adjusting to this illogical reality.   :duh: :duh: 

I also fully understand these comments may be considered snake-oil by many.  However, so was the initial introduction to the Audio Cap Theta loudspeaker capacitor using a Walkman-type CD player at Dennis Murphy's house (I think?).  Many folks heard the test, and testified regarding it's validity and impact.  Following the test, many others dismissed the results citing the scientific method used.  However, regardless of what many people thought, this was the test inspiring Parts Express to purchase a huge quantity of Audio Cap Theta capacitors.  From my perspective, folks need a good reason to spend considerable $$.   I heard the impact and I will be installing Platinum bypass capacitors in my home speakers.  If other folks don't, that's okay.

Dave
Title: Re: .1uf bypass testing and the 1801C
Post by: DSK on 27 Apr 2007, 06:44 am
Thanks Dave.

These positive results were before any break-in of the Platinums? Did they improve much/any with additional hours on them?

If I understand correctly, you are suggesting using a 0.1uF Platinum bypass cap on the midwoofer cap as well? What is the original midwoofer cap ....Solen?
Title: Re: .1uf bypass testing and the 1801C
Post by: David Ellis on 27 Apr 2007, 06:25 pm
Quote
These positive results were before any break-in of the Platinums?

Yes.

Quote
Did they improve much/any with additional hours on them?

According to Jeff, the Platinum shouldn't change during break-in.  The dielectric is good and has no "healing" properties. 

However, a very fine gentlemen ( a wire/cable nut) told me a few years ago that all of the old analog telephone lines were placed on a break-in signal for a few days and that some change was audible and measurable due to changes in the solder connections and minor changes in the wire itself.  As such there may be a very slightly change after break-in.

Quote
If I understand correctly, you are suggesting using a 0.1uF Platinum bypass cap on the midwoofer cap as well?

Unfortunately ($$), yes.

Quote
What is the original midwoofer cap ....Solen?

Sonicap Gen 1.

Dave
Title: Re: .1uf bypass testing and the 1801C
Post by: Danny Richie on 27 Apr 2007, 10:22 pm
Dave, my listening test revealed similar results.

I use the .1uF Sonicap Gen.2's by-passing the Erse poly caps in the standard crossover of our A/V series kits. The Gen.2 by-pass cap certainly takes it up a notch over the standard poly caps and does so with little added cost. They are only $2.70 each. This is a highly recommend low cost tweak.

I just hope the next batch is available soon (it should be here late next week) I have 1000 of them on order. I use a lot of them. :-)

I have also found that the Sonicap Platinum's as by-pass caps are really outstanding and without equal. I usually by-pass standard Gen.1 Sonicap with them. I have found them to be very noticeable in loudspeaker crossovers and electronics.

Anything really serious that I build gets Platinum by-pass caps. My D/A converter has them in it and so does my pre-amp. In fact my pre-amp comes with them from the manufacturer.

I am having a new set of tube mono-blocks custom built for me right now. Each amp has three .33uF Platinum's and six 1.0uF Platinum's in the circuit. Retail on just those caps is $1,494. Is it worth it. You beat it is !

My stock is pretty low on Platinum's right now too. I am down to about 30 pieces of .1uF. The only value I am out of right now is 1.0uF. If you need some let me know.
Title: Re: .1uf bypass testing and the 1801C
Post by: Christof on 30 Apr 2007, 11:14 pm
I wonder how many people overlook the bypass caps?  Thanks for sharing this info, Dave :thumb:

-c.
Title: Re: .1uf bypass testing and the 1801C
Post by: JoshK on 1 May 2007, 12:10 am
FWIW,

I have always read that bypass caps are best at 1/100'th the value for the least "spectral overlap".  No idea, myself, as I've not tested this, so take it FWIW. The .1uf is closer to 1/100'th than 1/10th...maybe this is why he chose this value??  :scratch:
Title: Re: .1uf bypass testing and the 1801C
Post by: David Ellis on 1 May 2007, 12:57 am
Quote
I wonder how many people overlook the bypass caps?

I bet most folks overlook bypass caps.  Heck, most folks believe all metalized poly caps are the same.  Overcoming the mental barrier regarding differences in capacitors is probably an easier step to take.  Overcoming the mental barrier that a very good Sonicap in a loudspeaker filter will actually benefit from a bypass capacitor is something that still causes me mental consternation.

I tested .1uf because that is what Jeff recommended I test.  Jeff has spent many nights puttering with this stuff, and understands the "why".   All of this is new to me in loudspeaker filters.  I have bypassed in the signal path of my source gear, but the impedance here is MUCH higher and the time-constant issues are commensurately significant.  This situation isn't present (relatively speaking) in the tweeter circuit of a loudspeaker.  I really didn't expect this to happen.

Dave
Title: Re: .1uf bypass testing and the 1801C
Post by: Guilhermejs on 31 May 2007, 12:46 am
Hello Dave,


          Thanks for being always imporving your awesome loudspeakers! So I need two 0,1uF capacitors per speaker, one for the tweeter and another for the midbass?

Regards,

Guilherme
Title: Re: .1uf bypass testing and the 1801C
Post by: David Ellis on 31 May 2007, 02:09 am
The number desired will be different depending on what capacitor you choose.  Strangely, the Sonicap Platinum had a positive impact on the woofer shunt capacitor too.  The Sonicap Gen 2 impact was not audible in this position.  I don't have an intellectual explanation for this  :scratch:.

So, my reccommendation is... if you are willing to buy the Sonicap Platinums, buy 6 of them for bypassing - one for each primary capacitor.  If wish to have a less expensive experiment, buy 4 Sonicap Gen 2 capacitors for the tweeter only.

Yes, I know the Sonicap Platinum capacitors are expensive :oops:, but for those wishing for the very best sound quality - the Sonicap Platinums are "all that".

Dave
Title: Re: .1uf bypass testing and the 1801C
Post by: Kris on 31 May 2007, 06:10 am
If one out of five caps have a "positive change" on SQ, then i think that cap is defective. Especially a 100nf cap.
Title: Re: .1uf bypass testing and the 1801C
Post by: David Ellis on 31 May 2007, 01:00 pm
Quote
If one out of five caps have a "positive change" on SQ, then i think that cap is defective. Especially a 100nf cap.

Where did you read/infer "1 of 5" ?

Title: Re: .1uf bypass testing and the 1801C
Post by: jipper on 7 Jun 2007, 03:40 am
Dave, will the 1801C go into production in the near future? and what sort of sensitivity and ohm rating will you target with this model?  Are you looking to increase sensitivity or are you satisfied with this is the 1801b?

As you can see I have not yet decided on my speaker purchase.  The 1801b looks to be a great match for something like the st70 but if/when I want to move towards an SET design with low power, I am not sure the 1801b can still be used.  And of course (some sarcasm here) I would like to try to make my purchases as practical as possible (future potential and what not).

thank you,
JP
Title: Re: .1uf bypass testing and the 1801C
Post by: David Ellis on 7 Jun 2007, 04:43 am
Quote
Dave, will the 1801C go into production in the near future? and what sort of sensitivity and ohm rating will you target with this model?

Yes.  The hold for the past 4 weeks has been availability of the .1uf Sonicap Platinum capacitors.  Jeff has been sold-out, but more should arrive in the next 1-2 weeks.  I needed more capacitors to complete a fully assembled pair of 1801C speakers including the

The 1801C will have roughly the same impedance as the 1801B.  It will dip to a low of about 6 ohms in the bass region.

The 1801C will be about 2db more sensitive.  This is commensurate with the raw sensitivity of the woofer.  The C95 is about 2db more sensitive than the W18.  However, I DON'T think 87-88db will be enough sensitivity for the average 8wpc 300b SET.  The Cary 572 SET (I have one) has enough juice, but it's a 20wpc amp. 

Also, I admire your apparent desire to reduce the amplifier complexity.  This is something I have tried too.  I have realized that quality parts are far more important than the size of the amplifier.  My stock Cary 572 is not a very good amplifier - IMO.

Dave



Title: Re: .1uf bypass testing and the 1801C
Post by: laserman on 16 Jul 2007, 09:02 pm
Dave, any further news to report about the 1801Cs?
Title: Re: .1uf bypass testing and the 1801C
Post by: Danny Richie on 16 Jul 2007, 09:46 pm
Quote
Yes.  The hold for the past 4 weeks has been availability of the .1uf Sonicap Platinum capacitors.  Jeff has been sold-out, but more should arrive in the next 1-2 weeks.  I needed more capacitors to complete a fully assembled pair of 1801C speakers


Bummer. I have had stock on them all the while Sonic Craft was out of stock on them. I am low now on that value but still have them in stock.
Title: Re: .1uf bypass testing and the 1801C
Post by: David Ellis on 17 Jul 2007, 01:40 am
I wasn't in a hurry, but do appreciate the offer. 

Jeff now has a good resupply of the .1uf Platinum and I have some in my workshop.

Dave
Title: Re: .1uf bypass testing and the 1801C
Post by: richny on 9 Sep 2007, 01:41 am
I am redoing my 1801b's with new cabinets (I got my hands on some great figured cherry) and I am thinking of doing the sonicap platinum bypass  of the woofer and tweeter caps.  Has anyone tried this upgrade yet and can they share their results.  I also am looking for confirmation that the right value for the cap is .1uf and not something lower.  thanks.

Title: Re: .1uf bypass testing and the 1801C
Post by: David Ellis on 9 Sep 2007, 02:40 am
Danny Richie www.gr-research.com (http://www.gr-research.com) affirmed my comments regarding the use of the .1uf Platinum bypass capacitors in crossover circuits.  He has used them many times with the same wonderful results.  Hence, I am not the only guy who has tried this with positive results.  I don't know who else is using them in loudspeaker filter circuits.  It seems there are a few folks, but I don't recall the manufacturer names.

I am fairly certain there isn't anyone in the DIY speaker community that has a/b tested the .1uf Platinum bypass in the 1801b.  I have only done this locally in a a/b test using Ralph's system.  You would be the first gent to do this (potentially).  Please do share your comments.

I did send an assortment of capacitors to Tony Gee for evaluation.   Hopefully his comments will be forthcoming fairly soon.

The bugger in this modification is the cost of those caps.  They are expensive.  5 years ago I would have never dreamed of spending about $28 for a .1uf capacitor for bypassing in a speaker.  $28 remains a difficult "pill" to swallow, but these caps do perform surprisingly well. 

I have a handful of these capacitors in my workshop.  Alternately, they may be purchased from Jeff at www.soniccraft.com (http://www.soniccraft.com)

And, where did you find the figured cherry veneer?

Dave
Title: Re: .1uf bypass testing and the 1801C
Post by: richny on 10 Sep 2007, 10:37 am
Thanks for the reply Dave.  I probably wouldn't do this if I was not redoing the cabinets since I like the way the 1801b's sound.  But given the opportunity and your comments on the potential benefit, I am considering it.   I agree it is a little on the expensive side though. 

I did my first set of cabinets in Red Oak as that was what I could get my hands on locally.  They came out pretty good but I found that it takes some practice to get the veneering perfect and I came to want something with a little more interesting grain to look at.   John@ diyspeakercabinets.com told me he had some nice cherry veneer on hand and he did the basic mdf boxes for me with the veneer (John did a great job by the way).  I bought some really nice figured cherry on-line from a small wood shop for the baffle and I am doing the rest of the job (attaching the baffle, cutting the driver holes, finishing the cabinets, etc.).   I hope to have something that looks as good as it sounds at the end of all this project.  I'll keep you posted on what I eventually decide to do. 
Title: Re: .1uf bypass testing and the 1801C
Post by: doug s. on 10 Sep 2007, 03:14 pm
FWIW,

I have always read that bypass caps are best at 1/100'th the value for the least "spectral overlap".  No idea, myself, as I've not tested this, so take it FWIW. The .1uf is closer to 1/100'th than 1/10th...maybe this is why he chose this value??  :scratch:
if this were the case, then why not go w/the 0.047uf caps?  personally, i would like to hear a test w/the smaller caps - even the 0.01uf caps.  two reasons.  1st, it yust seems to me, as a layperson, that smaller bypass caps would be better; second, they're cheaper.   :green:

doug s.
Title: Re: .1uf bypass testing and the 1801C
Post by: David Ellis on 11 Sep 2007, 01:34 am
Quote
if this were the case, then why not go w/the 0.047uf caps?

Because the guy most interested in positive results (i.e. the guy selling them :) ) tried smaller and larger bypass caps in loudspeaker filter circuits and told me the .1 works the best. 

In theory and practice a 1/10 ratio for bypassing seems very common, but for some reason that I don't understand, the .1uf works.  I have seen the .1uf used in a fair amount of source gear too and this is even further from the 1/10th cascade ration.

Gentlemen, I must admit that I am very surprised by this and it causes me pain to spend serious money on a .1uf capacitor.  Further, I truly don't have a valid theoretical explanation for theoretical explanation for this.  Sure, I have some guesses, but these guesses would be like throwing darts with a blindfold.

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second, they're cheaper.   
  I share this sentiment and did subject Ralph to various capacitors with the identities concealed.  The other caps were all covered with masking tape to cover their labels.  The other caps were all cheaper.  Unfortunately, Ralph chose the most expensive capacitor  :roll: .  So, it is what it is.  I heard it too.  I really wish that I could change the reality of this, but don't know how this could be possible.  Unfortunately, the good stuff just happens to also be very expensive.

However, the testing was done with very competent source gear.  My source gear is darn good, and Ralph's source gear is a scosh better.  I have not done a test with any consumer grade source gear because spending @$180 on loudspeaker bypass capacitors for use with such source gear is a very unwise purchase - IMO. 

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I'll keep you posted on what I eventually decide to do.   

Groovy,

Dave

Title: Re: .1uf bypass testing and the 1801C
Post by: Danny Richie on 11 Sep 2007, 01:53 am
Okay, maybe a bit of an explanation...

The by-pass cap is effective for a couple of reasons. One of which is the dissipation rate. The smaller the cap value the faster the discharge rate, and since the smaller cap is helping to discharge the storage of the larger one then one would think the smaller the better.

However, the larger the value the more information in the actually audible range can pass through it. Thus the top end may be more dominated by the by-pass cap in giving it a cleaner and clearer over all sound.

So it is a bit of a balance of a couple of things.

A .1uF has been my personal favorite value for by-pass caps used in loudspeakers especially in the tweeter circuit, and the best I have heard thus far have been the more expensive Sonicap Platinum's.
Title: Re: .1uf bypass testing and the 1801C
Post by: DSK on 11 Sep 2007, 10:30 am
Danny/Dave/others who have tried ....

How would you compare the scale of improvement between ...
a) upgrading speaker crossovers with the Sonicap Platinums bypasses; and
b) upgrading pre-amp input or output caps with Sonicap Platinums?

Obviously it will vary somewhat from case to case so I'm not after an exact ratio of difference ... just a general comparison like "about the same", "a) is a little more obvious", or "b) is a little more obvious". Thanks.
Title: Re: .1uf bypass testing and the 1801C
Post by: David Ellis on 12 Sep 2007, 02:46 am
I have swapped/upgraded coupling capacitors in every decent piece of source gear that I own.  IME, the subjective impact of a good capacitor in source gear is 3-5 times more profound than when used behind the tweeter in a loudspeaker.  This is simply because the tweeter capacitors only pass the high frequencies.  In a source gear coupling circuit the capacitor passes everything.  I am sure Danny has puttered with source gear too, but am not certain of his opinion regarding the relative impact of better capacitors in various parts of a system.

I would also like to comment that my experience and comments are not based solely on the Sonicap Platinum.  The Sonicap Platinum is one of several "better" capacitors that I have used.

Dave



Title: Re: .1uf bypass testing and the 1801C
Post by: richny on 16 Oct 2007, 11:35 pm
Well, I went ahead and did the by-pass caps as I built new cabinets for my 1801b's.  As Dave recommended, I used the sonicap platinum's (.1uf) and by-passed all 3 caps on the tweeter and the woofer.  I did one speaker at a time so I could do a side by side comparison.  The difference with the added caps was an audible improvement but I would say it was not overwhelming.  Both presentations were very good.  With the by-pass caps, the presentation was a bit more up front like moving up a few rows in a concert hall from the middle to closer to the front.  Overall clarity was slightly better with the caps particularly on average recordings.  (On very good recordings it was hard to hear the difference).  On some songs I perceived the lower clarity of the speaker without the caps as a slightly smeared sound by comparison.  Without the caps the presentation was also a little "darker" if that makes sense.  I asked my wife for her opinion without sharing mine.  After listening for a very short session, she come to the same conclusion as I, indicating the speaker with the by-pass caps was "clearer".
Overall, I judged the speaker with the by-pass caps as more musical and enjoyable for my tastes and I decided to keep the caps in the one and upgrade the second to match.  My equipment is not high end and that should be taken into consideration.  I listened to a variety of CD's on a Marantz SA8260 feeding a passive preamp (FT Audio "Little Wonder") and a PS Audio HCA-2 power amp.  With this grade of equipment, I would say that the overall improvement is probably not worth the time and cost to upgrade a finished speaker.  I used the vampire wire in the 1801b crossover and some high quality stuffing so my speakers are done for now.
Title: Re: .1uf bypass testing and the 1801C
Post by: David Ellis on 17 Oct 2007, 05:13 pm
Thanks very much for your comments and performing this experiment!  I fully agree with your sentiments and believe your comments are completely accurate.  The Platinum caps do make the speaker sound better, but they are not a value-oriented option. 

Hugh Dean and I discussed the Sonicap Platinum at length.  We both find it very painful to spend so much money on these capacitors.  However, we both agree they provide a perceptible positive impact that cannot be found using other conventional methods.  Seeking that last "ounce" of quality necessitates the Sonicap Platinum.

Title: Re: .1uf bypass testing and the 1801C
Post by: rez on 24 Oct 2007, 02:10 am
Hi Dave,
I have the sonicap plantinums in hand and will shortly be performing the "surgery" :).  Before actually connecting the wires I was wondering if there are there any issues with fixing the bypass caps directly to the main caps using something like a silicon caulking or are the bypass caps better mounted directly to the crossover board with the silicon?
Thanks,
rez
Title: Re: .1uf bypass testing and the 1801C
Post by: Bill Baker on 24 Oct 2007, 03:16 am
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Danny/Dave/others who have tried ....

How would you compare the scale of improvement between ...
a) upgrading speaker crossovers with the Sonicap Platinums bypasses; and
b) upgrading pre-amp input or output caps with Sonicap Platinums?

 As most AC'ers know, I am very fond of Teflon capacitors and they can be beneficial in many different products. As Danny mentioned previously, you would want a minimum value of .10uF and for the reasons he mentions in his post, larger values are still justified. In addition to what Danny mentioned, the larger the value, the more frequency range it passes resulting in more of the Teflon characteristic that is realized.
 

 Also keep in mind that Teflon takes MUCH longer to show it's potential that standard film caps. For those who evaluate them after only a few hours have not yet even scratched the surface of what is to come. In fact, you will have to put up with some so-so performance for quite some time. If you don't have a minimum of 200 hours on them, your evaluation is irrelevant.

 In preamp, amplifier, CD analog output..........upgrading to the SoniCap Platinums may or may not be a noticeable enhancement. This will depend on the system's ability to bring forth the potential these caps can provide. If your system is capable, the Platinums will perform. Just don't bypass your coupling caps as it is not the same result as bypassing x-over pieces.

 I will also add that the Platinum is among the best capacitor available for bypassing power supply filter caps.

 There are many that do not believe in esoteric capacitors. The only argument I can agree with is that they are expensive but sonically they do things I am not able to obtain from 'standard' pieces. Whether or not you can justify it can only be determined by your own ears but give them at least the benefit of the doubt and ample burn-in time before coming to conclusions.
Title: Re: .1uf bypass testing and the 1801C
Post by: David Ellis on 24 Oct 2007, 04:27 am
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Hi Dave,
I have the sonicap platinum's in hand and will shortly be performing the "surgery" .  Before actually connecting the wires I was wondering if there are there any issues with fixing the bypass caps directly to the main caps using something like a silicon caulking or are the bypass caps better mounted directly to the crossover board with the silicon?
Thanks,
rez

It doesn't really matter what the bypass capacitors are attached to, but they should be attached to something.  Most folks seem to attach the bypass to the primary capacitor and I generally practice this method.  I find that GE Pure Silicone works quite well for making a decent connection with plastic capacitors.  Liquid Nails is okay, but after a few years the Liquid Nails gets fairly stiff.  The GE Silicone remains quite flexible and pliable.  It will withstand some shock and maintain good adhesion.

And, thanks for responding to the query regarding bypass capacitors in source gear Bill.  I do have something to add regarding the break-in time for the Teflon Caps.  I do agree there is something that happens after a significant break-in, but I find a reasonably positive impact after initial installation.  Black Gate capacitors in source gear are very different.  In my opinion, Black Gate's sound murky and bad after initial installation.  These really do require significant break-in to sound better decent.

And... I still haven't emotionally adapted to the impact of these capacitors and their cost.  It remains traumatic for me :o.  I suppose I am into the Bargaining stage, but it's still difficult :duh:.  These capacitors really shouldn't sound so good :scratch:.  And I never imagined being willing to spend so much $$ on a .1uf capacitor :roll:.

Dave
Title: Re: .1uf bypass testing and the 1801C
Post by: rez on 13 Nov 2007, 04:41 pm
Hi again Dave,
I also thought that it might be a good idea to tone down the tweeter just a hair while I have the crossovers out for the bypass - my listening room is fairly reflective and the tweeters seem just a bit bright in this context.  I looked through your crossover notes but can't seem to find the recommended make of resistors.  I'm planning to use the 2db down option (8 ohms in series and 12.5 ohms in parallel) - which resistors and vendor do you recommend?
Thanks
Roman

Title: Re: .1uf bypass testing and the 1801C
Post by: Bill Baker on 13 Nov 2007, 05:15 pm
Hello Roman, If I might suggest a resistor type..... I would go with the 12 watt Mills non-inductive pieces. They will probably run you about $3-$4 each but this seems to be a minimal investment for such a nice speaker.

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Most folks seem to attach the bypass to the primary capacitor and I generally practice this method.

 I agree one this one. If you are gong to be using only one bypass capacitor and working with a design larger than a 1st order, bypass the first capacitor in the signal. Another thing I beleive in is installing them so that you can use the shortest possible lead length.
Title: Re: .1uf bypass testing and the 1801C
Post by: David Ellis on 13 Nov 2007, 08:36 pm
Roman,

When bypassing with the Sonicap Platinum I don't find the desire to reduce the tweeter spl just a scosh via resistors.  I found bypassing with the Sonicap Platinum had an all-positive impact when used around all of the capacitors in the 1801.  There was more information, and it was all good information.

However, when bypassing with the Sonicap Gen 2, I found a positive impact just behind the tweeter (I don't know why), but no impact in the shunt woofer circuit.  Also, the results were generally positive, but had a slight downside.  An audible disconnect happened between the tweeter and the woofer.  The tweeter sounded slightly more forward.  So, in this case, reducing the tweeter spl will be helpful.  It will reduce the presence of the tweeter slightly.

In the 1801, either the Mills MRA 5 or MRA 12 resistors will work just dandy.  www.soniccraft.com has both flavors.  I haven't done a good a/b comparison, but think the MRA 5 might sound better in my speakers.  The MRA 5 is smaller and should be less inductive.

Most folks have an 8, 15 resistor combination.  This is likely true for you also.  So, you will need to order some 12.5ohm resistors for the parallel component immediately behind the tweeter.

Dave

Title: Re: .1uf bypass testing and the 1801C
Post by: rez on 13 Nov 2007, 11:29 pm
Thanks Dave, I will definitely try the sonicap platinums on their own first and see how that sounds before tinkering with the resistors.

Also, thanks Bill for your thoughts on the other options.
Roman
Title: Re: .1uf bypass testing and the 1801C
Post by: rez on 23 Nov 2007, 03:52 am
Finally got the cap bypass done - I did all 6 with the .1 uf platinums.  I did one speaker first and listened... my impression was that the performance had moved more into the room, moved forward and there was a greater sense of 3 dimensional sound coming from the converted speaker.  These impressions were evident almost immediately and were confirmed with a variety of material.  I didn't spend too long listening for other differences except to characterize the sound overall as slightly more refined on the converted speaker.  This was subtle and with more time I could have a more in-depth report of its characteristics but I was too excited by the positive changes to wait any longer and went ahead and converted the second speaker.  For me this was a very worthwhile upgrade.
Title: Re: .1uf bypass testing and the 1801C
Post by: David Ellis on 24 Nov 2007, 12:03 am
Wonderful,

Please do offer some comments when your opinions on the Platinum capacitors are certain. 

Some folks claim there is a break-in period when using the Platinum capacitors.  I do have an opinion on the matter, but look forward to reading your comments.

Dave
Title: Re: .1uf bypass testing and the 1801C
Post by: David Ellis on 8 Dec 2007, 01:07 pm
I was chatting with a gent on the telephone yesterday and he mentioned that his older JBL 4312 speakers implemented bypassing.  Ironically, I recall this speaker during my early years of stereo intrigue while stationed overseas in Germany.  I thought the 4312 was a standout performer, but the BX changed inventory and had the Studio Monitor 10 when I was eventually able to purchase a new pair of speakers.  It was marginally inferior, but still performed quite well.  Anyhooo, here is a page from the 4312 users manual:

(http://www.ellisaudio.com/4312.jpg)

I was also struck by the response graph in the lower right corner of this page.  This clearly indicates one reason why loudspeakers are better today than in the good-old-days.  The lack of computer software would make a good typology nearly impossible - on par with a basketball getting stuck IN the backboard.   And quality control from unit to unit - yeah right  :roll:  :duh:.

Dave
Title: Re: .1uf bypass testing and the 1801C
Post by: David Ellis on 24 Aug 2008, 01:03 pm
Over the past few months there have been 2-3 more folks that upgrade ther 1801B speakers with .1uf Sonicap Platinum bypass capacitors.  The feedback was universally positive.

Dave
Title: Re: .1uf bypass testing and the 1801C
Post by: fred on 25 Aug 2008, 12:26 pm
I'm interested in installing the bypass caps, but....I have no idea where they go in the circuit.  Can you please describe?  (sorry, I'm an electronics dunce :dunno:).
Title: Re: .1uf bypass testing and the 1801C
Post by: David Ellis on 31 Aug 2008, 01:06 pm
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Insert Quote
I'm interested in installing the bypass caps, but....I have no idea where they go in the circuit.  Can you please describe?  (sorry, I'm an electronics dunce ).

Yes, the leads of the bypass capacitor are simply soldered to the leads of the primary capacitor.  I generally wrap the lead from the bypass capacitor around the primary capacitor at least once, then solder.  There are some photo's of lead connections here:

(http://www.partsexpress.com/projectshowcase/images/Veri024_small.jpg)

(http://www.partsexpress.com/projectshowcase/images/Veri020_small.jpg)

Also, there is valid theory and evidence to support very short lead lengths for a bypass capacitor, and avoiding interference from other stray magnetic fields, but it is my belief that this is NOT a valid concern for a loudspeaker circuit.  The only caution I might offer is that having 5-8" of excess lead from a bypass capacitor wrapped around an inductor would have a negative impact and should be sensibly avoided.

Dave