Phase Linear 400 Fan Assembly Project

[sebtus]

Recently i went and did full pl400 rebuild and i must say i'm am very happy with the results.
I have 4 ohm AR98LSi speakers which make my pl400 very hot, It does not help that i have it seating in the wood case inside a stereo cabinet. there is no air movement and it gets hooot!!. i was looking for a fan to install and i realize that there is nothing there to get. I see many homemade solutions and i thought that i have to come up with my own solution.

Well im not a expert when it comes to designing but i have ideas, and i would like to share one of them with you. Please be easy on me, lol.
I decided to make a design that would meet the following requirements.

- easy install simple design
- two fans - one for each channel
- fan control board to control fan speed based on the temperature
- something that i can afford and make myself. (i spend all my $$ on the upgrade lol)

I order all the necessary parts , some of them already came, and some are still being build by small children in china / not funny but true.

I decided to build a fan housing using a 3d printer.
My printer can not print one big piece so i made three pieces design, which once assembled will make one piece.

Piece I: Right channel housing
Piece II: Control board bridge
Piece III: Left Channel housing

I made the design for right channel and the bridge pieces and i get rest of my parts i will measure them again and if everything checks OK, the printing begins


here is the Right Channel housing design


the design is for a 4 fin sink, where the housing is force-fit onto two outside fins for each channel.
it holds one 80mm fan which will blow air in and then hot air will exit out around the fan(remember i have a wood case). or the fan can be install to pull air out. i don't know which will work better.

Right and left Channel housing will be connected together via the control bridge piece which will be seated in the space between right and left heat sinks

here is the bridge piece ,
Note: i will include into the design power switch, 12v female input connector for a power supply, control board, thermal probe, and fan failure buzzer once i get all the parts in.



Please let me know what you think and if you have any suggestions i take them now before the printing.
Thank you.

 

[laatsch55]

i LIKE IT BUD, VERY ELEGANT solution...

 

[bill7621]

I like it too. What are you going to use for the fan controller or are you designing your own?

 

[sebtus]

There are few available PC fan control boards which should work just fine. i have two coming to see which will work best. For the price it is not feasible to design and make one.

 

[kingman]

BRAVO!!!

 

[Bradrock]

There will be bonus points if you incorporate this very 'COOL' item, instead of just a boring fan:

http://www.ebay.com/itm/12V-6A-DIY-...id=100005&rk=1&rkt=4&mehot=pp&sd=122245768468


There is quite a variety of ideas when I searched '[FONT=&amp]Semiconductor Refrigeration'. In the past , I've alway's just searched for 'cooling fans'.
How about the electric refridgeration pads for laptops?
If gaming desktops can have refridgeration, then why not hi fi equiptment?
[/FONT]https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313.TR1.TRC0.A0.H0.TRS0&_nkw=Semiconductor+Refrigerator&_sacat=0

 

[sebtus]

Lol. This is nice but overkill. 5A to run it lol. And 3 fans. I wonder how loud it gets. I might just get one to play with it.
It is design for cpu. It won't work well with pl400 cooling heatsinks, i don't think.
Condensation is always an issue with this kind of cooling. I used water cooling for my PC rather than refrigerator coolers due to the frost/condensation build up in high humidity environment.
Fans are boring.... But they get the job done hehe.. the ones I intend to used run off 0.16A each. Variable speed. Very quiet, I hope.

I will attempt to print first piece on Monday. One part will take 11h to print, if everything goes as planned.

 

[laatsch55]

3D printing ain't fast, that's for damn sure....

 

[Billboard]

I need to add some fans to me PL 700B, they drive a pair of 4 ohm speakers (Ohm Is), and the amp does get hot, and will shutdown if I run it too long at a high volumes. The pros had trouble cooling these amps when they were used for sound reinforcement, I doubt a couple of muffin fans will be enough.

But couldn't hurt I guess.

 

[orange]

If you're needing fans to prevent thermal shutdown, forget switching, they come on the moment the amp powers up. Later is too late.

 

[WOPL Sniffer]

I need to add some fans to me PL 700B, they drive a pair of 4 ohm speakers (Ohm Is), and the amp does get hot, and will shutdown if I run it too long at a high volumes. The pros had trouble cooling these amps when they were used for sound reinforcement, I doubt a couple of muffin fans will be enough.

But couldn't hurt I guess.

If your amp is shutting down from heat, you are living on borrowed time. Its like a heart attack for amps. Sooner or later (more likely sooner) we will be having a memorial service for your 700B. To me, my amps are worth way more than any speaker. I'd rethink your strategy. If your car overheated from towing something too heavy, would you not unhook the load before the engine blew? Just me spouting again, sorry.

 

[laatsch55]

I need to add some fans to me PL 700B, they drive a pair of 4 ohm speakers (Ohm Is), and the amp does get hot, and will shutdown if I run it too long at a high volumes. The pros had trouble cooling these amps when they were used for sound reinforcement, I doubt a couple of muffin fans will be enough.

But couldn't hurt I guess.

The pros usually had them in racks of 2 to 4 amps. And had them maxed out to boot. A couple of 4 inch fans are plenty to cool a 700B.
I run a pair of 8 ohm speaks and turn my fans on when getting radical...

 

[orange]

I have a few computer fans myself...

 

[Billboard]

If your amp is shutting down from heat, you are living on borrowed time. Its like a heart attack for amps. Sooner or later (more likely sooner) we will be having a memorial service for your 700B. To me, my amps are worth way more than any speaker. I'd rethink your strategy. If your car overheated from towing something too heavy, would you not unhook the load before the engine blew? Just me spouting again, sorry.

If my car was overheating because of excessive load I would probably swap in a larger radiator.

The amp will never die, it can be rebuilt, heck last summer I replaced everything except a handful of parts (WOPL build). I love my Ohm speakers, Love my WOPL 700B, gonna pound the amp and the speakers into the ground, then rebuild them. I will add fans with an automatic fan control and blaze away, get the CPR paddles ready!

This board has been a little light on the repair, build side of things anyway.

 

[Netfly]

Hi Billboard,
I run a PL700 Series II and Ohm I's too. I do love these spearkers http://ohmspeaker.com/legacy-products/i/ and they can sure suck the power out of most amp.
My rule is if the power meters are to the right of half way, turn on the fan. By that time it's so loud you don't hear the fan anyway. I use a small box fan from behind, diagonally across the fins. I have the PL raised on 4 small wooden blocks, so air flows above, below and around it. Never had a shut down due to heat. Hope this helps.

 

[sebtus]

An update on the project:
i had to make some design adjustment before i could print. The printer had a hard time to figure out how to print everything. i had to simplify some of the sections to make it more print friendly. Once i did that i went to printing only to realize i don't have enough ABS filament to get this thing printed, i have PLA but its melting point is lower that ABS. ABS on order and i should get it soon.

Btw what is the safe heatsink temp for pl400 with the WOPL upgrade?

Another observation is that my left channel heatsink, the very last fin is pushed in by the transformer housing, about 5 mm. Is that for all of them? anybody knows?

 

[laatsch55]

Should be plumb and square, no biggie if not as long as the outputs mount up flat. No hard figures on heats ink temp, if it feels hot it is hot..

 

[WOPL Sniffer]

If my car was overheating because of excessive load I would probably swap in a larger radiator.

The amp will never die, it can be rebuilt, heck last summer I replaced everything except a handful of parts (WOPL build). I love my Ohm speakers, Love my WOPL 700B, gonna pound the amp and the speakers into the ground, then rebuild them. I will add fans with an automatic fan control and blaze away, get the CPR paddles ready!

This board has been a little light on the repair, build side of things anyway.

Remind me not to buy any of your abused equipment.

 

[sebtus]

Update:
I am printing left housing as i write this. I had a bit and issue with the misprint due to print coming off the print-bed and i have to use a "special" ABS solution to make it stick, it should work. I am 45% done on 3rd attempt (first with the ABS juice) and it is looking good so far.

This is the final design for fan assembly:


I had all my parts and my middle (control) part is ready for print.

 

[laatsch55]

Pretty cool bud...