you have no idea how much work time and money Allen Wright put into this 'concept'
and you might experience him the most stubbern and determined man you had ever met
but ofcourse you are absolutely right too
might be worth to note that in the days when the design of this amp begun, there was not the same sharing and spread of knowledge like we see it today
meaning, it was a lot more difficult and harder
its a concept
unfortunetely it was almost over before it begun
too complicated, very expencive, and not really needed
a bit like a stillborn child
as shame really
not sure, but I think it was one of the first hifi designs of this kind
and its already a vintage classic
hell, I dont know why I say this , and not even sure its true at all, but in this case I think it is
blondes have more fun
you can have HF garbage sneaked through mains xformer etc.
anyway - as I wrote - LM317 is up to task if other conditions are fulfilled ;
to name them - no HF going from rectifier , heater potential elevated to proper voltage , so heater -cathode diode leak is on adequate part of characteristic curve
then 317 is good enough
CCS + CVS ?
certainly not ; there is no need for that , for indirectly heated tubes
Vaccum State FVP5 preamp clone
Hello,
I plan to built a Vaccum State FVP5 preamp clone.I would try to do it at close as possible to the original one. That means to use the best parts and the best lay out and the best wiring.
I think it’s one of the best peamp ever built.
I only focus my attention to the line section because don’t need the phono section.
Description : the schematic looks quite easy but I must be very carefully during the building to make it stable.
See the attached schematic.
First question: As you can see 2 of the output valves from the output stage are biaised at 100V.
What would be the best valve combination :
* Imput stage valve + CCS valve of the same channel
* Combine the R+L input stage ?
I need a 250 V/ 100mA HV Power supply with following structure: Transformer + bridge + input choke and pi filter + regulation.
The Lundahl LL1628 with 2 coils should be my final choice.
What is the way to connect them ?
· 2 coils in serie => 10H on B+
· 1 coil (5H) on B+ and one in ground (5H)
See on attached files
What do you mean with the resistor (100 Ohm) on the ground ?
Please can someone help me to calculate the chokes values ?
Hello,
I plan to built a Vaccum State FVP5 preamp clone.I would try to do it at close as possible to the original one. That means to use the best parts and the best lay out and the best wiring.
I think it’s one of the best peamp ever built.
I only focus my attention to the line section because don’t need the phono section.
Description : the schematic looks quite easy but I must be very carefully during the building to make it stable.
See the attached schematic.
First question: As you can see 2 of the output valves from the output stage are biaised at 100V.
What would be the best valve combination :
* Imput stage valve + CCS valve of the same channel
* Combine the R+L input stage ?
I need a 250 V/ 100mA HV Power supply with following structure: Transformer + bridge + input choke and pi filter + regulation.
The Lundahl LL1628 with 2 coils should be my final choice.
What is the way to connect them ?
· 2 coils in serie => 10H on B+
· 1 coil (5H) on B+ and one in ground (5H)
See on attached files
What do you mean with the resistor (100 Ohm) on the ground ?
Please can someone help me to calculate the chokes values ?
Attachments
This is best, since the late Allen recommended not to use 1 dual tube for both channels.
Lundahl LL1628 is an excellent choice.
Your best option is 2 coils in series => 10H on B+
Yes, you are correct.
Which resistor are you referring to?
I'm not clear about what you are trying to do.
You can do either LC filtering or RLC filtering.
Since you are going to use Lundahl LL1628 in series configuration, LC is good option for filtering mains ripple.
Adding R is useful only if want to lower the voltage. If you use R, better have the same resistor on the (+) and (-) lines.
RTP3D PS simulation...
Hi,
I just made a duncanamps PSU simulation:
The Superreg needs minimum 50V headroom.
So the PS should deliver 350V.
I Got the hint what to use: 420V Powersupply, 160mA 10H Lundahl choke + 3 x 60uF Motorcaps and 2x 47R Resistor.
I made the simulation, but never reached 350V. I need at least 440VAC from the transformer...
Attached my simulation. Does the supereg require only 330V??? What is my bloody mistake here???
Regs, Dirk
Hi,
I just made a duncanamps PSU simulation:
The Superreg needs minimum 50V headroom.
So the PS should deliver 350V.
I Got the hint what to use: 420V Powersupply, 160mA 10H Lundahl choke + 3 x 60uF Motorcaps and 2x 47R Resistor.
I made the simulation, but never reached 350V. I need at least 440VAC from the transformer...
Attached my simulation. Does the supereg require only 330V??? What is my bloody mistake here???
Regs, Dirk
superreg will need , say , 15V of difference ( count also on regular -10% mains decrease) to work properly .
knowing that , and programmed current per superreg , go upstream and calculate voltage sags on each element in chain
that will tell you what's voltage needed at first element after Graetz
knowing that , and programmed current per superreg , go upstream and calculate voltage sags on each element in chain
that will tell you what's voltage needed at first element after Graetz