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  • Paul Carmody
    started a topic Current 2.1 amps

    Current 2.1 amps

    I apologize in advance if this topic has been covered recently, but I'm curious what 2.1 amplifiers are currently available to DIYers right now? I know PE limits linking to other vendors, but maybe no direct links, but if you could just describe where you might buy certain ones. I know these sorts of things come and go over the years, so I'm trying to get an idea of what's available right now at different price points and form factors.

  • mmbone4
    replied
    What Mike said...;-)

    Leave a comment:


  • Millstonemike
    replied
    Originally posted by mmbone4 View Post
    I have not tried the 24V on anything more that a 110V, but I would have to assume is a basic PSU. And this is a 3116 board so the power ratings are probably 10%.
    MB
    The amp's power ratings are the maximum W rms based on the TPA3116 chip's thermal limitations. The actual power out is defined by the PS voltage and the speaker impedance. The only way to exceed the thermal ratings at 24 V is to have 4 ohm speakers on the mains and a 2 Ohm driver(s) in the sub.

    Direct from TI's datasheet: the TPA3116 chip's distortion graphs at 24 V specify the following W rms:

    1% THD: 33 W @ 8 Ohms; 60 W @ 4 ohms; 120 @ 2 ohms (sub channel only)
    10% THD: 42 W @ 8 Ohms; 75 w @ 4 ohms 150 @ 2 ohms (sub channel only)

    The sub channel's 100 W limit is twice the L-R limit as the second chip's two channels are in a parallel configuration (PBTL) enabling twice the thermal dissipation (and 2 ohm impedance). I wouldn't worry about using 4 ohm speakers on the L-R channel to get 60 W rms (exceeding the 50 W thermal limit). All these ratings are based on a sine wave and music is never as power dense, maybe half to a third. And the dynamic peaks that require maximum watts are short lived while the chip / heat sink combination has thermal inertia to handle those peaks.

    Dollars to donuts the sub's LP filter is a 2nd order Sallen-key topology that uses two resistors and two capacitors to determine the filter's Fc and Q. Increasing the value of the two resistors can lower the Fc while keeping the Q the same. Prudent choice of two replacement caps can change the Fc and the Q in accordance with the Sallen-Key topology's standard equations.

    Alas, I don't have the amp to reverse engineer the filter and identify the specific SMT components ...

    The board's PS bypass cap is only 1800 uf. Hopefully the included PS has sufficient amps to handle peaks.

    Leave a comment:


  • mmbone4
    replied
    Hey Brian, so the 2 channels are run full range but have a tone control knob that actually works. I am not sure what the range is but definitely makes my FE85s sing. The sub channel is set at 180 and is not adjustable. There is a bass knob that is more a less, a sub volume. The board is super clean and marked well. I am sure it could be modified, but that is above my pay grade. I have not tried the 24V on anything more that a 110V, but I would have to assume is a basic PSU. And this is a 3116 board so the power ratings are probably 10%.

    Having said that, I cannot turn my over all volume knob on the amp more than 1/2. I am running 2 FE85s on a contouring network and a Tang W5 voxel sub, and this amp will push them to breaking with no distortion. It is very powerful.

    The amp that Jwjarch ordered will allow you to adjust the crossover for bass from 30-150hz and does work well. Not as powerful, but plenty of power to run you out of a room. I ordered several of these to try because I can adjust the bass crossover, and volume of fullrange and bass. Hope that helps...

    MB

    Leave a comment:


  • Brian Steele
    replied
    Originally posted by mmbone4 View Post
    Kevin, I bought the new PE 2.1 amp you mentioned. It is a beast. By the time you buy a 2.1 board from overseas ($35), buy a 24v power supply ($25) and a sure BT board ($25), you could have bought the new PE amp. It is a FX Audio re-branded. The bass is tight and strong. The 2 channels put out some very clean power. Much better sounding than most I have heard.
    ​Ooh, that amp comes so close to what I'm looking for that I actually might end up buying it for Christmas.

    ​Are the two main channels run full range or are they hi-passed, and if so is it at the same 180 Hz?

    ​Is it possible to adjust the LP filter for the subwoofer without extensive modifications to the amp?

    Does the 24V power supply really only work with 120V mains, or is it 110~240V like most PSUs these days?

    Are the power ratings at 1% or 10%?

    Leave a comment:


  • mmbone4
    replied
    Kevin, I bought the new PE 2.1 amp you mentioned. It is a beast. By the time you buy a 2.1 board from overseas ($35), buy a 24v power supply ($25) and a sure BT board ($25), you could have bought the new PE amp. It is a FX Audio re-branded. The bass is tight and strong. The 2 channels put out some very clean power. Much better sounding than most I have heard.

    What I like most is that I can connect AUX, RCA and have BT and chose my connection by pressing the power button multiple times and as it moves to the next input, it light up on the front. Very well thought out. The BT is 4.0 APTX and I was able to get a range of over 100'. There is an external antenna on it as well.

    Tom, sorry, the .1 is fixed to 180hz.

    The ONLY issue I had was that I was plush mounting it on a 2.1 enclosure. Has a lot of air moving as it has a TB W5 1138 in .25 enclosure. With this amp, the led's on the front just come to close to the holes in the face plate. They do not actually flush against the face plate. Anyway, the face plate leaks a lot of air in this instance. So if you are using as a stand alone...it is an incredible amp.

    I did purchase 2 more of the amps that jwjarch used and worked perfectly in this enclosure. AND, I can taylor the sound with adjustable xover, bass and mains.

    Anyway, the hunt continues.

    Leave a comment:


  • Dropcarve
    replied
    Here's a small one to consider. Same chip set as the 2.1 buyout amp. Built in sub control, duel power inputs and free cheap knobs included! Hopefully I'll find some time to tinker with it tomorrow.
    2.1 Tpa3110D2 Covered logo and QR code so as not to upset the P.E. overloads

    Leave a comment:


  • jwjarch
    replied
    I like it! I'm guessing 3116 based? Price is a little steep but could be worth it. Interested to see reviews when they start shipping.

    Leave a comment:


  • Kevin K.
    replied
    Originally posted by Paul Carmody View Post
    I apologize in advance if this topic has been covered recently, but I'm curious what 2.1 amplifiers are currently available to DIYers right now? I know PE limits linking to other vendors, but maybe no direct links, but if you could just describe where you might buy certain ones. I know these sorts of things come and go over the years, so I'm trying to get an idea of what's available right now at different price points and form factors.
    PE shouldn't have a problem with this link. https://www.parts-express.com/dayton...pply--300-3830

    Mr. Zarbo stumbled across it this morning and mentioned it in another thread. There's more questions about it than answers right now and it wont be available until mid December.

    Leave a comment:


  • mmbone4
    replied
    Great eye Jeff F, yes, that was my first ever build. I built it for my daughter. Have really been focusing on those type speakers for some time now. Mostly 2.1 with a down firing woofer, but that one sounded really great and was a fun build.

    Jwjarch, thanks. I thought about that and noticed in pics that the board was pretty well marked. And I can be very daring...so I will try that out.

    Millstonemike, that may be the way to go, is a true 2.1. I had thought about a voxel with 2 - FE85s or RS100's in their own enclosures.

    Thanks as always guys!

    Leave a comment:


  • Millstonemike
    replied
    Originally posted by mmbone4 View Post
    Thanks Tom. Appreciate your taking the time to write this. Was hoping to use with inside L/R connections but looks more like a sub amp as you mentioned with its 2 channels on the outside. But look forward to playing with it. Still love the Micro-Plate amp...

    Michael

    You may be able to tap the L-R output from inside the external plate. Those connections are hidden by the PCB. But the picture doesn't have enough resolution to see how that PCB may be removed. It may be possible to tap the main PCD itself. I'd need to put a scope to be sure.

    as is, you can always create detachable L-R speakers for stereo speration.



    Leave a comment:


  • jwjarch
    replied
    Originally posted by mmbone4 View Post
    Thanks Tom. Appreciate your taking the time to write this. Was hoping to use with inside L/R connections but looks more like a sub amp as you mentioned with its 2 channels on the outside. But look forward to playing with it. Still love the Micro-Plate amp...

    Michael
    Michael, if you're daring enough, you could solder direct to the board on the inside to get internal connections for L-R and even the power. It's a somewhat risky proposition but I think it's doable since everything is pretty clearly labeled on the PCB.

    I had my little foam core boom box turned up all day yesterday, playing everything from classic rock, to Latin pop, to jazz. It never faltered or even got warm. Neither did my power supply. I'm still very impressed by this amp. I agree, Tom. Hope PE tries to add this amp to their lineup. It would sell like crazy. I'm debating between getting another one of these amps to power a set of Heliums and a Voxel Sub build I'm working on, or going with a TPA3116 2.1 I already have laying around. Maybe I have to do a side by side comparison. Either way I wouldn't mind having a spare one of these for a future build.

    Leave a comment:


  • Jeff F.
    replied
    Originally posted by mmbone4 View Post
    Thanks Tom. Appreciate your taking the time to write this. Was hoping to use with inside L/R connections but looks more like a sub amp as you mentioned with its 2 channels on the outside. But look forward to playing with it. Still love the Micro-Plate amp...

    Michael
    Hey, is that a Helium boombox in your avatar?

    Leave a comment:


  • mmbone4
    replied
    Thanks Tom. Appreciate your taking the time to write this. Was hoping to use with inside L/R connections but looks more like a sub amp as you mentioned with its 2 channels on the outside. But look forward to playing with it. Still love the Micro-Plate amp...

    Michael

    Leave a comment:


  • tomzarbo
    replied
    Originally posted by mmbone4 View Post
    Hey Tom, I did the same thing and ordered this amp after I saw the comment above. Hopefully will be here in a few days. How does this compare with your 2.1 plate amp (2x15 /1x60)? Love to know.

    Michael
    Mike,
    It's really got a bit more power I think. I just hooked it up to my iPod and played a few songs through it and can confirm that it plays a good bit louder than my 2.1 plate amp.
    Plus, you can use this one as just a subwoofer plate amp with the switch on the back if you wanted. Mine just wouldn't be a good choice for that I don't think.

    I actually have the main volume turned up louder than the subwoofer volume, which is not usually the case with these smaller 2.1 amps... what I've found is the sub section is usually a bit underpowered, but not in this one.

    For size comparison, my amp is smaller at 4" x 4", this one is not a lot bigger, but it wouldn't fit in the small flat-pack cabinets PE sells for instance -- like the Quark-sized cabinets. Of course, this one is meant to live in a subwoofer because the only 'inside' connection is for the sub. So you'd have to so some cable jumping to get it to live in a L or R speaker like my 2.1 amp.

    My Micro-B amp subwoofer section doesn't cross over low enough to quite make me happy, and it's of course not adjustable. This new one is adjustable and seems to be crossing at pretty close to what's stated on the dial. That alone amazes me. For what you get for the money, it's kind of cool.

    I could see this used in the back of a 2.1 table radio with PE's new bluetooth preamp board on the front: https://www.parts-express.com/12-vdc...remot--320-348

    That would make a nice, and fairly cheap combo. You'd just have to rig up a way to get power to both, knocking down the amps 19v to 12v for the preamp. Shouldn't be hard for the guru's on Tech Talk to figure out easily enough.

    I bet you like it when you get it hooked up!

    Again, I really hope PE picks this product up, if it's made decently enough to last, it would make a nice addition to their line of little amp boards.

    TomZ

    Leave a comment:

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