Balanced F5 question

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well I would love one, but this 50 other guys thing may be a stumbling block for my fragile ego :D if so, 500USD if it merits it, which it sounds like it will. obviously that doesnt include the ...:eek:...shipping:bawling: awesome living not far from conrad (well ONLY in the next state) but not so hot being on the other side of the planet from Patrick. that could perhaps be a deal killer too, considering it will probably add well over 100USD to the price and could go with something custom for that 600USD total. though of course I would not need the sinks as I would get them directly shipped here. I dont for a minute think I could do as well as EUVL's design, but it would be mine and only mine
 
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Not to discourage anyone:
This amp can be built on the cheap way also.
Dissipation is quite the same as in the F5. So, 500va for two channels should work, even less. Look at stock F5.
F5 Psu filtering downscaled to 16v should work too.(may be a bit more capacitance to respect Q=CV)
The only thing is the cost of matching the devices though, as Thanh said, NN and PP output matching is the most important. Matched input jfets are not expensive.

I have built some F5 for cheap, using second hand heatsinks and transormers and some alu plates.
Just my two cents.
 
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Not to discourage anyone:
This amp can be built on the cheap way also.
Dissipation is quite the same as in the F5. ...
Bobo, i think that this amp has +/-16V PSU and 2 pairs of MOSFETs with each pair having Id of 2A. So, it makes 32V x 4A = 128W per channel. Standard F5 uses +/-24V with 1 pair of MOSFETs and Id of 1.3A - it means 48V x 1.3A = 62.4W per channel. It's almost double Pd if I'm not wrong...
 
This is the hifi2000 design you were talking about, with 10mm front plate ?

http://www.modu.it/pesante_diss_10mm.jpg

For me too thin. See how thick the PL front plates are .....

Our design is better, that I can say for sure. But of course always a matter of individual taste.



Patrick


That is the one. I like the sounds of your case better, and it would be great to help out the forum at the same time.
 
At work now so on the fly again.

Patrick have you taken in to account heath spreaders for the mossfet.

May be worth fitting the power fet on to a copper plate so to ditibute the heat on a larger area of the sink and maybe a further plate on top so to help with heat disipation and putting even pressure on the mossfet thus not relaiing on the fitting holes only.

May be worth looking in to it now as maybe if the sinks are anodised may be worth having an area of those bare and lapped.

As juma mention there is a fair bit of power involved
Al
 
The Conrad sinks are blank on the flat side.
The back face is about 10mm thick, so no real heat conduction problems.
Any spreader plate less than 10mm thick is not helping at all.

There are tricks to get heat spreading much better, but you don't want to know !!
Too complex, way too expensive, and then people would say over-engineering, not worth it.

All true, that is why it is hobby and not business.... :)


Patrick
 
Don't you think that such a good F5X design from me also does not deserve a gorgeous looking enclosure from the same designer ?
;)
Patrick


Definitely !
I am very much interested in a nice case. I like especially heavy, thick, machined, pass-style CNC-parts on the case.
 

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Like EUVL says, you guys are impatient! ;)
His proposed design is lovely, and he is correct- a massive case costs at least a semi-massive amount of money. OTOH compared to commercial gear we are
still spending much less.

To return his favor ;) : EUVL is making super nice case for himself that he might consider making copies of for people too.


We will attempt to get some case going- maybe a cheap andd sturdy and attractive and maybe a more expensive one. The idea isn't to make a lot of money for the forums, just some, and to get our members some thing which is hard to find : Good cases at reasonable prices.
 
Bobo, i think that this amp has +/-16V PSU and 2 pairs of MOSFETs with each pair having Id of 2A. So, it makes 32V x 4A = 128W per channel. Standard F5 uses +/-24V with 1 pair of MOSFETs and Id of 1.3A - it means 48V x 1.3A = 62.4W per channel. It's almost double Pd if I'm not wrong...

Yes, i was wrong by a factor of two.
I am so bad that i cannot count until two:D
Though, if stock F5 works with 300va, the balanced one will do it with 600.

Patrick.
The idea is to open the build to every wallet also.


Yes your amp deserves a great enclosure, though, some people here are able to diy such one.
I, for instance do not want monoblocks as working multi amp.
Too many cases.
 
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