THANKS!!!
Much appreciated!!
Searching this thread an alternate JFET mentioned was the 2SK880GR SMD. It has a higher IDSS value. Would it work for my application?
Not sure if it will fit on the pads on the SSHV2 board and it might be a pain to solder onto the pads because it is a SMD. Only one way to find out. Must measure the pads first. Ha!!
Thanks again.
Much appreciated!!
Searching this thread an alternate JFET mentioned was the 2SK880GR SMD. It has a higher IDSS value. Would it work for my application?
Not sure if it will fit on the pads on the SSHV2 board and it might be a pain to solder onto the pads because it is a SMD. Only one way to find out. Must measure the pads first. Ha!!
Thanks again.
Yes it will but its GR too so it should have the same IDSS spread (2.6-6.5mA) and chances. There are SOT23 to SIP3 adapter mini boards also. Look them up on ebay but watch the SMD pin-out for what adapter pin goes where on the K117 pads. Still you can always offset an IDSS deficiency by changing the 68K resistors to 82K as I mentioned (R9 R10). Its the simplest way with using the K117 you already have.
hi!
a quick one ... I went through the many pages, not all of them, of the discussion but I couldn't find a solution
I am using HVS2 in my prephono but I am still unsatisfied with the residual noise (it's 100Hz, hooked up the scope this morning and 100Hz was below its limits but I need to recheck tonight). I used a Paul Hynes reg before and it was quite... I shorted it by accident!
Raw PSU is 6X5 into 10H/30uF - 220R/30uF. HVS is in the PSU chassis due to room restriction in the signal chassis. CCS is set at 80mA vs 55mA required by the pre. Voltage drop from input to output of HVS is 45V.
Question: how can I improve the noise here and what residual 100Hz noise should i typically find with this PSU? A cap after the regulator? replace RC with an LC?
My speakers are high sensitivity so every fraction of mV really counts.
thanks!
a quick one ... I went through the many pages, not all of them, of the discussion but I couldn't find a solution
I am using HVS2 in my prephono but I am still unsatisfied with the residual noise (it's 100Hz, hooked up the scope this morning and 100Hz was below its limits but I need to recheck tonight). I used a Paul Hynes reg before and it was quite... I shorted it by accident!
Raw PSU is 6X5 into 10H/30uF - 220R/30uF. HVS is in the PSU chassis due to room restriction in the signal chassis. CCS is set at 80mA vs 55mA required by the pre. Voltage drop from input to output of HVS is 45V.
Question: how can I improve the noise here and what residual 100Hz noise should i typically find with this PSU? A cap after the regulator? replace RC with an LC?
My speakers are high sensitivity so every fraction of mV really counts.
thanks!
I think you should move the SSHV to the "signal chassis". The noise is most probably inducted to the cord between the PS and signal chassis. If you use your own layout (not PCB from group buy) you can move only "shunt part".
The shunt regs uses active circuit instead of output capacitor to achieve low output impedance so their "shunt" (like the last capacitor in common PS) must be as close as possible to the load.
Addition of a capacitor after a shunt regulator does mostly bad thing and won't solve the task you are thrying to achieve.
The shunt regs uses active circuit instead of output capacitor to achieve low output impedance so their "shunt" (like the last capacitor in common PS) must be as close as possible to the load.
Addition of a capacitor after a shunt regulator does mostly bad thing and won't solve the task you are thrying to achieve.
IMHO, in this case it is better to use a linear serial regulator instead and use "split capacitors" version with a relatively low electrolytic and good film capacitor in the signal case.
Try two wire conventional connection first. The proximity to raw PSU and the exposure of the long wire run between chassis probably induces rectified noise on the long sense wires.
Jumper F+ to S+ and F0 to S0 at the regulator's output connector and use only two rather thick twisted wires from S+ & S0 to the load. That is how you convert to conventional output.
Jumper F+ to S+ and F0 to S0 at the regulator's output connector and use only two rather thick twisted wires from S+ & S0 to the load. That is how you convert to conventional output.
That's exactly how I wired them. I will experiment a bit more tonight and try to get a decent measure of noise before and after the HVS.
Tipically, how much noise reduction should I see?
P.S. Check also with the scope in AC coupling on 20mV vertical and fast horizontal sweeps that the rail is not carrying high oscillation frequencies because they can cause indirect noises even if you could not see 100Hz ripple directly on the scope before. Try to lower the voltage drop across the reg to 20V and drop its current to 75mA too so to take some heat away from the CCS as well.
as a matter of facts it is not from the shunt regulator, I just assumed it was guilty as I installed it a few hours ago so this is the last mod I made to the pre.
noise from raw dc is 70mV rms @ 100Hz and basically flat after the SHVS. at the speaker's terminals there is 50Hz! booom! I disconnected the mac and HD from the multi-sockets and the hum dramatically reduced, still some is there. on certain random occasion the mac and HD pollute the pre.
I'll dig a bit more and find out how to reduce this ground loop.
noise from raw dc is 70mV rms @ 100Hz and basically flat after the SHVS. at the speaker's terminals there is 50Hz! booom! I disconnected the mac and HD from the multi-sockets and the hum dramatically reduced, still some is there. on certain random occasion the mac and HD pollute the pre.
I'll dig a bit more and find out how to reduce this ground loop.
that's completely random! it can play OK and quite for days and weeks and all of a sudden it starts humming heavily. mah?!?
I understand I need to check the input and find the last fraction of 50Hz in my pre, which is almost OK as of now, but this MAC and external HD interference puzzles me.
I understand I need to check the input and find the last fraction of 50Hz in my pre, which is almost OK as of now, but this MAC and external HD interference puzzles me.
Hi Salas,
I have used several of your SSHV2 regulators and they are great. However, in my phonostage I need a regulators to go down to somewhere between 80-90V (Input voltage is 140V). When I try to adjust my regulator it only goes down to about 95V. So I looked at the schematic and noticed that it is only specified for a minimum of 100V. Is there a way to adjust the component values to get the lower voltage?
I apologise if this has been asked for before, it's hard to read through over 500 pages of postings.
Cheers
Ian
I have used several of your SSHV2 regulators and they are great. However, in my phonostage I need a regulators to go down to somewhere between 80-90V (Input voltage is 140V). When I try to adjust my regulator it only goes down to about 95V. So I looked at the schematic and noticed that it is only specified for a minimum of 100V. Is there a way to adjust the component values to get the lower voltage?
I apologise if this has been asked for before, it's hard to read through over 500 pages of postings.
Cheers
Ian