Dreadnaught Avel-Lindberg 1000VA Transformer Group Buy?

nspindel

motorstereo wrote: »

jonicont wrote: »

When burning in, does volume matter or is just providing a signal enough?

I'm also still in awe at the sonic upgrade this thing has given me and I've still got a long ways to go on the burn in process.

Great to hear!

Moose68Bash

Guys, I have a question to which, unfortunately, I think I know the answer, but I'll ask fro input from those who undoubtedly know:

Shouldn't there be continuity through both the primary and secondary sides of the transformer when it is properly connected?

I installed my A-V 100VA transformer today; reassembled Larry's enclosure, and decided to test for continuity before I reinstalled the Dreadnought in my system. I got continuity on the secondary side, but not on the primary side.

Yes, I should have checked before I reassembled the enclosure, but I was impatient.

Before I take the enclosure apart to check without using the binding posts, I want to make sure I understand what these readings should be.

Thanks.

DarqueKnight

Yes, there should be continuity on the primary and secondary side, but not between primary and secondary.

Moose68Bash

Thank you, Ray.

I was pretty sure that was correct, but I wanted to be certain before disassembling the enclosure again.

Now, I guess I better hope that its a problem with one of my solder connections and not a problem with the primary side of the transformer.

drumminman

Probably something simple. Someone once posted that when you have a new issue with a piece of gear, most of the time it's related to the last change you made. I would start there and work back.

If you post a pic it might be easy to diagnose.

Moose68Bash

drumminman,

Thanks. I think I just found the problem.

It's not that I'm color blind, but I was doing the wiring in the evening under less than ideal light. I mistook the gray wire for the violet wire and therefore had the primary side wired incorrectly.

The transformer comes with the pairs of wires for the primary side "bundled" with black tubing, and I did not check whether they were bundled for parallel, rather than series, wiring. And, I didn't notice the color difference as noted above.

My bad!

drumminman

Excellent! When I built my first one I thought those colors were very close too. As I recall I had to shine a flashlight directly on them just to be sure I didn't mix them up.

Moose68Bash

Yes, correcting the "dufus" wirning mistake put the Dreadnought into fine working order!

Another investment in the education of a newbie!

Thank you, DarqueKnight and drumminman.

nspindel

So how's it sound?

Moose68Bash

Neil,

So far its been playing for a couple of hours, and it sounds better than the 670VA Toroid of Maryland transformer that it replaced. It has added depth and clarity to the rendering, and it is clear that my normal listening level for my preamp will be on 16-18 rather than 22-24 (on a scale of 0-59).

More later.

Thanks again for pulling this together!

motorstereo

I have a question for those in the know. I've done a bit of poking around here and I haven't found the answer yet. Correct me if I'm wrong but there's out of phase signals from the left speaker going to the right dimensional drivers and vice versa for the sda effect. I'm wondering just how the speakers get these out of phase signals when it's isolated from the opposite speaker's signal with the dreadnaught?

DarqueKnight

The out of phase signals are passed from one speaker to the other through inductive coupling in the transformer. What the transformer prevents is an electrical connection between the speakers which would cause an electrical short circuit with non common ground amps.

Mr_Hz

I am still waiting delivery. I leave out of town next Tues morning, not returning till late Friday afternoon. No doubt with my luck, delivery will attempt 3 times while I'm gone and send back ( I assume signature required?) May have to touch bases with A-L to see where my delivery is at and possibly make arrangements if not too late.

motorstereo

DarqueKnight wrote: »

The out of phase signals are passed from one speaker to the other through inductive coupling in the transformer. What the transformer prevents is an electrical connection between the speakers which would cause an electrical short circuit with non common ground amps.

Thanks once again DK. I had to google "inductive coupling" to get a grasp on exactly what that is and now I have a pretty good idea on how the dreadnaught works.
One more question if you don't mind. Why should the dreadnaught make the speakers so much easier to drive? It's quite noticeable that to get the same listening levels as pre-dreadnaught levels it takes a much lower setting on the volume knob. My amp puts out the same wattage at any impedance so it's not lowered impedance that's causing the increased sensitivity in my case. I'm still in awe of the overall upgrade the dreadnaught has given me and I'd like to understand a little bit better just why it's having such a profound effect

Moose68Bash

I, too, understand the theory behind how the Dreadnought works and, therefore, solves the problem of using non-common ground amps with SDA speakers.

Yet, the Dreadnought in my system that uses a common ground amp also delivers much higher sound quality with the Dreadnought v. the standard SDA interconnect that came with my 1Cs.

Moreover, going from the 670VA toroidal transformer to the 1000VA transformer also yields a palpable improvement in sound quality.

This part of it, I don't understand.

dpowell

I picked mine up from the post office yesterday and can't wait to get it hooked up! VR3 mod binding post plates with speakon connectors were installed this morning which means I'm totally without SDA effect until the dreadnaught is completed. Thanks again to all who made this possible.

Moose68Bash

dpowell wrote: »

I picked mine up from the post office yesterday and can't wait to get it hooked up! VR3 mod binding post plates with speakon connectors were installed this morning which means I'm totally without SDA effect until the dreadnaught is completed. Thanks again to all who made this possible.

You've got a great incentive to get it built! Have at it!

DarqueKnight

motorstereo wrote: »

Why should the dreadnaught make the speakers so much easier to drive? It's quite noticeable that to get the same listening levels as pre-dreadnaught levels it takes a much lower setting on the volume knob. My amp puts out the same wattage at any impedance so it's not lowered impedance that's causing the increased sensitivity in my case. I'm still in awe of the overall upgrade the dreadnaught has given me and I'd like to understand a little bit better just why it's having such a profound effect

The ground plane of an amplifier contains a lot of electrical noise. The Dreadnought provides isolation from that noise, therefore the signal sounds apparently louder, although, if you measured the pre-Dreadnought and post-Dreadnought signals with a sound level meter, they would measure the same. These analogies illustrate the concept:

Assume the pre-Dreadnought signal is at a level of 85 dB and that the signal contains 90% music and 10% noise. If the installation of the Dreadnought results in a signal that is 98% music and 2% noise, yet still at 85 dB sound level, the music will sound louder because you are hearing 8.8% more music and 80% less noise. Therefore, you find yourself turning the volume control down to "get back to" the sound level you were used to.

Another way to look at it is a conversation in a noisy, crowded room. If everyone else in the room stops speaking or if they lower the level of their voices to whispers, the person speaking to you will sound louder even though they are talking at the same level as before. The sound level that was adequate for a conversation in a noisy room is now unnecessarily, and perhaps uncomfortably, loud in a quiet room.

Moose68Bash

DarqueKnight,

As always, a great and clear explanation.

I think you've also explained the reason the SQ improves -- i.e., less noise in the signal, hence clearer music.

Thank you.

TennMan

I understand how the isolation transformer is needed with non common ground amps. That makes sense.

I have no doubt that the transformer does work to improve the quality of sound because you guys say it does. But, it seems odd that an isolation transformer can do a better job of connecting two speakers together than a straight piece of wire. It also seems odd to me that you can add a much much longer length of wire to the circuit that ties two speakers together (the windings in the transformer) and the volume of the speaker will increase. I'm not an electrical engineer but that all seems very odd to me.

Also, Anytime I mention installing a high quality switch in a circuit for some reason I hear "Don't do that. You don't want to add anything extra that might cause distortion." but adding a transformer seems to be OK. Doesn't that seem inconsistent at best?

TennMan

DarqueKnight gave a good explanation of how the dreadnaught works while I was typing and it makes sense. Thanks for explaining!

motorstereo

Thanks once again Darqueknight for answering another one of my questions in a way that I can now understand how this works.
If you don't mind I have yet one more. Since the ground plane of an amplifier has so much noise this now has me wondering. Would it be beneficial to add another one or possibly 2 more dreadnaughts to the negative wire going to the speaker? Would this reduce what little noise must be left yet even further or would this simply be overkill and not noticeable?

DarqueKnight

motorstereo wrote: »

Since the ground plane of an amplifier has so much noise this now has me wondering. Would it be beneficial to add another one or possibly 2 more dreadnaughts to the negative wire going to the speaker? Would this reduce what little noise must be left yet even further or would this simply be overkill and not noticeable?

Polk speakers designed for use with the AI-1 have the effects of the transformer accounted for in the design of the speaker. If you were to add more transformers, you will be exceeding the speaker's design and performance parameters in a bad way.

Also, a transformer is a four terminal device, meaning there are two input leads and two output leads. Putting a transformer in series with the negative speaker wire would mean that only one input lead and one output lead could be used and you would have an incomplete circuit.

motorstereo

Once again I thank you for your easy to understand explanation Darqueknight. I'll leave well enough alone then and enjoy the huge upgrade the dreadnaught has already given me.

dpowell

I'm speechless. I can't believe how good this thing sounds and it doesn't even have 5 minutes on it yet.

dpowell

Direct quote from the wife: "It sounds so much more detailed. Where did you put it and what does it do?"

drumminman

Tell her it's magic

motorstereo

dpowell wrote: »

I'm speechless. I can't believe how good this thing sounds and it doesn't even have 5 minutes on it yet.

Give it some time..........it gets even better. I'd have to rank this one as one of the very best mods I've done to mine and quite possibly the best ever. I've made electronics upgrades in the past that didn't have near the effect that the dreadnaught has.

Moose68Bash

drumminman wrote: »

Tell her it's magic

It is magic!

drumminman

What are folks using for feet on the cases?