In the PLH article Nelson says:
"If you send me a bag of high power Jfets, I’ll supply a schematic that will work with them, too."
Has anyone seen such a schematic?
"If you send me a bag of high power Jfets, I’ll supply a schematic that will work with them, too."
Has anyone seen such a schematic?
I had forgotten that I made such a promise. It is, however
very do-able. All you have to do is send me that bag. I
cannot be expected to supply the high power Jfets as well...
😎
very do-able. All you have to do is send me that bag. I
cannot be expected to supply the high power Jfets as well...
😎
Circuit should be reserved for the PL custom power jfets
Maybe the color green will make it get to the production line sooner...A step forward at least, is to replace the input IRF610 with a J-FET. I've done that and I do see an improvement. As a matter of fact, I put 2 2SK147 in parallel as the input stage in place of the IRF610.
I have not tried it yet, but I would expect interesting results
with the SJEP170R550.
😎
with the SJEP170R550.
😎
How would one make a PLH with a dual power supply?
In the article that was left as a future exercise.
In the article that was left as a future exercise.
I'll work on the latest JLH dual supply version with power BJT's as I have a large supply and they are much cheaper. I'll add the current sources using DM2540 depletion FETS though.
You can transformer couple the input so as to use a split supply with DC
coupled output - this way you can reject the supply rail noise, something
you don't have to do when ground is the lower rail.
Alternatively you would put one or two front end transistors to level-shift
the input down to the Gate of the driver transistor - but then you have the
original JLH circuit with three stages instead of two.
If you had a very very quiet negative rail, you could make it work as is.
😎
coupled output - this way you can reject the supply rail noise, something
you don't have to do when ground is the lower rail.
Alternatively you would put one or two front end transistors to level-shift
the input down to the Gate of the driver transistor - but then you have the
original JLH circuit with three stages instead of two.
If you had a very very quiet negative rail, you could make it work as is.
😎
I asked to re-open this thread because it seems to be the course that I am on.
Given this circuit and costs aside would it be best to use a LSK389 setup in parallel?
I would like to try it in Pass PLH instead of IRF610 use LSK389 tied in Parallel or is it better to use 2x LSK170 descrete devices. May help on setting it up properly. Papa, I see your interview with them over there. Can you suggest one of their products for use as input stage of PLH in place of IRF610? I am in the process to make a PCB for this!
Given this circuit and costs aside would it be best to use a LSK389 setup in parallel?
I would like to try it in Pass PLH instead of IRF610 use LSK389 tied in Parallel or is it better to use 2x LSK170 descrete devices. May help on setting it up properly. Papa, I see your interview with them over there. Can you suggest one of their products for use as input stage of PLH in place of IRF610? I am in the process to make a PCB for this!
Last edited: