Model 14 Rebuilding L pad ...confused on what version to use

[ttalmage1]

I have disassembled a pair of Model 14s I bought last winter....When I pulled the L pads I noticed that both had
the duel inductor coils. The differences between the two was that pad A had two (2) factory 6 ohm capacitors
wired side by side in parallel .. the other B pad had only one 6 ohm. Both pads had the 2 ohm capacitor and the 470
ohm capacitor.

The other difference between the L pads is the A pad (with the two 6 ohm capacitors) has a 7.5 ohm resistor instead
of the 10 ohm on pad B.

Should I rebuild as pad A with a total capacitance uf =12 ...replace with a 10 uf seen in most drawings or use the pad B
6uf configuration?? Finally ... the resistor should I use the 7.5 or 10 ohm?

Thanks,
Trent2t

[xinu]

The terminology you are using to describe the M14 crossover doesn't make any sense to me.

I suggest using your favourite search engine and enter "altec model 14 crossover".

BTW -Capacitance is labeled and measured in farads, Resistance is labeled and measured in ohms.

[ttalmage1]

The terminology you are using to describe the M14 crossover doesn't make any sense to me.

I suggest using your favourite search engine and enter "altec model 14 crossover".

BTW -Capacitance is labeled and measured in farads, Resistance is labeled and measured in ohms.

Sorry... two pads ....all caps are 6uf and 2 uf not ohms.... rookie error!!!

Still need questions answered .....

The other difference between the L pads is the A pad (with the two 6 uf capacitors) has a 7.5 ohm resistor instead
of the 10 ohm on pad B.

Should I rebuild as pad A with a total capacitance uf =12 ...replace with a 10 uf seen in most drawings or use the pad B
6uf configuration?? Finally ... the resistor should I use the 7.5 or 10 ohm?

[mah]

Schematic(1500Hz): Analysing Model 14 crossover

Ignore the rest of the post.

[Earl K]

According to Richard C. there were 2 or 3 variants made of the M14 crossover .

Here are 2 of them ( the woofer & horn are represented in these pics as resistor & coil values > so don't get confused when you can't find them in your own network ) .

Choose one type and go from there .

( Right-Click & Open the pics in new tabs to see full-size for readable text )





The third type appears to be this one ( which Mah provided the link for ).

[ttalmage1]

According to Richard C. there were 2 or 3 variants made of the M14 crossover .

Here are 2 of them ( the woofer & horn are represented in these pics as resistor & coil values > so don't get confused when you can't find them in your own network ) .

Choose one type and go from there .

( Right-Click & Open the pics in new tabs to see full-size for readable text )





The third type appears to be this one ( which Mah provided the link for ).

Thanks!!.... recapping this weekend...

[mah]

The circuit boards have the same component lay-out with some component value differences. The component IDs are printed on the boards and are shown in the 3rd schematic in the Earl K post, above.

Most values are the same in the 3 versions, except for:

1st schematic: C4=6uF, L1=0.25mH, L2=0.67mH

2nd schematic: C4=10uF, L1=0.25mH, L2 not used.

3rd schematic: C4=12uF, L1=.20mH, L2=0.60mH.


Trent, you probably have one each of schematics 1 and 3 if your boards each have 2 chokes. If so, you could restore them to original and then see if you have a preference after a period of auditioning.

[mah]

Trent, Re the 10ohm resistor mentioned in your original post: Do you have another version of a Model 14 factory schematic?

The article linked to, here, describes and shows pics for FOUR versions:

Altec Lansing Model 14, Part 1 - Audiophile Nirvana

Unless there is a fifth version(with 2 inductors), the inductor values shown in schematic 3, above, may be incorrect or the claim of L1=0.25mH and L2=0.67mH in the article may be incorrect.

I would support the idea that schematic no.3 should show L1=0.25mH and L2=0.67mH. Thus the only difference between schem. 1 & schem. 3 is C4(6uF vs 12uF), thus simplying crossover matching.

- - - Updated - - -

Pro. version:

http://www.greatplainsaudio.com/vint...spec_sheet.pdf

Single choke crossovers in the 9842s????, maybe.

4 different crossovers for the model 14 in its short life at the end of the Altec Consumer Product era seems odd but you ever know with Altec.



Model 14 pics:

Crossover Help Needed With ANOTHER Pair of ALTECS

[mah]

Some Altec literature:

AL 6061-4: http://www.lansingheritage.org/image...home/page2.jpg

AL 1712-7: http://www.lansingheritage.org/images/altec/catalogs/1984-pro/page12.jpg

AL 6068: Dropbox - Altec Pro Speaker Systems

AL 6069: Dropbox - Altec Pro Speakers

[ttalmage1]

Trent, Re the 10ohm resistor mentioned in your original post: Do you have another version of a Model 14 factory schematic?

The article linked to, here, describes and shows pics for FOUR versions:

Altec Lansing Model 14, Part 1 - Audiophile Nirvana

Unless there is a fifth version(with 2 inductors), the inductor values shown in schematic 3, above, may be incorrect or the claim of L1=0.25mH and L2=0.67mH in the article may be incorrect.

I would support the idea that schematic no.3 should show L1=0.25mH and L2=0.67mH. Thus the only difference between schem. 1 & schem. 3 is C4(6uF vs 12uF), thus simplying crossover matching.

- - - Updated - - -

Pro. version:

http://www.greatplainsaudio.com/vint...spec_sheet.pdf

Single choke crossovers in the 9842s????, maybe.

4 different crossovers for the model 14 in its short life at the end of the Altec Consumer Product era seems odd but you ever know with Altec.



Model 14 pics:

Crossover Help Needed With ANOTHER Pair of ALTECS

MAH.......Considering using 10uf cap ..... splitting the difference between 6 uf cap and 12 uf cap.... what do you think?