@UKToecutter:
Maybe it would be the best to make a list of all the guys who would like to have PCB's?
cheers,
matthias
Matthias,
I already have.
Please see my signature. There is a link to a list
The E007 is a much nicer one, but difference between 7" and 12" height will likely be marginal as well.
Base thickness is the limiting factor beyond 7 to 8 inches height, as you can see from the thermal image.
To get any slope beyond 8 inch height requires a base thickness in the order of 3/5" or more and high performance fins, the ridged potato chip look (with or without chocolate).
(cigarette boats have two engines because rotation of a screw has a net resulting force in the transverse plane, a single engine boat pulls to one side. Surface drive screws have the highest rotational efficiency at those speeds. Mercury racing 552ci => 1350HP each)
Folks:
While very excited about the prospect of building an F5T v3, I do confess some nervousness about the heatsinking of this amplifier. As a newbie, I rely on the expertise of others on this site. Andy has clearly done admirable work, but the F5T heatsinking requirements appear to be daunting. I'd rather construct more expensive fan-less monoblocks that promised long-term reliability than a slightly noisier stereo amp (whisper quiet fans are still whispering), though a single box would certainly simplify things. I don't mean to disparage anyone here or to sew discord, but how much easier would the F5T build be if the boards were split into P and N pcbs?
One other question: if split F5T boards were available, would it be feasible to mount one 8" or 9" above the other on paired Heatsink USA E007 sinks that were, say, 24" tall? I'm imaging a 24" high, 20" wide, 10" tall enclosure. Just how big must a fan-less stereo F5T built from the E007s be?
Regards,
Scott
While very excited about the prospect of building an F5T v3, I do confess some nervousness about the heatsinking of this amplifier. As a newbie, I rely on the expertise of others on this site. Andy has clearly done admirable work, but the F5T heatsinking requirements appear to be daunting. I'd rather construct more expensive fan-less monoblocks that promised long-term reliability than a slightly noisier stereo amp (whisper quiet fans are still whispering), though a single box would certainly simplify things. I don't mean to disparage anyone here or to sew discord, but how much easier would the F5T build be if the boards were split into P and N pcbs?
One other question: if split F5T boards were available, would it be feasible to mount one 8" or 9" above the other on paired Heatsink USA E007 sinks that were, say, 24" tall? I'm imaging a 24" high, 20" wide, 10" tall enclosure. Just how big must a fan-less stereo F5T built from the E007s be?
Regards,
Scott
Scott,
I share many of your concerns.
However, there is no way that my wife would entertain an amplifier in the lounge that was 2' high!!!!
For that reason, I choose to go deeper (400mm) rather than higher and I will use some 'Quiet PC' fans.
My heatsinks will be external rather than internal.
I know that DIYer's will come up with many innovative solutions to the problem.
In reallity, however much we simulate, the 'proof of the pudding is in the eating' so the saying goes.
At this point in time I know of no F5 Turbo V2's and V3's that have been built to the new schematic so we don't currently have a benchmark.
Also the dissipation will vary dependant on what each individual chooses for his supply rails and how 'hot' he bias's.
Me, I'm only looking for about 100W into 8 Ohms so I will be conservative with my AC supply.
Comments welcome.....
Andy
100W output at 8ohms, with a good amount of bias will give you about 300W from the wall pr ch. that can not be done from one heatsink without forced cooling.
..total agreement.
People entertaining the idea that a 250mm deep stereo V3 is possible...even with forced cooling it would be a task and then some.
V3 is a BEAST no doubt about it.
but most will not use it. if they can build them as monoblocks, the 5U 500mm chassis from modushop can be used. 2pc for V3 monoblocks. 1pc for V2 stereo amp. every colling issues solved.
100W continuous output power in 8 Ohm means 40V peak.
Add 5V for losses : 45V rails.
100W Class A in 8 Ohm means 2.5A bias.
With 45V rails : 225W output stage dissipation, of which the heatsinks will have to swallow ~220W.
But why full Class A ?
Bias to 25W in 8, the rest in AB : 110W for the heatsinks !
Still desire full Class A : go fan blown or build yourself a huge stereo power amp.
(me balanced X-files, 50W Class A, rest AB, 2 boards on 1 heatsink tunnel, with those pretty Noctua fans that Ihquam posted)
how about 2 output boards and one front-end board?
then they dont need to mount front-end board on heatsinks, and it will be easy to adjust bias and ofsett without unbolting the heatsinks.
This is what i consider a balanced option ...nice choice
Bought a couple of those fans yesterday....very good stuff, perfect for us
they are 12 v, if run at 9...will be dead silent.
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