Announcement

Collapse
No announcement yet.

Gainclone... here we go.

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

  • Gainclone... here we go.

    Just ordered my first batch of parts for my first gainclone; LM3886 stereo kit from chipamps.com. Still debating dual mono or stereo, but I've got 250VA toroid, power entry parts, various case parts and a Bantam DAC on the way.

    Cold weather project! Not sure where I'm going to use it yet. By the time this one's done, I'll be debating another speaker project I'm sure.
    ~Mark

    Stuff I've builded http://techtalk.parts-express.com/co...lies/smile.png

  • #2
    Re: Gainclone... here we go.

    I for one will watch your updates with interest, i have been toying with the idea of doing a gainclone of my own lately, and will be interested to hear / see your partslist, mono / stereo choice, and all other details you care to share....hopefully lots of detail! :D

    Comment


    • #3
      Re: Gainclone... here we go.

      Good luck. I really want to try building one some time but I currently have 2 decent amps so no reason really. I'm going to concentrate on speakers and subs and other stuff for a while, eventually tho. I want to see what all the fuss is about with those Gainclones, let us know how it goes?

      Comment


      • #4
        Re: Gainclone... here we go.

        Originally posted by evilskillit View Post
        I want to see what all the fuss is about with those Gainclones
        well for the 3years off/on reading at DIYaudio.. there is purest group(if you can call them that), that prefer the minuim amount of parts in the audio signal path. the Gainclone is a amp that requires very few parts to operate. i was going to build some BPA200 using Digi's pcb's, never happened. I do have a chipamp.com kit, never finished it but did listen to it a bit. the thing that is really interesting is unregulated it runs really cool vs regulated power supplies. the bass seems tighter on regulated supplies vs unregulated. though the top end sounds better with a unregulated supply. just things i have noticed on some old Altec Lansing Bookshelf speakers..

        Comment


        • #5
          Re: Gainclone... here we go.

          mark, i'm real intrested in this too. please update often.
          " To me, the soundstage presentation is more about phase and distortion and less about size. However, when you talk about bass extension, there's no replacement for displacement". Tyger23. 4.2015

          Quote Originally Posted by hongrn. Oct 2014
          Do you realize that being an American is like winning the biggest jackpot ever??

          http://www.midwestaudioclub.com/spot...owell-simpson/
          http://s413.photobucket.com/albums/pp216/arlis/

          Comment


          • #6
            Re: Gainclone... here we go.

            The damages so far:

            Gainclone Dual Mono Kit from chipamps.com @ $90

            Bantam Dac from Glassjar Audio @ $43

            Two ALPS "Blue Velvet" pots from AMB Audio Shop @ $32

            250VA 18V+18V Toroid and various other parts from PE @ $106

            For a total of $271. Good Lord. Is that crazy or what? Oh well.

            I'm shooting for a design that will handle 4 ohm loads well while remaining cool; 18V should yield a rail voltage in the 24~25VDC range. For heat sinks, I'm going to butcher a couple of old Variable Frequency Drives laying around the shop. We have a good sheet metal guy that works cheap and can burn anything out on the laser, steel or aluminum. For the case however, I'm stuck on the idea of a laminated outer shell made out of Baltic Birch. I'm going back up to Woodcraft at some point this week to see what they've got in back.

            One of my goals in the project is to stay away from the whole "old VCR case loosely filled with amp parts" look. Over the last week I've seen several dozen implementations, and I'm surprised at how sloppy some of the assemblies have been regarding aesthetics. So, with that in mind, I'm gonna get all of my large displacement parts, and see if I can't put the squeeze on internals without compromising performance. Shielding will be a must I think, especially with the toroid. Twisting audio path conductors to reduce EMI and keeping runs as short as possible will also be out front in the priorities list. I'm visualizing an amp with a footprint of no more than 8" x 10" @ a height of 3" to 4".

            Functionally, aside from selectable DAC or Line Level in with pot, I'm going to try to keep the signal path clean. No Bass / Treble / Balance.

            Of course, all of this could be BS as I tend to design / engineer on the fly. *insert evil Muahaha here* :D A few days ago I was asking myself what I would use this amp for. That was a stupid question. How am I supposed to eventually test my own speaker abominations without juice?

            Project justified.
            ~Mark

            Stuff I've builded http://techtalk.parts-express.com/co...lies/smile.png

            Comment


            • #7
              Re: Gainclone... here we go.

              Dude, you totally have the right mindset for this hobby. Bravo!

              I'm following with interest, can't wait to see how it turns out, although I have no doubt at all that it will be very, very cool, both literally and figuratively speaking.


              Mark
              You go your way, I'll go mine. I don't care if we get there on time.

              ~Pink Floyd

              Comment


              • #8
                Re: Gainclone... here we go.

                Originally posted by WWWJD View Post
                For the case however, I'm stuck on the idea of a laminated outer shell made out of Baltic Birch. I'm going back up to Woodcraft at some point this week to see what they've got in back.
                I also went to the back of my local Woodcraft and saw they had a board of cherry, about 9" wide and (curiously) 9/16" thick. Results for the gainclone below.

                Recently I've had a DAC project get lodged in my brain. You can buy the guts already assembled on ebay and you basically just have to build the case. This case caught my eye:



                Minus the embossed lettering, a thick front panel of frosted plexiglass or lexan, the rest would be solid wood. I think it could be quite cool ;)
                Attached Files
                Last edited by jclin4; 11-10-2009, 02:51 PM.

                Comment


                • #9
                  Re: Gainclone... here we go.

                  How does that cherry case you show behave thermally? Pretty solid?
                  ~Mark

                  Stuff I've builded http://techtalk.parts-express.com/co...lies/smile.png

                  Comment


                  • #10
                    Re: Gainclone... here we go.

                    The bottom of the case is metal and the two LM1875 chips are mounted directly against the bottom so it acts like a heat sink.

                    The bottom warms up a bit if I leave the amp on, but does not get hot. It barely gets warm if I only play a CD or two.

                    Comment


                    • #11
                      Re: Gainclone... here we go.

                      also that gainclone is the 20 watt per channel amp and has a lower voltage transformer. I purchased it from tim rawson did some mods then sold it to jclin4. it runs very cool due to the lower voltage transformer. It has very nice mid / treble sound. I used to power sats with it from 80hz up. I believe jclin4 is running it from 80hz and up after he added his nice wood case mod. The heat sink is the large thick aluminum base plate.

                      Comment


                      • #12
                        Re: Gainclone... here we go.

                        There running full-range, driving Roman's Microbes. I plan to build a sub later, probably using the Tang Band W6-1139SI and the Dayton 70 Watt plate amp.
                        Attached Files

                        Comment


                        • #13
                          Re: Gainclone... here we go.

                          I must be getting old I had forgotten if you added the sub. So they are doing more work with the bass then I thought!

                          Comment


                          • #14
                            Re: Gainclone... here we go.

                            For those of you that have experimented heavily, or moderately.. or whatever(:D)... the chipamp.com kit incorporates the option for NFB..

                            My understanding is that NFB is there to negate IM distortion by inverting it through the feedback loop.. but I've also read that it tends to muddy up the low end and affect overall bandwidth of the amp. I'm just curious which will be the lesser evil. As easily as it's applied in the loop, I'm debating on putting a NFB switch somewhere in the signal path local to the board. A miniature toggle is easy enough to find. Of course, like I said in an earlier post, I'm already doing it. I'm already adding bells whistles. Pfft.
                            ~Mark

                            Stuff I've builded http://techtalk.parts-express.com/co...lies/smile.png

                            Comment


                            • #15
                              Re: Gainclone... here we go.

                              The Bantam... powered by the USB? And if so, do you have any idea how much current it draws?
                              nothing can stop me now

                              Comment

                              Working...
                              X