It shows one channel of the complete PLR circuit, as I can remember. Like I said earlier, I used dual footprints, TO-92 & sot-23 so it is not exactly as it was originally drawn. I recall I tried to use the zetex parts in a simulation, thd numbers rose, I am not sure why or if that represented reality since I never made or tested the circuit. That's it for PLR onto X-Altra discussion.
The hifisonix page with all the relevant links to the audioXpress web pages has now been updated
X-Altra RIAA Phono EQ Preamp
The detailed supplementary information (specs, BOM, noise measurement methodology, assembly instruction details etc) can be found here https://audioxpress.com/files/attachment/2732
You can buy a digital copy of the magazine with the article (plus of course lots of other great audio stuff in the same issue) via the link on the hifisonix webpage above.
Details on the board sets will go up on the hifisonix website in the next few days. I wont release them until the 2nd article is published so you can look at the complete thing before you decide to move forward with the project.
X-Altra RIAA Phono EQ Preamp
The detailed supplementary information (specs, BOM, noise measurement methodology, assembly instruction details etc) can be found here https://audioxpress.com/files/attachment/2732
You can buy a digital copy of the magazine with the article (plus of course lots of other great audio stuff in the same issue) via the link on the hifisonix webpage above.
Details on the board sets will go up on the hifisonix website in the next few days. I wont release them until the 2nd article is published so you can look at the complete thing before you decide to move forward with the project.
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PCB sets for the X-Altra MC/MM preamp are now available here
X-Altra RIAA Phono EQ Preamp
The 2nd part of the project covering the MM preamp stage, filters and PSU will be published in the March issue of audioXPress along with measurements.
X-Altra RIAA Phono EQ Preamp
The 2nd part of the project covering the MM preamp stage, filters and PSU will be published in the March issue of audioXPress along with measurements.
The regulators are in the MC and MM circuits and are powered from the +-15 V rails like this:-
The reference voltages for the regulators are derived from the divider chain formed by R13,14,15 and 16.
For the MC +-5V regulator, U3 and U4 are the regulators (LM4562- lo noise and high PSRR all the way out to 100 kHz). The current draw in each rail is c. 3.5 mA.
From the same reference divider mentioned above, we get +10V which is fed into pin 3 of U19 and U26 which is half an LM4562 and forms the +10 V regulator for the MM front end.
The wide band noise of these LM4562 regulators is about 7nV.
The reference voltages for the regulators are derived from the divider chain formed by R13,14,15 and 16.
For the MC +-5V regulator, U3 and U4 are the regulators (LM4562- lo noise and high PSRR all the way out to 100 kHz). The current draw in each rail is c. 3.5 mA.
From the same reference divider mentioned above, we get +10V which is fed into pin 3 of U19 and U26 which is half an LM4562 and forms the +10 V regulator for the MM front end.
The wide band noise of these LM4562 regulators is about 7nV.
Bonsai,
I wanted to follow up on an email I had sent you a few weeks ago. A number of components do not seem to line up between my PCB silkscreen and the XLS BOM posted in audioXpress Supplementary Material | audioXpress. For example, D7/D8 MUR-820s on the PCB appear to be marked as D4/D5 on the BOM, C43 on the PCB appears to be C78 in the BOM, C45/C46 on the PCB is C71/C72 on the BOM, U10/U9 are LM7815s on the PCB but marked U20/21 in the BOM, etc.
My PCB is marked V1.0 July 2020 / V1 June 2020, unsure if the BOM is outdated or if I have an older version of the PCB. Has anyone else noticed these discrepancies? Bonsai, any possibility to release a BOM with references that match the PCB silkscreen?
Thanks,
Greg
I wanted to follow up on an email I had sent you a few weeks ago. A number of components do not seem to line up between my PCB silkscreen and the XLS BOM posted in audioXpress Supplementary Material | audioXpress. For example, D7/D8 MUR-820s on the PCB appear to be marked as D4/D5 on the BOM, C43 on the PCB appears to be C78 in the BOM, C45/C46 on the PCB is C71/C72 on the BOM, U10/U9 are LM7815s on the PCB but marked U20/21 in the BOM, etc.
My PCB is marked V1.0 July 2020 / V1 June 2020, unsure if the BOM is outdated or if I have an older version of the PCB. Has anyone else noticed these discrepancies? Bonsai, any possibility to release a BOM with references that match the PCB silkscreen?
Thanks,
Greg
Greg, there may be some small discrepancies since the latest version of the board (the one you have and the same one that is been sold is the latest version - no other earlier versions have or are being sold) had some minor updates from the previous development version. The ground lifter was added in the final version - I guess the BOM did not reflect that - apologies
I will post up on my website in an hour or so the BOM off the PCB which will clarify these few discrepancies.
I will post up on my website in an hour or so the BOM off the PCB which will clarify these few discrepancies.
Hello dubbio, unfortunately no plans for pre-stuffed boards at this stage. You do need to be able to place SMD (down to 0805) for this project.
However, there are many good videos for manual SMD placement on YouTube - once you get the hang of it, you will prefer it to leaded components.
All you need a very fine tipped soldering iron, fine tipped tweezers and 0.5mm diameter solder to place parts down to 0805.
However, there are many good videos for manual SMD placement on YouTube - once you get the hang of it, you will prefer it to leaded components.
All you need a very fine tipped soldering iron, fine tipped tweezers and 0.5mm diameter solder to place parts down to 0805.