Proposed Parts List for Model 19 Crossover

[BillWojo]

I started a proposed parts list to build my own Model 19 crossovers. I am trying to keep as close to the same parts as Altec used but some things are not specified in the schematic.

The inductors used in the stock crossovers are iron core, these are air core. Does that make any difference?

I have a question concerning the wire gauge, I think that 18AWG should be fine but I may be off basis on that. I'm not an EE so would the more experienced folks on here chime in please? Looking at the schematics I see that both the high and low frequency's pass through inductor L1, maybe the heavier but costlier 14AWG would be better?

C1 and C4 are not exact values, I could not find exact matches. The ones I picked out are 5% tolerance. Will these be ok or should I stack 2 capacitors to get the exact value like I did for C3?

R2 and R4 are not exact values, I could not find exact matches. The ones I picked out are 2% tolerance. Again, is this close enough?

I will update this as answers come in. I know that the rough cost to build two crossovers using this parts order is about $215.00. I am looking to keep this a decent quality build and not use over the top components. Looking at fancy pants caps and inductor's I could see this easily costing over 1000.00 bucks to build. Not looking for that. Not saying that you shouldn't do it, I just can't afford it. Another member here is looking to do the same as me.
Help me come up with a reasonable cost DIY crossover build.
Thanks for any input.

BillWojo



All part numbers are from Parts Express unless otherwise noted.

Capacitors: Solen or Jantzen (C4 is a Jantzen, no close value in a Solens)

C1 8mfd---8.2mfd PN: 027-564 $6.73 each
C2 16mfd---16mfd PN: 027-578 $9.29 each
C3 21mfd---11mfd PN: 027-571 $7.94 each Note: To get 21 mfd, use both the 10mf and
11mfd caps wired in parallel.
10mfd PN: 027-568 $7.50 each
C4 6mfd---6.2mfd PN: 027-558 $4.73

Inductors: Jantzen

L1 0.3mH----0.3mH 18AWG $6.70
Or use heavier gauge at additional cost
0.3mH 14AWG $14.41
L2 2.7mH----2.7mH 18AWG $16.48
L3 0.77mH--0.75mH 18AWG $7.81 Note: 0.77mH is not a stock component.

Resistors: R2,4,5,6 are non inductive resistors, Dayton Brand

R1 + R3 8ohm L-Pad----8ohm, 100 Watt PN: 260-262 $12.95 each (includes knob, hardware and plate)
R2 + R4 3.9 ohm, 10 Watt---4.0 ohm, 10 Watt PN: 004-4 $1.38 each (could not find 3.9 ohm)
R5 2ohm, 10 Watt------2.0 ohm, 10 Watt PN: 004-2 $1.38 each
R6 3ohm, 10 Watt------3.0 ohm, 10 Watt PN: 004-3 $1.38 each

[mah]

Use the same AWG that Altec used. The crossovers were designed to handle more power than is usually applied in domestic use.

Anyone know the original wire gauge used?

[BillWojo]

I'm all for that mah but without seeing a set of originals I have no idea what AWG that they used. From my reading it seems that you can go larger in the wire diameter (smaller AWG number) as it reduces the resistance in the inductor but as you go bigger the inductors themselves get really big and very expensive.
Also, would it make a difference being Altec used iron core inductors and my parts list uses air core inductors? I believe that the air core inductors are better than iron core inductors. The iron core inductors may use a lighter or heavier AWG in their construction? GPA builds a Model 19 crossover replica with air core inductors. Does anyone have one and can you measure the wire diameter? It would be interesting to measure the wire diameter of the iron core inductors as well.

Here is a list of wire diameters measured in thousands of and inch and the corresponding AWG number.

12AWG = 0.081
13AWG = 0.072
14AWG = 0.064
15AWG = 0.057
16AWG = 0.051
18AWG = 0.040
20AWG = 0.032

If anyone could help with some of this information, it would be a big help.
Thanks

BillWojo

[mah]

Members, here, should be able to give you the DC resistance of the original inductors.

I see a can of worms being opened.

[BillWojo]

Ok, one more post before bed. According to the Jantzen website the power ratings for there inductor coils is as follows.

18AWG 300Watts RMS
15AWG 500Watts RMS

Since the rating of the Model 19 is way below that, I "think" we should be safe.

I see that I left the PN for the inductors out of the list above. I'll add them sometime tomorrow. If you go to the Parts Express website and punch in any of the PN, the part will pop up and you can see all the info on it.

Quick question, how come the format changes and my post get squished into a column when I post it?

BillWojo

[Elitopus1]

I wonder what brand GPA uses? They have the exact values on their new M19 xover.

It sucks that many of the values that Altec used are now hard to find. I recapped some N801 xovers and Jantzen (as well as a few others) had the 18uf. For my N501 xovers the 28uf are very hard to find. There isnt enough room inside the box to stuff 2 caps to add up to the single value.

Bill-
I am interested to see your final xovers. I need to build or buy some 1200hz xovers for my 616 duplexes