BrianDonegan said:
Yes, I have a quote. and considering that they're great chunks of aluminum and Australia is as far away from here as it's possible to get it isn't too expensive, but still it'd be a lot cheaper to buy ten heatsinks than it would two.
Sea freight is an option of course, it's ridiculously cheap but it takes 10-12 weeks. I guess if I ordered them now I'd just about be ready to use them in 3 months...nah, maybe not, the biking season starts about then, should have ordered them four months ago!
cheers
Chris
Re: Heatsinks from Conrad
I might be up for a couple of the big double flanged versions, I have lots of T03 devices that I really need to find something to do with.
bremen nacht said:
I might be up for a couple of the big double flanged versions, I have lots of T03 devices that I really need to find something to do with.
I had one channel up and running and was doing some DC measurements to verify that everything was ok when I shorted the positive rail to the output
I had done some measurements with my scope and everything looked great until my little short.... Ohhh well tomorrow I will go through all transistors and verify that they still work.
Terry - this seems to happen to the all of us 🙂
\Jens
Running again....
Some numbers for the 10 transistor version:
DC on output: < 50mV (unmatched transistors)
AC out: 42V RMS loaded by 8 ohms = 220W into 8 ohms. 4ohms untestet yet.
The small overshoot seen on my prototypes is now smaller (maybe due to better Cdom parts... still looking into this)
Will start testing the second channel later today (I hope)
\Jens
Some numbers for the 10 transistor version:
DC on output: < 50mV (unmatched transistors)
AC out: 42V RMS loaded by 8 ohms = 220W into 8 ohms. 4ohms untestet yet.
The small overshoot seen on my prototypes is now smaller (maybe due to better Cdom parts... still looking into this)
Will start testing the second channel later today (I hope)
\Jens
Jacco,
Yes 42V RMS
Rails unloaded = about 70V
Loaded = about 65V
You can use this general rule:
Vout max (peak) = Rails - 6V
\Jens
Yes 42V RMS
Rails unloaded = about 70V
Loaded = about 65V
You can use this general rule:
Vout max (peak) = Rails - 6V
\Jens
Yes, I can attest to that. My Leach clone measures Vout = 44V before clipping at Vrail = 50V.
Looking for artwork for "Smaller Leach Amp"
Jens
I was looking all over the Delta Audio website, but could not find PCB patterns for the 6 transistor Leach board that you completed in May 2005.
Since I've joined the forum after the group buy, I would like the opportunity to make my own board.
Is there any way you could make the PCB artwork available?
Thanks in advance
Andy
Jens
I was looking all over the Delta Audio website, but could not find PCB patterns for the 6 transistor Leach board that you completed in May 2005.
Since I've joined the forum after the group buy, I would like the opportunity to make my own board.
Is there any way you could make the PCB artwork available?
Thanks in advance
Andy
Hi,
I also updated the website with a zipfile containing all the needed files for board production.
Goto: http://www.delta-audio.com/Leach-Clone-6.htm
\Jens
I also updated the website with a zipfile containing all the needed files for board production.
Goto: http://www.delta-audio.com/Leach-Clone-6.htm
\Jens
jens,
do you still have spare boards the 10transistor versions? or are you offering them as a kit on your website?
thanks
do you still have spare boards the 10transistor versions? or are you offering them as a kit on your website?
thanks
Tony,
This is my hobby, so there will be no kit unless it is a GB.
I still have a few boards left for the 10 transistor version email me so we can arrange postage etc.
\Jens
This is my hobby, so there will be no kit unless it is a GB.
I still have a few boards left for the 10 transistor version email me so we can arrange postage etc.
\Jens
I'm sorry...
I must be dumber than you assume.
I cannot use Gerber and drill files and such. I'm making boards by hand, not giving them to a factory. I can only use common graphics images. ( or something that can be printed from Eagle )
Links like the above do not work.
(I know someone will say "It does work for me!" -- not very helpful)
I've spent five hours yesterday going through every post in the thread, my eyes are tearing, and I'm exhausted.
There were no plain graphics images of the foil patterns that I could find.
I don't know what else to do.
I'm left with the only option to re-draw a graphic line-by-line, from the photographs of the boards.
(which seems rather odd, since this material is probably close at hand for somebody, somewhere)
Andy
Andy,
I'm sorry, I thought you wanted the gerbers...
When I get home I will generate PDFs and upload them to my website.
You might want to get factory made boards, as there are plated holes under some of the caps. These will not get soldered using double sided PCBs
\Jens
I'm sorry, I thought you wanted the gerbers...
When I get home I will generate PDFs and upload them to my website.
You might want to get factory made boards, as there are plated holes under some of the caps. These will not get soldered using double sided PCBs
\Jens
Thanks Jens
I can't really afford getting factory production for 2 boards (unless of course enough members are interested in another GB!).
I've had enough practice getting around the plated-through problem, believe me.
You stick a fine wire through the hole first, bend it flat with the board on both sides, solder on both sides, using minimal solder, and snip off excess . You solder to the side of the hole, not directly above it, so as not to clog the hole with solder.
You then insert your component and solder on the bottom as usual.
Presto!
The pre-soldered wire will wicker solder through the hole and fill the hole with solder during component soldering.
If the hole is too small for 2 wires you enlarge it.
You can also use a tiny eyelet (like a rivet) to make an electrical connection between the 2 sides of a hole.
They sell them here:
http://www.internationaleyelets.com/eyelets.htm
Most of their types cost about $6-7 USD per 100. You would only use a few eyelets per board--only in the most difficult holes.
Andy
I can't really afford getting factory production for 2 boards (unless of course enough members are interested in another GB!).
I've had enough practice getting around the plated-through problem, believe me.
You stick a fine wire through the hole first, bend it flat with the board on both sides, solder on both sides, using minimal solder, and snip off excess . You solder to the side of the hole, not directly above it, so as not to clog the hole with solder.
You then insert your component and solder on the bottom as usual.
Presto!
The pre-soldered wire will wicker solder through the hole and fill the hole with solder during component soldering.
If the hole is too small for 2 wires you enlarge it.
You can also use a tiny eyelet (like a rivet) to make an electrical connection between the 2 sides of a hole.
They sell them here:
http://www.internationaleyelets.com/eyelets.htm
Most of their types cost about $6-7 USD per 100. You would only use a few eyelets per board--only in the most difficult holes.
Andy
JensRasmussen said:
thanks, reason i asked is there are still others asking for them, i will ask them to contact you, thanks
Hello,
I see that there is someone interested in leach PCB with 6 bjt, like me, so I think that it would be possible to start another buy group if there will be other people interested.
I have built the leach ampli, using the master of Prof. Leach and modern transistors, but too much wires represent a serious risk of oscillation in high frequencies, infact during the firs test, on only one channel an expensive tweeter burn out!
Becouse in Italy we say that "every beatle is beatiful for its mother", I gave the ampli, whitout any information on inner tecnology, to an audiophile group for listening test.
They said me that the ampli sounds very well, also in the comparative test with some famous commercial ampli, only the backstage is not completly definited and that it has the sound of bjt ampli (of course!), not very warm like mosfet.
Now I will buid a definitive version with particular care for phase error to improve the backstage listening impression and I need of two PCBs on Rasmussen design that seems (to me) very well done (and Thougt first!).
Sorry for my English, I'm Italian mothertongue, and bye bye, Giuseppe.
I see that there is someone interested in leach PCB with 6 bjt, like me, so I think that it would be possible to start another buy group if there will be other people interested.
I have built the leach ampli, using the master of Prof. Leach and modern transistors, but too much wires represent a serious risk of oscillation in high frequencies, infact during the firs test, on only one channel an expensive tweeter burn out!
Becouse in Italy we say that "every beatle is beatiful for its mother", I gave the ampli, whitout any information on inner tecnology, to an audiophile group for listening test.
They said me that the ampli sounds very well, also in the comparative test with some famous commercial ampli, only the backstage is not completly definited and that it has the sound of bjt ampli (of course!), not very warm like mosfet.
Now I will buid a definitive version with particular care for phase error to improve the backstage listening impression and I need of two PCBs on Rasmussen design that seems (to me) very well done (and Thougt first!).
Sorry for my English, I'm Italian mothertongue, and bye bye, Giuseppe.
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