LX-mini Crossover Article

[Nelson Pass]

Don't forget that the J113 and 2SK170 have different pinouts.

If 2SK170 is a follower then 1 ma idss matching is adequate.

 

[elwood625]

Don't forget that the J113 and 2SK170 have different pinouts.

Thank you, I forgot to mention that. They were not hard to install, I used a magnifying glass to make sure the pins were not shorted together.

 

[rich31td]

Here is my LXmini ACV built, think the signal wires are a bit long.

 

[Norgaard]

Here is my LXmini ACV built, think the signal wires are a bit long.

It is not that they are long, - it is that they are long enough for you to twist them - and then you should
Looking great! - and fun to see the Mini ASP in the same box as the 521.x ASP

 

[namghiwook]

I built this LXmini crossover and measured DCs according to the LXmini crossover article.

These are guiding DCs

R47, R48, R49 ~ 0.5 V DC this will vary a bit, depending on the Jfets
R50, R51 ~ 11 V DC
R13, R14, R15, R16 ~ 0.7 V to ~1.0 V DC
R35, R36, R37, R38 ~ 0.7 V to ~1.0 V DC
R39, R40, R41, R42 ~ 0.0 V DC
R1, R2, R3, R4 R31, R32 ~ 12 V DC

... and I measured.

R47 (0.8), R48 (0.8), R49 (0.8) <= some high values

R50 (10.88), R51 (10.88)

R13 (1.46), R14 (1.45), R15 (1.48), R16 (1.47) <= some high values

R35 (1.36), R36 (1.45), R37 (1.48), R38 (1.46) <= some high values and R35 is little bit lower than others

R39 (0.003), R40 (0.003), R41 (0.000), R42 (0.001)

R1 (12.27), R2 (12.0), R3 (12.24), R4 (12.0), R31 (10.53), R32 (10.58)

Are these acceptable?

 

[namghiwook]

Can I provide preamp 40Vpp output as input source of this LXmini crossover?

 

[Nelson Pass]

Not recommended. The standard supply is 24 volts, so maybe 20v peak to peak, with distortion.

 

[namghiwook]

@Nelson Pass
Thank you for reply.

 

[teknofosssil]

Hey all. I have been MIA for a while with other projects. I'm wondering if the3 way LX-mini crossover project that NP hinted at in his original article for the analog crossover (for the LX-mini's). I am going to be using my minis as part of my HT system since I am downsizing and combing my 2 systems. Thanks! -T

 

[Nelson Pass]

You mean the Lxminis plus sub?

 

[teknofosssil]

Yes, for dipole subs.

Thx!

 

[khoasonphong]

I got a lot of pair 2SK246 and J103 BL grade. Someone can give some advices, is it possible to do it with my JFETs ?

 

[Zen Mod]

yes, no changes

you'll just have slightly higher Rout, due to lower xconductance vs. originally used

 

[khoasonphong]

always you , thank you.
maybe we need a buffer like B1 after XO.
my system: LOW will be put my BA3 - DEF amp, and HI will be next B1-THF single end amp.
Wonderful christmas time. ha

 

[Zen Mod]

you're good, no need for additional buffers

I mean - try, if you like it, you know what to do

use best PSU you can think of, it always pays off

 

[khoasonphong]

yeah, already start .

 

[bjohng]

NP "You mean the Lxminis plus sub?"

My10 year old minidsp just died and is no longer supported. I would prefer to replace it with the analog unit if it is likely to become available any time soon -
3 way including dipole subs.

Thanks

 

[Manolo47]

I built this xover 3 years ago. Wonder that suddenly the Low frequency output volume in one channel is much lower than in the other.
So, what part in that section would be likely compromised in your opinion?
And I can order a new kit and built it.
Thanks for looking

 

[mworthin]

NP "You mean the Lxminis plus sub?"

My10 year old minidsp just died and is no longer supported. I would prefer to replace it with the analog unit if it is likely to become available any time soon -
3 way including dipole subs.

Thanks

There is a kit here: https://linkwitz.store/product/asp-lxmini2-nelson-pass/. Here is a photo of my PCB build.

 

[elwood625]

Low frequency output volume in one channel is much lower than in the other.

I think the first part to check would be the 25K input pot. After that, look for poor solder connections on that channels Low freq. circuit.

Please post pictures of your crossover, both sides of the PCB, this will help others give you better advise than mine.