Re-locating Crossover Boards to Make Upgrades Easier (2.3TL)
Bubinga99
Posts: 283
While doing a crossover upgrade I moved the crossover boards in my original 2.3TL's and mounted them on risers, so that the big capacitors replacing the originals (especially the small NP electrolytics) could be installed on both sides of the board.
The extra room with 2-sided mounting gives you a lot more options on mounting the new components, without contorted leads and weird component orientations as you try to squeeze things in. I also mounted all the resistors on the backside.
Thought I'd post some pics in case anyone wanted some ideas on trying something similar.
Below is a pic of the upgraded crossover board on risers. I made the risers from some leftover UHMW sheet stock I had lying around, but you could also order some standoffs like this:
http://parts.digikey.com/1/parts/442407-standoff-m-f-hex-6-32thr-1-37-l-4823.html
with length appropriate for the diameter of your capacitors that you mount on the backside.
The base board is just a hunk of plywood scrap and the risers are screwed in from the back. Then I glued the base board to the speaker cabinet. I was able to orient it near enough to the large 16mH inductor so the factory leads on the crossover board reached (though it would be easy to replace with slightly longer leads if needed):
(The double set of holes for the PR came that way from the factory)
The crossover board then just sits on the 4 risers, screwed in for easy removal in the future, if needed.
The only component that still ended up with some contorted leads was the 1/2 ohm resistor replacing the polyswitch (because the solder pads are small and right next to each other). Also, the original 22 ohm resistors in the tweeter crossover circuit were mounted vertically, but they had fairly large metal traces on the back so I just scraped away some of the solder mask and lap soldered the new resistors horizontally on the backside.
Another odd thing I noticed on both my pairs of 2.3TL's is that the 750pf capacitor in parallel with the 16uF capacitor (in the tweeter circuit) is only connected on one side. Looks like they left out a jumper. So it was never in the circuit. Didn't matter in the end because I took all the 750pf caps out.
The extra room with 2-sided mounting gives you a lot more options on mounting the new components, without contorted leads and weird component orientations as you try to squeeze things in. I also mounted all the resistors on the backside.
Thought I'd post some pics in case anyone wanted some ideas on trying something similar.
Below is a pic of the upgraded crossover board on risers. I made the risers from some leftover UHMW sheet stock I had lying around, but you could also order some standoffs like this:
http://parts.digikey.com/1/parts/442407-standoff-m-f-hex-6-32thr-1-37-l-4823.html
with length appropriate for the diameter of your capacitors that you mount on the backside.
The base board is just a hunk of plywood scrap and the risers are screwed in from the back. Then I glued the base board to the speaker cabinet. I was able to orient it near enough to the large 16mH inductor so the factory leads on the crossover board reached (though it would be easy to replace with slightly longer leads if needed):
(The double set of holes for the PR came that way from the factory)
The crossover board then just sits on the 4 risers, screwed in for easy removal in the future, if needed.
The only component that still ended up with some contorted leads was the 1/2 ohm resistor replacing the polyswitch (because the solder pads are small and right next to each other). Also, the original 22 ohm resistors in the tweeter crossover circuit were mounted vertically, but they had fairly large metal traces on the back so I just scraped away some of the solder mask and lap soldered the new resistors horizontally on the backside.
Another odd thing I noticed on both my pairs of 2.3TL's is that the 750pf capacitor in parallel with the 16uF capacitor (in the tweeter circuit) is only connected on one side. Looks like they left out a jumper. So it was never in the circuit. Didn't matter in the end because I took all the 750pf caps out.
Post edited by Bubinga99 on
Comments
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nice job! I will be doing mine one of these days and this will help out a lot.The Gear... Carver "Statement" Mono-blocks, Mcintosh C2300 Arcam AVR20, Oppo UDP-203 4K Blu-ray player, Sony XBR70x850B 4k, Polk Audio Legend L800 with height modules, L400 Center Channel Polk audio AB800 "in-wall" surrounds. Marantz MM7025 stereo amp. Simaudio Moon 680d DSD
“When once a Republic is corrupted, there is no possibility of remedying any of the growing evils but by removing the corruption and restoring its lost principles; every other correction is either useless or a new evil.”— Thomas Jefferson -
I like that method..I might try it.Most people just listen to music and watch movies. I EXPERIENCE them.
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If possible, I'd also add a standoff to the center of the board to minimize vibration."He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss the abyss also gazes into you." Friedrich Nietzsche
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If possible, I'd also add a standoff to the center of the board to minimize vibration.
This is a great suggestion.
Nice work on the rebuild, BubingaVTL ST50 w/mods / RCA6L6GC / TlfnknECC801S
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