steenoe said:
Seems we are not gonna get bored for a while
Luckily, although he has many rabbits under da' hat, Nelson pulls them out one by one, so we are neither bored nor overwhelmed! I wouldn't like to see too many new projects at once! Then many people would be reading, contemplating, but only few building...
So far, Lego approach works best!
Vix
steenoe said:
Maybe not excactly a Blues frontend, which is mostly working as a J-fet buffer, but I guess too that if there is an additional gainstage its a J-fet thing. Maybe more like a diffpair, assuming its a X'ed F3? The F5 could be the active crossover for mating a woofer to a fullrange speaker. Seems we are not gonna get bored for a while
Steen
I say, F6 will be F3 with a beefier CCS (Aleph of course) and another Cascode branch for the additional current through the LU jfet.
would this be an appropriate place to ask for a recommendation for heat sinks for the F4? I am looking to build the four channel, balanced configuration using the schematic in the service manual. My least favorite part is casing projects up, so I promised myself I would start here this time to ensure things actually get completed
Thanks in advance!
Thanks in advance!
While crossovers exist on our site, I would sure be interested in Nelson's insights into how he does it. It may include passive components at line level. Yes we know it can be done, but some nice comments based on experience are always a great help.
I certainly need to cross my full range to a bass speaker in a bi amp configuration and I know I'm not alone!
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As far as heatsinks, as we just discussed , look at any of the First Watt amps and since you are doing the balanced configuration, double the size. NO doubt even bigger is good..
I just posted this http://www.diyaudio.com/forums/showthread.php?postid=1234285#post1234285 but thought it is more appropriate to ask here.
Variac:
"
As far as heatsinks, as we just discussed , look at any of the First Watt amps and since you are doing the balanced configuration, double the size. NO doubt even bigger is good..
"
so, are you implying that it's possible to put the balanced configuration in a single chassis?! Any particular recommendations?
"
As far as heatsinks, as we just discussed , look at any of the First Watt amps and since you are doing the balanced configuration, double the size. NO doubt even bigger is good..
"
so, are you implying that it's possible to put the balanced configuration in a single chassis?! Any particular recommendations?
Steen:
I haven't had much luck with the search engine, I've read all the posts with "heat sink" in the title and having problems finding older First Watt amp threads that talk about heat sink sizing
Any idea on what size I should be looking for? I was considering two 400mmx160mmx40mm which measure Rt°C/W = 0,23. I'd prefer to go with this one, as it will match my other DIY stuff and includes a full case. Other than that, I guess there is always the surplus sales large plates that measure 11-5/8" x 26" x 1-1/8" high or 11-9/16" x 18" x 1-1/8" high.
I haven't had much luck with the search engine, I've read all the posts with "heat sink" in the title and having problems finding older First Watt amp threads that talk about heat sink sizing
Any idea on what size I should be looking for? I was considering two 400mmx160mmx40mm which measure Rt°C/W = 0,23. I'd prefer to go with this one, as it will match my other DIY stuff and includes a full case. Other than that, I guess there is always the surplus sales large plates that measure 11-5/8" x 26" x 1-1/8" high or 11-9/16" x 18" x 1-1/8" high.
luvdunhill said:Steen:
I haven't had much luck with the search engine, I've read all the posts with "heat sink" in the title and having problems finding older First Watt amp threads that talk about heat sink sizing
Any idea on what size I should be looking for? I was considering two 400mmx160mmx40mm which measure Rt°C/W = 0,23. I'd prefer to go with this one, as it will match my other DIY stuff and includes a full case. .....................
nope ;
you'll get (320W/2 x 0,23 x 1,1) + 25=65,48 deg C ....in best case
what's C/W ratio for these?
what's my target temperature? around 50 deg C?It doesn't seem to say. Here's a link:
http://www.surplussales.com/Heatsinks/HeatSink1.html
I guess perhaps my best option would be a custom heat sink?
luvdunhill said:
It doesn't seem to say. Here's a link:
http://www.surplussales.com/Heatsinks/HeatSink1.html
I guess perhaps my best option would be a custom heat sink?
go to www.apexjr.com and look has Steve something for you......
you can always mail to steve and ask for more info
or check ebay
luvdunhill said:Steen:
I haven't had much luck with the search engine, I've read all the posts with "heat sink" in the title and having problems finding older First Watt amp threads that talk about heat sink sizing
Any idea on what size I should be looking for? I was considering two 400mmx160mmx40mm which measure Rt°C/W = 0,23. I'd prefer to go with this one, as it will match my other DIY stuff and includes a full case. Other than that, I guess there is always the surplus sales large plates that measure 11-5/8" x 26" x 1-1/8" high or 11-9/16" x 18" x 1-1/8" high.
In my view it would be more practical to build two normal stereo versions of the F4 with the added bonus of being able to run them balanced so they act as two monoblocks. Nice and flexible.
You even gets the added bonus of being able to move the amps
The heatsinks you mention should be good for monoblocks, if you have 4 of them. Do you have a picture of them?
Steen
steenoe said:
In my view it would be more practical to build two normal stereo versions of the F4 with the added bonus of being able to run them balanced so they act as two monoblocks. Nice and flexible.
You even gets the added bonus of being able to move the amps
The heatsinks you mention should be good for monoblocks, if you have 4 of them. Do you have a picture of them?
Steen
I am starting to agree about the separate chassis. At this point, I'm just looking for the largest, single heatsink I can find. I've come up with these:
http://www.surplussales.com/Heatsinks/HeatSink1.html
and the MF35-151.5 from Conrad. I've e-mailed surplussales about the thermal resistance of the two largest heat sinks on the above page. It "seems" that the (HSK) 6-H001-A is will have a lower thermal resistance than the Conrad MF35-151.5...
Then there's the heatsinks at www.apexjr.com that Zen Mod refered to above... the price is definitely right, but I wish they were black ... choices, choices...
Also, maybe with so many people buying F4 PCBs there can be a group by of the R-Theta heatsinks again?