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DavidLS 16th February 2013 04:34 AM

Updating an Ellis 1801 Crossover
I built Ellis 1801s from kit in 2004. Have been down a rabbit hole chasing SET amps and high efficiency speakers for the past 3-4 years and sadly my 1801's have been sitting on my work bench for most of that time. Still love my Frugelhorns and EL84 set amp but have recently bought a new McCormack DNA amp that has breathed new life into my neglected Ellis Audio speakers.

Looking at other full range speakers for sale I have begun to appreciate again how good the 1801s are particularly with the right amp and high quality source(s).

The 1801s have Sonicap capacitors (think Gen 1). Back in the day Dave Ellis talked lots about the improvements that came with bypassing them with .1 uf Sonicap Platinum Capacitors. So today I bought 6 Platinum Caps.

I am also thinking about re-wiring the speakers - I made a poor job of it in 2004 and actually had Dave Ellis rebuild one crossover for me that I had made a mess of. I don't understand guage and quality of wire so have been asking Jeff what I should use for tweeter and woofer (the Ellis is a two way).

I have always found the 1801s a little dark - always been mid-range speakers. So looking to improve the top end. I have excellent sources - a Lampizator dac for digital and WellTempered turntable with Lyra Kleos and Nagra phono for vinyl.

Spent half of my upgrade money on the caps but say I had an additional budget of $250 to $400 tops, any thoughts on what else I could do while I have the speakers and crossover apart?

Thanks for feedback and discussion.


Jeff Glowacki 16th February 2013 07:16 AM


Hello, and thank you for posting in our forum. You mention that you find your speakers a bit on the dark side. This is a bit odd as most found them a tad bright as I recall.

Which DNA? Pre? General description of the room? Can you describe the XO along with the type of resistors and coils...binding posts...cabinet stuffing? Perhaps a schematic?

Further, I wonder if, at some point, Dave chose to pad the OW1 slightly down from flat?


DavidLS 16th February 2013 02:24 PM

Yes maybe the Ellis' are dark compared to my other speakers - Frugelhorns driven by a lively el84 amp (Decware).

My new McCormack was a brand new DNA-125 that had been stored in a warehouse somewhere. A nice amp.

The 1801's are a very large and heavy standmount. Takes some power to get them going.

Here is a link to a pdf of the kit instructions -

there were various versions of the crossover which was designed by Dennis Murphy but I don't have the schematic. Used mills resistors, 14ga goertz inductors, goertz magnet wire for tweeter and teflon coated for woofer. 3 way brass binding posts. And I used standard polyester stuffing although Dave recommended Black Hole. Towards the end of the run Dave recommended using Vampire Copper wire as an upgrade - mine is the basic goertz.

Not sure of the values of the Gen 1 capacitors - one of my thoughts was to upgrade the caps to something like Deuland Cast or Mundorf Silver and Gold. But was getting expensive so thought I would try the bypass route that Dave Ellis recommended.

My room is small - about 12x13 and listen nearfield and off axis at my computer desk. Have the Alexander String Quartet playing their Beethoven Quartets this morning but just as likely to have Lucinda Williams or Wilco playing.

Jeff Glowacki 18th February 2013 01:09 AM


I'm thinking that none of the things you are planning will brighten up your speakers. They will be improvements, but not in the direction of brighter. Again, those speakers are rarely dark. Without a schematic, my thoughts are that you have two potential issues that I see. 1) I'm thinking that your tweeter might be padded down. It seems to me that Dave Ellis offered a couple of padding levels. If this is the case, you could improve things by changing a couple of resistor values. 2) Poly stuffing sucks. I would highly recommend BH5, but I sale it and do not wish to appear as if I am pushing my wares. I think you could improve things by just removing the polyfill, and placing duct board type insulation on all the side panels. I would not place it directly on the front panel or any of the braces.

All the upgrades you have mentioned are good ideas, but you need to address your problem first. If the 1801 is dark, you have a problem IMO.

DavidLS 18th February 2013 02:48 AM

Interesting post Jeff. Didn't take me long to get screwdriver and knife out to perform some surgery.

I removed about a basketball sized pile of poly and some egg crate shaped foam. Could probably stuff a couple of the small cushions on the couch with what came out. Left foam that lines outside wall and floor / ceiling.

Hooked things back up and right away what a difference. Dark is gone - literally the muffle is gone. Bass much more detailed and natural sounding. That was simple. Listening to some Clifford Brown trumpet - very nice.

Still want to do the cap bypass upgrade but scratching my head about why I hadn't figured this one out. Thanks for the troubleshooting.


Vladco 18th February 2013 04:06 AM

You could ask Dave directly about 1801b crossover. It's not a public domain but he could send it to you. He is a very nice person.

Jeff Glowacki 18th February 2013 05:05 AM

Good point:o I did not even consider this as it has been years since I have heard from Dave. I don't know where I got the idea, but I kind of thought he was retired so to speak.

David, be sure to ask Dave if it is OK to email me the schematic. I had seen it at one time, but that was long ago. I do not believe your Platinums have sailed yet. While this is still a good idea, there are other things to consider. BH5 is one, and wire is another. Do you know what kind of posts he is using?

You will want to spend some time listening and evaluating. Once you have a list of desired improvements arranged in the order of importance, we can begin to address them efficiently. BTW, I am glad to hear things have turned around so quickly:D

DavidLS 18th February 2013 02:18 PM

I have sent an email.

the binding posts are bi-wire brass nut screw type posts. They may sound good but don't function great as they are always loose with with one of the nuts on either side wiggling free from a tight connection.

By the way the poly and foam was actually the recommendation on the build site - based upon removing it I may have used too much poly behind the woofer...the image of one of our couch pillows over the drivers is not a good one. Black Hole 5 was recommended as an upgrade but was not seen as value for dollar spent from old posts I have read.

The old Ellis Audio discussion board is archived but readable at Audio Circle.

DavidLS 18th February 2013 06:03 PM

the cap values are:

tweeter = 6.2 uf and 8.2 uf
woofer = 5.1 uf

the caps used are sonicap - think Gen 1

so what I am curious about is whether I am likely to get better results by bypassing with a cap like the sonicap platinum or am I better off replacing perhaps the tweeter caps with platinums or mundorfs, or something like the dueland cast. Just don't know enough about how these work and understand there is proabably value in trying something and listening to the results.

Jeff Glowacki 21st February 2013 08:56 AM

While we finished our conversation via email, be sure to post any questions you have as you perform your upgrades. And of course, I will be interested to read your assessment of the results.

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