Today I under went the pain of creating a new pattern for the LED display part, adding the pattern to a new Combo part which has through hole and surface mount pads, updated the board layout slightly and exported new gerbers. The display board was version 3 so I have named this one 3.1 since it is a minor update.
And Here is the Build and test instructions.
Build Instructions for Rotary Encoder Volume Control
Be sure to use good anti-static practices and quality no-clean lead free solder. You should be confident in making quality solder connections. Digital troubleshooting is as simply as connecting a voltmeter to ground and probing IC pins looking for High Logic (4.0-5.0v) or Low Logic state (0 to ~.28 v). You can look at part data sheets to understand the Digital Logic symbols. And you must be able to follow a signal through a schematic and understand what it should be and do. Example: a high logic goes to a pin of a Hex inverter (six gates in one chip and inverts the logic H in L out, or L in H out) and you should know to look for a low logic out.
Remote Board Build
1. Start by soldering on U1 the surface mount transmission encoder. Easier to do if you have liquid flux, dip a tooth pick into the flux and put a film on the solder pads of the PCB. Place the encoder chip on the board and use the tooth pick to move in around so the legs align with the solder pads. BE SURE IT IS IN THE CORRECT ORIENTATION. Use a very fine tip soldering iron, temperature controlled. Tin the tip and wipe off most of the solder leaving a small amount. Use the toothpick to pin the chip to the PCB pushing down in the middle of the chip with one hand. Make sure it is still aligned then touch one corner leg of the chip at the PCB and the minimal solder on the tip should flow on the board. Touch the joint for minimum time to flow the solder, usually only a second, do not hold for long. When the joint cools, be sure the chip is still aligned, if not heat the leg and push the chip off and start again, then move on to the opposite corner, re-tin the iron tip. If the chip is still aligned you can remove the tooth pick from holding down the chip. Repeat soldering for each corner, then all legs, re-tinning the iron every leg or two, this ensures you are using the minimum amount of solder. Too much solder can bridge two legs, use solder wick to remove extra solder if you get a solder bridge. When done, clean the board with isopropyl alcohol on a cotton swab and inspect the solder joints with a magnifying glass. Re-touch any suspect joints.
2. Stuff and solder the small parts: resistors and diodes making sure the diodes are oriented correctly.
3. Stuff and solder the FET and the modulator chip U2.
4. Solder in the caps and the battery holder.
5. Solder the Infrared LED in vertically leaving the legs long. After soldering fold the LED legs over at the PCB to right angle so the LED sticks forward of the front of the board.
6. Solder in the momentary contact switches, aligning the in the center of the silkscreen footprint.
7. Set aside for testing later.
Power Supply Board Build
1. Solder on the heat sink for U1. The apply some thermal grease to the backside of the regulator and use a 4-40 or M3 screw and matching nut to secure the regulator to the heat sink and solder the legs.
2. Solder on the other small parts, be sure the capacitors are correctly oriented, positive to square pads, and the bridge rectifier is correctly oriented notch to the silkscreen line positive.
3. Solder on the transformer, pin 1 to the square pad.
4. Connect a power cord to the PCA and set the switch to local AC voltage. Being careful with live power, plug in the power cord and see that you have five volts on the output connector.
Digital Board Build
1. Insert and solder in place the ICs making sure of the orientation.
2. Insert and solder the de-coupler caps and the voltage supervisor U7.
3. Insert and solder the SIP riser headers J5 and J4.
4. Insert and solder the DIP headers J1 and J2.
5. Solder in a 12” red and black 18 gauge wire to the 5 volts connector, red, positive, to the square pad.
Display Board Build
1. Solder on U4, the remote control decoder. Use the same technique as for remote board encoder.
2. Solder on U12, the PROGRAMMED EEPROM, SOIC chip using the same technique as U4 decoder.
3. Solder on all resistors and diodes making sure to orient the diodes correctly. The LEDs D3 and D4 mount as tight to the board as possible.
4. Solder in the rest of the ICs making sure to orient them correctly.
5. Solder in the capacitors, orient C5 correctly.
6. Solder in the Infrared receiver vertically then fold back 90 degrees over U4.
7. Solder on the LED seven segment displays, be careful to put the single common anode part to DS1, the other three common cathode parts to DS2-DS4. Be careful of orientation, the decimal point LED should be towards the middle of the board.
8. Solder in the momentary contact switches, aligning them in the center of the silkscreen footprint.
9. Solder the pin headers J2 and J3 to the BACK side of the board.
10. Solder in a 12” red and black 18 gauge wire to the 5 volt connector J1 in red, positive, to the square pad on the BACK side of the board.
11. Solder in the rotary encoder, S1.
Test the Digital and Display boards
1. Connect the 5 volt wires from the Digital and Display boards to the power supply board connector making sure of proper polarity.
2. Connect a ribbon cable from the Digital board Port A to the back of the Display board Port A being sure of the orientation, red strip to pin one on each board.
3. Connect a ribbon cable from the Digital board Port B to the back of the Display board Port B being sure of the orientation, red strip to pin one on each board.
4. Plug in the power cord being careful of the high voltage. The Display LEDs should light up showing zeros. Turning the rotary encoder knob should increment the volume 3 LEDs up and down. Test the push buttons for mute and input selection. Resolve any problem before going any further.
5. When the PS, Digital and Display boards are tested and working then put batteries into the remote and test is aiming the infrared transmitter at the receiver on the Display board from about 6 feet, 2 meters, away. Make sure there isn’t any direct fluorescent light on the receiver, it can interfere with transmission. The transmission ACK LED on the Display board should light when receiving a transmission. Test all four buttons on the remote. Resolve any problem before going any further.
6. Once all is verified as working then go to build the Analog board.
Analog Board Build
1. Insert and solder in place the IC making sure of the orientation.
2. Insert and solder the de-coupler cap.
3. Insert and solder the transistors making sure of the orientation.
4. Insert and solder the diodes making sure of the orientation.
5. Insert and solder the smaller resistors.
6. Insert and solder the larger resistors making sure of the value of the resistors and position.
7. Insert and solder the relays making sure of the orientation.
Testing of the Analog Board
1. On the Digital board put a standoff in each corner. A ½”#6-32, or 12mm equivalent metric standoff, female/male. Put the male end through the Digital board from the back side and screw a ¾” #6-32, or 18mm metric equivalent, female/female standoff to the male end of the four standoffs. Mate the Analog board to the Digital board through the header holes J1 and J2. Put four #6-32x1/4” screws through the Analog board to the standoff so you have Analog board above the Digital board.
2. The header pins sticking through the Analog board generally make good enough contact for testing. The 5 volt two pin connector can be solder as it is not hard to heat and separate the boards if necessary.
3. Test each input connection: Put an Ohmmeter to the ground pin, pin 1 (square), of the input connector and to pin 2 then pin 1 to 3, left and right. It should show as open. Start at input 1 and some volume number displaying other than 0. Select the input on the display board and you should see some resistance. Test each input.
4. Turning the rotary encoder you should see the display go up and down and hear the relay clicks, connect the ohmmeter across the volume output connectors J9 and J10, you should see the resistance varying with the volume number.
5. You can connect audio inputs and outputs to the Analog volume board and listen to the audio. When you are satisfied all is working the boards can be added to a chassis. Use 1 5/16” or 32 mm standoffs at the end of the Analog board that hangs out beyond the digital board so it won’t flex. Only when all is installed and tested then you can solder the header pins from the Display board to the Analog board.
Build Instructions for Rotary Encoder Volume Control
Be sure to use good anti-static practices and quality no-clean lead free solder. You should be confident in making quality solder connections. Digital troubleshooting is as simply as connecting a voltmeter to ground and probing IC pins looking for High Logic (4.0-5.0v) or Low Logic state (0 to ~.28 v). You can look at part data sheets to understand the Digital Logic symbols. And you must be able to follow a signal through a schematic and understand what it should be and do. Example: a high logic goes to a pin of a Hex inverter (six gates in one chip and inverts the logic H in L out, or L in H out) and you should know to look for a low logic out.
Remote Board Build
1. Start by soldering on U1 the surface mount transmission encoder. Easier to do if you have liquid flux, dip a tooth pick into the flux and put a film on the solder pads of the PCB. Place the encoder chip on the board and use the tooth pick to move in around so the legs align with the solder pads. BE SURE IT IS IN THE CORRECT ORIENTATION. Use a very fine tip soldering iron, temperature controlled. Tin the tip and wipe off most of the solder leaving a small amount. Use the toothpick to pin the chip to the PCB pushing down in the middle of the chip with one hand. Make sure it is still aligned then touch one corner leg of the chip at the PCB and the minimal solder on the tip should flow on the board. Touch the joint for minimum time to flow the solder, usually only a second, do not hold for long. When the joint cools, be sure the chip is still aligned, if not heat the leg and push the chip off and start again, then move on to the opposite corner, re-tin the iron tip. If the chip is still aligned you can remove the tooth pick from holding down the chip. Repeat soldering for each corner, then all legs, re-tinning the iron every leg or two, this ensures you are using the minimum amount of solder. Too much solder can bridge two legs, use solder wick to remove extra solder if you get a solder bridge. When done, clean the board with isopropyl alcohol on a cotton swab and inspect the solder joints with a magnifying glass. Re-touch any suspect joints.
2. Stuff and solder the small parts: resistors and diodes making sure the diodes are oriented correctly.
3. Stuff and solder the FET and the modulator chip U2.
4. Solder in the caps and the battery holder.
5. Solder the Infrared LED in vertically leaving the legs long. After soldering fold the LED legs over at the PCB to right angle so the LED sticks forward of the front of the board.
6. Solder in the momentary contact switches, aligning the in the center of the silkscreen footprint.
7. Set aside for testing later.
Power Supply Board Build
1. Solder on the heat sink for U1. The apply some thermal grease to the backside of the regulator and use a 4-40 or M3 screw and matching nut to secure the regulator to the heat sink and solder the legs.
2. Solder on the other small parts, be sure the capacitors are correctly oriented, positive to square pads, and the bridge rectifier is correctly oriented notch to the silkscreen line positive.
3. Solder on the transformer, pin 1 to the square pad.
4. Connect a power cord to the PCA and set the switch to local AC voltage. Being careful with live power, plug in the power cord and see that you have five volts on the output connector.
Digital Board Build
1. Insert and solder in place the ICs making sure of the orientation.
2. Insert and solder the de-coupler caps and the voltage supervisor U7.
3. Insert and solder the SIP riser headers J5 and J4.
4. Insert and solder the DIP headers J1 and J2.
5. Solder in a 12” red and black 18 gauge wire to the 5 volts connector, red, positive, to the square pad.
Display Board Build
1. Solder on U4, the remote control decoder. Use the same technique as for remote board encoder.
2. Solder on U12, the PROGRAMMED EEPROM, SOIC chip using the same technique as U4 decoder.
3. Solder on all resistors and diodes making sure to orient the diodes correctly. The LEDs D3 and D4 mount as tight to the board as possible.
4. Solder in the rest of the ICs making sure to orient them correctly.
5. Solder in the capacitors, orient C5 correctly.
6. Solder in the Infrared receiver vertically then fold back 90 degrees over U4.
7. Solder on the LED seven segment displays, be careful to put the single common anode part to DS1, the other three common cathode parts to DS2-DS4. Be careful of orientation, the decimal point LED should be towards the middle of the board.
8. Solder in the momentary contact switches, aligning them in the center of the silkscreen footprint.
9. Solder the pin headers J2 and J3 to the BACK side of the board.
10. Solder in a 12” red and black 18 gauge wire to the 5 volt connector J1 in red, positive, to the square pad on the BACK side of the board.
11. Solder in the rotary encoder, S1.
Test the Digital and Display boards
1. Connect the 5 volt wires from the Digital and Display boards to the power supply board connector making sure of proper polarity.
2. Connect a ribbon cable from the Digital board Port A to the back of the Display board Port A being sure of the orientation, red strip to pin one on each board.
3. Connect a ribbon cable from the Digital board Port B to the back of the Display board Port B being sure of the orientation, red strip to pin one on each board.
4. Plug in the power cord being careful of the high voltage. The Display LEDs should light up showing zeros. Turning the rotary encoder knob should increment the volume 3 LEDs up and down. Test the push buttons for mute and input selection. Resolve any problem before going any further.
5. When the PS, Digital and Display boards are tested and working then put batteries into the remote and test is aiming the infrared transmitter at the receiver on the Display board from about 6 feet, 2 meters, away. Make sure there isn’t any direct fluorescent light on the receiver, it can interfere with transmission. The transmission ACK LED on the Display board should light when receiving a transmission. Test all four buttons on the remote. Resolve any problem before going any further.
6. Once all is verified as working then go to build the Analog board.
Analog Board Build
1. Insert and solder in place the IC making sure of the orientation.
2. Insert and solder the de-coupler cap.
3. Insert and solder the transistors making sure of the orientation.
4. Insert and solder the diodes making sure of the orientation.
5. Insert and solder the smaller resistors.
6. Insert and solder the larger resistors making sure of the value of the resistors and position.
7. Insert and solder the relays making sure of the orientation.
Testing of the Analog Board
1. On the Digital board put a standoff in each corner. A ½”#6-32, or 12mm equivalent metric standoff, female/male. Put the male end through the Digital board from the back side and screw a ¾” #6-32, or 18mm metric equivalent, female/female standoff to the male end of the four standoffs. Mate the Analog board to the Digital board through the header holes J1 and J2. Put four #6-32x1/4” screws through the Analog board to the standoff so you have Analog board above the Digital board.
2. The header pins sticking through the Analog board generally make good enough contact for testing. The 5 volt two pin connector can be solder as it is not hard to heat and separate the boards if necessary.
3. Test each input connection: Put an Ohmmeter to the ground pin, pin 1 (square), of the input connector and to pin 2 then pin 1 to 3, left and right. It should show as open. Start at input 1 and some volume number displaying other than 0. Select the input on the display board and you should see some resistance. Test each input.
4. Turning the rotary encoder you should see the display go up and down and hear the relay clicks, connect the ohmmeter across the volume output connectors J9 and J10, you should see the resistance varying with the volume number.
5. You can connect audio inputs and outputs to the Analog volume board and listen to the audio. When you are satisfied all is working the boards can be added to a chassis. Use 1 5/16” or 32 mm standoffs at the end of the Analog board that hangs out beyond the digital board so it won’t flex. Only when all is installed and tested then you can solder the header pins from the Display board to the Analog board.
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Last line of Testing of the Analog Board: Only when all is installed and tested then you can solder the header pins from the "Display board to the Analog board", should be Digital board to Analog Board. The boards stack and un-soldering the long header is a pain so wait to solder until all is tested and working.
John,
After a long hiatus I came back to this thread last week. As you may recall I had built 3 working sets of your early boards but given their large size I couldn’t find a case big enough to install them in. I figured I would get around to building my own cases large enough to hold them with, but I didn’t think it would be almost three years! In any event, I was getting ready to install them in with CC-XBOSOZ preamps and I wanted to see what has improved. I see it has come a long way!
My problem is that the consensus has been that that XBOSOZ works better with the attenuation after the preamp rather than in the front. That would require the ability to separate the switching output from the attenuation input. Looking at your boards, both the old main board and the new analog board, it appears to be plenty of space to kluge something like that by cutting the traces running from switching to the attenuation section and inserting IO. It wouldn’t look pretty, but I could probably make it work.
Now I know that your position from the beginning has been that the attenuation should be in the front, but I think you should be agnostic on this. Put in IO for those who want it and jumpers for those who don’t. That would make it usable for either application. Further, there is a large segment of the audio population with all digital inputs that do their switching on the DAC. That would allow them easy access directly to the attenuation section.
One other issue that has bothered me for some time is the spacing of your input connections. While the outputs will take a standard header, the inputs will not. Now I know that your position is that the inputs are better hardwired. I don’t necessarily think you are wrong on that but I know that during the initial testing phase I want to use headers so I can easily take the board in and out of the system even if I do plan to eventually hardwire them. It makes my life much easier.
Neither one of these changes should require much work but they would go a long way towards making your fine project more flexible.
Regards,
Roy
After a long hiatus I came back to this thread last week. As you may recall I had built 3 working sets of your early boards but given their large size I couldn’t find a case big enough to install them in. I figured I would get around to building my own cases large enough to hold them with, but I didn’t think it would be almost three years! In any event, I was getting ready to install them in with CC-XBOSOZ preamps and I wanted to see what has improved. I see it has come a long way!
My problem is that the consensus has been that that XBOSOZ works better with the attenuation after the preamp rather than in the front. That would require the ability to separate the switching output from the attenuation input. Looking at your boards, both the old main board and the new analog board, it appears to be plenty of space to kluge something like that by cutting the traces running from switching to the attenuation section and inserting IO. It wouldn’t look pretty, but I could probably make it work.
Now I know that your position from the beginning has been that the attenuation should be in the front, but I think you should be agnostic on this. Put in IO for those who want it and jumpers for those who don’t. That would make it usable for either application. Further, there is a large segment of the audio population with all digital inputs that do their switching on the DAC. That would allow them easy access directly to the attenuation section.
One other issue that has bothered me for some time is the spacing of your input connections. While the outputs will take a standard header, the inputs will not. Now I know that your position is that the inputs are better hardwired. I don’t necessarily think you are wrong on that but I know that during the initial testing phase I want to use headers so I can easily take the board in and out of the system even if I do plan to eventually hardwire them. It makes my life much easier.
Neither one of these changes should require much work but they would go a long way towards making your fine project more flexible.
Regards,
Roy
Hi Roy,
Yes a long time away. With the digitally weighted design, the first design, I would suggest using the new resistor values 20k, 10k, 5k, 2.5k, 1.25K, 625, 312, 156 ohm. That way the input resistance doesn't drop below 300 ohms.
But if you are using the preamp gain section to drive the volume resistance network it won't be a problem. With 2 cuts on the board, or 4 for balanced, you can place the gain section between the input and the volume section.
I am not wed to the volume resistance first then the gain section. I like it in my system as having the gain section low impedance output drive 20 feet of interconnect cable from the preamp on the left side of the room to the mono block amps next to the speakers in the front of the room works well.
I can make the changes to the PCB to allow input first, then either preamp or volume resistance. I would use the Rev 3 main board design. even though the discrete one-shot is a bit kludgy to an engineer it works, where as the Version 5 with the discreet one-shot is marginal in timing and the display can flicker. Hence the new design that uses an EEPROM to control the volume LEDs which is elegant but requires a programmed EEPROM, which I can supply. Also the 7-segment LEDs in though-hole went End-of-Life so I created a dual foot print LED for SMD or through-hole.
Have you checked out the new design of a constant input resistance ladder design? It has all the changes except the jumper option for gain or volume first, and is more compact, a little bit.
I did build one preamp with Pass Aleph P gain boards after the volume section and it was magic. Gave it to a friend who is really enjoying it.
So give me a laundry list of changes to the first design and I will see about updating the board.
BTW their are header pins for the input and connectors, I will look them up and give you the part numbers. I know wiring and unwiring a lot of inputs is a real pain.
Yes a long time away. With the digitally weighted design, the first design, I would suggest using the new resistor values 20k, 10k, 5k, 2.5k, 1.25K, 625, 312, 156 ohm. That way the input resistance doesn't drop below 300 ohms.
But if you are using the preamp gain section to drive the volume resistance network it won't be a problem. With 2 cuts on the board, or 4 for balanced, you can place the gain section between the input and the volume section.
I am not wed to the volume resistance first then the gain section. I like it in my system as having the gain section low impedance output drive 20 feet of interconnect cable from the preamp on the left side of the room to the mono block amps next to the speakers in the front of the room works well.
I can make the changes to the PCB to allow input first, then either preamp or volume resistance. I would use the Rev 3 main board design. even though the discrete one-shot is a bit kludgy to an engineer it works, where as the Version 5 with the discreet one-shot is marginal in timing and the display can flicker. Hence the new design that uses an EEPROM to control the volume LEDs which is elegant but requires a programmed EEPROM, which I can supply. Also the 7-segment LEDs in though-hole went End-of-Life so I created a dual foot print LED for SMD or through-hole.
Have you checked out the new design of a constant input resistance ladder design? It has all the changes except the jumper option for gain or volume first, and is more compact, a little bit.
I did build one preamp with Pass Aleph P gain boards after the volume section and it was magic. Gave it to a friend who is really enjoying it.
So give me a laundry list of changes to the first design and I will see about updating the board.
BTW their are header pins for the input and connectors, I will look them up and give you the part numbers. I know wiring and unwiring a lot of inputs is a real pain.
John,
Thank you, I really appreciate your openness to design changes that enhance flexibility. I didn't know of a header that fit your inputs but would welcome that information. In fact, it should be in the BOM as at least an option. I can't think of any other changes for the analogue board and will order it when you provide the gerbils.
Yes I am aware of your new resistance network and plan to take advantage of it. I have ordered the boards (5 each) from JLCPCB and they are very inexpensive. I will be more than happy to replace the analogue board with a new more flexible version. I will give the old ones away for postage to people who don't need the flexibility. I should have them next week
I went ahead and started ordering parts for the analogue board and found them to be painfully expensive. Only issue I found was obtaining the 6.65K resistors (6.81K part list). best I could find was the Dale CMF556K6500FHEB. Do you have a better option?
I have been working on parting the other boards and am developing a issue list on the BOM, but I will save that for another post.
Thanks again for your willingness to add enhancements!
Regards,
Roy
Thank you, I really appreciate your openness to design changes that enhance flexibility. I didn't know of a header that fit your inputs but would welcome that information. In fact, it should be in the BOM as at least an option. I can't think of any other changes for the analogue board and will order it when you provide the gerbils.
Yes I am aware of your new resistance network and plan to take advantage of it. I have ordered the boards (5 each) from JLCPCB and they are very inexpensive. I will be more than happy to replace the analogue board with a new more flexible version. I will give the old ones away for postage to people who don't need the flexibility. I should have them next week
I went ahead and started ordering parts for the analogue board and found them to be painfully expensive. Only issue I found was obtaining the 6.65K resistors (6.81K part list). best I could find was the Dale CMF556K6500FHEB. Do you have a better option?
I have been working on parting the other boards and am developing a issue list on the BOM, but I will save that for another post.
Thanks again for your willingness to add enhancements!
Regards,
Roy
For the 3 Pin header the part number is 292132-3 and the matching connector is 179228-3.
For the 6.81k resistor an alternate part is RN70D6811FB14, there is 9 in stock. Any value that is close is fine so long as all four are the same so you have channel matching. I prefer the Vishay/Dale RN series large body resistors, RN65 or RN70, they have a less distortion and sound pretty good, and not as expensive as the Caddocks.
So you are using the new design volume control and want the option to insert the preamp gain section between the input selection and the volume section. That is a minor change to the Analog board. I will see if I can find some time to work on it tonight, then post gerbers.
For the 6.81k resistor an alternate part is RN70D6811FB14, there is 9 in stock. Any value that is close is fine so long as all four are the same so you have channel matching. I prefer the Vishay/Dale RN series large body resistors, RN65 or RN70, they have a less distortion and sound pretty good, and not as expensive as the Caddocks.
So you are using the new design volume control and want the option to insert the preamp gain section between the input selection and the volume section. That is a minor change to the Analog board. I will see if I can find some time to work on it tonight, then post gerbers.
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John,
Thanks for your prompt response with the part numbers for the input connectors and the board changes. I ordered 5 from JLCPCB this morning and should have them in about a week. The boards were only $18 but the shipping was $30. When I bought the whole set of 4 shipping was only $36 so its much better to order as many different boards as possible a one time. In any event, I will send you one when they arrive.
I grabbed the last 9 resistors that you suggested but with 3 boards I will need 12. I guess I will need to investigate the Caddocks.
I am going to need 3 of your eproms, let me know how much they are and I’ll paypal you.
I have been going through your BOM and attempting to order parts that I can’t easily move from your earlier boards. A high priority for me is the relays. They are extremely difficult to move without damage. But with 3 boards that is 90 relays which even at the 100-level pricing that still runs $170 dollars.
I am having several part issues. On the Analogue Board you have a new relay driving transistor and have changed the design to only use 9 rather than 18 as before. The problem is its availability. The 2N3904BU is out of stock at Mouser and Digi-key and Octopart didn’t show inventory at any of the other major distributors. Do you have a viable substitute?
On the power supply board, I will have no problem moving the parts over from the old main board. However, new buyers will have problems with the switch. It seems to be out of stock everywhere until at least November.
The Display Board’s BOM still has the part number for the obsolete LED display parts. You have indicated that the board will now take those or the newer surface mount versions but there is no part number for them. I don’t think I will have a problem moving mine but that will not help new buyers.
I believe the remotes I have now should still work. Never did get the second version board you set to work but I am sure it’s a surface mount chip issue which I will address when necessary.
Regards,
Roy
Thanks for your prompt response with the part numbers for the input connectors and the board changes. I ordered 5 from JLCPCB this morning and should have them in about a week. The boards were only $18 but the shipping was $30. When I bought the whole set of 4 shipping was only $36 so its much better to order as many different boards as possible a one time. In any event, I will send you one when they arrive.
I grabbed the last 9 resistors that you suggested but with 3 boards I will need 12. I guess I will need to investigate the Caddocks.
I am going to need 3 of your eproms, let me know how much they are and I’ll paypal you.
I have been going through your BOM and attempting to order parts that I can’t easily move from your earlier boards. A high priority for me is the relays. They are extremely difficult to move without damage. But with 3 boards that is 90 relays which even at the 100-level pricing that still runs $170 dollars.
I am having several part issues. On the Analogue Board you have a new relay driving transistor and have changed the design to only use 9 rather than 18 as before. The problem is its availability. The 2N3904BU is out of stock at Mouser and Digi-key and Octopart didn’t show inventory at any of the other major distributors. Do you have a viable substitute?
On the power supply board, I will have no problem moving the parts over from the old main board. However, new buyers will have problems with the switch. It seems to be out of stock everywhere until at least November.
The Display Board’s BOM still has the part number for the obsolete LED display parts. You have indicated that the board will now take those or the newer surface mount versions but there is no part number for them. I don’t think I will have a problem moving mine but that will not help new buyers.
I believe the remotes I have now should still work. Never did get the second version board you set to work but I am sure it’s a surface mount chip issue which I will address when necessary.
Regards,
Roy
EEPROMs are $5 but with shipping in and out makes it around $10 each.
For the relays, I have a Metcal solder station and I have tips for most chips so I can heat all legs at once and the part drops out. If you wanted to send me the 3 boards I can desolder the relays and ship all back, with the EEPROMs, for the cost of shipping.\
On the 2N3904, it is just an NPN transistor being used as an analog switch so any small signal transistor should work. The BC549 works well and it cheap and in stock.
For the AC selection switch, it is nice to have but you can just use jumpers in place of the switch until it is available. I had to do that on some power supply boards for the preamp.
The Through Hole LED is available in Green and Red and maybe some other colors but
blue seems to be the most wanted so you can use ACSC56-41QBWA/D-F01.
On desoldering the through-hole LEDs be careful the pins are connected to a circuit board inside the LED housing and can be pulled out too easily. If you can do all pins at once and quickly it isn't a problem. If you send relay board to unsolder you can include the display board and I can remove the LEDs also, not hard for me with the Metcal.
I will update the BOM and repost. If you have any thing else for the BOM let me know.
Thanks,
John
For the relays, I have a Metcal solder station and I have tips for most chips so I can heat all legs at once and the part drops out. If you wanted to send me the 3 boards I can desolder the relays and ship all back, with the EEPROMs, for the cost of shipping.\
On the 2N3904, it is just an NPN transistor being used as an analog switch so any small signal transistor should work. The BC549 works well and it cheap and in stock.
For the AC selection switch, it is nice to have but you can just use jumpers in place of the switch until it is available. I had to do that on some power supply boards for the preamp.
The Through Hole LED is available in Green and Red and maybe some other colors but
blue seems to be the most wanted so you can use ACSC56-41QBWA/D-F01.
On desoldering the through-hole LEDs be careful the pins are connected to a circuit board inside the LED housing and can be pulled out too easily. If you can do all pins at once and quickly it isn't a problem. If you send relay board to unsolder you can include the display board and I can remove the LEDs also, not hard for me with the Metcal.
I will update the BOM and repost. If you have any thing else for the BOM let me know.
Thanks,
John
John,
I will take you up on your fine offer to remove the components from my boards. To bring the weight down I will remove the power supply sections from the main boards before I ship them.
Your choice of a CCF60 for a substitute is interesting. I have heard it said that there was very little difference in "Dell" resistors between military and industrial besides the specs. For grins I worked out a comparison chart on values and pricing. The BOD is made up of 10 RN65 and 5 RN70 resistors. This is how values compare with the available CCF60 resistors.
I assume the determination of where to use 65 vs 70 resisters was made based on closeness to nominal value. If the difference in sound quality is minimal and we would like to match the nominal value as closely as possible and obtain the best pricing then purchasing mostly CCF60 with the exception of the 3 farther out of tolerance values makes the most sense.
Regards,
Roy
I will take you up on your fine offer to remove the components from my boards. To bring the weight down I will remove the power supply sections from the main boards before I ship them.
Your choice of a CCF60 for a substitute is interesting. I have heard it said that there was very little difference in "Dell" resistors between military and industrial besides the specs. For grins I worked out a comparison chart on values and pricing. The BOD is made up of 10 RN65 and 5 RN70 resistors. This is how values compare with the available CCF60 resistors.
I assume the determination of where to use 65 vs 70 resisters was made based on closeness to nominal value. If the difference in sound quality is minimal and we would like to match the nominal value as closely as possible and obtain the best pricing then purchasing mostly CCF60 with the exception of the 3 farther out of tolerance values makes the most sense.
Regards,
Roy
John,
I received 5 sets of your V3.0 boards today and was dry fitting the stacking of the analogue and digital boards and was puzzled by the placement of the digital board over the connectors. Looking at the tracing and the ample space on the board I see no reason why the two center holes couldn’t be moved back on the analogue board to have the digital board sit in the “front” of the stack and not impede access to the input connections. The same is true of the power connectors. It would also make the digital-to-display connectors shorter. I assume that the 1 by 12 pin J1 to J5 connection must be the showstopper in that regard. It must not have been easy to move J1 to the front of the board. It looks like it might be possible by reversing the connections but that might require a change in board size. Am I correct?
Regards,
Roy
I received 5 sets of your V3.0 boards today and was dry fitting the stacking of the analogue and digital boards and was puzzled by the placement of the digital board over the connectors. Looking at the tracing and the ample space on the board I see no reason why the two center holes couldn’t be moved back on the analogue board to have the digital board sit in the “front” of the stack and not impede access to the input connections. The same is true of the power connectors. It would also make the digital-to-display connectors shorter. I assume that the 1 by 12 pin J1 to J5 connection must be the showstopper in that regard. It must not have been easy to move J1 to the front of the board. It looks like it might be possible by reversing the connections but that might require a change in board size. Am I correct?
Regards,
Roy