Right here is my nice little TX pcb supplying 2X 18V to the regs.
One for the clock and one for the Digital 5V.
The Analogue 5V and DAC clock 5V regs get there 12V from the Marantz TX. Nothing else uses this rail now.
The sound feels slightly more open again but I will test over night and report back.
One for the clock and one for the Digital 5V.
The Analogue 5V and DAC clock 5V regs get there 12V from the Marantz TX. Nothing else uses this rail now.
The sound feels slightly more open again but I will test over night and report back.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
rowemeister said:Right here is my nice little TX pcb supplying 2X 18V to the regs.
One for the clock and one for the Digital 5V.
The Analogue 5V and DAC clock 5V regs get there 12V from the Marantz TX. Nothing else uses this rail now.
The sound feels slightly more open again but I will test over night and report back.
Wow Brent,
Nice pics. You leave no space unused...
Not enough room now for a tubestage
Ray.
Well, here's yesterday's homework: I've added a calculation for the new transformer in my spreadsheet.
The first four windings are required for the player, and i've added three 9,5V/150mA windings for 5V purposes. This will allow even the use of two stage regulators if i'm not mistaken.
The 9,5V nicely corresponds with the already required 9,5V for the player, and i've made the +/-12V windings twice that voltage. It will make the manufacturing easier/cheaper I hope.
I upped the required currents considerably, and still haven't reached 30VA, so there's room for some more, but I doubt if it is needed. But this is just a first attempt, what do you guys think?
Regards,
Ray.
The first four windings are required for the player, and i've added three 9,5V/150mA windings for 5V purposes. This will allow even the use of two stage regulators if i'm not mistaken.
The 9,5V nicely corresponds with the already required 9,5V for the player, and i've made the +/-12V windings twice that voltage. It will make the manufacturing easier/cheaper I hope.
I upped the required currents considerably, and still haven't reached 30VA, so there's room for some more, but I doubt if it is needed. But this is just a first attempt, what do you guys think?
Regards,
Ray.
Thanks for that homework, Ray
One suggestion:
Since Vf and Vftd use up 165 and 26mA respectively,
I think they should get a little more overhead - what about 300 and 75mA?
To get to 30VA, I raised the other current ratings as well:
+/-12V 2x19V 2x200mA
+/-10Y or +5V 2x9V 2x750mA
Vf display 3,4V 300mA
Vftd display 14V 75mA
Ext. clock+DAC 9,5V 200mA
DAC D 9,5V 200mA
DAC A 9,5V 200mA
This adds up to 29,62VA
I have no idea.
As soon as we agree on a winding scheme, I can ask for quotes.
Yes, I would also want this custom trannie to be better than the KI one...
One suggestion:
Since Vf and Vftd use up 165 and 26mA respectively,
I think they should get a little more overhead - what about 300 and 75mA?
To get to 30VA, I raised the other current ratings as well:
+/-12V 2x19V 2x200mA
+/-10Y or +5V 2x9V 2x750mA
Vf display 3,4V 300mA
Vftd display 14V 75mA
Ext. clock+DAC 9,5V 200mA
DAC D 9,5V 200mA
DAC A 9,5V 200mA
This adds up to 29,62VA
poynton said:
I have no idea.
As soon as we agree on a winding scheme, I can ask for quotes.
Yes, I would also want this custom trannie to be better than the KI one...
Hi Michael,
The main reason I didn't give the display more overhead is because the heater voltage is critical. If you give this winding a higher current, the voltage will become higher because you only draw 165mA. Since it is not regulated, the display will not like that. It's like the heater voltage with tubes. At this low voltage, a small increase can lead to a lot of extra current (the heaters are low-ohmic).
The manufacturer will wind the transformer assuming that when all windings draw their maximum current, the voltages should be as stated. Since that is not likely to happen here, all voltages will be a bit higher already.
I think 200mA is more than enough for the heaters, and 50mA will be fine for the negative display voltage.
The other voltages are all regulated, so 200mA is perfect.
Except for the +/-10V for the CD63.
I would keep that one 9,5V because it is also unregulated. The current for this one is too high, remember that all the stuff that now hangs on the +5V rail is going to be powered by the other windings.
You don't have to reach 30VA, it's not bad to have a 25VA tranny on a 30VA core
It will leave some room for a ground shield and plenty of isolation, since we have a lot of windings on the core.
Regards,
Ray.
The main reason I didn't give the display more overhead is because the heater voltage is critical. If you give this winding a higher current, the voltage will become higher because you only draw 165mA. Since it is not regulated, the display will not like that. It's like the heater voltage with tubes. At this low voltage, a small increase can lead to a lot of extra current (the heaters are low-ohmic).
The manufacturer will wind the transformer assuming that when all windings draw their maximum current, the voltages should be as stated. Since that is not likely to happen here, all voltages will be a bit higher already.
I think 200mA is more than enough for the heaters, and 50mA will be fine for the negative display voltage.
The other voltages are all regulated, so 200mA is perfect.
Except for the +/-10V for the CD63.
I would keep that one 9,5V because it is also unregulated. The current for this one is too high, remember that all the stuff that now hangs on the +5V rail is going to be powered by the other windings.
You don't have to reach 30VA, it's not bad to have a 25VA tranny on a 30VA core
It will leave some room for a ground shield and plenty of isolation, since we have a lot of windings on the core.
Regards,
Ray.
Michi124 said:
No problem. The drawback of more knowledge is that I have to be careful I don't overdo all this 'engineering' thinking in simple situations that don't require it
I guess the +/10V winding current can be scaled up a bit after all, since the TCA drivers can handle up to 40V! (missed that one...)
With all the voltages covered, i'm very curious about that quote you mentioned!
Regards,
Ray.
Now then Ray you mention scaleing up the voltage on the 9.6v winding (cd63) because the TCA can handle up to 40V.
Now the 5v rail also comes from this winding via bridge and reg.
A standard reg can handle a maximum input of 35V and the Audiocom regs (which I use) have a maximum voltage input of 24V.
So a maximum voltage of 14V would be needed so that the TX is a straight swap into a standard player. This should after rectification give approx. 20V.
Hope I made sense. lol
Now the 5v rail also comes from this winding via bridge and reg.
A standard reg can handle a maximum input of 35V and the Audiocom regs (which I use) have a maximum voltage input of 24V.
So a maximum voltage of 14V would be needed so that the TX is a straight swap into a standard player. This should after rectification give approx. 20V.
Hope I made sense. lol