More Model 19 questions

My 19's are clones, with 416Z woofers and 9028A horn drivers. Presently they are tri-amped with the horn/woofer x-over at 24 db/oct 1200 hz. Sounds really nice.

But I have a curiosity as to what the originals sounded like. I'd like to try the passive crossovers. So I have an 8ohm horn driver and a 16-ohm low frequency speaker.

Can I build the original x/o and hang a 16 ohm resistor across the woofers? Swap the woofers for 8 ohm versions? Build the Zilch version and adjust for the higher woofer impedance?

Any input appreciated.

thanks
Les

Quote:

---

Originally Posted by les winter

Can I build the original x/o and hang a 16 ohm resistor across the woofers? Swap the woofers for 8 ohm versions? Build the Zilch version and adjust for the higher woofer impedance?

---

Unless you have HF compensation in your active setup, you're not hearing M19 performance.

Build Z19s, doubling the L and halving the C in the lowpass for 16 Ohm woofers. If the HF ends up out of the adjustable range (too "hot"), lower the bridge cap from 6uF to 4 uF to increase the overall HF attenuation....

Thank you Zilch. I should have included that I am using the compensation from the original 19's for the horns. Has anyone listened to both the Z19's and the originals and commented? I searched around but didn't see anything posted.

thanks again.
Les

One or two builders have compared them. I suspect a large element in their preference for Z19s is that the components are all new, and to spec. Nobody's done the Solen vs. Dayton vs. whatever thing yet.

The alternative source of HF drive in Z19 results in a wider range of adjustability and reduced interdependence of the controls, i.e., they're easier to get "right." They are also biampable, for those who might desire even further SPL freedom, or prefer to run the HF on toobes.... ;)

Tubes is me.

Thanks for your input.

I have the big inductors on hand.

I'll do the Z19.

regards
Les

What is the "Zilch" version of that XO? Where can I see the schematic for it?

Pardon me, I am pretty new to this forum.

thanks,

Abe

Quote:

---

Originally Posted by les winter

I'll do the Z19.

---

Report your findings, please.

[We'll want pics, too. ;) ]

Quote:

---

Originally Posted by amandarae

What is the "Zilch" version of that XO? Where can I see the schematic for it?

---

http://www.hostboard.com/forums/alte...ml#post1845497

Scroll back from there to see measurements of current GPA 902-8a driving 811, 511, and MR931 using it.... :)

Thank you very much Zilch!!

Two other questions if you do not mind, first, can I use it for a 416/802D combo? Second, what is the effect with regards to sensitivity? In other words, with your XO in use, what will be the sensitivity rating of the speakers?

Thanks very much in advance!

Abe

Zilch: here is a pic of the completed 19 w/o the ducts and without the foam on the horn.

Quote:

---

Originally Posted by amandarae

Two other questions if you do not mind, first, can I use it for a 416/802D combo? Second, what is the effect with regards to sensitivity? In other words, with your XO in use, what will be the sensitivity rating of the speakers?

---

416 is a Model 19 woofer.

The system sensitivity is a function of the woofer sensitivity, so long as the HF compression driver has sufficient efficiency to balance with it.

802Ds do not have tangerine phase plugs, and to the extent that it relies upon them, you'll not be able to achieve extended high-frequency response using Model 19 HF compensation topology. If that's what you're after, you'll need 802-8G or 902 class compression drivers.

Quote:

---

Originally Posted by les winter

Zilch: here is a pic of the completed 19 w/o the ducts and without the foam on the horn.

---

Mighty beautiful work, I must say.... :Star::Star::Star::Star:

Thanks Zilch!

Thanks Zilch.

I built the 19Z's and like them. I'm adjusting them now. Do you know if anyone came up with suggested settings in ohms for the l-pads?

If I settle on using the 19Z I will rebuild with oil-filled motor run caps. I used Bennics and other stuff I had on hand for this go around.

Nice design Z.

regards
les

The optimum settings vary with driver/horn/woofer combination. For any particular one, it is possible to determine the optimum settings via system response measurements, measure the resistances of the control elements out of the circuit, and substitute the equivalent fixed resistances in lieu of the L-pads. Key to Z19 is its versatility in providing the requisite HF comp and attenuation for a variety of system component compilations including the Altec standards as well as considerably beyond them....

Is there a plans section anywhere for a Z19 ,with recommended components and all that stuff ,that's easy for a basic diy'er to accomplish ? Like a step by step intro etc?

:)

Quote:

---

Originally Posted by DaveCan

Is there a plans section anywhere for a Z19 ,with recommended components and all that stuff ,that's easy for a basic diy'er to accomplish ? Like a step by step intro etc?

---

Follow the link in Post #7 of this thread. There's a layout pic, schematic, and parts list provided.... :)

Are the level controls on the Model 19 pots or L-pads used as pots? Anyone know?

thanks
Les

Hi Les,

For the 8 ohms, you can use 8 ohm pots (two of the three legs) with a proper rating. For the 32 ohms, it is easier to get an L pad and use the 32 ohm leg(terminal 1 and 2) than finding an appropriate 32 ohm potentiometer.

ERSE - L-Pad 8 ohm 15 watts per channel. You might want to check this site also https://www.madisound.com/store/index.php?cPath=404_83

I use Fostex R80B for my N501-8A clone and the Yung LP50 for my 1201.

abe