I have 6 pairs (12 pieces) of the 8.5 wide x 8.5" long x 2" fin heat sinks.
They are plenty enough for 6 mono blocks or 3 stereo amps.
The smallish chassis I had drawn earlier with one heat sink per side was good for a 25 -35 watt stereo version also.. But it wouldn't support a stereo 50 watter.
The only reason I am not making small mono blocks with these are the cost and time required to fab the chassis.
They are plenty enough for 6 mono blocks or 3 stereo amps.
The smallish chassis I had drawn earlier with one heat sink per side was good for a 25 -35 watt stereo version also.. But it wouldn't support a stereo 50 watter.
The only reason I am not making small mono blocks with these are the cost and time required to fab the chassis.
lgreen said:
Love the copper clamping bars, and the nice chamfered holes.
For a lawyer you're a good engineer, Mr Green.
What are the spare bars for ?
lgreen said:
HI John,
I'm very interested in the outcome of your X as well. I have been listening to the one I made from the boards you sent me. It really does have a nice sound but compaired to the KSA50 it is anemic. The Krell just has a bunch more slam than the X. If you have good results from your X I may think about adding more outputs to mine.
Blessings, Terry
jacco vermeulen said:
Love the copper clamping bars, and the nice chamfered holes.
For a lawyer you're a good engineer, Mr Green.
What are the spare bars for ?
Well nothing gets by Jacco, I'm glad he was not my boss back when I was digging ditches for summer money.
The extra bars (note that some don't have holes in them) are extras (because I always screw up) but if I don't I'm going to use them for the same thing with a bridge-parallel GC that I'll make for fun after the next amp- a Leach.
... Which I am going to ask Terry to help me with. Then we can compare our Krells, Aleph's and Leach's.
The A-X is almost done, I've just got to drill and tap another heatsink for those pesky copper bars, hook up some connectors to the input boards and figure out how to power it up without a variac and without blowing all the matched mosfets.
GB parts arrived here up north!!!
Fedex just called and told me that they have a package for me. Unfortunately I'm on a different adress now (my mistake thou) so it will take an extra day or so for the regular mailservice to get it to me.
So I'm expecting the jolly, fat guy in red with his raindeers to be here before the weekend 😀
Fedex just called and told me that they have a package for me. Unfortunately I'm on a different adress now (my mistake thou) so it will take an extra day or so for the regular mailservice to get it to me.
So I'm expecting the jolly, fat guy in red with his raindeers to be here before the weekend 😀
lgreen said:
Trench Attorney,
days like these i regret not residing in California, not just for the weather. (But then Mr. Nelson Pass and Mr. John Curl would have to sew me for harassment when i pop up in their front lawn every day)
jacco vermeulen said:
When you pull into the San Diego bay with your yacht just let me know what time the party starts.
Heat sink prices
Hi all-
As I mentioned in the following post I have the heat sinks I was going to use for my Krell for sale.
Price per PAIR is $25 or $40 for two pair.
http://www.diyaudio.com/forums/showthread.php?postid=863932#post863932
I am listing here since they were bought specifically for my KSA clone, but if Al feels it is required I can move this to the "market place" thread.
I wanted to offer them here first.
Al, your call.... Should I stay or should I go now..... Sorry had to throw in some music lyrics since this IS an audio forum. 😀
Hi all-
As I mentioned in the following post I have the heat sinks I was going to use for my Krell for sale.
Price per PAIR is $25 or $40 for two pair.
http://www.diyaudio.com/forums/showthread.php?postid=863932#post863932
I am listing here since they were bought specifically for my KSA clone, but if Al feels it is required I can move this to the "market place" thread.
I wanted to offer them here first.
Al, your call.... Should I stay or should I go now..... Sorry had to throw in some music lyrics since this IS an audio forum. 😀
Re: Heat sink prices
Fine by me, it's a big scary world outside our cozy little Krell band of brothers.
rabstg said:
Fine by me, it's a big scary world outside our cozy little Krell band of brothers.
trimmer settings on Al's boards
Just wondering what the optimum setting for r105 and r126 should be when running +-40V rails. I don't have my power supply together yet but my boards are stuffed. I'd like to have the trimmers matched between each board before I run power through them. For some reason I think it will be easier to match bias and DC offset if both channels start at the same place.
Thanks!
Brad
Just wondering what the optimum setting for r105 and r126 should be when running +-40V rails. I don't have my power supply together yet but my boards are stuffed. I'd like to have the trimmers matched between each board before I run power through them. For some reason I think it will be easier to match bias and DC offset if both channels start at the same place.
Thanks!
Brad
Start with bias set to minimum, offset pots midrange. Connect the power, null DC, then slowly crank up the bias, 100mV at a time, leaving five minutes or so between adjustments to allow everything to settle in. When you have the bias set roughly where you want it, run the amp for an hour or so, then tweak the settings to the exact level required. Then, if you need to, you can adjust the DC for a final time.
I found that when I first turned the amp on to set bias the bias was limited, then as it warmed up bias increased and I had to keep turning it down until finally it roughly stabilized after about 30 min.
This is why its a good idea to set bias at a very low value and let the amp warm up-- because as it does you will see the bias increase.
On the bright side, even if you have bias set wrong and its at the max instead of the min, the max will not be so high as to blow up everything before you realize which end is which and can turn it down.
Closing in on #6000 and K-Amps is no where to be seen. Revenge!
This is why its a good idea to set bias at a very low value and let the amp warm up-- because as it does you will see the bias increase.
On the bright side, even if you have bias set wrong and its at the max instead of the min, the max will not be so high as to blow up everything before you realize which end is which and can turn it down.
Closing in on #6000 and K-Amps is no where to be seen. Revenge!
I can't help myself, I am compelled to ask a stupid question...
How do I know which way is max and which is min when it's not powered up?
~Brad
How do I know which way is max and which is min when it's not powered up?
~Brad
googler said:
Not a stupid question, I worried about this a lot. In practice it won't matter, because as I said-- a cold start will not have a dangerous bias (I think.....) even if the pot is at the max. I would put the trimpot in the middle, on power on turn it one way and watch the bias go up, turn it the other and watch it go down.
However, to really answer your question. If you want to measure the resistance the wiki says-
Ping Mark Gulbrandson
Mark,
Wondering if you could contact me off list at bobgroger@hotmail.com . I have sent you several emails but they seem to have hit the spam filter. This is Re: Krell boards order
Thanks!
Bob G.
Mark,
Wondering if you could contact me off list at bobgroger@hotmail.com . I have sent you several emails but they seem to have hit the spam filter. This is Re: Krell boards order
Thanks!
Bob G.
googler said:
lgreen said:
Yes, sorry, sometimes I expect too much knowledge, because I have built so many of these I assume everyone else has too...
lgreen said:
I'm not sure that is correct. If memory serves me, I burned up some resistors because I had the bias set to max instead of minimum. I've started using the light bulb in series with the mains for first start up of a project. It will let you know if you have too much draw, usually without any damage.
Blessings, Terry
Hi Still4given,
I agree wholeheartedly. Cheap and simple and so far foolproof.
The plug+bulb+socket wait on the shelf for next use.
I agree wholeheartedly. Cheap and simple and so far foolproof.
The plug+bulb+socket wait on the shelf for next use.
Hi All-
Repute has offered to help me kit out the rest of these parts tomorrow. He has also agreed to collect and ship for me since I am VERY busy getting the house ready to sell next month.
If anyone wants kits or heat sinks please send me an email but send paypal payments to:
repute@hotmail.com
Hopefully "better service, same price".... 🙄 Sorry had to.
Repute has offered to help me kit out the rest of these parts tomorrow. He has also agreed to collect and ship for me since I am VERY busy getting the house ready to sell next month.
If anyone wants kits or heat sinks please send me an email but send paypal payments to:
repute@hotmail.com
Hopefully "better service, same price".... 🙄 Sorry had to.
