Announcement

Collapse
No announcement yet.

New LCD Preamp Board to play with...

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • New LCD Preamp Board to play with...

    I purchased this LCD preamp board a few months ago from another site. It seemed too good to be true, but I gave it a try, it was cheap enough.

    It's got a roughly 4" screen, a main board with an SD card input, a USB input, it also has an RCA jack video/audio input/output board with a built-in voltage regulator to take the 12V to 5V, and a button/IR input board.
    I haven't hooked it to an amp board which would run full tilt yet, just my Lepai 2020 amp with the volume at 2/3rds or so. Seems quiet enough, but I'm sure I'll have issues with noise... I know how to get around that now thanks to you guys, though.

    This is going to be used as an input device/bluetooth preamp for another table radio... probably a Bantam-ish type of arrangement if I can package it all nicely.

    One of the things I am going to have to figure out is how to actuate the buttons. I'd rather not resolder new buttons, I'm hoping for a way to make a button type arrangement that will just push on these buttons... just fasten this board behind the actual buttons like they normally do. I'm not sure how to go about that, though. I've seen a piece of aluminum with slices between the buttons which allow for the aluminum to move a bit. I had a Radio Shack cassette deck that had those types of buttons. That would probably be the easiest, but I wonder what else there is to push these types of buttons. I admit, I haven't looked very hard online, there may be an obvious solution to that one. The pic shows how close the buttons are... maybe a raised 'bar' of some type so the finger can feel it easy enough. I'll have to think about that a bit.

    Another thing is the input/output board. Even when the unit is powered off with the remote, the voltage regulator is still on and creating heat... not much, I know, but still. Is that okay? Are those things safe enough to not worry about? It is heat-sinked... and during use I've seen temps under 90 degrees usually with my wireless thermometer. I'm going to test it under bluetooth use to see how much current it draws to see what it's really doing. Thanks for that advice in the 'Toni Table Radio' thread.

    I tapped the USB with the unit turned off in hopes that I could use that with a relay to turn on/off the whole shebang with the amp, but no such luck, it's always powered on. I have a cool lighted on/off switch I can use anyway, no biggie there. The board is tiny SMT stuff... one stray blob of solder would bridge, like, 20 components or something...

    Once they sent me the manual PDF and I figured out how to turn of the Chinese language from the screen, it seems to work really well. It's not touch screen, but it's intuitive on how it works... it will also play videos I think and pictures like a picture frame; MP3's etc. It has a pretty high resolution screen from my eye. Kind of crazy for what I paid. Like I say, I haven't really listened to it much for sound quality wise, but it sounds on par with other inexpensive preamp devices similarly priced. I imagine for a radio it will be fine.

    I really just wanted to share my next mini-obsession for the time being!

    TomZ
    Attached Files
    *Veneering curves, seams, using heat-lock iron on method *Trimming veneer & tips *Curved Sides glue-up video
    *Part 2 *Gluing multiple curved laminations of HDF *Cello's Speaker Project Page

    *Building the "Micro-B 2.1 Plate Amplifier -- Part 1 * Part 2 * Part 3 * Part 4 * * Part 5 'Review' * -- Assembly Instructions PDF

  • #2
    Will you have to use the board with the buttons or can the remote do everything it can do? Looking forward to whatever you come up with on this, it looks cool.
    My "No-Name" CC Speaker
    Kerry's "Silverbacks"
    Ben's Synchaeta's for Mom
    The Archers
    Rick's "db" Desktop CBT Arrays
    The Gandalf's

    Comment


    • #3
      Looks like a cool protect, adding a screen like that to a table radio is next level!

      Comment


      • #4
        On the buttons, here's what I'd do. Go to the hardware and get nylon spacers of the T-shape variety. These normally come in black or natural/off-white. Drill for the shaft diameter through the front of the panel in question. This will keep the t-neck behind the panel and be what hits the PCB buttons. Most of these spacers will have a hole in the middle, flush at both ends. I would counter-bore for a flush-head screw on the T end so you can add maybe a wooden shaft extension for looks out the front while keeping the screw hidden internally.


        Hope this visual helps with the picture. You might have to wax the wood/nylon and hole to get better operation.

        Later,
        Wolf
        Click image for larger version

Name:	Button.jpg
Views:	1
Size:	7.2 KB
ID:	1366577
        "Wolf, you shall now be known as "King of the Zip ties." -Pete00t
        "Wolf and speakers equivalent to Picasso and 'Blue'" -dantheman
        "He is a true ambassador for this forum and speaker DIY in general." -Ed Froste
        "We're all in this together, so keep your stick on the ice!" - Red Green aka Steve Smith

        *InDIYana event website*

        Photobucket pages:
        http://photobucket.com/Wolf-Speakers_and_more

        My blog/writeups/thoughts here at PE:
        http://techtalk.parts-express.com/blog.php?u=4102

        Comment


        • #5
          Originally posted by Kevin K. View Post
          Will you have to use the board with the buttons or can the remote do everything it can do? Looking forward to whatever you come up with on this, it looks cool.
          I haven't actually messed around with it enough to know if I need the buttons or not to do all functions, but I do want to use them... remotes are flaky on these things, plus the IR receiver is on that board as well.

          Originally posted by kenrhodes View Post
          Looks like a cool protect, adding a screen like that to a table radio is next level!
          That's what I was thinking!

          Originally posted by Wolf View Post
          On the buttons, here's what I'd do. Go to the hardware and get nylon spacers of the T-shape variety. These normally come in black or natural/off-white. Drill for the shaft diameter through the front of the panel in question. This will keep the t-neck behind the panel and be what hits the PCB buttons. Most of these spacers will have a hole in the middle, flush at both ends. I would counter-bore for a flush-head screw on the T end so you can add maybe a wooden shaft extension for looks out the front while keeping the screw hidden internally.


          Hope this visual helps with the picture. You might have to wax the wood/nylon and hole to get better operation.

          Later,
          Wolf
          [ATTACH=CONFIG]n1366577[/ATTACH]
          Wolf, thanks for the input. I'll check those nylon spacers out at the home depot this weekend. Sometimes it's knowing what hardware and bits are available... browsing through the hardware aisle is fun just to see what you can do what with. I'll look more at your drawing when I get home, but thanks for the effort in drawing that too.
          TomZ
          *Veneering curves, seams, using heat-lock iron on method *Trimming veneer & tips *Curved Sides glue-up video
          *Part 2 *Gluing multiple curved laminations of HDF *Cello's Speaker Project Page

          *Building the "Micro-B 2.1 Plate Amplifier -- Part 1 * Part 2 * Part 3 * Part 4 * * Part 5 'Review' * -- Assembly Instructions PDF

          Comment


          • #6
            Originally posted by tomzarbo View Post
            Another thing is the input/output board. Even when the unit is powered off with the remote, the voltage regulator is still on and creating heat... not much, I know, but still. Is that okay?
            TomZ
            Should be fine. Any device that can be turned on by the remote is never actually off, only in partial standby (otherwise the remote could not turn it on).

            For the buttons, I would mount the PCB in a faceplate with a hole for each button. Then create a "template" for the function identification. You may be able to do that with one of these "1x3" Engraved Nameplate" from the bay. Pick you're font and type size and model it in Powerpoint as I did (or some other program). Then tell the seller to align the line of text centered and bottom.
            Click image for larger version

Name:	Faceplate.png
Views:	1
Size:	117.3 KB
ID:	1366580
            Last edited by Millstonemike; 02-22-2018, 06:08 PM.

            Comment


            • #7
              Uh-Oh..... what's that smell? Awwww Nuts.

              Yeah, I let out the magic smoke on one of these units, thank goodness I picked up a spare.

              I noticed that there were two different versions being sold, one with the additional 12-5v input/output board and one without. I wondered if both shared the same motherboard and if I could just power the motherboard with 5v and everything would work fine... it didn't.

              I accidentally left the 12v supply plugged into the input/output board with the wall wart plugged in. Then I pulled the 5v feed line from that board and gave it 5v from a separate power supply to see if the main unit would power up. I didn't mean to leave the 12v supply plugged in, but I didn't think that would cause the magic smoke to be released. I left the other cables connecting the input/output board connected to the motherboard, but they should only be carrying audio and video back and forth. Not sure why it fried, but oh well... I just won't do that again.

              Maybe if I unhooked all the cables from the motherboard to the input/output board it wouldn't have fried. Maybe I'll try that later with the second unit. It seems weird that there would be two different motherboards produced when both require 5v anyway.

              At any rate... I put a few videos, pictures and mp3's on a USB flash drive and it played all but one just fine. You can even fast forward the video. The resolution looks pretty good, but it is a small screen. I think it's 4.3" diagonal. It also will display pictures on the screen while MP3's play music. It's a pretty cool little thingy to mess with... It's bringing out the kid in me I think. I'm having fun just exploring the various features. I purchased two of them... amazingly, they were under $18 each shipped! I don't even feel that bad about borking one at that price!

              You can for instance, change the way the pictures fade or transition to each other and set how long the pics display. There is also a screen which displays a list of songs on the USB drive and shows a small little spectrum analyzer, though it's kind of wonky in it's operation... but it is reading the signal from the music anyway instead of just dancing randomly like some of these cheap thingys. There are a few EQ settings too, though I'm staying away from that. It will do an auto-search for the strongest FM stations and save them, so when you're in FM mode, tapping to the next track will give you the next station. It pulled in 4 stations for me with no antenna attached, not too bad I guess. The antenna connector is two wires, though, not sure which I should hook the antenna to? Also, it is supposed to be able to record music from FM I think, if you have a drive plugged in, have not tried that yet.

              So, I wanted to see what the current draw was, and it looks like around 140 milliamps draw with it powered off, and around 280 milliamps with it on and playing a video through the USB drive with the volume bumped up to almost maximum, which I thought would be a good test of it's current draw. But... that was through the input/output board which also has a voltage regulator reducing 12V to 5V, which I'm sure is sucking up a bit of power. I bet the 5v version of this thing is much easier on current draw.

              I want to use the 5v version so I can bring the voltage to it with one of these cool "DC to DC isolated convertors" outlined in the following thread to eliminate ground-noise issues when powered with an amp board. ----> http://techtalk.parts-express.com/fo...98#post1358598

              After church I might get the other one out and try to power it with 5v without hooking up the other lines to see if that powers it up.... I bet it does... I'd like to see what the current draw is on that one at 5v.

              Yeah, I'm blabbering, but It's just I've got some cool stuff to play with...
              .....but MWAF is coming quickly and I've got to start making sawdust on that project if I want to have it ready in time!

              I haven't been able to do any work in my basement for a few weeks as our basement flooded a few weeks ago because our sump pump failed. Big mess, but I'm back in business now, thank God!

              TomZ
              *Veneering curves, seams, using heat-lock iron on method *Trimming veneer & tips *Curved Sides glue-up video
              *Part 2 *Gluing multiple curved laminations of HDF *Cello's Speaker Project Page

              *Building the "Micro-B 2.1 Plate Amplifier -- Part 1 * Part 2 * Part 3 * Part 4 * * Part 5 'Review' * -- Assembly Instructions PDF

              Comment


              • #8
                Well... nope.
                This 12v board doesn't work with a 5v direct to the motherboard. The 5v version must be a slightly different design. Good news though, I didn't destroy the screen on the one I fried.

                I forgot to say thanks Mike, for the engraved plate suggestion. That's a good idea that I hadn't thought of. I did see some 'button covers' on a few different websites that look like they 'may' work, but these buttons have very shallow protrusions on the black 'push-in' part, which I don't really see anything specifically made for these. I'll keep looking and thinking... no rush time-wise, just thinking out loud, and putting together ideas.

                I really just wanted to start gathering some stuff to put these together with... I hate getting ready to build something and find that I don't have what I need to plan the last few ideas for assembly.

                TomZ


                *Veneering curves, seams, using heat-lock iron on method *Trimming veneer & tips *Curved Sides glue-up video
                *Part 2 *Gluing multiple curved laminations of HDF *Cello's Speaker Project Page

                *Building the "Micro-B 2.1 Plate Amplifier -- Part 1 * Part 2 * Part 3 * Part 4 * * Part 5 'Review' * -- Assembly Instructions PDF

                Comment


                • #9
                  Originally posted by tomzarbo View Post

                  I haven't been able to do any work in my basement for a few weeks as our basement flooded a few weeks ago because our sump pump failed. Big mess, but I'm back in business now, thank God!

                  TomZ
                  In what respect did it fail? Floatswitch, motor, no power, etc. It should be relatively easy to design an alarm for your set up so it won't happen again.

                  I like basements and had a house with one in Pennsylvania where I lived for a time. However always the danger of flooding or moisture. Here in California few if any houses have basements.
                  Don't worry, if your parachute fails, you have the rest of your life to fix it.

                  If we all did the things we are capable of doing, we would literally ASTOUND ourselves - Thomas A. Edison

                  Some people collect stamps, Imelda Marcos collected shoes. I collect speakers.:D

                  Comment


                  • #10
                    Originally posted by Wolf View Post
                    On the buttons, here's what I'd do. Go to the hardware and get nylon spacers of the T-shape variety.

                    Later,
                    Wolf
                    [ATTACH=CONFIG]n1366577[/ATTACH]
                    ​I believe that it is called a "flange."

                    Comment


                    • #11
                      Originally posted by thekorvers View Post

                      In what respect did it fail? Floatswitch, motor, no power, etc. It should be relatively easy to design an alarm for your set up so it won't happen again.

                      I like basements and had a house with one in Pennsylvania where I lived for a time. However always the danger of flooding or moisture. Here in California few if any houses have basements.
                      When I pulled it out, it was literally eaten through from the inside out. It was a pretty good pump actually; it lasted 8 years. The problem is that my water softener dumps its brine solution into the sump 3 times a week, and this is obviously bad for the cast iron housing. I plan on taking the hose that dumps the brine solution out of the house directly without going into the crock. Since it uses water pressure to operate, I believe that it will have no issue going up the 5 feet, and on to the exit point. I just have to keep it from freezing, but I should be able to figure that out easy enough.

                      I ordered and installed an alarm that will go off if the water goes above a specific point and it is installed and working. There are several that work well and are relatively inexpensive. I SHOULD be good to go at this point, but I still find myself checking the basement every morning and when I get home from work. Oh well.

                      Basements are great... they are temperature-constant and handy to get to, compared to the garage -- which always seems to be too cold or too hot for me. I do paint out there, though. Lacquer is too stinky to do inside.

                      TomZ


                      *Veneering curves, seams, using heat-lock iron on method *Trimming veneer & tips *Curved Sides glue-up video
                      *Part 2 *Gluing multiple curved laminations of HDF *Cello's Speaker Project Page

                      *Building the "Micro-B 2.1 Plate Amplifier -- Part 1 * Part 2 * Part 3 * Part 4 * * Part 5 'Review' * -- Assembly Instructions PDF

                      Comment


                      • #12
                        Originally posted by tomzarbo View Post
                        I plan on taking the hose that dumps the brine solution out of the house directly without going into the crock. Since it uses water pressure to operate, I believe that it will have no issue going up the 5 feet, and on to the exit point. I just have to keep it from freezing, but I should be able to figure that out easy enough.
                        Tom, I did this when I lived in Millstone Twp.

                        The water exiting the softener will make five feet vertical easy. It's powered by your well pump / expansion tank (don't you have a second floor shower?).

                        The top of my basement was at least a foot above ground level. I cored a hole through the concrete and installed PVC (always, always, any holes in the foundation above ground level). The PVC exited the foundation and immediately went down underground maybe a foot down and out 20 feet with a downward grade to a dry well I constructed. Note: It's easier to go through the sheathing/siding above the foundation. It backwash never freezes as: (1) It's brine; and (2) The brine drains completely into the dry well were it settles below the frost line. Note: the backwash will kill the grass.

                        Digging the dry well was "fun" (8' diameter 7 ' down). I practiced digging alternating sides, good posture (bent at the knees, not the waist, etc.) and got a great workout over several days.

                        As a side note, I upgraded my system in another house to a 2-tank alternating system. Three benefits: There's always fresh water available; Fresh water from the operating tank is used to flush the recovering tank; and given the 2-tank system is more complex, it also includes a water meter. Back washing is only triggered by usage, not "every other night at 3:00 am). This saved lots of salt,

                        Last edited by Millstonemike; 02-27-2018, 09:56 AM.

                        Comment


                        • #13
                          Originally posted by Millstonemike View Post

                          Tom, I did this when I lived in Millstone Twp.

                          The water exiting the softener will make five feet vertical easy. It's powered by your well pump / expansion tank (don't you have a second floor shower?).

                          The top of my basement was at least a foot above ground level. I cored a hole through the concrete and installed PVC (always, always, any holes in the foundation above ground level). The PVC exited the foundation and immediately went down underground maybe a foot down and out 20 feet with a downward grade to a dry well I constructed. Note: It's easier to go through the sheathing/siding above the foundation. It backwash never freezes as: (1) It's brine; and (2) The brine drains completely into the dry well were it settles below the frost line. Note: the backwash will kill the grass.

                          Digging the dry well was "fun" (8' diameter 7 ' down). I practiced digging alternating sides, good posture (bent at the knees, not the waist, etc.) and got a great workout over several days.

                          As a side note, I upgraded my system in another house to a 2-tank alternating system. Three benefits: There's always fresh water available; Fresh water from the operating tank is used to flush the recovering tank; and given the 2-tank system is more complex, it also includes a water meter. Back washing is only triggered by usage, not "every other night at 3:00 am). This saved lots of salt,
                          So THAT's where you got your name from, I always wondered. Well, I live in PILESgrove township... I guess I'd avoid using "PilesTom" as a screen name for obvious reasons... it would just be a pain in the b*u*t*t.

                          Anyway, thanks a lot for the info. We do have a well, and a second floor shower. I read online that the water pressure would easily have the force to drain the brine solution, but was trying to call my water softener service people for confirmation. You answered that question. I know what you mean about the backwash killing the grass. When we moved into this house 6-7 years ago, there was a huge 'dry river bed' of killed off grass where the former owners never moved the 20' hose. I reseeded the grass in that area and now I move the hose every week or so to prevent dead grass.

                          I've actually thought about putting a drainage system in for the crock drainage, maybe later on I will, it would make life easier. But for the softener, I could use a much smaller arrangement. I think I've read that they normally use about 10-15 gallons per regen cycle. Yeah, we have an old mechanical timer which just runs no matter what. When we water the lawn, I have to do manual regen cycles to keep the water fresh.

                          Again, thanks for the information, now I know what I'm doing this coming Saturday.

                          TomZ
                          *Veneering curves, seams, using heat-lock iron on method *Trimming veneer & tips *Curved Sides glue-up video
                          *Part 2 *Gluing multiple curved laminations of HDF *Cello's Speaker Project Page

                          *Building the "Micro-B 2.1 Plate Amplifier -- Part 1 * Part 2 * Part 3 * Part 4 * * Part 5 'Review' * -- Assembly Instructions PDF

                          Comment


                          • #14
                            [QUOTE=tomzarbo;n1367101]

                            So THAT's where you got your name from, I always wondered. Well, I live in PILESgrove township... I guess I'd avoid using "PilesTom" as a screen name for obvious reasons... it would just be a pain in the b*u*t*t.

                            I've been online over 20 years. Never once has "Millstonemike" been taken when registering a new account, anywhere.

                            BTW: When I installed that two tank system, all the plumbing was next to the backyard hose bib. I installed two valves so I could flip between softened and raw water to the hose bib and use the raw water for the grass away from the house.

                            Comment


                            • #15
                              So, I got the 5V versions of this LCD Preamp board a few days ago, fired one up tonight.

                              Seems to work fine, just like the others. I'm trying to anticipate how I'm going to need to hook this up to an amp, thinking that another of the isolated DC to DC converters will be needed to reduce/eliminate noise to the amp.

                              I used my multimeter inline of the positive 5 volts going to the unit (actually it was 4.5V as that is what my adjustable power supply produces) and I got .32 amps on the bigger and separate, 10 amp plug/setting. So that's around 320 milliamps draw if I'm doing my decimal point-hopping correctly... I had on a video which I suspected would be the biggest draw, but bluetooth may actually draw a bit more. That's a bit more than I thought it would be, but it is doing a full 4.3" screen backlit, as well as preamp, nested menu items running, and video processing of the whole thing... I guess that's not too much of an amperage draw.

                              Anyway, the DC/DC converters I used on the other preamp/faceplate won't do the trick here, I need something beefier, or a beefier version of the same thing. That was discussed on the "Interesting power supply issue" thread here: http://techtalk.parts-express.com/fo...98#post1358598

                              I think this one is what I need. It's the SPBW03F-05 which is an Isolated DC/DC Converter, 9-36Vin 5Vout 600mA.

                              Here's the data sheet for it: http://www.meanwellusa.com/productPdf.aspx?i=794

                              It's about $10/ea. at mouser, about the same cost as the other one. It's a few bucks more than just using a voltage regulator assembly, but it allows me to run say, 16 volts to the 50 watt per channel amp board to get full power out of it, and still give the preamp 5 volts of isolated power. I won't know for sure if I need it until I get an amp hooked up to it and test it out, but I just wanted to give a little update on where this is going for those interested... or just bored.

                              TomZ

                              *Veneering curves, seams, using heat-lock iron on method *Trimming veneer & tips *Curved Sides glue-up video
                              *Part 2 *Gluing multiple curved laminations of HDF *Cello's Speaker Project Page

                              *Building the "Micro-B 2.1 Plate Amplifier -- Part 1 * Part 2 * Part 3 * Part 4 * * Part 5 'Review' * -- Assembly Instructions PDF

                              Comment

                              Working...
                              X