Nick wrote:
If you want I will find you the chap I bought the devices from.
Yes pleas nick that would be Handy
I can get the F5 boards from Diy audio shop I had hoped I could have got a set of the semiconductor from the shop as well would make sense to supply then with the boards as an option
OK thank you nick
Found him
Right one more bit of advice required if that's ok pleas
Heatsinks Pair
For one F5 amp which Conrad Heatsinks would you pick from?
1. MF35-100 Flat C/Watt for 80 °C rise Thermal Resistance 0.28
2. MF35-151 "Flat C/Watt for 80 °C rise Thermal Resistance 0.21 http://www.conradheatsinks.com/products ... 0_350.html
Or the smaller MF30-1F-75 Flange Thermal Resistance 0.37
Well, the idle current is 1.3A, 24v, so thats 31W a device, or 62W a a side. If you aim for a device temperature of 45C or so, and 25C ambient, thats 20C, So that would mean you are looking for a 0.32C/W heatsink, So from that list I would go for the 0.28C/W one. But remember the amp sounds best with the devices hot, so using too large a heatsink is to be avoided. If its a bit cool, you can always nudge the current up a bit if you use a 300VA transformer as that will have loads of spare capacity.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
Cant say about anyone else. I am suggesting that some of your suggested money saving decisions may be a mistake (IMHO). Using the power supply and amp boards and transistor sets makes it a much simpler build and removes a number of things that could go wrong.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
Nick wrote:Cant say about anyone else. I am suggesting that some of your suggested money saving decisions may be a mistake (IMHO). Using the power supply and amp boards and transistor sets makes it a much simpler build and removes a number of things that could go wrong.
Well yes
I am just looking at what's involved in the F5 project at the moment see if it's viable for me to build it as I don't want to go down the same path as I did with the valve amp I feel I went the wrong way there
Right So far the F5 pcbs and psu Boards from the diy audio shop http://www.diyaudio.com/store/amplifier ... oards.html
Matched Semiconductor sets from chap in Australia if he still does them
Heatsinks from Conrad
I find this confusing to work out so I always think go for the biggest to be safe but was just tiring to shave some cost of shipping and would prefer the flanged version MF30-1F-75 for an easier build but this one maybe to small @ Thermal Resistance of 0.37
PSU TX I have already 300VA 18-0-18
So biggest cost is heatsinks and maybe psu caps
pre65 wrote:Colin, if you get the Australian heatsinks what are you using for a case ?
Well case build would be based on the retailed F5 and the one nick and most others build using the heatsinks as the back bone of the case yes I know it's easier to say than do but how hard can it be to drill some holes and bolt it Together
Yes, that was the point I was trying to make, the modushop case is complete and the heatsinks are just fine for the F5. Peters boards do not use flange mounting, even though the Pass originals did.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.