Water-cooled Aleph idea

[MEGA-amp]

I've been itchin to go ahead with water-cooling for quite some time now. I've spoken to NP regarding raising the front end bias on the Aleph, and he definitely helped me figure out what needed to be changed. Do any other values around the front end need to be changed if i'm doubling the front end bias? FQP3P20 for the diff pair and 12 FQA19N20C for the outputs.

The cold plate is part# 6P-12, 10"x12", 0.0033 Rth, 6 pass. The part is 200USD; a bit pricey, but better than shelling out 500-600 or more for huge sinks.

http://www.d6industries.com/HeatSinks.htm




and of course my favorite cheat sheet is attached:

[Serge66]

Hi Mega-Amp,
Actually, I have been toying with the idea of a water cooled transistor amplifier. So far, I have been building vacuum tube amps, and now to drive my Magnepan MG12QR to reasonable levels, I have been thinking of a T amp. With water cooling. The only draw back that I can think of is the fan noise.

Have you visited websites offering CPU water cooling systems? They may offer a cheaper solution than d6 industries. Have a look at Tom's hardware. That's where I noticed a German manufacturer http://www.webshop-innovatek.de/asse...-innovatek.de/
You can communicate with them in English, no problems. They may have a reseller in the US.

I should be able to start work on this amp next year. Hopefully. I'll post text and pix.

Serge

[Redshift187]

I have used Innovatek water cooling in my PC in the past. If you get a good radiator, you can cool the water by convection alone (without a fan). I was water cooling my chipset, video card and cpu without a fan. The radiator was outside the case. HighSpeedPC sells Innovatek in the U.S., but they no longer seem to sell the radiator I had.

[Serge66]

Hi Redshift,
Yes, you are right. Innovatek offer the option of using either active (fan+radiator) or passive cooling (larger radiator, no fan).
I plan to use the active cooling to save space.

What do you think of the price. Would it be cheaper than 6d industries?

Serge.

[twitchie]

If I may offer my 2cents here - if you're just in the proof of concept phase, you can go the same route pioneer computer watercoolers went - diy waterblocks and raid the autoparts counter, pond/aquarium pumps

You may want to work on soldering skills and just solder copper tubing to a copper plate (it works pretty well), or you can just take a small heatsink and epoxy a water box around it (works pretty well too) and drill/tap pipe fittings into it.

A cheap aquarium pump should be in the $30-50 range (I had a small RIO way back then, don't remember the model number - then I bought a 400GPH unit later on).

For cooling the water, try the junkyard - scrounge up a heatercore - most of the extreme computer watercooling radiators were originally heatercores or oil coolers. I picked up one brand new from the auto parts store for a 80's chevrolet chevette.

In the end, it's your project, so just make sure you have fun with it and be sure to post plenty of updates and pictures

[MEGA-amp]

At around 1280watts dissipation for my setup, I think those may be a bit small for this application. I will be using a car radiator, 2 dc car fans, and a used dishwasher pump @ 1-5 gal/m(variac adjustable). The cooling unit will have to be run remotely of course due to noise and space constraints. I'm just not sure how much I can increase bias and voltage. According to that sheet, 50watts fet dissipation, 73c junction temp, i should be safe, but how far can you push these numbers when your water cooling?


edit> yes its definitely an experiment to see how far you can push it. I'll post some pics as I progress....might be a while though.

[bluemartini]

Have you read GROLLINS post on water cooling?

Water cooled audio circuitry

[Serge66]

Hi Twitchie,
Yes, that the Spirit of DIY.
Hi Mega-amp,
Do you need that much power?

I intend to build a 50W RMS (into 4 ohms) transistor amp.
At the moment, I feel that is right. My Williamson (tube) has an output of 22W. Depending on the CD quality, that can be a bit low.
But I can double the power to 100W RMS very easily using the X concept. Bridged amp.

Serge

[MEGA-amp]

Do you need that much power?

Of course not. Its definitely a proof of concept project. I don't have a set pair of speakers, the ones I have now aren't even mine, and they're many in my project folder that i'd like to experiment with. This would provide a solid foundation for just about any speaker combination I want to try.

[Redshift187]

Wow, yeah a PC water cooling setup would be too small. I was using what looked like a heater core (12 passes of copper inside the fins), and I was only dealing with about 200W of heat.