Ah, very nice indeed! Well done James, thank you! 
James, how would somebody print just the silk screen?
Salas, for me, being new to the whole audio thing, I lack the experience you have in voicing various parts, so, I try to help how I can. I don't have a reference system yet to do proper listening experiments, but once I finish a high voltage regulator for the tube headphone amp, then I should be able to do it. I was hoping that people like you, who have trained ears, will at some point try one of the promising versions and reports the findings. But I'm aware that it takes a lot of time and effort to try new circuits, and people are skeptical of new, untried circuits.
James, how would somebody print just the silk screen?
Salas, for me, being new to the whole audio thing, I lack the experience you have in voicing various parts, so, I try to help how I can. I don't have a reference system yet to do proper listening experiments, but once I finish a high voltage regulator for the tube headphone amp, then I should be able to do it. I was hoping that people like you, who have trained ears, will at some point try one of the promising versions and reports the findings. But I'm aware that it takes a lot of time and effort to try new circuits, and people are skeptical of new, untried circuits.
Hi Salas,
Hooked up my first V1 built to a Le Pacific RIAA variant using regular quality components and heard loud hum from both speakers. It measures 24.6 V on load.
Do not have similar problem with my linear regulator. What could have I done wrong?
Hooked up my first V1 built to a Le Pacific RIAA variant using regular quality components and heard loud hum from both speakers. It measures 24.6 V on load.
Do not have similar problem with my linear regulator. What could have I done wrong?
It works but the CCS not, so it passes ripple, is one scenario.
Are your Mosfets both hot?
Another scenario is that the BC550 you had to reverse, was killed when put wrong.
Are your Mosfets both hot?
Another scenario is that the BC550 you had to reverse, was killed when put wrong.
But you did not answer about scenario #1. Are your Mosfets both correctly working? See their Vgs, see Voltage drop on R1. (If BC550 was not the problem.)
Yes, as salas mentioned, check with the diode tester on your dmm the npn.
You may want to hook up a power resistor of about 500ohm and test it that way. Sanity checks:
* voltage between base and emitter pins of the BC550 should be around 0.66V
* voltage between gate and source on each mosfet should be around 4V
* voltage before the series mosfet should be more than 24V in your case, probably 26 and up
* add a small 1ohm, 2ohm, 0.5ohm or similar resistor between the drain of the shunt mosfet and ground, and check the voltage across it, then divide by the value of the resistor, and see what the current through the shunt is
Good luck, let us know how it pans out.
You may want to hook up a power resistor of about 500ohm and test it that way. Sanity checks:
* voltage between base and emitter pins of the BC550 should be around 0.66V
* voltage between gate and source on each mosfet should be around 4V
* voltage before the series mosfet should be more than 24V in your case, probably 26 and up
* add a small 1ohm, 2ohm, 0.5ohm or similar resistor between the drain of the shunt mosfet and ground, and check the voltage across it, then divide by the value of the resistor, and see what the current through the shunt is
Good luck, let us know how it pans out.
Iko,
No offence ment but some of my prototypes look worse than yours. Mr.Pass showed me how to do it in the A40 diy article.😉
Jam
No offence ment but some of my prototypes look worse than yours. Mr.Pass showed me how to do it in the A40 diy article.😉
Jam
None taken. You mean this?
http://passdiy.com/pdf/a40.pdf
on page 9? Wow, 1978!
I like prototyping, no pressure to make it pretty (except when salas asks for pictures
)
http://passdiy.com/pdf/a40.pdf
on page 9? Wow, 1978!
I like prototyping, no pressure to make it pretty (except when salas asks for pictures
)
Yep.......that's the one. Boy I must be getting old. Mr.Pass was a pioneer back then.
Jam
P.S. by the way that amp isn't half bad even by today's standards.
Jam
P.S. by the way that amp isn't half bad even by today's standards.
Thanks Salas,
Iko, will this do the trick?
Just print this off after correcting the scale, add on top of the bare perfboard and start pinning the components - the legs of the IRFPs are a bit over 1mm dia so will need pre drilling - same with the "Weidmuller" sockets, but don't really need them unless adjusting the voltages.
I remember a conversation about adding some voltage trimming adjustment, but couldn't find a way without dramatically increasing the Zout, so I just play about with different zeners (and have also tried zeners + reg or green trimming leds in series) and it works just fine.
Iko, will this do the trick?
Just print this off after correcting the scale, add on top of the bare perfboard and start pinning the components - the legs of the IRFPs are a bit over 1mm dia so will need pre drilling - same with the "Weidmuller" sockets, but don't really need them unless adjusting the voltages.
I remember a conversation about adding some voltage trimming adjustment, but couldn't find a way without dramatically increasing the Zout, so I just play about with different zeners (and have also tried zeners + reg or green trimming leds in series) and it works just fine.
Salas,
.......this begs the question, sonically what is the difference between the zener and trimpot?
Jam
.......this begs the question, sonically what is the difference between the zener and trimpot?
Jam
3k3 calculates for 1.07uV of Johnson noise over 20kHz @ 40 C.
12V Zeners have been found to have about 0.5uV
The resistor noise will be white while the Zener noise will approximate pink.
In my HV shunt I use a resistor Vref driven by a ring of two. Sounds soft. Try it for yourself.
12V Zeners have been found to have about 0.5uV
The resistor noise will be white while the Zener noise will approximate pink.
In my HV shunt I use a resistor Vref driven by a ring of two. Sounds soft. Try it for yourself.
Thanks Salas. I had planned to try that next. I suppose the Zener should provide stiffer regulation ................hmm, maybe a zener trimpot combination to narrow the range of adjustment.
Hi Salas/Iko,
Both the MOSFETs seemed working; Q1 is warm while Q4 heats up quite quickly.
Will measure the voltages as suggested.
Both the MOSFETs seemed working; Q1 is warm while Q4 heats up quite quickly.
Will measure the voltages as suggested.
Damnit!!
And it only needs a couple more spare donuts and a bit of space for a vertical Bourns trimpot in series with the 10mm zener and/or the Weidmuller plug/socket for this option - this will be variation "SR-V1.i" now!
And it only needs a couple more spare donuts and a bit of space for a vertical Bourns trimpot in series with the 10mm zener and/or the Weidmuller plug/socket for this option - this will be variation "SR-V1.i" now!
HI, is normal that shunt start at 44.20 and stabilized at 44.95 after 5/7min. for thermal effect , ie when out mosfet rich 51°
Hi Salas/Iko,
Found the problem...forgot to test it with smoothing caps before the input to the shunt regulator. It is working well already powering my RIAA pre and the noise floor is lower compared to the linear regulator I used earlier.
I used common components for my built. Is there any particular component(s) in the circuit that I could change to make it even better?
Many thanks for the great help.
Found the problem...forgot to test it with smoothing caps before the input to the shunt regulator. It is working well already powering my RIAA pre and the noise floor is lower compared to the linear regulator I used earlier.
I used common components for my built. Is there any particular component(s) in the circuit that I could change to make it even better?
Many thanks for the great help.
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