You can probably get away with just 2 amps. If it will be prohibitively difficult to get into the enclosure to replace it should it fail eventually, might be worth using 4 total.
In general, series components will increase the resistance, parallel components will decrease it, how much depends on the specific component and frequency.
Hard to know what the bluetooth receiver will do compared to a phone or tablet, depends on the particular bluetooth module being used and the phone/tablet it is compared to. Will have to hook it all up to see.
https://www.massdrop.com/buy/ai-101da-integrated-amplifier-with-usb-dac
6 hours left to get it for $208 shipped 🙂
I have a pretty good DAC/Headphone amp already so I didn't join, but good deal.
In general, series components will increase the resistance, parallel components will decrease it, how much depends on the specific component and frequency.
Hard to know what the bluetooth receiver will do compared to a phone or tablet, depends on the particular bluetooth module being used and the phone/tablet it is compared to. Will have to hook it all up to see.
https://www.massdrop.com/buy/ai-101da-integrated-amplifier-with-usb-dac
6 hours left to get it for $208 shipped 🙂
I have a pretty good DAC/Headphone amp already so I didn't join, but good deal.
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Yes I signed up but out of my price range since I have a sound setup in every room including outside and one in the garage! Thanks tho. I will be enclosing the speakers all by themselves with removable lid. The amp/Bluetooth /dc-to-dc converter and battery/ies will get there own box. Like a musicians head unit and satellites? That's why so many questions regarding the output and all is I a preplanning for when the bt unit and DC converter eventually arrive from China. Thanks Jensen, I will be hooking it all temporarily to see what configuration works best. I initially wanted the most output but my girl keeps telling me to TURN THE DAMNED THING DOWN!!!!!! HAHA, I then turn it up louder! but only for a few seconds, hehe
Class AB is smaller than some TPA31xx boards
I just built the Apex FX8 amp - it is very small (50mmx50mm board) for a fully discrete thru hole component 100w class AB amp. I am still waiting for the MOSFET output stages to arrive so the ones shown are mockups to get the scale of the device.
My recent experience is that these discrete class AB's sound better than the TPA31xx amps.
I just built the Apex FX8 amp - it is very small (50mmx50mm board) for a fully discrete thru hole component 100w class AB amp. I am still waiting for the MOSFET output stages to arrive so the ones shown are mockups to get the scale of the device.
My recent experience is that these discrete class AB's sound better than the TPA31xx amps.
I ordered the boards from a Gerber file from thread. Custom PCBs are $10 for 10 if 5cm X 5cm or smaller.
These boards are extremely high quality - like commercial production boards. I used Seeed studio.
These boards are extremely high quality - like commercial production boards. I used Seeed studio.
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I know very little but isn't class a, a/b very inefficient? Good for AC power only? But sound great? How much do you have into the build all in?
I would be interested to compare that board to a well done TPA board. I have a feeling most of the difference in sound is down to quality components, and a board layout someone actually put thought into. The Chinese TPA boards have neither of those things generally.
Hmm, looks like I need to get on top of assembling my Mord board to find out.
Hmm, looks like I need to get on top of assembling my Mord board to find out.
You got that right. All components bought in bulk from Aliexpress. The output lateral mosfets are the most expensive parts at $5/pair the PCB is $1. The rest of the parts are no name Chinese caps, and 1% resistors, no name signal transistors, VAS transistors, diodes, terminal blocks, etc. maybe $2. So total cost is about $8. Of course I have enough parts to make 10 amps except for the MOSFETs. Other cost is a heatsink and dual rail 35v power supply. Once you get into class A or class AB amps the power supply is something you have and can use between amps for testing. In reality a dedicated toroidal transformer 300VA dual rail 35v power supply will set you back about $70. I have found that cheap $4 CPU heatsink with fan can remove all the heat you want rather than massive aluminum finned heatsink.
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I have a cheap Dx class AB amp and it sounds better than any of my TPA's - this latest FX8 is an attempt to see if size can be shrunken down even more. Different topology than Dx though as this one uses lateral MOSFETs and designed by Apex Audio.
Yes, it is easier to get good sound out of class A or AB than class D, but that isn't to say it cant be done. My current most frequently used amps are class AB (Pair of Dayton APA150 in the office and a pair of AudioSource AMP100 for the living room TV). Unfortunately space and heat concerns are pushing me to need more efficiency as I change things around in my setup.
I am confident that with a good board layout these TPA chips can sound at least as good as my current setup, even with a crap layout they get close. Really looking forward to trying out the bigger brother TPA3251 and TPA3255 chips at some point.
Plus, running on DC power from an SMPS is just so much easier, smaller, cheaper, and more efficient. That said, I do have a nice supply I built with an 800VA 45V toroidal transformer and 47mF output. It's huge, but its just for the lab, would never integrate it into anything.
To get a different output voltage I have a 1kVA variac with a 140V overwinding output option. The variac is also really handy for testing and repairing SMPS supplies. You can slowly wind up the voltage and watch the current, rather than just plug it into the wall and watch some things explode.
I am confident that with a good board layout these TPA chips can sound at least as good as my current setup, even with a crap layout they get close. Really looking forward to trying out the bigger brother TPA3251 and TPA3255 chips at some point.
Plus, running on DC power from an SMPS is just so much easier, smaller, cheaper, and more efficient. That said, I do have a nice supply I built with an 800VA 45V toroidal transformer and 47mF output. It's huge, but its just for the lab, would never integrate it into anything.
To get a different output voltage I have a 1kVA variac with a 140V overwinding output option. The variac is also really handy for testing and repairing SMPS supplies. You can slowly wind up the voltage and watch the current, rather than just plug it into the wall and watch some things explode.
My amps so far outside of class D:
-TDA7298 (modified per OS Destroyer recommendations) with 12v SMPS
- No name LM3886 with Burr Brown OPA2604 front end with 250VAC toroid
- Dx amp by Destroyer X with 35v Dx PSU
- Circlophone quasi class A with inverted JFET input (35v Dx PSU with 250va toroid and four 4700uF caps)
- Pass ACA class A (19v SMPS)
- JLH headphone amp class A (used as speaker amp)
So far I have compared with 3116 and TDA8932.
Still need to try 3118 PBTL and TDA7498 and finally IRS2092.
-TDA7298 (modified per OS Destroyer recommendations) with 12v SMPS
- No name LM3886 with Burr Brown OPA2604 front end with 250VAC toroid
- Dx amp by Destroyer X with 35v Dx PSU
- Circlophone quasi class A with inverted JFET input (35v Dx PSU with 250va toroid and four 4700uF caps)
- Pass ACA class A (19v SMPS)
- JLH headphone amp class A (used as speaker amp)
So far I have compared with 3116 and TDA8932.
Still need to try 3118 PBTL and TDA7498 and finally IRS2092.
I have the following 311x amps:
-point to point dead bug 3118 flip chip following TI EVM board
-DUG v0 3116 FM caps and no bootstrap snubber
-Ybdz (original Wiener amp) 3116 with oscons and bootstrap snubbers
-YJ blue black with oscons, bootstrap snubbers, 3.3uF film cap on input
-SMAKN 3116 (stock)
-Sanwu 3116 PBTL monoblocks
-Sanwu 3116 Bluetooth
-Sure 3110 8w
-DUG v1 3116 (to be built)
-Dr Mord 3132(?) to be built
If I compare it will be with Ybdz and Sanwu PBTL.
-point to point dead bug 3118 flip chip following TI EVM board
-DUG v0 3116 FM caps and no bootstrap snubber
-Ybdz (original Wiener amp) 3116 with oscons and bootstrap snubbers
-YJ blue black with oscons, bootstrap snubbers, 3.3uF film cap on input
-SMAKN 3116 (stock)
-Sanwu 3116 PBTL monoblocks
-Sanwu 3116 Bluetooth
-Sure 3110 8w
-DUG v1 3116 (to be built)
-Dr Mord 3132(?) to be built
If I compare it will be with Ybdz and Sanwu PBTL.
My favorite is 3118 Sanwu stock mono. Cuz I can't follow the mod threads and don't want my amps to go poof! They all have there uses. I just wired one up for grandsons bedroom in like 30 mins. Fun. Keep looking for the Nirvana, might be the next, or the next??? Lol
Hey X, is there a bom and instructions for the AB amp build somewhere? Hopefully with your cheap china source for components?
I like the Sanwu mono too. One nice thing about class D is that power supplies are cheap and plentiful and small. With class AB they are expensive and heavy. And the amps actually go poof up in glowing embers and smoke of you mess something up. I have had more than a few transistors and their base resistors fry and go poof. Class D 311x's have never died on me. Never. Totally self protected (except for reverse polarity on supplies).
OK, I read between the lines. Stick with simple, cheap, and less fire hazard for this novice newbie! I would try the pass amp kit on this site but don't have the bread. AmpC or thereabouts?