[greenhorn]

I bought an SMSL SA98 and was blown away by the sort of drive it had. Costing 6K, and the size of a small paperback, the sort of drive it could push to large speakers was amazing.

While browsing ebay for another project, i stumbled onto these

http://www.ebay.com/itm/DC20V-to-DC3...wAAOSwFAZTs8Mj

It's a TDA 7498 (same chip as the smsl) board for 11.5 USD

I searched around for a DC to DC convertor that could drive it, and found this

http://www.ebay.com/itm/DC-DC-600W-1...8AAOSwu4BV4V2S

this should be able to push 120-150W to the board(@12 & 14.4W) , and the TDA amp can run around 55W of clean power in BTL mode, twice in PBTL

together, for 1.5K, you can get an amp that could costs half of the usual 2 channel amps while running cooler ( these are class D)
Even if you want an LPF, you can get one for 7-8 USD.


If you want something more powerful, there are higher current supply boards, and amp boards as well.

Wondering if anybody has experimented in this area?

[navin]

Originally Posted by greenhorn

I bought an SMSL SA98 and was blown away by the sort of drive it had. Costing 6K, and the size of a small paperback, the sort of drive it could push to large speakers was amazing.

While browsing ebay for another project, i stumbled onto these

http://www.ebay.com/itm/DC20V-to-DC3...wAAOSwFAZTs8Mj

It's a TDA 7498 (same chip as the smsl) board for 11.5 USD

I searched around for a DC to DC convertor that could drive it, and found this

http://www.ebay.com/itm/DC-DC-600W-1...8AAOSwu4BV4V2S

this should be able to push 120-150W to the board(@12 & 14.4W) , and the TDA amp can run around 55W of clean power in BTL mode, twice in PBTL

together, for 1.5K, you can get an amp that could costs half of the usual 2 channel amps while running cooler ( these are class D)
Even if you want an LPF, you can get one for 7-8 USD.


If you want something more powerful, there are higher current supply boards, and amp boards as well.

Wondering if anybody has experimented in this area?

I assume you have heard of the gainclone (not to be confused with the gaincard made by 47 labs). A simple execution of this gainclone can be found here http://www.shine7.com/audio/pa100.htm

The Gainclone is based on either the 1875, 3875 or 3886 chips and uses a minimal of external parts. You can read more about it here
https://chipamp.com/
http://diyaudioprojects.com/Chip/chip.htm
http://liquidaudio.com.au/lm3886-chip-amp/

There is even a whole section of diyaudio that is dedicated to chip amps
http://www.diyaudio.com/forums/chip-amps/
and at diyaudioprojects too
http://diyaudioprojects.com/Forum/viewforum.php?f=10

[greenhorn]

Yup, I've seen a few Class T/D & other chip amp based builds, but most are run on mains using linear power supplies.

The above combos, I felt would need some care around automotive application related issues such as

• matching the switch mode PSU's with the amp boards,
• how these boards handle noise from the PSU's
• how to tune their output as they are not well regulated ( output changes with input, so managing the 12v-14.4V shift when they are boosted to proportionately higher voltages)
• EMI shielding
• muting & speaker protection?