AI-1 Dreadnought with common ground amp

[drumminman]

As far as I can tell no one has tried this. Theory is that it may improve sound quality, but there's only one way to find out

My Avel-Lindberg transformer arrived yesterday, and my case from TF66 is on its way, so looks like I may be the first! The amp is an Odyssey Stratos Stereo Plus.

Been thinking about upgrading to Odyssey Monoblocks or a Wyred 4 Sound amp (neither of which are common ground) to get more power in the system so even if there's no difference or a degradation of sound with the AI-1, I should be able to use it down the road.

Hope to get it functional, if not finished, by this weekend. Stay tuned!

[heiney9]

No problem building it for future use, but why would you use it when you don't need it; on a common ground amp? In fact I'm not sure I would do that because it may be detrimental to your amp or the speakers. I would investigate it 100% to see how it will interact with a common ground amp before using it. It might not hurt anything, but then you can't be sure 100%.

H9

[Joe08867]

I agree with Brock on this. It may cause harm and won't sound better with the dreadnought than without. You are just adding stuff to signal for no reason by adding it.

And like he said I don't know if that can harm a common ground amp. In theory I don't think it should but I would be hesitant to test it on an Odyssey Stratos.

[heiney9]

Theory is that it may improve sound quality

Care to expound with some solid details?

H9

[Big Dawg]

Actually, if you search the site, you'll find a number of instances where people have used the AI-1 with common ground amps. As far as I can tell, the consensus is that you will hear no difference, at best, and will likely hear a small degradation of sound quality, at least from the SDA drivers.

[drumminman]

Care to expound with some solid details?

H9

Solid details - uuuhhhhhh, don't have any.

In reading DK's post on building the Dreadnought I saw this idea brought up, and he replied that he thought removing the SDA signal from the amplifier's ground could make an audible improvement. Selected quotes from the original post:

There is actually less electrical hardware with the AI-1. When you use a pin/blade cable and strap, the SDA signal is gounded through the amplifier's ground...and comes with all the electrical noise in the amplifier's ground path.

The AI-1 isolates the SDA signal from the amplifier's ground path, therefore you get a potentially cleaner signal.

People have asked about using an AI-1 with a common ground amp, but I don't recall reading a report from someone who did it. This is on my long list of things to try, but I haven't gotten to it yet.

I don't know of a reason why an AI-1 couldn't be used with a common ground amp.

I would think that taking the SDA signal out of the amplifier's ground path is a good thing, even for a common ground amp.

I suppose I could check with Odyssey, but I can't think of a reason that it would hurt the amp or the speakers. The signal is being isolated from the amps ground path.

[drumminman]

Big DawgDo you recall if this was with the Dreadnought or the stock AI-1?

[Toolfan66]

You will be fine using the dreadnought..

[heiney9]

See you do have some supporting evidence. Should have posted that in the intial post.

Go for it and be sure and do a detailed write-up.

H9

[drumminman]

See you do have some supporting evidence. Should have posted that in the intial post.

Only someone's intuition. But that's enough for me to give it a shot.

I have three mods I've wanted to try in the last couple of weeks: wool felt around the tweeters, replacing inductors in the Xover and building and installing the DK Dreadnought.

After researching the first, I still want to do it, but my enthusiasm is not what it was.

As for the second, there's more to it than I originally thought since Polk no longer has info on the inductor values. I'll need to buy an LCR meter, pull the Xovers, pull the inductors and measure 'em.

But the Dreadnought seems easy since DK did all the heavy lifting, and my gut feeling is that it might make a SQ improvement. A write-up will definitely happen!

[Toolfan66]

IMO you will hear an improvment and be wondering why you waited so long, Just be sure to use some quality cables with it.

I have used my Dreadnought with my Pioneer Receiver with no problems what so ever, So I beleive you will be fine running the DN without issues..

[brgman]

Tool what are you using Carver TFM's with yours?

[Polkie2009]

+1, when I bought a used Dreadnaught here a couple of years ago or so, I remember reading somewhere in all the pages concerning the dreadnaught , that someone had used one with a common ground amp and liked it. Something was mentioned like Toolfan66 mentioned about them wondering why they hadn't tried it before. I may go ahead and try it on my sda's .

[drumminman]

Finished the Dreadnought yesterday morning, and a test IC cable yesterday afternoon. The construction of the Dreadnought is similar to DarqueKnight's: Avel-Lindberg transformer, dynamat on the case, aluminum enclosure from TF66 (DK's was from Par Metal I think), Cardas binding posts, rubber spikes left over from a sub woofer. I may replace the spikes with brass, but the DN sits on a piece of marble in front of a fireplace so I thought these may be better.

Anyway, I didn't want to cut into two halves the IC Cable I was using as it's a labor intensive diy effort that sounds great, so I used some leftover wires from another project. I realized that if the system SQ sounded worse with the DN installed I'd have to alter the good cable anyway to see if the lesser quality cable was an issue, but I couldn't wait to hear the AI-1 in my system.

So, I connected the negative run of cable at each speaker to the negative MW binding posts, and the positive to the extra bp I installed a while back that replaced the IC cable pin socket. Turned on the system and let everything warm up for a couple of hours.

I had Marvin Gaye's "What's Goin' On" in the CDP from earlier in that day so I hit play. What I heard was a more relaxed soundstage that projected a little further into the room, with a little more depth front to back. The spousal unit happened by so I asked her if she heard any difference, and her reply was "It sounds bigger, but softer at the same time". Interesting!

I'm thinking that the A-L transformer probable needs some time to burn in a little, since the only time it has a signal is when music is playing. The sound will probably change a little.

Next up is Flim and The BB's, "This Is A Recording". This a nice, hard to categorize jazz CD, well recorded with a large soundstage. The band has synthesizers, wood winds, electric bass, acoustic drums. Each instrument seemed to occupy it's place in the soundstage a little more definitively. Notes had a slightly more natural decay, with the timbre of each instrument more relaxed sounding. Percussion had nice transients, drums good tone.

Next up Eva Cassidy "Live At Blues Alley". Her voice sounded better than I've heard it. Occasionally on this CD it sounds like she over drives the vocal mics when she sings at the top of her range, but that stridency was lessened with the DN in the system. The soundstage side to side was about the same, but again the front to back 3D quality was enhanced. The speakers disappeared more than before, with the sensation that the musicians were in the room. Guitars had that live quality where I could hear not just the notes or chords played, but the associated harmonics too.

Next up was The Band, "The Last Waltz" remastered, the 4 CD set. I played CD #4 and heard more of what I described above.

To sum up, the DN enhanced qualities already present in my 2.3TL's. The soundstage not only grew, but had increased presence as well. Instruments and vocals had a more natural, organic tone. There was slightly more decay with the notes of each instrument or vocals, which gave them a more realistic quality. Every thing in the band sounded as if it occupied it's place on stage a little more definitively. I heard increased smoothness, but as much or more slam when the music called for it. In fact, one of the comments DK made in his original post is that no longer felt the need to upgrade is monoblocks to get more power. I understand what he's talking about as my common ground Stratos sounds like it has another 50-75 wpc.

My cost for building this: $130 for the transformer (shipped), $70 for the case from TF66 (again - very nice workmanship Larry!) and $52 for the binding posts for a total of $252. Was it worth it? For me, an absolute yes! I enjoyed the system before, but this takes sound quality up another notch.

[Toolfan66]

Pics!!!!!

[drumminman]

Pics!!!!!

Sadly I have no idea how to post pics here. Got an old (2 mp) digital camera that still works though.

Man, you were spot on when you said I would wonder why I hadn't done this before