OK, I'm stupid....need help with layout from schematic.

[sootshe]

Need help from the experts.

 

I've settled on the attached schematic design & can anyone help me to confirm the layout I have come up with from this schematic?

 

I'm not sure about the connection to the 3636 auto former.

 

 

[ClaudeJ1]

For which speaker? The + on your midrange speaker goes to a number tap on the Autoformer. The Minus on your midrange goes to the Zero on the autoformer. Looks like your capacitor value to the Autoformer is  could be the wrong value depending on what frequency you want to block/rolloff.

 

Also, your drawing of the Autoformer is incomplete and should show X and Y as inputs also, along with the 5. Just tell me how many DB of attenuation you need and I can tell you how to do the input AND output on the Autofomer. The 10 ohm resistor keeps the impedance that the amplifier sees as a constant 8 ohms. The Tweeter and woofer have no attenuation, only the midrange.

[sootshe]

45 minutes ago, ClaudeJ1 said:

For which speaker? The + on your midrange speaker goes to a number tap on the Autoformer. The Minus on your midrange goes to the Zero on the autoformer. Looks like your capacitor value to the Autoformer is  could be the wrong value depending on what frequency you want to block/rolloff.

 

Also, your drawing of the Autoformer is incomplete and should show X and Y as inputs also, along with the 5. Just tell me how many DB of attenuation you need and I can tell you how to do the input AND output on the Autofomer. The 10 ohm resistor keeps the impedance that the amplifier sees as a constant 8 ohms. The Tweeter and woofer have no attenuation, only the midrange.

 

Hello Claude,

This is for a set of Belles with Crites cast frame woofers, A55G mids & JBL 2404 tweets.

 

I think -6db would be a good starting point for the mids. 

I think I understand where the mid driver connections go to, so that I am able to adjust the attenuation (the outputs from the crossover)....it's the inputs that I am not sure about... where to connect the wires from the .2mH inductor & whatever else connects to the input.

 

Looks like your capacitor value to the Autoformer is  could be the wrong value depending on what frequency you want to block/rolloff.

 

I didn't think there was a cap going to the 3636? This is where I need help.....am I connecting everything correctly?

 

Thanks for your assistance.

 

[sootshe]

Do you mean like this?

 

 

[mboxler]

The .2mh inductor needs to be in series between the 40uf cap and the 3636, like you have the .15mh inductor between the 2.2uf and 3.9uf caps.

 

The .15mh inductor should not be in series with the 2.2uf and 3.9uf caps.  Connect the two caps together, draw a line from the middle of that connection

to one side of the .15mh inductor, then connect the other side of the .15mh inductor to common.

 

Place a 10 ohm resistor across taps 0 - 5 of the 3636.

 

[OO1]

7 minutes ago, mboxler said:

The .2mh inductor needs to be in series between the 40uf cap and the 3636, like you have the .15mh inductor between the 2.2uf and 3.9uf caps.

 

The .15mh inductor should not be in series with the 2.2uf and 3.9uf caps.  Connect the two caps together, draw a line from the middle of that connection

to one side of the .15mh inductor, then connect the other side of the .15mh inductor to common.

 

Place a 10 ohm resistor across taps 0 - 5 of the 3636.

 

THANK YOU ------

[mboxler]

2 hours ago, ClaudeJ1 said:

The Tweeter and woofer have no attenuation, only the midrange.

 

If you know what mid driver you will be using, and you want the ability to attenuate the tweeter, remove the .2mh inductor from the input, and we can calculate it's replacement and position it between tap 3 and the mid driver.  Now, if you want to attenuate the tweeter by 3db, attach the 2.2uf cap to tap 4 instead of tap 5.

[sootshe]

Do you mean like this?

 

[mboxler]

More like this.   I missed something earlier, and deleted the wire from the "top" of the 40uf cap to tap 0.

 

Sorry for the poor "Paint" job.  I may find something else after my coffee kicks in.

 

 

[sootshe]

Awesome.......I just can't seem to get my head around this.....and the "paint job" is fabulous.

 

Isn't the 3636 supposed to have two inputs?

The "0" & either "x, y or 5"

 

I've redrawn your sketch so things don't get too messy & here's a photo of a build from the net. (Don't know if this helps or not)

Cheers, John

 

 

 

[mboxler]

Looks like the output to the squawker is inverted, so think I allowed for that in the attached.

 

The "output" from the .2mH inductor should connect to Tap 5, x, or y, as well as one end of the resistor.   The other side of the resistor to common (tap 0).

Mid - should connect to Tap 1, 2, 3, or 4.

 

I moved the common bar connection from Mid - to Mid +, so that Tap 0 is always connected to the common bar.

 

So, for -6 db, input 0 - 5, output 3 - 0 .

 

Hard to tell, but the pictures show only three wires attached to the 3636 as well.  Tap 0 is both input and output and connected to common.

 

I reserve the right to disagree with myself later, but for now this seems right.  See what you think.

 

Mike

[sootshe]

I don't think the connection to the autoformer is right.Keep in mind that the autoformer in the attached build is a 3619 & not a 3636. 

 

If you look at the auto former connection values in post #1 you can see that the input has to be:   0 & either x,y or 5......so two connections

 

& the output is : 0 & either 1,2,3 or 4........so also two connections, that would go back to the mid + & mid - on the connection block. 

[mboxler]

Sorry, but I don't seem to follow, unless you want to connect tap 0 to input IN- ?  That wouldn't hurt, but tap 0 is already connected to the common bar at Mid+.

 

Let's say you do.  Connect IN- to tap 0.  Connect the "output" of the .2mH inductor to either x,y, or 5.  Two connections

 

I drew 4 possible connections "above" the 3636 indicating either 1,2,3,or 4.  Connect this wire to Mid-.   Connect tap 0 to Mid+.  Two connections.

 

Regarding the crossover photo.  It's hard to tell from the 3619, but it appears that...

    Tap 0 to common

    Tap 5 to inductor and Mid +

    Tap 2 to Mid -.

So, input 0 - 5, output 2 - 5.  Not your normal connection, but if my calculations are correct, you get a 1.546 turns ratio, (3.78 db attenuation), and phase reversal.

It will work, but attenuation levels of taps 1 - 4 are not standard.

 

I'm not sure how to wire the 3636 that way.

 

Sorry I'm not helping.

 

Mike

[sootshe]

In the last diagram layout I'm confused about "I moved the common bar connection from Mid - to Mid +, so that Tap 0 is always connected to the common bar."

 

In the layout you show a connection to the Mid+......from Tap 0....so how can Tap 0 be connected to negative?

[mboxler]

5 hours ago, sootshe said:

In the last diagram layout I'm confused about "I moved the common bar connection from Mid - to Mid +, so that Tap 0 is always connected to the common bar."

 

In the layout you show a connection to the Mid+......from Tap 0....so how can Tap 0 be connected to negative?

 

It's unfortunate that the terms Plus and Minus. Positive and Negative, and even Ground worked their way into speaker terminology.  They are either misleading or flat out wrong. 

 

I wonder if you changed the crossover input and output labels from "+" and "-" to Red and Black?  The only purpose of the labels is to help with the amplifier

and driver connections.  Perhaps things will be a little clearer???

 

Mike

 

[Deang]

Right, since a crossover is AC, there is no "ground". The right word is "common". Because of polarity, plus and minus are still important points of reference.

 

Zero on the 3636 is the same as minus on the barrier strip. You can connect all common connections to the same point.

 

Do not use Bob's chart to figure attenuation, it won't work with this particular filter.

 

The original Super AA worked just like the original Universal, in that the common connection for the squawker was NOT connected to the barrier strip (network side). That 'minus' connection is made with the movable jumper. 

 

Here is the attenuation chart for the 3636 using this design.

 

                            + -

0.08638 -21.27 X 4

0.09687 -20.28 Y X

0.10362 -19.69 2 1

0.10880 -19.27 5 Y

0.14519 -16.76 3 2

0.18325 -14.74 Y 4

0.20567 -13.74 5 X

0.20795 -13.64 4 3

0.24881 -12.08 3 1

0.25119 -12.00 1 0

0.29205 -10.69 5 4

0.29433 -10.62 X 3

0.35314 -9.04 4 2

0.35481 -9.00 2 0

0.39120 -8.15 Y 3

0.43952 -7.14 X 2

0.45676 -6.81 4 1

0.50000 -6.02 3 0

0.50000 -6.02 5 3

0.53639 -5.41 Y 2

0.54314 -5.30 X 1

0.64001 -3.88 Y 1

0.64519 -3.81 5 2

0.70795 -3.00 4 0

0.74881 -2.51 5 1

0.79433 -2.00 X 0

0.89120 -1.00 Y 0

[Deang]

.

 

[sootshe]

OK....

so now I'm getting more & more confused.

 

Let's take a step back.....so the layout I"ve attached here now is correct & we just have to figure out the connections to the 3636??

 

If someone can draw on the layout where I need to attach & also which of the output taps on the 3636 are  + (red) & - (black) to the barrier strip crossover side connection. 

 

[sootshe]

7 hours ago, Deang said:

Right, since a crossover is AC, there is no "ground". The right word is "common". Because of polarity, plus and minus are still important points of reference.

 

Zero on the 3636 is the same as minus on the barrier strip. You can connect all common connections to the same point.

 

Do not use Bob's chart to figure attenuation, it won't work with this particular filter.

 

The original Super AA worked just like the original Universal, in that the common connection for the squawker was NOT connected to the barrier strip (network side). That 'minus' connection is made with the movable jumper. 

 

Here is the attenuation chart for the 3636 using this design.

 

                          + -

0.08638 -21.27 X 4

0.09687 -20.28 Y X

0.10362 -19.69 2 1

0.10880 -19.27 5 Y

0.14519 -16.76 3 2

0.18325 -14.74 Y 4

0.20567 -13.74 5 X

0.20795 -13.64 4 3

0.24881 -12.08 3 1

0.25119 -12.00 1 0

0.29205 -10.69 5 4

0.29433 -10.62 X 3

0.35314 -9.04 4 2

0.35481 -9.00 2 0

0.39120 -8.15 Y 3

0.43952 -7.14 X 2

0.45676 -6.81 4 1

0.50000 -6.02 3 0

0.50000 -6.02 5 3

0.53639 -5.41 Y 2

0.54314 -5.30 X 1

0.64001 -3.88 Y 1

0.64519 -3.81 5 2

0.70795 -3.00 4 0

0.74881 -2.51 5 1

0.79433 -2.00 X 0

0.89120 -1.00 Y 0

 

Hello Dean,

 

I sent you an email a while back to see if you could build me one of these. Maybe you don't do that anymore?

 

I'm after a shallow slope design that is smooth & easy to listen to, so researched a lot of your builds & designs. I rarely listen at more than 90db, usually around 85db, so from what I have read this type of design is the way to go. Do you think I can do better than this design? Are there better improvements from newer designs? 

[Deang]

I used to think there was a right answer but I've given up with that nonsense. There is no right answer. People just like different things and there is no way to predict what a person will prefer. Having tried them all, I've always preferred the Klipsch Type AA, but like Al once told me, "you're just one guy in one room", which is very true.

 

At your listening levels, either network would work fine. They both sound good, but they do not sound the same.

 

I don't have time for a side business right now. The pandemic has me remotely managing three junior engineers and two dozen projects. 

 

The resistor goes across taps 5 and 0, and the other end of the .20mH inductor also connects to tap 5.

 

Run a wire from tap 0 to the grounding bar on the barrier strip. You can even slide it under a screw supporting any of the negative connections.

 

You will need an L-Pad for the JBL. If memory serves (usually doesn't), you'll need to knock 3dB off of that thing.