Pass F4, F5 and Aleph J - which runs coolest?

[stoolpigeon]

In terms of heating up my listening room I am wondering which of these designs runs coolest.

I ask because I have the parts to build all of them but for the next year or two will have a rather small non airconditioned room.

Thanks, sp

 

[Danger Mouse]

I have only the J and the F5.
But there the F5 is the cooler Amp of the both. (same Heatsink size)

 

[buzzforb]

Aleph J and F4 dissipate roughly 105.6W at stock settings. The F5 disspates roughly 88W,

 

[stoolpigeon]

Thanks buzzforb for the figures and Danger Mouse your experience seems to support them.

Cheers, sp

 

[Zen Mod]

Aleph J and F4 dissipate roughly 105.6W at stock settings. The F5 disspates roughly 88W,

moi thinks that Pa deliberately keeps us confused , all these years

 

[generg]

yes it is con fusion that holds us together.....

 

[buzzforb]

I am confused.

 

[buzzforb]

Oh! AJ has two pair per channel. Double that figure

 

[Zen Mod]

Que?

 

[buzzforb]

If he is considering the store board for the aleph j , then he has four get per channel biased at 1.2A each and running 22V rails. Bout 200w per stereo amp, correct? F4 has 3 pairs at about .4A each and 22V rails, making about 100w for stereo. F5 has single pair biased at 1A, I think, not sure, and 22 v rails makes 88W. I am sure I missed something. Thinountain air getting to my brain.

 

[luvdunhill]

All three are the same into 8 ohms. Clones may differ.

 

[buzzforb]

Yes, but the OP's question was concerning heat, not power.

 

[Zen Mod]

assuming 2x22Vdc is resulting PSU voltage from 2 x 18Vac Donut , and all values are taken from Papa's FW pdf's :

F4 : 200mV across 0R47 means : (0V2/0R47) x 44Vdc x 3 =56,17W dissipation/channel

F5 : 0V59 across 0R47 means : (0V59/0R47) x 44Vdc x 1 = 55,23W dissipation/channel

J , nothing else but :

Place the amplifier in a well-ventilated location, as it draws 200 watts
during operation and requires as much opportunity to cool itself as
possible.

misleading , all the time ............ in other words : ook ya , use your head , nothing is carved in stone



edit : conclusion - one need different eggs , to posh them on different FW amps

 

[OllBoll]

The one with the biggest heat sinks of course =)

And the amps can be downscaled, in the AJ for example you could fairly easily if I remember correctly halve the bias and remove one output pair thus halving dissipation.