I am getting good enough results from 2 300VA 26VAC x2 transformers...
For a single I would go for 500VA+
Slightly higher rails wil also not be bad, say maybe a 2 x 28VAC transformer... (once again all youwould need to adjust is the zener.. although the kit ones will work fine, there is a bit more power to be had if you then switch the two 16V ones out for a 33V zener.... you can just bridge the position of the second zener.
Sorry for the delays in comming back to you, electricity supply is erratic here to say the least... (what happens when governments buy submarines for kickbacks rather than power stations). My dinner tonight went straight from the oven to the bin as the power went off midway through preperation...
Guess its peanut butter sandwitches tonight... and it would not suprise me if we go without power for another 2 hour session...
For a single I would go for 500VA+
Slightly higher rails wil also not be bad, say maybe a 2 x 28VAC transformer... (once again all youwould need to adjust is the zener.. although the kit ones will work fine, there is a bit more power to be had if you then switch the two 16V ones out for a 33V zener.... you can just bridge the position of the second zener.
Sorry for the delays in comming back to you, electricity supply is erratic here to say the least... (what happens when governments buy submarines for kickbacks rather than power stations). My dinner tonight went straight from the oven to the bin as the power went off midway through preperation...
Guess its peanut butter sandwitches tonight... and it would not suprise me if we go without power for another 2 hour session...
I have 2 toroids of 2x30VAC/300VA,is that to much volts for this amp?
Maybe I could wirewound some turns of 3volts or 4 volts so I could lower the output voltage.
Maybe I could wirewound some turns of 3volts or 4 volts so I could lower the output voltage.
You are looking at 42V rails, suspect that may require a parallel set of extra transistors with emitter resistors, I will ask Carlos later when we speak again and let you know.
It is all rigth..... 42V is the upper limit to a single pair
But, to be more safe, avoid the use of 4 ohms loads...you can use 6 ohms or 8 ohms speakers.
regards,
Carlos
But, to be more safe, avoid the use of 4 ohms loads...you can use 6 ohms or 8 ohms speakers.
regards,
Carlos
What about I add a few turns on the toroid of let us say 3 Volts?
So I could deside what voltage 27 Volts or 33 Volts.
So I could deside what voltage 27 Volts or 33 Volts.
PSU Progress
I just wanted to share my progress to this point.
I received some electrolytics today from apexjr. Really nice buy @ $2 each for 12000uF 50V caps. I sure it's overkill, but that's one of the things that makes this hobby so much fun!
http://picasaweb.google.com/salesmonster/DXHRIIPowerSupplyPSUBuild
I just wanted to share my progress to this point.
I received some electrolytics today from apexjr. Really nice buy @ $2 each for 12000uF 50V caps. I sure it's overkill, but that's one of the things that makes this hobby so much fun!
http://picasaweb.google.com/salesmonster/DXHRIIPowerSupplyPSUBuild
Nordic said:
Nordic or Carlos
Can it be done with extra transistors and emitter resistors to be safe for using a 2 x30 VAC toroid?
Hi man, sorry, I was a little cut off from communications... no power = no computer = no coms...
Will give you feedback today.
Wait I see Carlos allready replied
"It is all rigth..... 42V is the upper limit to a single pair Post #584
But, to be more safe, avoid the use of 4 ohms loads...you can use 6 ohms or 8 ohms speakers.
regards,
Carlos"
Will give you feedback today.
Wait I see Carlos allready replied
"It is all rigth..... 42V is the upper limit to a single pair Post #584
But, to be more safe, avoid the use of 4 ohms loads...you can use 6 ohms or 8 ohms speakers.
regards,
Carlos"
Is it not better to play safe and use 2 more transistors?
If yes do I've to make some changes of some values of components?
If yes do I've to make some changes of some values of components?
you will as far as I know just duplicate the output sections...
Will draw it for you in a little while..
2 extra resistors and the transistor each side...
With that much voltage you also need to modify the regulation to the front end by adjusting the zeners on the side with one or 2 in series, to drop about 5V.
say in the region of 38V for the zeners.
Will draw it for you in a little while..
2 extra resistors and the transistor each side...
With that much voltage you also need to modify the regulation to the front end by adjusting the zeners on the side with one or 2 in series, to drop about 5V.
say in the region of 38V for the zeners.
Yep, the ones at the side. The only other zener is the 12V that sets up the CSS for the front side. That one stays standard...
In fact the amp could in theory work without the transistor and zeners there on the sides, simply bridgeing the transistor with a 82R resistorso voltage can make it to the front side...
Will have more power but less quality in sound...
The benefit of the higher voltage is that you can use a large margin of it to regulate the front end and keep power output higher...
Of course without the regulation, full power is available to the amp... the 42V.
With the regulation, the outputs are only driven by the amount of volts you let through to the diffirential and voltage multiplier...
The Output transformers just supplies the current the output load needs to follow the instructions to keep the output voltage at whatever the voltage multiplier tells it to be at any instant, over said load.
In fact the amp could in theory work without the transistor and zeners there on the sides, simply bridgeing the transistor with a 82R resistorso voltage can make it to the front side...
Will have more power but less quality in sound...
The benefit of the higher voltage is that you can use a large margin of it to regulate the front end and keep power output higher...
Of course without the regulation, full power is available to the amp... the 42V.
With the regulation, the outputs are only driven by the amount of volts you let through to the diffirential and voltage multiplier...
The Output transformers just supplies the current the output load needs to follow the instructions to keep the output voltage at whatever the voltage multiplier tells it to be at any instant, over said load.
So if I understand it correctly,instead of 32V zeners(2x12V) I need 38V zeners.And also need two more output-transistors and resistors?
you meant 2 x 16....
You can use less or more regulation so the 38V is not set in stone...
You can use any 2 voltage zeners in series to make up approximately that amount of voltage.
And yes, 1 extra output transitor for each rail
1 extra 4.7 resisor to the base of each of those
and one 0R33 emmiter resistor for each.
You can use less or more regulation so the 38V is not set in stone...
You can use any 2 voltage zeners in series to make up approximately that amount of voltage.
And yes, 1 extra output transitor for each rail
1 extra 4.7 resisor to the base of each of those
and one 0R33 emmiter resistor for each.
Yes 2x16V
Can you make a drawing for me just to be shure where those extra transistors are coming?
Can you make a drawing for me just to be shure where those extra transistors are coming?
Thanks Nordic.
It's an idea why not making an other layout where you can mount 4 output transistors and the needed resistors.I think there are a lot of people having tranies of 2x30VAC or 2x35VAC.What do you think?
It's an idea why not making an other layout where you can mount 4 output transistors and the needed resistors.I think there are a lot of people having tranies of 2x30VAC or 2x35VAC.What do you think?
The 2 x 35 trannies could be used on the P1 if you have more than one...
The P1 started off as a 4 transistor unit and grew to 6 for the sake of safety.
But it is not a bad idea.
The P1 started off as a 4 transistor unit and grew to 6 for the sake of safety.
But it is not a bad idea.
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