So long as there is not a ground lift on that power supply board, that would be the way to do it. If there is a ground lift, you would need to separate the power supply ground from the chassis. Remember to install the jumpers from the center v+ and v- to ground to take it from a dual power supply to a bipolar.
You will need the higher voltage switch. At least I can't think of a way to make a 12v switch work. I would do it between the IEC and the transformer on the hot leg of the mains so that when the switch is off, it takes the hot out of the circuit.
You will need the higher voltage switch. At least I can't think of a way to make a 12v switch work. I would do it between the IEC and the transformer on the hot leg of the mains so that when the switch is off, it takes the hot out of the circuit.
Thanks, @Mikerodrig27 Yes, the jumpers are in. Here is the circuit. How do I tell if there is a ground lift?
Hot leg of the mains. Got it 👍
Hot leg of the mains. Got it 👍
Hello Rankstranger,
J1 and J2 have to be jumpered to get a symmetrical power supply with + xx V and - xx V.
GND (of the PSU / between J1 and J2) gets connected to earthground of your IEC-inlet.
From earthground / IEC-inlet also a connection to the case!
The Audio-GND of your amp-pcb (Waynes Line Stage) can be connected directly to GND of your PSU or
you use a ground-loop-breaker ( 10 Ohm - resistor or combined with diodes) to get a groundlift.
A groundloopbreaker is only necessary if you have groundloops / humproblems.
Cheers
Dirk
J1 and J2 have to be jumpered to get a symmetrical power supply with + xx V and - xx V.
GND (of the PSU / between J1 and J2) gets connected to earthground of your IEC-inlet.
From earthground / IEC-inlet also a connection to the case!
The Audio-GND of your amp-pcb (Waynes Line Stage) can be connected directly to GND of your PSU or
you use a ground-loop-breaker ( 10 Ohm - resistor or combined with diodes) to get a groundlift.
A groundloopbreaker is only necessary if you have groundloops / humproblems.
Cheers
Dirk
Attachments
Thanks, @cubicincher and @sov yes, J1 and J2 are jumpered.
Can the PSU ground, the earth ground from the iec and the audio ground from the pcb all connect to the chassis at the same point? Is that what a star-ground is or have I misunderstood that?
Can the PSU ground, the earth ground from the iec and the audio ground from the pcb all connect to the chassis at the same point? Is that what a star-ground is or have I misunderstood that?
Yup, that is a kind of starground then. Test it if it is silent. If not - add a groundloopbreaker.
Cheers
Dirk
Cheers
Dirk
Quick question. Still working on my balanced Wayne’s preamp. I’m using two Amb o22 power supplies in a separate chassis with two 20VAC 25VA Antek torroidals for 18V+-
Both Wayne’s boards are populated and waiting on the chassis.
Only thing I’m having hard finding options for are the volume pot.
I found a couple options but want to be sure either of these would work. I’m not able to find many other options.
https://www.ebay.com/itm/4024226884...ar=672540936137&widget_ver=artemis&media=COPY
https://hifiocean.com/collections/volume-controls/products/balanced-volume-control
Both Wayne’s boards are populated and waiting on the chassis.
Only thing I’m having hard finding options for are the volume pot.
I found a couple options but want to be sure either of these would work. I’m not able to find many other options.
https://www.ebay.com/itm/4024226884...ar=672540936137&widget_ver=artemis&media=COPY
https://hifiocean.com/collections/volume-controls/products/balanced-volume-control
The quad gang Alps looks good.
Also consider using (2) standard stereo (two-gang) pots, one for each channel... two knobs may seem inconvenient at first glance but is actually quite nice in practice, you have a much bigger selection of potentiometers, and you get balance control with no additional circuitry.
Also consider using (2) standard stereo (two-gang) pots, one for each channel... two knobs may seem inconvenient at first glance but is actually quite nice in practice, you have a much bigger selection of potentiometers, and you get balance control with no additional circuitry.
If you’re doing a balanced BA2018 have you looked at Lenny’s Muses options at Academy Audio? He has a balanced input/Muses board (not cheap) but they are easy to incorporate into the BA2018 (see his App Notes) and sound great. You could even use two of his VCX single-ended kits if implementing 6L6’s dual volume control.
https://www.academyaudio.com/
https://www.academyaudio.com/
Thanks Derekr. I have looked at kits like this, but curious for anyone that goes this route, do you drill holes yourself for it? I know this would require perfect alignment for the xlr on the back. And of course getting a perfect rectangle cut is hard with a drill.
CNC is an option, how could I easily get a chassis made where I can just install and no drilling required?
I normally do my own drilling for build but CNC would be required for that kit.
CNC is an option, how could I easily get a chassis made where I can just install and no drilling required?
I normally do my own drilling for build but CNC would be required for that kit.
Dneu2011:
I purchased an Academy Audio system for my BA2018 project and paid to have the RCA jacks not soldered onto the VCM board. I also had Lenny change the display labels for the six inputs and make a minor change to the VCM to better align with the BA2018 preamp. I've had that two chassis preamplifier in my main system for a few years and am besotted with it. Academy Audio provides great service and an excellent product.
That said, if you're so inclined you could always not uninstall the original RCA jacks and drill the access holes yourself. A dimensional diagram for the VCM board is available on Academy Audio's website.
Regards,
Scott
I purchased an Academy Audio system for my BA2018 project and paid to have the RCA jacks not soldered onto the VCM board. I also had Lenny change the display labels for the six inputs and make a minor change to the VCM to better align with the BA2018 preamp. I've had that two chassis preamplifier in my main system for a few years and am besotted with it. Academy Audio provides great service and an excellent product.
That said, if you're so inclined you could always not uninstall the original RCA jacks and drill the access holes yourself. A dimensional diagram for the VCM board is available on Academy Audio's website.
Regards,
Scott
Attachments
Dneu2011:
I should have mentioned that I used Front Panel Express to drill, mill and engrave my BA2018's front and rear panels. Not cheap, but they offer a valuable service.
Regards.
I should have mentioned that I used Front Panel Express to drill, mill and engrave my BA2018's front and rear panels. Not cheap, but they offer a valuable service.
Regards.
I also use the Front Panel Express free software to design the entire chassis - you can then get perfect rectangles with rounded corners, perfectly spaced holes of any shape etc - and send the pdf files (saved in 100% scale) to a local trophy engraving business with a good laser cutter and provide them with perspex sized to fit all six panels - about 12mm oversized in length and width. In a few days I get back a complete chassis and, if you’ve done your design carefully, everything bolts together and bolts in perfectly. Considerably cheaper than metal but some people prefer the metal. Been doing this for years with no hum or interference issues.
Quick question. I’m almost done with the balanced build but realized, dang I don’t know how to wire the inputs and outputs. What I THOUGHT is that I need TWO full Waynes boards (one for each channel). Left channel for one and right channel for the other.
Looking at one board, there is a V+, V-, and GND per section (2 sections), so in my case with my two boards I have 4 total. I am now wondering, can one full board not be used V+ to pin 2, V- to pin 3, and GND to pin 1 (one section gets the left, and the other gets the right)
But, I see the outputs only have Out, and GND. I looked through the whole thread and didn't see any builds with a balanced wiring scheme.
Any help is appreciated.
Looking at one board, there is a V+, V-, and GND per section (2 sections), so in my case with my two boards I have 4 total. I am now wondering, can one full board not be used V+ to pin 2, V- to pin 3, and GND to pin 1 (one section gets the left, and the other gets the right)
But, I see the outputs only have Out, and GND. I looked through the whole thread and didn't see any builds with a balanced wiring scheme.
Any help is appreciated.
