swimtoview
Member
- Joined
- Mar 2, 2016
- Messages
- 15
At the risk of showing my complete ignorance, I have prepared a vero layout for the Langevin AM-16 preamp. I’ve been interested in building a few of these and thought it would be a good opportunity to learn how to read schematics and do layouts. I’d really appreciate any advice you can give to both forward my learning and help prepare an efficient layout for this pre. I have attached a preliminary layout image and the schematic used can be found at http://cinemag.biz/application_notes/PDF/AN-107.pdf.
I like the idea of veroboard since it doesn’t require etching or waiting on an ordered pcb. Please offer any input you can on errors or possible ways to be more efficient. I tried to lay this out in a way that all traces and cuts could be seen. I believe I could make it about 5 columns smaller by placing some components diagonally, however being that it is going in a 1u enclosure, this layout is plenty small to fit depth-wise.
I really don’t have a solid understanding of wiring the transformers, pots, and switches. In this layout, I use the JLM Go Between https://www.jlmaudio.com/shop/go-between-kit.html with variable pad on the input to handle phantom power, phase, and pad. I'm also considering adding the JLM FetDi as well https://www.jlmaudio.com/shop/fet-di.html. Do you think the DI is a good plan or better to use an external DI?
For visual purposes, I placed a column of cuts to separate the in and out of the transformers. I used the 600ohm impedance wiring for the XLR in jack. If you think it should be switchable impedance, please let me know how to do this. I couldn’t figure out how to do it with an SP3T switch. Also does anything need to be done with the transformer wires that are not shown to be connected on the schematic?
On the output I’ve used an SPST for switching between high and low power mode and the CAPI or Hairball 600 ohm variable attenuator http://capi-gear.com/catalog/product_info.php?products_id=256. I really don’t understand the transformer wiring. I see on the schematic to tie the green and blue wires for the center tap, but I don’t know where the center tap should go from there. I’m also assuming I can save column space by twisting the transformer wires that are connected to each other and soldering them both to a single hole.
I gather that the downward triangles are to ground, but I don’t understand which ground they’re going to. I believe one is to the chassis, and I’m guessing that one is the downward triangle consisting of lines rather than an outline of the triangle. I really don't know though so please clear this up for me.
I’d also really appreciate any advice you can give on powering the pre. I’d like to fit 4 of these in a single chassis with a separate power supply. So which power supply kit would be needed to power 4 of these AM-16’s between the JLM Power Plant 2 https://www.jlmaudio.com/shop/power-plant-kit.html or Power Station https://www.jlmaudio.com/shop/powerstation-kit.html. If there are other kits you would recommend, I’m all ears. I’d like to design one from scratch, but for a learning project I figure it would be good to go with a kit. I learned a lot from building the AML EZ-P1A kits. Fantastic, well organized, and well documented instructions for those newer to diy.
Thanks for taking a look!
I like the idea of veroboard since it doesn’t require etching or waiting on an ordered pcb. Please offer any input you can on errors or possible ways to be more efficient. I tried to lay this out in a way that all traces and cuts could be seen. I believe I could make it about 5 columns smaller by placing some components diagonally, however being that it is going in a 1u enclosure, this layout is plenty small to fit depth-wise.
I really don’t have a solid understanding of wiring the transformers, pots, and switches. In this layout, I use the JLM Go Between https://www.jlmaudio.com/shop/go-between-kit.html with variable pad on the input to handle phantom power, phase, and pad. I'm also considering adding the JLM FetDi as well https://www.jlmaudio.com/shop/fet-di.html. Do you think the DI is a good plan or better to use an external DI?
For visual purposes, I placed a column of cuts to separate the in and out of the transformers. I used the 600ohm impedance wiring for the XLR in jack. If you think it should be switchable impedance, please let me know how to do this. I couldn’t figure out how to do it with an SP3T switch. Also does anything need to be done with the transformer wires that are not shown to be connected on the schematic?
On the output I’ve used an SPST for switching between high and low power mode and the CAPI or Hairball 600 ohm variable attenuator http://capi-gear.com/catalog/product_info.php?products_id=256. I really don’t understand the transformer wiring. I see on the schematic to tie the green and blue wires for the center tap, but I don’t know where the center tap should go from there. I’m also assuming I can save column space by twisting the transformer wires that are connected to each other and soldering them both to a single hole.
I gather that the downward triangles are to ground, but I don’t understand which ground they’re going to. I believe one is to the chassis, and I’m guessing that one is the downward triangle consisting of lines rather than an outline of the triangle. I really don't know though so please clear this up for me.
I’d also really appreciate any advice you can give on powering the pre. I’d like to fit 4 of these in a single chassis with a separate power supply. So which power supply kit would be needed to power 4 of these AM-16’s between the JLM Power Plant 2 https://www.jlmaudio.com/shop/power-plant-kit.html or Power Station https://www.jlmaudio.com/shop/powerstation-kit.html. If there are other kits you would recommend, I’m all ears. I’d like to design one from scratch, but for a learning project I figure it would be good to go with a kit. I learned a lot from building the AML EZ-P1A kits. Fantastic, well organized, and well documented instructions for those newer to diy.
Thanks for taking a look!