diy mini amp not loud enough (whoda thunk!)

[petey twofinger]

i built a battery powered minamp using some car speakers , a sure tda 2024 15 watt tripath stereo amp . the "front end" is a korg pandora x5 . anyway i am a little surprised that it isn't as loud as i had imagined it would be . looking around i saw about impedance mismatching when you plug an ipod into a stereo . this lead me to ponder that perhaps if i had some sort of boost circuit between the pandora and the tda tripath amp it would perform much better (loud) .

i have monkeyed around and read a little about boosters so i ended up building an oorman mosfet bost . i also saw on beavis hifi he had a jfet circuit for ipod to stereo . anyone famaliar with this conundrum ?  any recommendations ? ideally it would be quiet , provide the right range of gain (i know) not use too much power , and sound great (hah) , i am impressed with the pandora sound quality , it is pretty loud but i really think something in between will set this thing off like a rocket . i have some mini speakers i could chop that circuit in , also a circuit from some pc speakers that has a headphone jack , but thats in my cbg ....

as far as powering goes the amp has a 12 volt sla , and internal ac power supplies/dc regulators for 4.5 volts , 9 , and 12 . so i can run it ac or dc . it also powers the sustainer in my fernandes thru a custom hacked mic cable that carries 9 volts to the guitar .

i can not access the bevis hifi site , curious if someone had that page (jfet ipod pre) or schmo saved , a vero would be a dream come true  ! another option may be a mini headphone amp (ipod booster) , i have seen those too , but not sure . realize this is an oddball , but figured it wouldn't hurt to ask . (sorry i am not an EE , i am a goof) i just figured maybe someone had been thru something similar and could maybe point me in the right direction so i can save time , being disabled with this chronic back pain sucks . it kinda makes me want to cut the tinker time down if i can .

i can post more info about the pandora and the actual amp if needed , i am uploading a huge video to  YT right now so bandwidth is tight ....

should i try and measure the output of the pandora and then see if i can get specs for the tripath amp to see how much headroom i have ?

thanks in advance for any feedback , ideas , or insults directed towards my lethargy and (lack of) intelligence !!

[electrosonic]

The Beavis Audio site has been mirrored by "the Internet archive".  Check it out here...
http://web.archive.org/web/20110202101410/http://beavisaudio.com/

Andrew.

[Earthscum]

The Beavis Audio site has been mirrored by "the Internet archive".  Check it out here...
http://web.archive.org/web/20110202101410/http://beavisaudio.com/

Andrew.

Actually, http://www.beavisaudio.com/ is back up and running. Make sure to thank him, if you get the chance. I love his site.  However, now his Hi-Fi site is gone. http://beavishifi.com/

http://web.archive.org/web/20110202101410/http://beavishifi.com/ is archived, however the Fet Preamp was newer than the wayback is showing... I actually know which one you're talking about, but I had checked it out about 2 weeks ago, so can't remember much of it, my apologies.

You could build just about any buffer to address the impedance mismatch issue. Or, what I would probably do, is make a simple IC buffer/gain using TL072 or something of the likes. I don't imagine you'd need more than about 10x gain, really, but I'm like you, more of a goof and definitely not an EE, lol. So, my luck would be that 10x isn't nearly enough, but I'm thinking along the lines of boosting a .1V instrument level closer to 1V line levels. I tried this with a computer speaker setup and it seemed to work pretty decent. iPuds and mp3 players put out a much hotter signal than my bass does. It was one of those "Hrrmmm... I wonder..." things. 

[petey twofinger]

thanks ES .

is bevis hifi gone forever ?

i saved a ton of his stuff , unfortunately i only saved a link to that page ...

i had looked around for a schemo that i liked , actually a few times , and didnt find anything .