This is my first project and I'm looking for some advice on the best way to implement this.
The run down is I have two small chassis to house all the components of my Headphone Amplifier and DAC project.
Chassis 1 contains:
(1) IEC fused plug
(1) Kevin Ip Custom Display kit (modified with ackodac AKR75 5V 200mA-800mA regulator) for Soekris DAC (needs 5Vdc input) Only using the display controller board/ NOT the input board.
(1) compact soft touch/soft start circuit/small trafo 6VA to ONLY power display for DAC (kevin ip display board/display) This also serves as the softstart softtouch button on the front of the chassis
(2) Soekris Dam1021 DACs (approx input power range 8V-12V bipolar input)
(2) LT3042 "the wire" quad parallel PSU's (with upper and lower heatsinks)(each PSU using rails in bipolar setup to power each dam1021 @ 9Vdc each)
***note: all PSU will be closely mounted to whatever it will power and braided 4 wire solid core silver wire/teflon coated will be used to hookup the connection- should be 2-3inches max!.
(1) LT3042 "the wire" quad Parallel PSU (with upper and lower heatsinks)@ 5Vdc for Rail 1, 3.3Vdc for Rail 2 (this psu i'm a little concerned it may run a little warm with the higher than needed AC input but with the heatsinks I believe it may be OK) note: each rail is rated at 800mA, and can likely do a little more with heatsink's from what I understand.
(1)DIYINHK 768khz USB xu216 (powered from one rail of lt3042 3.3Vdc and needs upwards of 800mA at peak,400mA normal load)
(1)Toslink Module pcb (powered from normunds board (approx 20mA)
(1)HDMi i2S input module (audio-gd brand) powered from normunds board
(approx 25mA)
(2)XLR 3pin output
(2)RCA connectors output
(1)RCA digital s/pdif input
(1) 6pin mini XLR output (audio outputs* from chassis 1 to chassis 2)
*1pair for SE signal, 2 pairs for balanced signals (these will be the signal input for each headphone amplifier in chassis 2, please comment on best implemtation to wire with this 6pin XLR, twisted pair? shielding or not?) Going to use Norne Audio Therium 6core occ silver wire for this cable.
(1) 14pin 28mm aviation socket for input of transformer secondaries from chassis 2
1 Set Metal openings 28mm FDY28 Aviation Plug Socket Connector 14PIN 26pin | eBay
and using this wire to connect 12pins of the 14
Alpha Wire 1896 12C 12 Conductor 20 Gauge Unshielded Cable per Foot 12C 20AWG | eBay
1pair (2wires) - 5Vac (for 3.3Vdc psu rail)
1pair (2wires) - 7Vac (for 5Vdc psu rail)
2pair (4wires) - 8Vac (power for DAC 1 w/bipolar supply of 9Vdc)
2pair (4wires) - 8Vac (power for DAC 2 w/bipolar supply of 9Vdc)
1pair (2wires) - carry a signal from Potentiometer in chassis 2 to connect to the digital Volume control of the dac, I believe it operates at a 3.3V.
(all transfomers will be in chassis 2, and secondaries will exit chassis with the aviation 28mm 14pin plug and have 8inch cable to connect chassis 2 to chassis 1)
MY BIG QUESTION IS... is the cable with straight unshielded wire OK, or should I make another wire with twisted pairs, individually shielded, etc etc. what suggestions are best for this application?
Chassis 2 contains:
(1) IEC Plug (fused)
(1) "the wire" SE-SE (with heatsinks) headphone amplifier (powered @ 12.6Vdc)
(1) "the wire" BAL-BAL (with heatsinks) headphone amplifier (powered @ 14.6Vdc)
(1) potentiometer 10K
https://www.digikey.com/product-detail/en/bourns-inc/3852A-282-103AL/3852A-282-103AL-ND/1088602
(just now thinking how I need to have two wires for this to go from chassis 2 to chassis 1 and connect to the dac/normunds board to control volume. NOT connected to BALBAL or SESE. I guess the two extra positions on the 8" cable can be used for that. I'm definitely going to have to remake that cable and salvage the aviation plugs. Two chassis's is proving to be a major challenge. But it's what I could get and afford.)
(2) "the wire" LT3042 Quad Parallel PSU (with upper and lower heatsinks)
psu1 setup - input of 11.5Vac and hooked up to SE-SE @ 12.6Vdc
psu2 setup - input of 11.5Vac (larger 1.3A secondary) and hooked up to BAL-BAL @ 14.6Vdc
(3) Simon Tuned O-Core transformers
#1 - 115V-0 50/60hz
sec1- 12V-0 - 1A
sec2- 9V-0 - 2A
sec3- 7V-0 - 2A
sec4- 5V-0 - 2A
#2 - 115V/120V/0 50/60hz
sec1,2,3,4 - 8V-0 - 1.6A (one pair of sec for each Dac)
#3 - 115V/120V/0 50/60hz
sec1,2 - 11.5V-0 - 1.3A (for BALBAL)
sec3,4 - 11.5V-0 - 1A (for SESE)
I have been thinking of building a shield around both headphone amplifiers. basically aluminum walls surrounding the PSU and amplifiers from the surrounding transformers. would this be a good idea?
My main question is the connections between chassis. Any suggestions would be helpful. And I would like to know the best way to implement a star ground when using two chassis. I notice some people add some caps to the end of their ground points or something like that anyhow. I've tried to read more on this subject and since i'm fairly new to this stuff, i'm learning as I go. One website I found talks about Hybrid grounding.
Audio System Grounding And Troubleshooting | Core Audio Technology
I have a feeling my short 8inch 14pin connector cable I made may not be good enough (wrapped with mylar shielding under the sleeve). and twisted pairs would be more ideal? for all 12pins needed.
Is there a more elegant way to do this? I want to still use both chassis and the softstart buttons on each of them.
The run down is I have two small chassis to house all the components of my Headphone Amplifier and DAC project.
Chassis 1 contains:
(1) IEC fused plug
(1) Kevin Ip Custom Display kit (modified with ackodac AKR75 5V 200mA-800mA regulator) for Soekris DAC (needs 5Vdc input) Only using the display controller board/ NOT the input board.
(1) compact soft touch/soft start circuit/small trafo 6VA to ONLY power display for DAC (kevin ip display board/display) This also serves as the softstart softtouch button on the front of the chassis
(2) Soekris Dam1021 DACs (approx input power range 8V-12V bipolar input)
(2) LT3042 "the wire" quad parallel PSU's (with upper and lower heatsinks)(each PSU using rails in bipolar setup to power each dam1021 @ 9Vdc each)
***note: all PSU will be closely mounted to whatever it will power and braided 4 wire solid core silver wire/teflon coated will be used to hookup the connection- should be 2-3inches max!.
(1) LT3042 "the wire" quad Parallel PSU (with upper and lower heatsinks)@ 5Vdc for Rail 1, 3.3Vdc for Rail 2 (this psu i'm a little concerned it may run a little warm with the higher than needed AC input but with the heatsinks I believe it may be OK) note: each rail is rated at 800mA, and can likely do a little more with heatsink's from what I understand.
(1)DIYINHK 768khz USB xu216 (powered from one rail of lt3042 3.3Vdc and needs upwards of 800mA at peak,400mA normal load)
(1)Toslink Module pcb (powered from normunds board (approx 20mA)
(1)HDMi i2S input module (audio-gd brand) powered from normunds board
(approx 25mA)
(2)XLR 3pin output
(2)RCA connectors output
(1)RCA digital s/pdif input
(1) 6pin mini XLR output (audio outputs* from chassis 1 to chassis 2)
*1pair for SE signal, 2 pairs for balanced signals (these will be the signal input for each headphone amplifier in chassis 2, please comment on best implemtation to wire with this 6pin XLR, twisted pair? shielding or not?) Going to use Norne Audio Therium 6core occ silver wire for this cable.
(1) 14pin 28mm aviation socket for input of transformer secondaries from chassis 2
1 Set Metal openings 28mm FDY28 Aviation Plug Socket Connector 14PIN 26pin | eBay
and using this wire to connect 12pins of the 14
Alpha Wire 1896 12C 12 Conductor 20 Gauge Unshielded Cable per Foot 12C 20AWG | eBay
1pair (2wires) - 5Vac (for 3.3Vdc psu rail)
1pair (2wires) - 7Vac (for 5Vdc psu rail)
2pair (4wires) - 8Vac (power for DAC 1 w/bipolar supply of 9Vdc)
2pair (4wires) - 8Vac (power for DAC 2 w/bipolar supply of 9Vdc)
1pair (2wires) - carry a signal from Potentiometer in chassis 2 to connect to the digital Volume control of the dac, I believe it operates at a 3.3V.
(all transfomers will be in chassis 2, and secondaries will exit chassis with the aviation 28mm 14pin plug and have 8inch cable to connect chassis 2 to chassis 1)
MY BIG QUESTION IS... is the cable with straight unshielded wire OK, or should I make another wire with twisted pairs, individually shielded, etc etc. what suggestions are best for this application?
Chassis 2 contains:
(1) IEC Plug (fused)
(1) "the wire" SE-SE (with heatsinks) headphone amplifier (powered @ 12.6Vdc)
(1) "the wire" BAL-BAL (with heatsinks) headphone amplifier (powered @ 14.6Vdc)
(1) potentiometer 10K
https://www.digikey.com/product-detail/en/bourns-inc/3852A-282-103AL/3852A-282-103AL-ND/1088602
(just now thinking how I need to have two wires for this to go from chassis 2 to chassis 1 and connect to the dac/normunds board to control volume. NOT connected to BALBAL or SESE. I guess the two extra positions on the 8" cable can be used for that. I'm definitely going to have to remake that cable and salvage the aviation plugs. Two chassis's is proving to be a major challenge. But it's what I could get and afford.)
(2) "the wire" LT3042 Quad Parallel PSU (with upper and lower heatsinks)
psu1 setup - input of 11.5Vac and hooked up to SE-SE @ 12.6Vdc
psu2 setup - input of 11.5Vac (larger 1.3A secondary) and hooked up to BAL-BAL @ 14.6Vdc
(3) Simon Tuned O-Core transformers
#1 - 115V-0 50/60hz
sec1- 12V-0 - 1A
sec2- 9V-0 - 2A
sec3- 7V-0 - 2A
sec4- 5V-0 - 2A
#2 - 115V/120V/0 50/60hz
sec1,2,3,4 - 8V-0 - 1.6A (one pair of sec for each Dac)
#3 - 115V/120V/0 50/60hz
sec1,2 - 11.5V-0 - 1.3A (for BALBAL)
sec3,4 - 11.5V-0 - 1A (for SESE)
I have been thinking of building a shield around both headphone amplifiers. basically aluminum walls surrounding the PSU and amplifiers from the surrounding transformers. would this be a good idea?
My main question is the connections between chassis. Any suggestions would be helpful. And I would like to know the best way to implement a star ground when using two chassis. I notice some people add some caps to the end of their ground points or something like that anyhow. I've tried to read more on this subject and since i'm fairly new to this stuff, i'm learning as I go. One website I found talks about Hybrid grounding.
Audio System Grounding And Troubleshooting | Core Audio Technology
I have a feeling my short 8inch 14pin connector cable I made may not be good enough (wrapped with mylar shielding under the sleeve). and twisted pairs would be more ideal? for all 12pins needed.
Is there a more elegant way to do this? I want to still use both chassis and the softstart buttons on each of them.
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I don't have a direct link. Using google translate in chrome makes it pretty quick to find btw. I recommend his store for lots of parts. Anyhow. Would love to get some advice on the technical stuff 🙂
I'm going to likely choose a different knob for this project actually. I plan to machine the face of my other chassis to allow the knob to be slightly recessed maybe 1/8th inch or so and possible add some lighting ring underneath it if I figure out how. I plan to do all yellow lighting to match the display. The back panels I'm working on and will have front panel express cut some 3mm black anodized alum panels. I never imagined this project to be so challenging. I really depend on the help of a lot of people on this website and hope someone who really knows their power supply setup to help me answer some questions I have. Would love to know more about grounding improvements, star ground and adding caps or resistors etc. I see them in the lampizator but don't know how important they are. (Shrug)
With all the transformers in the same chassis there my be interference. Turning them at a tanget to one another will help or shield them...
I made a couple preamps using a similar idea. I used acrylic sheet mounted behind the aluminium front:
http://www.diyaudio.com/forums/anal...lector-attenuator-tube-stage.html#post2828555
http://www.diyaudio.com/forums/anal...ol-relay-r2r-input-selection.html#post4366871
Thanks for sharing that info Max! I would love to do something like that. I plan to make it subtle yellow glow and about a 1mm ring or so. The whole theme will be yellow color....and the two chassis will have their own names....
officially called "DUSK" for the amp, and "DAWN" for the DAC.
from dusk til dawn i'll be listening to music 🙂
officially called "DUSK" for the amp, and "DAWN" for the DAC.
from dusk til dawn i'll be listening to music 🙂
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