So I've just started this hobby several months ago and completed my first project which was the FW F6 and it sounds fantastic driving Klipsch Forte IV's so I am going to get rid of my Schiit Ragnarok 2 (PM if interested)... which brings me to the next project, a Pass pre-amp.
During the last few months I've stockpiled many components and have several Pass amp boards (F4, M2x) and pre-amps (Waynes LS, BA-1 & 3 gain stages). I am planning to be able to switch out the boards in the amp and build a pre-amp where I can switch out the gain stages.
Requirements for pre-amp:
My question is in regards to splitting the audio signal in this setup.
I have been trying to research a few different scenarios for accomplishing this:
A) tap the volume pot, isolate and buffer the split signal in some kind of simple opamp buffer. I tried searching for a pcb board that would make this possible and I found this buffer board https://phonoclone.com/diy-bb.html - it doesn't seem to be in production but I may have some luck contacting RJM directly. I imagine I would have to split the line from the volume pot to a board like this and also to the gain stage.
B) tap the output of the gain stage and add 100R and 220kR resistors to isolate the second output, like the Noir headphone amp
C) have one output RCA and use a y-splitter... I am skeptical of this solution, but I'm a dummy when it comes to all of this right now and I would not want to over-engineer a solution
Any comments on the project as well as how to go about the dual output is appreciated, thank you in advance!
During the last few months I've stockpiled many components and have several Pass amp boards (F4, M2x) and pre-amps (Waynes LS, BA-1 & 3 gain stages). I am planning to be able to switch out the boards in the amp and build a pre-amp where I can switch out the gain stages.
Requirements for pre-amp:
- Singe input (RCA's)
- Support 64 step khozmo stepped attenuator (it takes a 5V/1A supply, I have a regular board from tubecad for this https://glass-ware.stores.yahoo.net/dulv.html)
- Support any of the Pass gain stages with a +/-24V supply- I plan on using either a regulator board from tubecad or the super reg which I bought form the diyaudiostore
- Two RCA outputs- one to go to the Pass amp and another pair that will go to a powered subwoofer (ideally after the volume attenuation)
My question is in regards to splitting the audio signal in this setup.
I have been trying to research a few different scenarios for accomplishing this:
A) tap the volume pot, isolate and buffer the split signal in some kind of simple opamp buffer. I tried searching for a pcb board that would make this possible and I found this buffer board https://phonoclone.com/diy-bb.html - it doesn't seem to be in production but I may have some luck contacting RJM directly. I imagine I would have to split the line from the volume pot to a board like this and also to the gain stage.
B) tap the output of the gain stage and add 100R and 220kR resistors to isolate the second output, like the Noir headphone amp
C) have one output RCA and use a y-splitter... I am skeptical of this solution, but I'm a dummy when it comes to all of this right now and I would not want to over-engineer a solution
Any comments on the project as well as how to go about the dual output is appreciated, thank you in advance!
Attachments
I am in the process of doing the same, I do have the F7 clone and also positive VFET amps with the Wayne's line stage powering the Forte IIIs. Now plan is to take a parallel outputs from line stage to these amps and use VFET for HF and F7 clone for Mids/LF and see how it works out. I might end up with up with impedance mismatch not sure but still doable.
Thanks
no mismatch in impedance, both mentioned amps having high enough Rin to not present a problem
though, you always need trimpot or pot as volume, in front of amp which needs attenuation
one is always louder
only in cases where you're using identical amps, and passive xover designed as a whole, only arranged for biamplification - in that case no need for any vol. pot
though, you always need trimpot or pot as volume, in front of amp which needs attenuation
one is always louder
only in cases where you're using identical amps, and passive xover designed as a whole, only arranged for biamplification - in that case no need for any vol. pot