I'm building the PS and was confused as to why there are 3 9.1 V Zeners for the negative rail. I then spent a long time rereading everything and found this post by Kari-
So having Z8-Z10 as 4.5V zeners is different from the more current version at Kari's website ruffneck which lists Z1-Z10 as 9.1 V Zeners.
Which is it?
So having Z8-Z10 as 4.5V zeners is different from the more current version at Kari's website ruffneck which lists Z1-Z10 as 9.1 V Zeners.
Which is it?
lgreen said:
Hi Lgreen,
I think 4.5 is the correct value for Z8-Z10. If I remember correctly,
the negative rail should be around -10 after regulation. This
requires the zener reference voltage to be about 14V (3x4.5 is
close enough)
Cheers,
Dennis
schematic?
Ok, let me look at the schematic of the PS....oh wait there isn't one. Guess I'll rip out the 3 9.1 V zeners I put in due to Kari's BOM and buy the parts at about $1 and pay the extra $10 shipping for 3 small components to install next week.
I've been part of a lot of GB's and this has so far been the absolute worst by far. This GB has been completely F'd up by the lack of schematics, failure of communcation and errors. Glad I got my boards after waiting for months because I never thought that they would actually arrive. Some of you are still waiting so I consider myself lucky, actually.
But i'm still a little upset by the lack of status updates and lack of design info. I'll go quietly now, sorry for the outburst. I do appreciate the boards and the help of many of you in this thread. A little frustrated that's all.
Ok, let me look at the schematic of the PS....oh wait there isn't one. Guess I'll rip out the 3 9.1 V zeners I put in due to Kari's BOM and buy the parts at about $1 and pay the extra $10 shipping for 3 small components to install next week.
I've been part of a lot of GB's and this has so far been the absolute worst by far. This GB has been completely F'd up by the lack of schematics, failure of communcation and errors. Glad I got my boards after waiting for months because I never thought that they would actually arrive. Some of you are still waiting so I consider myself lucky, actually.
But i'm still a little upset by the lack of status updates and lack of design info. I'll go quietly now, sorry for the outburst. I do appreciate the boards and the help of many of you in this thread. A little frustrated that's all.
I was looking at the power supply and wanted to ask a few questions.
Since the voltages are not symmetrical wouldnt it be a good idea to use lower voltage caps on the negative side at a higher capacitance?
whats the point of using 100V caps on the negative side when we can use something at alower voltage?
Since the voltages are not symmetrical wouldnt it be a good idea to use lower voltage caps on the negative side at a higher capacitance?
whats the point of using 100V caps on the negative side when we can use something at alower voltage?
Re: schematic?
😡 😡 😡 😡 😡
Ok, have ever organized a gp?
Sure you can use lower voltages, that's why the caps are snap-in type. I used the same footprint because of "symmetry" of the board.
lgreen said:
😡 😡 😡 😡 😡
Ok, have ever organized a gp?
promitheus said:
Sure you can use lower voltages, that's why the caps are snap-in type. I used the same footprint because of "symmetry" of the board.
I am sorry if people in this thread think I am naging but I want to know what is the status of the parts GB!
It is over 2 weeks since the organizer posted in this thread. I just want to know how the assembly went if Coloumb has made any listening tests and when we can expect delivery of the parts!
Best regards /// Carl-Fredrik
It is over 2 weeks since the organizer posted in this thread. I just want to know how the assembly went if Coloumb has made any listening tests and when we can expect delivery of the parts!
Best regards /// Carl-Fredrik
Coulomb said:Boy, take a little break for personal reasons and the doom and gloomers come out of the woodwork!
Here is a link to view the parts kits assembled on a pair of Kari's boards as well as some notes on construction. I will start preparing kits for shipping this coming week. I will get a few parcels wieghed at the Post Office and start sending out shipping invoices the week after next.
Regards
Anthony
http://www.briangt.com/gallery/album12
I dont think he is waiting for the boards!
/// Carl-Fredrik
PS question
Power supply question, i've built them up and tested.
I replaced the 3 9.1V zeners on the negative supply with 3 zeners rated for 4.3V (500mA). Turning this on I get only about -7.5V, this doesn't seem right.
Measuring across the string of 3 zeners, its about 10.5 Volts, and I have -14VDC at the output of the R in the CRC filter. I'm using a load of 3.5K on the output.
For the positive rail I get 60VDC out of the regulator instead of 64V, i've got 93VDC going into the regulator with R in the CRC at 56 ohms.
comments/help?
Power supply question, i've built them up and tested.
I replaced the 3 9.1V zeners on the negative supply with 3 zeners rated for 4.3V (500mA). Turning this on I get only about -7.5V, this doesn't seem right.
Measuring across the string of 3 zeners, its about 10.5 Volts, and I have -14VDC at the output of the R in the CRC filter. I'm using a load of 3.5K on the output.
For the positive rail I get 60VDC out of the regulator instead of 64V, i've got 93VDC going into the regulator with R in the CRC at 56 ohms.
comments/help?
Hi,
10,5- 7,5 = 3V = ca. Vgs wich is allright. The zeners should give a voltage around 3-4 volts above the one you want because of the gate-source voltage (zener is at the gate, output at the source)
William
10,5- 7,5 = 3V = ca. Vgs wich is allright. The zeners should give a voltage around 3-4 volts above the one you want because of the gate-source voltage (zener is at the gate, output at the source)
William
Hi lgreen,
As William mentioned, the zener voltage should be 3-4V
above the desired regulated value, to account for the
VGS of the mosfets. Your positive rail results make
sense to me.
I'm puzzled why the zener voltage on the negative rail
isn't closer to 13V...
Dennis
As William mentioned, the zener voltage should be 3-4V
above the desired regulated value, to account for the
VGS of the mosfets. Your positive rail results make
sense to me.
I'm puzzled why the zener voltage on the negative rail
isn't closer to 13V...
Dennis
-7.5 is starting to get a little on the shy side, but should still work fine, as it leaves about 4.5V across the CCS resistor that sets the bias current. Worst case is that you might have to adjust the value of the CCS resistor to get the optimal bias current, but that is easy-peasy stuff.
Cheer, Terry
Cheer, Terry
how
ok, how do you get the "optimal" value? is it by listening? distortion measurements? a current value you think is pretty good?
ok, how do you get the "optimal" value? is it by listening? distortion measurements? a current value you think is pretty good?
The optimal value will depend on the value of the positive rail and R1/6 and R2/7. You want R1/6 and R2/7 to have about half the positive rail voltage across them. 40-50mA on each half of the balanced circuit should work nicely, making the CCS current in the 80-100 mA range.
Cheers, Terry
GB update
Anyone have an updae on the parts BG for the X-BOSOZ ?
Its been a while now since we heard anything about it!
Is it to much to ask for regular updates? Maybe once a week it can't take more then 5 minutes to write about the progress or even write about no progress.
Anyone have an updae on the parts BG for the X-BOSOZ ?
Its been a while now since we heard anything about it!
Is it to much to ask for regular updates? Maybe once a week it can't take more then 5 minutes to write about the progress or even write about no progress.
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