The DIY 2.1 amplifier. Should I build it? Would you buy it?

[bdiermeier]

Re: The DIY 2.1 amplifier. Should I build it? Would you buy it?

Definitely interested.

This might be a wierd question, but would it be possible to use teh base board to send a mono out to a sub that already has an amplifier as well?

And since it is possible to send the mono out, would it then be possible to run both amp boards bridged, with the high pass? Kind of like a "dual mono"? Or would you still have to run one board in stereo, and leave the other unpopulated?

[tyger23]

Re: The DIY 2.1 amplifier. Should I build it? Would you buy it?

And since it is possible to send the mono out, would it then be possible to run both amp boards bridged, with the high pass? Kind of like a "dual mono"? Or would you still have to run one board in stereo, and leave the other unpopulated?

First things first - the board is being designed to only fit two boards in a piggy back method. Thus, only the base board (populated with two amp boards) will fit into the case it is being designed for.

So, with that in mind, it is possible to use the two boards in a stereo PBTL mode (one board for left and one board for right). The mono signal could be output to an external amplifier via RCA jack, if desired.

Alternatively, you could put the base board and THREE separate PBTL configured amp boards (one for left, one for right, one for mono) into a custom case.

I'm going to try and figure out how to add the series caps and pull down resistors (as mentioned by Fred) to the design next week. This will make it more flexible, I'm just running out of room ;).

[bdiermeier]

Re: The DIY 2.1 amplifier. Should I build it? Would you buy it?

I think you misunderstood my question- but managed to answer it anyways. I was looking to do exactly what you just listed as an option- two boards in stereo PBTL mode, with the mono going to an external amplifier.

Thanks!

[tyger23]

Re: The DIY 2.1 amplifier. Should I build it? Would you buy it?

Guys - just a quick update. I have received the amp case, but the boards from China have not shown up yet. Sadly, I'm globe trotting for the next two weeks (Brazil then Taiwan), so I'm not going to be able to do much even if the amp boards arrive tomorrow. I really want to wait on those to make sure everything fits and to be able to measure and add mounting holes in the right places.

Silver1omo - please resend your tracking information, as I have misplaced it.

[djg]

Re: The DIY 2.1 amplifier. Should I build it? Would you buy it?

Here's a little 2.1 I'm building in anticipation of the great success of Tyger's amp. Tyger's Mariposas in 3/4" wood, and DanP's little NRNP TB sub.

[Silver1omo]

Re: The DIY 2.1 amplifier. Should I build it? Would you buy it?

Silver1omo - please resend your tracking information, as I have misplaced it.

Sent you a PM. Please let me know if you got it.

[bdiermeier]

Re: The DIY 2.1 amplifier. Should I build it? Would you buy it?

What sort of current would this board (using two amp boards) require? I picked up some transformers that were going to be scrapped which are 25v (obviously I'd have to regulate the voltage), but they are 350va. Is that just too much? I know you can't have too much current, but I don't want a ton more than I need.

[tyger23]

Re: The DIY 2.1 amplifier. Should I build it? Would you buy it?

Sorry for the delayed reply. The answer will depend on the DC voltage being applied to the amps, the speaker loading, and how loud you want to listen. The TPA3116 would be the highest power, so I'll use that. Now, worst case would be running the stereo amp with 4-ohm loads at 26v DC. This would yield about 85w/channel. Then, running the mono amp in PBTL mode at 26V DC into a 2-ohm load would yield about 160W.

Assuming 90% efficiency, the amp would consume (85 + 85 + 160) / 0.9 = 366W. Tack on about 3dB of headroom, and you could actually demand about 732W. At the given voltage of 26V, this would be about 28A.

Now, normal usage of 8-ohm satellites and a 4-ohm sub, and normal listening levels, these numbers won't be nearly this high. I'm expecting a 20v, 150w laptop power supply to be more than sufficient, and I expect a 24v, 200w supply to provide more current than the amp can thermally dissipate.

Anyways - you can never have too much current. Only too much space required to supply that current, or too much voltage.

[tyger23]

Re: The DIY 2.1 amplifier. Should I build it? Would you buy it?

For anyone wanting to know the status on this and/or wondering where I've been:

1. I have received the TDA7492 amps. Thanks Silver1OMO!

2. I ordered the TPA3116 amps over a month ago. After going 3000 rounds with USPS to figure out where they went - I discovered they were delivered to an old address I no longer live at. I'm trying to recover them, but I don't think I'll be able to. So, I've ordered another set from Yuan Jing. Hopefully these go to the right address.

3. In the past 2 months, I've flown over 40,000 miles and have been on the road more than I've been home. My wife and kids aren't happy - but that's what the job requires sometimes. Hopefully that will change soon, but I don't know if it will.

As soon as the second set of TPA3116 amps arrive, I hope to verify the mounting holes and gerber out the boards. I'm so sorry for the delays. Thanks for the patience!

[tyger23]

Re: The DIY 2.1 amplifier. Should I build it? Would you buy it?

HOORAY!!!!

The TPA3116 boards (the second set) arrived today! Also, I'm leaving in a few minutes to spend a week at the "audio think tank" conference known as Project BBQ. This is basically a conference of some of the greatest minds in audio gathering to drink beer, play music, and contemplate the future of all things audio. Hopefully, I'll be able to get some good feedback and reviews on the schematics/layout and I'll get this thing sent off to production next week.

http://www.projectbarbq.com/

Thanks again for all the community support!

[djg]

Re: The DIY 2.1 amplifier. Should I build it? Would you buy it?

"The sound of Chinese manufacturing"

[Asbot]

Re: The DIY 2.1 amplifier. Should I build it? Would you buy it?

In Comfort Tx. I live Just south of Abilene.

[tyger23]

Re: The DIY 2.1 amplifier. Should I build it? Would you buy it?

Most up-to-date schematics and layout. These include the series capacitors in the output path (which can be optionally shorted), and they include a change to a more commonly available and cheaper RCA connector. This last change may require some finagling during the final assembly for the component height, but it should be worth it to drop the costs by more than $1.

Reviews and comments appreciated. The virtual grounding technique in the schematics and the point-to-point grounding technique in the layout are the most suspect for now.

Thanks!

activefilter - Project.pdf

baseboard - PCB.pdf

[devinkato]

Re: The DIY 2.1 amplifier. Should I build it? Would you buy it?

Any updates on this project?

[tyger23]

Re: The DIY 2.1 amplifier. Should I build it? Would you buy it?

The design is ready to go. I am headed to Taiwan (again) and will solicit some more feedback on the best layout and fabrication houses there and we will get going shortly.