Sorry Fred Dieckman..
Sorry Fred, no intention to flame or anything. Just got exited seeing someones well-intended and well reasoned post brushed aside.
Your explanation DOES make sense, of course, as (most) all of your posts do.
Jan Didden
Sorry Fred, no intention to flame or anything. Just got exited seeing someones well-intended and well reasoned post brushed aside.
Your explanation DOES make sense, of course, as (most) all of your posts do.
Jan Didden
Re: Re: Re: Re: Re: Re: Uh Oh another expert.........
Hi,
This isn't same. R78 and 74 and LED(?) make voltage divider (factor k) for sensing dropout of PS. Upper FET will very sharp switch off when PS drop below Vgs*k. With this voltage divider you can adjust that upper FET switch off at 30-35V, what is with your diode impossible.
Regards
janneman said:
Hi,
This isn't same. R78 and 74 and LED(?) make voltage divider (factor k) for sensing dropout of PS. Upper FET will very sharp switch off when PS drop below Vgs*k. With this voltage divider you can adjust that upper FET switch off at 30-35V, what is with your diode impossible.
Regards
Diode
I think you might want to mute before supply discharged enough to discharge the cap enough to turn off the MOSFET. That is a slow transition also and they relay will chatter trough this transition without hysteresis.
Something this looks like the type of relay I think they might by using:
http://oeiwcsnts1.omron.com/pdfcatal.nsf/PDFLookUpByUniqueID/3E7E37F140B99F35862568FF0050EF69/$FILE/D20G5V20100.pdf
I think you might want to mute before supply discharged enough to discharge the cap enough to turn off the MOSFET. That is a slow transition also and they relay will chatter trough this transition without hysteresis.
Something this looks like the type of relay I think they might by using:
http://oeiwcsnts1.omron.com/pdfcatal.nsf/PDFLookUpByUniqueID/3E7E37F140B99F35862568FF0050EF69/$FILE/D20G5V20100.pdf
Fred is right, you'll need this second MOSFET or a similar trick if you power the relay from the main supply rail. I didn't mention that for my circuit I've used a separate supply with a small smoothing capacitor, so on switch-off this supply goes down very quickly.
Al
Al
24 volts..... I stand corrected by the gracious lady with all deference due. I am I right in assuming its a 2 form c?
1 out 2 .........
I will be more careful since I am being monitored. I shudder to think of the reaction to my interpretation of how the rest of the circuit works..........
There is only one thing in the world worse than being talked about, and that is not being talked about. - Oscar Wilde
I will be more careful since I am being monitored. I shudder to think of the reaction to my interpretation of how the rest of the circuit works..........
There is only one thing in the world worse than being talked about, and that is not being talked about. - Oscar Wilde
Re: Re: Re: Re: Re: Re: Re: Uh Oh another expert.........
Indeed. I stand corrected.
Jan Didden
moamps said:
Indeed. I stand corrected.
Jan Didden
Fred Dieckmann said:
And I think the 24 V relays are quite common as I could not remember ever seing a 48 V one in my catalogues. For instance http://www.elfa.se/ seem to have some 80 different relays using 24 VDC but only 3 that use 48 VDC (which I did not know about). As a matter of fact I thought 5, 12 and 24 was standard issue and 48 V was the exception in the everyman supply chain.
Schematic does mention "Right Channel Shown",
So there is a Left Channel, and another Mute Relay "K2".
The 2-24V coils are probably in series as in the Aleph Preamps.
So there is a Left Channel, and another Mute Relay "K2".
The 2-24V coils are probably in series as in the Aleph Preamps.
side track...
Just a thought... my two pennies... on mixing analogue and digital techniques for the muting...
I've got quite a bit more caps on my PS and on my Aleph P boards, than used in the original schematics. Just because it was easier for me, since I had some leftover in my scrap box.
This makes the time for the "turn on thump" to be around 15 - 20 seconds...
The muting circuit goes on after only one - two seconds, which IS enough time, since I need less than 100ms to boot up my PIC (getting the power to the right level + restart of the chip). The first thing it does is to reduce the volume to 0, then go to sleep for 20 seconds and then set the volume to the "last" value.
Just my two...
The muting (analogue part) works fine, and is based on the Aleph P 1.7 schematic, althoug broken off on a separate board.
//magnus
Just a thought... my two pennies... on mixing analogue and digital techniques for the muting...
I've got quite a bit more caps on my PS and on my Aleph P boards, than used in the original schematics. Just because it was easier for me, since I had some leftover in my scrap box.
This makes the time for the "turn on thump" to be around 15 - 20 seconds...
The muting circuit goes on after only one - two seconds, which IS enough time, since I need less than 100ms to boot up my PIC (getting the power to the right level + restart of the chip). The first thing it does is to reduce the volume to 0, then go to sleep for 20 seconds and then set the volume to the "last" value.
Just my two...
The muting (analogue part) works fine, and is based on the Aleph P 1.7 schematic, althoug broken off on a separate board.
//magnus
Karen said:
Thanks a lot Karen !!
Please can you deliver Mr. Pass the following message : "Sorry for attacking
and chosen a strong title like this one for explaining what I have changed. I'm someone
who often likes to do something in a disrespectfully way."
As I wrote the thread, I thought, that the experts are coming up, analyze my changes
and kill them with words like : "You crazy crackpot from germany ... what you have done
can't work ...."
I didn't expect that anyone replies with words like : "Ok you are right and it's your way to do so."
But what happened ? The experts explain me the function of the original mute circuit and the
non experts announce their ordinary comments.
Sometimes it's better to find his own way.
toshiba
P.S.
I really respect the work of Mr.Pass. His amps sounds incredible.
Sure, he is one of the greatest, perhaps the greatest !
But could it be the reason, that it is forbidden to do some changes ?
Stump the chump
"Nice one Tazzy!"
You are allowed ( and probably encouraged by some) to doubt me. You will find that is an international sport. It keeps me on my toes and gives me a chance to start fights over several continents on any given subject. If Steve Eddy gets involved, they can go on for days..........
"Nice one Tazzy!"
You are allowed ( and probably encouraged by some) to doubt me. You will find that is an international sport. It keeps me on my toes and gives me a chance to start fights over several continents on any given subject. If Steve Eddy gets involved, they can go on for days..........
I relay wasn't kidding
"48 V was the exception in the everyman supply chain."
I guess I was in Telecom too long. I have seen thousands and had about 6 six relay maufacturers on my approved vendors list.
"48 V was the exception in the everyman supply chain."
I guess I was in Telecom too long. I have seen thousands and had about 6 six relay maufacturers on my approved vendors list.
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