F6 Illustrated Build Guide

[6L6]

Aleph run hotter than F6, so don’t worry about the comparative difference.

4U400 is enormous for F6, I’m not surprised it runs nice and cool.

You can increase bias if you like, you’ve got the heatsink for it. 😎

 

[ToNi_P]

Thanks 6L6, in this case, I might crank it up a little more 🙂

 

[Zen Mod]

Is that expected?

give us detailed explanation of thermal interface, you did for output devices

 

[audioexplorations]

22c is room temp for most, so this is odd, I always remembered my F6 getting toasty in a 20c room

 

[Jcris]

My F6 heatsinks never really got that hot. Warm to the touch after a bit but certainly not hot. I think that’s expected and considered normal. Check the Mosfets with an IR thermometer.

 

[ToNi_P]

@Zen Mod I used Keratherm(from the store). Nothing else.

 

[ToNi_P]

@Jcris I did, it reads 20 degree C 😅

 

[Halauhula]

I like your third stage or KC filtering g in the dual mono power supply! I assume you are using polypropylene motor run caps as TungstenAudio recommended? Lots of space in that new 400mm deep chassis.

Turning to your issue, can you check to make sure that you are using the correct value source resistors for the output MOSFET transistors? What value do you think you have installed?

 

[Zen Mod]

@Zen Mod I used Keratherm(from the store). Nothing else.

if you're sure that you have it all properly, then go to 40W per device, 80W per channel and case will show it

with effective rails , +/-22V5dc, shoot for 1A77, which is 830mV across 0R47

 

[barossi]

Would the only advantage then be lower THD?

 

[Zen Mod]

and, most likely, better sound

try it - whatever Iq you want, decide with your own brain

 

[ToNi_P]

@Halauhula It's the PSU Zen mod used in the LuDef thread. The F6 is the Kit from the store. I measured all resistors before soldering.
@Zen Mod Im pretty sure the thermal interface is fine. I had it biased at 0.8V but went down to 0.6 again because I just wasn't sure that everything is ok.
I've been listening to music with it for the last two days though, and before that I had it running for the biasing process also for a couple hours on end. I will go up to 0.8V tomorrow and check if it warms up a little.
Thank you guys for the support.

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[Zen Mod]

it'll be warm enough in 4U/400 @80W

if you're not blasting on amp with AC, it'll be at least 25C above ambient

use palm, and trust in it more if your temp. meter is showing funny values

 

[ToNi_P]

@Zen Mod I do use my palm! When I foam the milk for my cappuchino, I check with my hand, too. The milk should not be warmer then 60°C 🤓
Also I remember quite well, how warm my Aleph J was in the 4U/300. I think 6L6 was right. I expected similar behavior than with Aleph J. But most likely bigger case and cooler running amp was confusing me. But I find it still unusually cool with 20°C. I will check again tomorrow. And at some point swap cases most likely. I'll put F6 in the 4U/300, SissySit in 4U/400 and then when I find some time, do the CodyT mod to Aleph J 🙂

 

[Zen Mod]

for what I care, you can put SissySIT in all 3 cases