F5 power amplifier

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#5,321
jackinnj said:
Note that the mounting hole for the Fairchild devices seems designed for a metric screw. I have drilled it out to accommodate US/UK screw sizes without ill effect.

I also received some TO-220 analogs to the TO-247's which are now difficult to source. Hopefully I can test these in the next couple of weeks.

By the way, the US Post Office just reported this morning that they had a software meltdown for package tracking in the US. Most packages mailed from October 1st this year can't be tracked.
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Thanks for the update, Jack. Keep up the good work 🙂
 
#5,322
jackinnj said:
Note that the mounting hole for the Fairchild devices seems designed for a metric screw. I have drilled it out to accommodate US/UK screw sizes without ill effect.


Thanks for that information Jackinnj, I had done the same and thought that may have been the reason my F5 had a premature death. Good to know.[/COLOR]

I also received some TO-220 analogs to the TO-247's which are now difficult to source. Hopefully I can test these in the next couple of weeks.

By the way, the US Post Office just reported this morning that they had a software meltdown for package tracking in the US. Most packages mailed from October 1st this year can't be tracked.

Good thing they're working on fixing Health Care next![/COLOR] Not Political
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Ron
 
#5,325
CBRworm said:
Have there been many F5 deaths while within the original design parameters?

I'm curious because mine runs about 16 hours a day and as of yet I have not added any protection for the speakers.
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Just check for offset every few weeks and when you turn on/off amp/speakers watch for excursion which will indicate DC.
You probably knew that but just in case.
Uriah
 
#5,326
CBRworm said:
Have there been many F5 deaths while within the original design parameters?

I'm curious because mine runs about 16 hours a day and as of yet I have not added any protection for the speakers.
Click to expand...

CBR,

My fault entirely, this was my first attempt at building a SS amp. Very much a Noob.
The Amp is stable and a great performer. So say those who have built them correctly, and those of us who had the pleasure of attending BA3.
Chocolate is the appropriate adverb. Just like Nelson says.

BTW, "CBR", any reference to the dog?

Ron
 
#5,327
Renron said:
CBR,

My fault entirely, this was my first attempt at building a SS amp. Very much a Noob.
The Amp is stable and a great performer. So say those who have built them correctly, and those of us who had the pleasure of attending BA3.
Chocolate is the appropriate adverb. Just like Nelson says.

BTW, "CBR", any reference to the dog?

Ron
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No, CBR is the motorcycle I ride. Luckily Honda has kept the CBR designation for many years - I haven't had to change this username since I picked it in the early 90's. Ironically the model of the bikes have been 600F2, F3, F4 and now 1000RR - which might be why this line of amps caught my attention.

My F5 has also been rock solid despite my numerous attempts to improve it. It literally runs all day every day at levels from barely audible to much louder than I would have thought such few watts could provide. My speakers are known to be amp killers (vintage infinity - highly reactive, low impedance and low efficiency), but this amp has dealt with them very well so far. The only precautions I take are an oscilloscope on the outputs to watch for clipping. People who know me don't believe me when I say this, but the F5 has displaced my Adcom GFA-555ii as my daily amp. I never would have believed I could be this happy with less than 150 watts per channel. I am typically a horsepower guy.

The one thing I did differently is that I have the heatsinks turned inwards and a (nearly) silent 120mm fan that moves air over them and over the power supply without moving any air over the amp boards themselves - they only get convection. My heatsink temps end up being in the mid 40's and the case temperature is usually in the mid 50's.
 
#5,328
CBRworm said:
and now 1000RR

Boy, you live life dangerous

It literally runs all day every day at levels from barely audible to much louder than I would have thought such few watts could provide.

Sounds like a describtion of my RVF400(Honda ofcourse)

My heatsink temps end up being in the mid 40's and the case temperature is usually in the mid 50's.
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Creative convection cooling is...cooool
But I dont understand how air inside amp can be hotter than your heatsinks
Though I plan to use convection cooling solely to cool down the supply caps
Trying to figure out a way to shield the caps from heatsink, and Jfets maybe :scratch2:

Man, I sure hope this cascoded input is going to happen, keeping F5 nice and hot fore another round
 
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#5,332
jackinnj said:
Note that the mounting hole for the Fairchild devices seems designed for a metric screw. I have drilled it out to accommodate US/UK screw sizes without ill effect.

I also received some TO-220 analogs to the TO-247's which are now difficult to source. Hopefully I can test these in the next couple of weeks.

By the way, the US Post Office just reported this morning that they had a software meltdown for package tracking in the US. Most packages mailed from October 1st this year can't be tracked.
Click to expand...

Hopefully this didnt affect shipments after 10/20, where does one get the tracking number from?
P>S> Had Email from Tech-DIY, I shouldnt have even been concerned. How great someone is willing to put all this and more together for an easy purchase.
Russellc
 
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#5,334
thanh1973 said:
Not yet. But I will definitely be giving it a go.
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I sure hope you will

I have searched spec sheet
But I dont understand
2SK135/2SJ50 appears to be TO-3 power devices :scratch1:
 

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