Hi Roy,
So I can do silkscreen labels anywhere on the board. Not sure where you would like exactly. I did label the input out and Vol In R and L for the jumper section. I should add a couple vias for the grounds as well to make things easier.
So let me know and I can do more on any or all the boards.
I have a few extra Analog board of the 1.0 variety, which I now labeled 1.2 on the silkscreen for the newest board, I buy them in lots of 10, but can apply the resistors to that. I will have to build another digital board also to do the testing as my first set is soldered and I wouldn't want to try to undo a 12 pin SIP.
The Display and Digital board made it to version 3 by the time I got the design correct. The minor updates now are 3.x on those boards.
Only the Power Supply board stayed at 1.0, not much to them.
So I can do silkscreen labels anywhere on the board. Not sure where you would like exactly. I did label the input out and Vol In R and L for the jumper section. I should add a couple vias for the grounds as well to make things easier.
So let me know and I can do more on any or all the boards.
I have a few extra Analog board of the 1.0 variety, which I now labeled 1.2 on the silkscreen for the newest board, I buy them in lots of 10, but can apply the resistors to that. I will have to build another digital board also to do the testing as my first set is soldered and I wouldn't want to try to undo a 12 pin SIP.
The Display and Digital board made it to version 3 by the time I got the design correct. The minor updates now are 3.x on those boards.
Only the Power Supply board stayed at 1.0, not much to them.
I have updated Post #1 with info at the bottom of the post for where to find the latest posts for each design.
And I received a notice from the machine shop that my new back panel and face plate have been shipped. Looking forward to having my Preamp back in place. Though it is an Aleph P in design for the gain section I think it has better sound than my purchaced Pass Aleph P, though not by much, might be in the input and output Caps, if you look at the pics of my preamp you will see very large film caps, with lots of them on the output.
And I received a notice from the machine shop that my new back panel and face plate have been shipped. Looking forward to having my Preamp back in place. Though it is an Aleph P in design for the gain section I think it has better sound than my purchaced Pass Aleph P, though not by much, might be in the input and output Caps, if you look at the pics of my preamp you will see very large film caps, with lots of them on the output.
John,
The only thing that I thought was really important on silk screening was the polarity of the power and IO. If spacing is tight at the inputs just labeling one connector would be sufficient. Same is true with the attenuator outputs and the connector IO as long as they are pin compatible. Also good to know at a glare which connector IP is in or out.
I personally think that putting the connector IO, including ground, pin compatible with the attenuator output is important. It eases connectivity and avoids confusion for those who want to take advantage of the flexibility.
Does that mean that you don't want my extra boards. I can always give them away for cost if you don't.
Also, I have one question on the display board BOM. What is the value of C16? It is listed as a decoupling cap (0.1uf) and as an encoder cap (0.001uf). I checked and it is listed the same way on the original display board. Don't know why I didn't catch it then.
Regards,
Roy
The only thing that I thought was really important on silk screening was the polarity of the power and IO. If spacing is tight at the inputs just labeling one connector would be sufficient. Same is true with the attenuator outputs and the connector IO as long as they are pin compatible. Also good to know at a glare which connector IP is in or out.
I personally think that putting the connector IO, including ground, pin compatible with the attenuator output is important. It eases connectivity and avoids confusion for those who want to take advantage of the flexibility.
Does that mean that you don't want my extra boards. I can always give them away for cost if you don't.
Also, I have one question on the display board BOM. What is the value of C16? It is listed as a decoupling cap (0.1uf) and as an encoder cap (0.001uf). I checked and it is listed the same way on the original display board. Don't know why I didn't catch it then.
Regards,
Roy
John,
The analog board looks good. There is no question about IO or polarity. It looks like the IO spacing between the + and - is different than for ground so it will be wire only, no connectors. I can live with that as the ccs-x-bosoz uses spades for IO, so it can be easily disassembled during testing.
Great catch on the power supply output voltage polarity. I hadn't tested mine yet. I generally test power before connecting to circutary but I might not have been looking that closely on polarity
.
There are a couple of silkscreen/part issues with the display board. U10 doesn't have the notch that indicates the front of the chip. You can tell if you look at the position of the decoupling capacitor and the direction of vertical chips on the board, but it could cause a problem for new DIY builders.
Also, C14 is an electrolytic capacitor. The oblong symbol used is one generally used for other types of capacitors and the polarity isn't indicated.
I also noticed that the decoupling capacitors don't maintain the same form factor throughout the board. This is by no means a serious problem, as the leads are long enough to handle the difference in spacing, but it makes installation slightly more difficult.
Finally, Q1, the 2N3904BU, is out of stock at Mouser and Digi-Key at least until 2022. I was able to transfer mine for my older display boards but wonder if there is a viable alternative for new builders.
Regards,
Roy
The analog board looks good. There is no question about IO or polarity. It looks like the IO spacing between the + and - is different than for ground so it will be wire only, no connectors. I can live with that as the ccs-x-bosoz uses spades for IO, so it can be easily disassembled during testing.
Great catch on the power supply output voltage polarity. I hadn't tested mine yet. I generally test power before connecting to circutary but I might not have been looking that closely on polarity
.There are a couple of silkscreen/part issues with the display board. U10 doesn't have the notch that indicates the front of the chip. You can tell if you look at the position of the decoupling capacitor and the direction of vertical chips on the board, but it could cause a problem for new DIY builders.
Also, C14 is an electrolytic capacitor. The oblong symbol used is one generally used for other types of capacitors and the polarity isn't indicated.
I also noticed that the decoupling capacitors don't maintain the same form factor throughout the board. This is by no means a serious problem, as the leads are long enough to handle the difference in spacing, but it makes installation slightly more difficult.
Finally, Q1, the 2N3904BU, is out of stock at Mouser and Digi-Key at least until 2022. I was able to transfer mine for my older display boards but wonder if there is a viable alternative for new builders.
Regards,
Roy
When I upgraded the PCB software from 2.x to 4.x it does things differently, like the patterns for the chips. Instead of the notch at the end of a chip it has a dot next to pin 1, along with the square pad for pin 1. So the added chips have the new pattern. I prefer the old pattern but I guess that's progress.
For the decoupling caps, I saw they came in different lead spacings depending on part number so I used a middle of the road size for each so they may be different.
C14 in the BOM is an Electrolytic but it is a timing cap for the 7555 and it can be film or anything. I choose the round can on the BOM by price.
For the decoupling caps, I saw they came in different lead spacings depending on part number so I used a middle of the road size for each so they may be different.
C14 in the BOM is an Electrolytic but it is a timing cap for the 7555 and it can be film or anything. I choose the round can on the BOM by price.
Last night I removed 83 relays in about 30 minutes and 12 LED displays in another 30 minutes. 1 minute to remove the 3 decoder chips and another 30 minutes to remove excess solder from the legs and then straighten them all. I was going to ship the parts and boards back tomorrow but before I do is there anything else you need removed?
As they say, good tools are niiiice.
Thanks,
John
As they say, good tools are niiiice.
Thanks,
John
The Metcal soldering station with basics retails for around $1K, more with the tips and extras but I got mine from a company going out of business in the Silicon Valley for $0.10 on the dollar. Mine is a P2SE-01, it is older, you can get them used for around $100 on eBay but that is just the Power Supply, then you need the iron and the tips. They use RF down the cable to the tip and keep the heat spot on and heat almost instantly. Probably the best soldering station I have used. The EEPROM are $7 each and I will let you know about the shipping when I come back from the Post Office tomorrow in a PM.
John,
Finally got the new boards and the parts you were kind enough to remove from my main boards for me. Over the last few days I was able to put together three sets of boards and the cables for the initial digital board to display board test.
Unfortunately I am not getting success with any combination of boards. Powering it on results in a random number display on the volume LEDs (DS2-4) and no display on DS1.
Turning the rotary encoder does not result in any changes and pushing buttons has no results.
I am fairly sure on the cabling, although to get the "red wire" on the dot requires turning one of the connectors over before installing. If you try having the connectors on the same side of the wire, you can't get the red wires to align with the dots.
As I am reusing the LED displays, it appears that DS1 on all three display boards didn't survive the transfer as I would expect them to light even if with garbage.
I can't see any oblivious installation issues and I would expect the display board would start up at 0 even if it wasn't connected to the digital board. Is it possible that the eproms (U12) were not programed before you sent them out?
Regards,
Roy
Finally got the new boards and the parts you were kind enough to remove from my main boards for me. Over the last few days I was able to put together three sets of boards and the cables for the initial digital board to display board test.
Unfortunately I am not getting success with any combination of boards. Powering it on results in a random number display on the volume LEDs (DS2-4) and no display on DS1.
Turning the rotary encoder does not result in any changes and pushing buttons has no results.
I am fairly sure on the cabling, although to get the "red wire" on the dot requires turning one of the connectors over before installing. If you try having the connectors on the same side of the wire, you can't get the red wires to align with the dots.
As I am reusing the LED displays, it appears that DS1 on all three display boards didn't survive the transfer as I would expect them to light even if with garbage.
I can't see any oblivious installation issues and I would expect the display board would start up at 0 even if it wasn't connected to the digital board. Is it possible that the eproms (U12) were not programed before you sent them out?
Regards,
Roy
DS1 should light up so long as the Display board has power even without the ribbon cable connected. I can't imagine all three LEDs having a problem.
First check voltage and polarity is correct at the PS and each board.
The EEPROMs were programmed, if they were not it would light all the LED segments on all the digits.
First thing to check it that the two timer chips are running. U3 should be around 9 hz and U8 a couple hundred hertz. Then see that the output from the U8 timer to the flip-flop U11 output is toggling then the LED selects from U10 are changing, sequencing the LEDs.
Walk through the mute circuit so you can watch the LED toggle, the button should work.
Worst case, send me at least one set of boards and cables and I can troubleshoot. I have mine working in my preamp to compare with.
First check voltage and polarity is correct at the PS and each board.
The EEPROMs were programmed, if they were not it would light all the LED segments on all the digits.
First thing to check it that the two timer chips are running. U3 should be around 9 hz and U8 a couple hundred hertz. Then see that the output from the U8 timer to the flip-flop U11 output is toggling then the LED selects from U10 are changing, sequencing the LEDs.
Walk through the mute circuit so you can watch the LED toggle, the button should work.
Worst case, send me at least one set of boards and cables and I can troubleshoot. I have mine working in my preamp to compare with.
John,
Good first advice. I built all boards at the same time from the same part order. It seems logical that if I made a mistake, that I made it to all three. Since all boards are acting the same, that would be my first assumption.
Voltage and polarity correctness was checked prior to connecting the boards and always rechecked before power was enabled. I am assuming that a problem exists, at least on the display board since I do not start up with "0" on the volume, but a random sequence.
While the input display LED does not light, what number should it show as a default? Also, think you were saying that the mute logic is contained on the display board, at least as far as the LED is concerned, so it should toggle on and off with the mute button? On my three boards the red mute light will come on for a while for varying lengths of time but doesn't stay on. I suspect that is because pin 15 of J2 is not connected to the digital board.
Before I refresh my Boolean logic knowledge I am going to double check my components one more time in great detail.
Regards,
Roy
Good first advice. I built all boards at the same time from the same part order. It seems logical that if I made a mistake, that I made it to all three. Since all boards are acting the same, that would be my first assumption.
Voltage and polarity correctness was checked prior to connecting the boards and always rechecked before power was enabled. I am assuming that a problem exists, at least on the display board since I do not start up with "0" on the volume, but a random sequence.
While the input display LED does not light, what number should it show as a default? Also, think you were saying that the mute logic is contained on the display board, at least as far as the LED is concerned, so it should toggle on and off with the mute button? On my three boards the red mute light will come on for a while for varying lengths of time but doesn't stay on. I suspect that is because pin 15 of J2 is not connected to the digital board.
Before I refresh my Boolean logic knowledge I am going to double check my components one more time in great detail.
Regards,
Roy