"Improved RIAA by Jax"-Power supply help needed!!!
Hi!
This thread is mostly to the Author of this Phono preamp - Mr. Jax but anyone who wants to join the discussion is welcome!
I very want to build the "improved RIAA" from the Mr. Jax site http://crude.axing.se/ but I don't know how to do the power supply!
I'm in need to find out some more information and I'd appreciate any help given!!
I'm the beginner in that issue and for me it's a magical thing!
I need a very simple circuit of PSU!!
So Mr. Jax if You are able to help, I will be thankful! Maybe You've got PCB circuit of Your preamp?? I'm asking because I'm afraid to do the ground trax by myself. Any instructions of building that Preamp and PSU will be helpful!!
Sorry for My English
Cheers
Piotr
Hi!
This thread is mostly to the Author of this Phono preamp - Mr. Jax but anyone who wants to join the discussion is welcome!
I very want to build the "improved RIAA" from the Mr. Jax site http://crude.axing.se/ but I don't know how to do the power supply!
I'm in need to find out some more information and I'd appreciate any help given!!
I'm the beginner in that issue and for me it's a magical thing!
I need a very simple circuit of PSU!!
So Mr. Jax if You are able to help, I will be thankful! Maybe You've got PCB circuit of Your preamp?? I'm asking because I'm afraid to do the ground trax by myself. Any instructions of building that Preamp and PSU will be helpful!!
Sorry for My English
Cheers
Piotr
There are a couple of 250V psu in the tubes forum, and at the rate the discussions are going, this will get their nod 😀
300-0-300 -> 5U4-G - 10uF - 10H choke - 47uF - 10H choke - 47uF - dropping resistor - 0D3 + 0C3 in series + 0.1uF
will give you 250V of so...
note: i was lazy and did not validate this
300-0-300 -> 5U4-G - 10uF - 10H choke - 47uF - 10H choke - 47uF - dropping resistor - 0D3 + 0C3 in series + 0.1uF
will give you 250V of so...
note: i was lazy and did not validate this

Well 😀
I actually recommend a stabilized power supply for this. Do a search for the very long thread called Frank's ultimate preamp or something like that, there is a circuit using an ECL85 which will do fine as a PSU for the RIAA.
I have something similar in my preamp but no schematic handy at the moment. It's using EZ90, EL90, EC92 and 85A2.
I actually recommend a stabilized power supply for this. Do a search for the very long thread called Frank's ultimate preamp or something like that, there is a circuit using an ECL85 which will do fine as a PSU for the RIAA.
I have something similar in my preamp but no schematic handy at the moment. It's using EZ90, EL90, EC92 and 85A2.
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