Hi,
I'm looking for schematics or general design remarks about amp designs for portable gear (not necessarily battery powered though)
So far I've been playing around with those hybrid modules like the LM1875 or TDA1562 but I'm not really happy with their sound so I'm looking for alternatives, even if it means going discrete
hope this is the right place to ask
thanks
Sukandar
I'm looking for schematics or general design remarks about amp designs for portable gear (not necessarily battery powered though)
So far I've been playing around with those hybrid modules like the LM1875 or TDA1562 but I'm not really happy with their sound so I'm looking for alternatives, even if it means going discrete
hope this is the right place to ask
thanks
Sukandar
Steve Eddy said:
Yep....If I could find a xfmr that would give me an about x10 voltage gain. With maybe 10 kOhm in? More realistically perhaps 600 Ohm in.........🙂 and drive the fets ........
dimitri said:
IMO these outputs are the greatest thing since peanut butter. This circuit is a little differant in that it uses feedback.
hitsware said:
Well, if you're using a digital source, your Red Book output is 2 volts RMS. To get your 6 watts or so, you'd only need a gain of 5.
I finally got 'round to ordering up the transformers so should let you know how it sounds in a couple weeks. I've already done a lower current version (about 160mA) using 1:1 transformers for driving headphones and it sounds fantastic. Just need to scale it up with some 1:5 transformers and higher current output devices.
se
hitsware said:
If it's output impedance isn't unusually high. The transformer in question is optimized for a 150 ohm source impedance. So if you're in that range you're looking at a little under 1dB loss so you'll get about 1.82 volts at the primary and about 9 volts at the secondary. So you can still get close to 5 watts at the end of the day. Which would be a difference of just over 1dB compared to 6 watts.
By the way, I just posted the 1:1 headphone version here:
http://www.diyaudio.com/forums/showthread.php?s=&postid=264145#post264145
se
I would call a 10W SE class A amplifier less than small and portable 
Anybody a discrete high-quality low-power suggestion in class AB?
Dirk
Anybody a discrete high-quality low-power suggestion in class AB?
Dirk
Sukandar said:
What exactly didn't you like in the way LM1875/3875 sounds (the version you build of course)?
I beleave the LM3875 is the perfect candidate.
Sukandar said:
Hi Sukandar,
May be the Son of Ampzilla or the Grandson.
http://home.kimo.com.tw/skychutw/ampzilla/index.html
Must be possible to use FETs for the inputstage like 2SK389 & 2SJ109....
😎
🙂 hi sukandar,
how about trying this, AN7178. its a dual channel 12 pin amp rated at 5.8w per channel. you can power it from 9v to 16v.🙂
how about trying this, AN7178. its a dual channel 12 pin amp rated at 5.8w per channel. you can power it from 9v to 16v.🙂
sukanda,
please give more information on the use of the device you want to build. The smallest portable amp i build so far is battery powered, about 1*1*2 cm , 1W based on SSM2211 SMD chip.
A real high quality amp is something like http://www.passdiy.com/projects/zenv4-1.htm and this is some kg, not portable anymore, and i doubt you have portable speakers to have any advantage on such an amp in mobile use.
- Status
- Not open for further replies.