My New Amplification Project (moved from another thread)

[jimfisheye]

Well, that's sure a lot nicer than what I've been mixing on!

I'll have to send you a couple works in progress and have you tell me what they actually sound like.

 

[HomerJAU]

My new amps arrived last week. I was pleasantly
shocked when I saw the 20kg shipping box, hand made:

Here’s the amps in my cabinet, they were heavier than I expected (the large solid heat sinks):

First impressions on sound: These sound very detailed with a little more bass and mid range over the old. Definitely much cleaner at higher volume when pushing out reference levels. Very happy with what I’m hearing so far.

I’ve let them run for three 4 hr sessions playing 5.1 pretty loud, mostly unattended and they get quite hot. On one warmer day they both hit 46 deg C after about 3hrs (114F) on the top lids

I’m going to retro fit thermal pads between SMPS heat sinks and chassis walls and chassis bottom to see if I can get the temp down a few degrees. Keeping lower temp will prolong life.

Maybe I’ll need a couple of small Hifi rack fans (silent).

 

[LuvMyQuad]

I’ve let them run for three 4 hr sessions playing 5.1 pretty loud, mostly unattended and they get quite hot. On one warmer day they both hit 46 deg C after about 3hrs (114F) on the top lids

I’m going to retro fit thermal pads between SMPS heat sinks and chassis walls and chassis bottom to see if I can get the temp down a few degrees. Keeping lower temp will prolong life.

Maybe I’ll need a couple of small Hifi rack fans (silent).

I thought I read somewhere that the newer class D modules radiate alot of thier heat toward the bottom of the board. Would you say yours exhibit that characteristic?

 

[HomerJAU]

I ordered some 310mm x 310mm Graphite Thermal Pads (0.13mm thick) rated at 20 degC/mK heat conductivity from Digi-Key in Minnesota on Tuesday morning at 8:00am MEL time. It just arrived at 11:00am on Thursday morning !!! Just 2 days and 3hrs from time of order to me in Melbourne, Australia via UPS (free as my order was over $50 AUD.

Thatt’s got be a record for delivery time?

 

[HomerJAU]

I thought I read somewhere that the newer class D modules radiate alot of thier heat toward the bottom of the board. Would you say yours exhibit that characteristic?

Most of the heat is via the SMPS and Amplifier boards which have large heat sinks at bottom.Next time I do a test run in I’ll take temperature readings on all 4 sides,top and bottom. This will be prior to adding any thermal pads.

I will then repeat tests at same ambient temperature after I fit the thermal pads to compare. On AudioScienceReview there’s threads about adding thermal paste to amplifier heat sinks but no one has done proper before and after testing.

I chose pads over paste as paste needs replacement in as little as 3 years whereas graphite pads will last much longer (many, many years). These graphite thermal pads have a higher thermal conductivity rating than paste too and less messy. Will it make a significant difference? I’ll know next week...

It seems accepted in electronics that for each 10 degC of temperature rise causes 50% less capacitor life. So it’s worth trying to lower the temp as these amps are going to be with me for a long time (I hope )

 

[timothyemerson]

Looking awesome! Coincidentally, I just received these yesterday MULTIFAN S7, Quiet USB Cooling Fan, Dual 120mm, watched a movie last night with them exhausting on top of the receiver and it's way cooler - almost like it hasn't even been on. In tighter positions, the fans can also be placed vertically next to your hardware and exhaust or blow the air into the machines. In terms of the racket they make, I had them spinning away on high and didn't notice them even during quiet parts of the movie (I sit about 3 metres from them).

 

[HomerJAU]

I had them spinning away on high and didn't notice them even during quiet parts of the movie (I sit about 3 metres from them)

Thanks. I was looking at these for my amps and was wondering about their noise level. Is your AVR enclosed or on an open shelf?

My chassis only have small air slots but I’m sure they’d help.

 

[timothyemerson]

Thanks. I was looking at these for my amps and was wondering about their noise level. Is your AVR enclosed or on an open shelf?

My chassis only have small air slots but I’m sure they’d help.

Mine's semi-open shelf with a fair amount of breathing room above it. The whole front of the unit is open and there are gaps at the back for all of the wiring which facilitates a decent amount of airflow - looks pretty similar to yours. Here's a pic:



Just let me know if you have any other questions about the fans.

 

[boxhead]

I ordered some 310mm x 310mm Graphite Thermal Pads (0.13mm thick) rated at 20 degC/mK heat conductivity from Digi-Key in Minnesota on Tuesday morning at 8:00am MEL time. It just arrived at 11:00am on Thursday morning !!! Just 2 days and 3hrs from time of order to me in Melbourne, Australia via UPS (free as my order was over $50 AUD.

Thatt’s got be a record for delivery time?

Wow. I remember being impressed when Burning Shed could get an order to Australia in 5 days, but this takes the cake.