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Amp/preamp design

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  • DuctapemasterDuctapemaster Posts: 90
    edited 2007-06-22 19:00
    The hardest part about this will be the hard drive interface...I can't find much information (there is some however) on google about an IDE interface to a microcontroller. I'm going to post a new topic in the forums to see if anyone has any idea how to do it.

    And even if I can't get an IDE interface working, the PINK module controlling my amp is still a cool idea...

    -Dan
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-06-22 19:40
    Hard Drive interface? Wow, you’re going all out on this! =)

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    Chris Savage
    Parallax Tech Support
  • DuctapemasterDuctapemaster Posts: 90
    edited 2007-06-22 19:43
    Yeah, I've been thinking about it...basically I would like to implement a standalone MP3 player into the stereo so I can get rid of the 50ft cable that runs around my room from my computer to my stereo. I'm not really sure whether I will for sure implement this, as I have been researching interfaces to the iPod that allows me to get song/album/artist info and control the iPod. We'll see how it goes.
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-06-22 19:50
    You could use a Vinculum Module for that. Have you see the VMusic2 Module? It allows you to use a USB Thumb Drive to store MP# files and play them via microcontroller command.

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    Chris Savage
    Parallax Tech Support
  • DuctapemasterDuctapemaster Posts: 90
    edited 2007-06-22 20:01
    Haven't heard of that...I will have to look into it! Sounds...promising...

    Hard drive interfaces are a lot of work from what I've gathered...
  • DuctapemasterDuctapemaster Posts: 90
    edited 2007-06-22 20:10
    I looked at that module, but the only problem I see is that you can't get the mp3 IDE tags (artist/album/song name). Maybe you can, but I haven't found anything on it. Other than that, it looks fine for what I'm doing.
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-06-22 20:56
    Well I was just reading through the VDAP firmware as well as the specifications for the VS1003 decoder chip used and neither supports that function (ID tags). So you have two choices…You could try another module (Rogue’s uMP3 may or may not support this) or you could create on the thumb drive, a text file with the song information so the microcontroller could access it to know the info for each MP3. I have actually written a program which could in theory create this file on the USB drive while renaming the files to be small and numeric. Take care.

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    Chris Savage
    Parallax Tech Support
  • DuctapemasterDuctapemaster Posts: 90
    edited 2007-06-23 00:04
    The main functions I am looking to have are an IDE interface or USB interface (I have 10 gigs of music to store...) and some way to read an ID3 tag (It's not IDE like I said before). I can't find anything about the uMP3 that allows me to read ID3 tags, so I guess it wont work. I will look at some more option tonight and see what I can get.
  • DuctapemasterDuctapemaster Posts: 90
    edited 2007-06-23 04:27
    Well, I think I have found how to do what I want. I was looking at the FTDI/Viniculum website and found that I could just use a USB interface to the SX and then a separate decoder IC for MP3's. If I use the USB interface, I can get the ID3 data off the hard drive (I will be using a 2.5" USB hard drive) and display it and send all the other MP3 data to the decoder IC as it requests it.

    Now, for the hard part. I was looking through all the documents on the Viniculum and FTDI site and I cannot find anything that even resembles a command list. I keep reading that the interface is easy to use because it uses simple ASCII commands, but I can't find any listing! I even looked through the datasheet for the chip used in the interface and the firmware datasheet(s). The firmware datasheets aren't really for the application I'nm planning so they dan't really apply anyways, but nevertheless, the data on commands is slim to none. Can you look on the sites and see if you can find anything???

    Thanks,

    Dan
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-06-23 20:45
    What you want is the Firmware Specification for the VDAP firmware. On page 13 is the VMUSIC commands although I get the impression they’re designed around the VS1003.

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    Chris Savage
    Parallax Tech Support
  • DuctapemasterDuctapemaster Posts: 90
    edited 2007-07-02 19:38
    I had some time to look over the VDAP firmware document and it seems that the VDRIVE module is what I want. I have a 20GB hard drive laying around from an old iPod, so I'll just go and buy a case for it on eBay (USB of course) and use that for storage. As for the MP3 part, I have been looking at the STA013 MP3 chip (some info here) that will take the binary output from the module and output sound. Any suggestions before I buy one of the modules?

    EDIT:

    Well, I was looking at the specs for the VMUSIC module and it seems that it uses an extended command set instead of a completely different one, so in theory, I could determine the song artist/album/title from the folder structure it's stored in and the name of the file. What do you think? I got this info here

    -Dan

    Post Edited (Ductapemaster) : 7/2/2007 7:46:58 PM GMT
  • DuctapemasterDuctapemaster Posts: 90
    edited 2007-08-07 22:17
    Well, summer's coming to an end and I have yet to do anything other than research on this project. My situation has changed significantly however. I was looking at new stereo systems for my room and my parents offered to give me one we were not using. I got a nice Denon receiver (100 watts per channel), a Technics 5 CD changer, and a set of VERY nice Enrgey speakers (2 satellites and an 8 inch powered sub). All together, the system is worth about $1500...a big change from my cheap Phillips system from K-mart... I absolutely love the new system and it sounds incredible!

    So, now that I have a nice set of speakers and a nice amp, I don't need to build a "big and powerful" amp anymore. I was looking at the so-called GainClone amps and they seem to fit my need (want?) at the moment. I think I will just build a small-ish amp and use it as mostly a fun project instead of a replacement for current equipment. I have found this site and they sell some nice PCB/kit combos. I think that I will just buy a kit for the amp and build my own interface/gadgets around it. I don't have much (almost none) experience in analog electronics design, and it would be hard for me to troubleshoot and fix the amp if something goes wrong with my design, so I think I'll stick with something that I know will work.

    So now that thats all said, I have some questions. What are the advantages/disadvantages to a dual mono and a stereo design? The noticeable difference to me is that the dual mono block design uses separate power supplies for each amp and the stereo one uses one power supply for both boards. Also, I was looking at a passive preamp design. Do I really need one? Can't I just use the preamp output of my receiver? That would take care of input switching and a preamp if I chose to do that.

    Thanks in advance.

    -Dan
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-08-08 17:23
    Dan,

    I can’t speak for everyone but I build amplifiers because I like to have something that nobody else has and I take pride in that it was built by my own hands. Each system has been totally custom and used different parts, cabinets, etc. I could easily buy any amplifier I wanted but it makes me feel better to use something on a daily basis that I built myself. When I first started my design business back in 1991 I had 6 monitors (all composite, with some RGB capable) in a semi-circular pattern around my bench. I had a Commodore 64, 128D, Amiga 500, Amiga 3000 and two game consoles (Sega Genesis and SNES). I built my own digital A/V switcher so that I could route any output to any monitor. I could also choose which audio went to my custom amplifier and which audio went to my cassette deck for recording. The amplifier was a 4-input unit but I only used two because the A/V switcher did most of the work. Suffice it to say, when people came over to my shop they were quite impressed with what they saw since even the desk was custom built. The monitors that had switchable inputs had a PC and the Amiga RGB outputs connected to them. The PC ran my BBS at the time. If you want to do something like that I would start off with one of the GainClone designs. They’re mostly based on the LM3886 and are nice amplifiers, easy to build, and can use a single supply just fine. The trick I found is getting a Power Transformer that is not overkill for one. Ever since Mark V Electronics closed the sources seem limited. Take care.

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    Chris Savage
    Parallax Tech Support
  • JunkieJunkie Posts: 38
    edited 2007-08-29 07:07
    Chris:

    Couldnt agree more whatever you have mentioned in your post is true for me as well coz like you I too could buy any electronic thing i could but then again it doesnt give·more satisfaction and pride when compared to a gainclone of preamp done by oneself. What I say to artist brother of mine is "creativity perhaps is an in build feature of humans, for a painter a painting could be art for him, for a sculptor, a sculpture is a form of art for him.·For us people desiging a circuit, then PCB layout and component placement, then encapsulating it in a self made box and making it play music again and again, is definitely a form of art and creativity"

    Sorry for just disappearing but hopefully back now.
  • pwillardpwillard Posts: 321
    edited 2007-08-29 14:24
    RE; DIY Amps

    Chris and others... I could not agree more.· I just finished a quad Chipamp PCB layout for my PC sound system replacement to go from stereo to surround sound.· My old Circa 1977 Realistic STA-720 finally smoked (Power supply failure gutted it, too much to repair). I've yet to build it but I'm taking my time.·

    After reading this thread, I really inclined to have more·techy stuff in it and possibly some remote control versus having a knobs to turn.· I'll let you know how I do.

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    There's nothing like a new idea and a warm soldering iron.
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-09-04 17:04
    Well I know we all sometimes suffer the inevitable lack of time to finish projects when we want to, but eventually they’re done on my end and when they are I do have a feeling of overall satisfaction.· It was interesting when I lived in NY because my family would see my home-brew electronics and they would become family legend.· =)

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    Chris Savage
    Parallax Tech Support
  • WilliebuiltWilliebuilt Posts: 6
    edited 2008-07-25 22:53
    Hello!· I'm hoping Moderator Chris is still onboard this with this topic.· I am new to the forum, having just signed up today.

    Assuming you are still moderating this thread, I am posting this msg in regards to your projects discribed in the past here.· In a March 17, 2005 posting you mentioned your use of the LM1307 IC.· (I found this posting via a Google search for the LM1037).· I am in desperate need of a couple of LM1037 ICs, and hope that you can point me to a source for this obsolete IC.· I found a source, but they don't seem to care about the hobbyist.· They have a minimum purchase of $300 per item!

    Your projects, as well as other were very interesting.· I don't possess the expertise that is projected, but I still enjoy reading about them and learning in the process.

    Here's hoping you are still onboard.· Being a moderator, I hope you have access to my email address so you can reply directly instead of muddying up the thread.

    Thank you for any assistance you may be able to provide.

    Williebuilt
  • Bob Lawrence (VE1RLL)Bob Lawrence (VE1RLL) Posts: 1,720
    edited 2008-07-26 03:31
    You an get a few from Ebay $US 30 + shipping *12 available)


    LM1037 Integrated Circuit LM1037
    Item number: 380026774105

    cgi.ebay.com/LM1037-Integrated-Circuit-LM1037_W0QQitemZ380026774105QQihZ025QQcategoryZ4663QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

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    Aka: CosmicBob
  • WilliebuiltWilliebuilt Posts: 6
    edited 2008-07-26 16:25
    Thank you Cosmic Bob!· I guess my search on eBay wasn't
    thorough enough.· I really appreciate your reply.

    Oh, Yes....great "Moniker"· ---Cosmic Bob.·

    Many thanks.

    Williebuilt
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2008-07-29 15:36
    Willie,

    Yes, I am still on-board…the thing is, the Sandbox is low on the priority list so I usually let messages here build up before trying to catch up. I doubt I have any LM1037N chips left. If I do I would have saved the last couple to repair any of my previously build custom amplifiers. As you have found, they’re not easy to get which is why I have moved on to other chips, also discussed in this thread. It’s kind of funny you bringing this thread up again because I have recently started gathering up all the parts I had for the two amplifiers I was working on. I’m actually under the wire to get them done before winter as I have been without an amplifier in my house for quite some time now. The projects will be returned to very shortly. It’s just been a little busy here at Parallax. But that’s a good thing!

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    Chris Savage
    Parallax Tech Support


    Post Edited (Chris Savage (Parallax)) : 8/12/2008 8:00:08 PM GMT
  • WilliebuiltWilliebuilt Posts: 6
    edited 2008-07-29 17:11
    Chris..........Thank you very much for your reply.· I figured that would be the case.· I fully understand the "spares" issue.

    I have located a couple of sources for the LM1037N.· One was provided by a member of the forum.

    In one case, I thought I had found a gold mine in that one source provided a quote for $7.90 each.· Great!·- I thought until I read the fine print.· I had to purchase 19 pieces because of a minimum order reqirement.

    Another sources, here in CA has a bunch on hand, but they have a $300 per line item minimum requrement!

    I have another source in the works, but the price is not firmed up as yet.· I am almost afraid to persue the·matter!

    Regarding another comment in your reply, you indicate you moved on to other chips.· Did you find any A & I equivalents?· Or did you have to redesign your circuit?· I do not possess the expertise to design ckts such as these, so I am limited to the original design.· I do, however, find the discussions in your thread to be educational and interesting.· I compliment you for sharing your expertise.

    Again, thanks for your reply.

    Sincerely,

    Williebuilt
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2008-07-29 17:47
    Willie,

    I moved on to other designs. These chips were designed for single-supply systems anyway, and I had been moving toward dual-supply across the board for a long time. How many of the chips do you need? I can see what I have. I can't make any promises though.

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    Chris Savage
    Parallax Tech Support
  • WilliebuiltWilliebuilt Posts: 6
    edited 2008-07-29 18:23
    Hello Again Chris!

    I am looking for·three LM1037N chips minimum (includes a spare).· However, I will gladly pay a reasonable price·for up to·five pieces.· The design is not mine.· These chips are replacements for two chips that have bought the farm as the saying goes.· Murphy's law saw to that when I dropped a screwdriver onto the circuit board.· Couldn't have been any more accurate as it placed a direct short on the power leads and copper paths.· Must have created a surge that the chips couldn't handle.

    Thank you very much for your help!

    Williebuilt
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2008-08-01 17:04
    Okay, I sent myself a message to my home office to remind me to look when I get there (since I already forgot until I saw your reply). I will know today. If I have a few to spare I will send them to you. Just out of curiosity, do you have any orders pending with Parallax? If you did I could just drop it in the box going out. If not I’ll just mail it USPS. But I am getting ahead of myself…let me see if I have any first.

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    Chris Savage
    Parallax Tech Support
  • WilliebuiltWilliebuilt Posts: 6
    edited 2008-08-01 17:53
    Hello Chris!· No, I don't not have anything pending.· Thank you very much for your efforts.

    Williebuilt
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2008-08-01 21:50
    Willie,

    You’re in luck…I just checked one of my parts cabinets and I have 8 of these chips left. Contact me via PM. Take care.

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    Chris Savage
    Parallax Tech Support
  • WilliebuiltWilliebuilt Posts: 6
    edited 2008-08-03 04:10
    Hello Chris!· Did you receive my two msgs I sent?

    I sent them via PM.

    Williebuilt
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2008-08-06 16:14
    Sorry, I did as I was leaving Friday and so since they were marked read I didn't notice them this last weekend. I will take care of it now.

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    Chris Savage
    Parallax Tech Support
  • SavageCircuitsSavageCircuits Posts: 199
    edited 2024-02-12 00:08

    Has anyone heard from Dave Paton in the last 14 years? The system says he hasn't been on since April of 2010. Just curious if anyone knew him outside these forums.

    EDIT: Looks like everyone in this thread is inactive. :/

  • MicksterMickster Posts: 2,581

    I miss quite a few of those who've moved on, many of whom I never really interacted with but enjoyed their company.

    Craig

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