Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Solid State Amplifiers => The Newcomer's Forum => Topic started by: tylerfronheiser on February 21, 2012, 12:04:46 AM

Title: Preamp for 3w amp
Post by: tylerfronheiser on February 21, 2012, 12:04:46 AM
Hey everyone. I am gonna start building my first amp soon and would like some suggestions for a diy preamp. This is the power amp section i am getting, http://www.vellemanusa.com/products/view/?country=us&lang=enu&id=521723. I want to run everything off a 9v dc power supply. I would also like to have a three knob tone control and either a separate gain channel or gain settings in the preamp. Thank you.
Title: Re: Preamp for 3w amp
Post by: J M Fahey on February 21, 2012, 01:53:49 AM
Hi tyler.
Nice kit, but it will never provide 3W.
The chip makers sell it as a 2W amp, and that with a 12V supply.
With 9V it will barely provide 1W.
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CDQQFjAA&url=http%3A%2F%2Fwww.st.com%2Finternet%2Fcom%2FTECHNICAL_RESOURCES%2FTECHNICAL_LITERATURE%2FDATASHEET%2FCD00000202.pdf&ei=Wz5DT471O8WcgQeMu_ynCA&usg=AFQjCNHmE2g6esO68odtNLwsP9z0cCgv-Q (http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CDQQFjAA&url=http%3A%2F%2Fwww.st.com%2Finternet%2Fcom%2FTECHNICAL_RESOURCES%2FTECHNICAL_LITERATURE%2FDATASHEET%2FCD00000202.pdf&ei=Wz5DT471O8WcgQeMu_ynCA&usg=AFQjCNHmE2g6esO68odtNLwsP9z0cCgv-Q)
Title: Re: Preamp for 3w amp
Post by: tylerfronheiser on February 21, 2012, 02:49:45 AM
Hey thank you for the reply. I was gonna make a ruby amp or some variation of it, but i thought this would be a little more power. Is there something else anyone could recommend?
Title: Re: Preamp for 3w amp
Post by: phatt on February 21, 2012, 09:05:33 AM
Well you might like this;
http://www.ssguitar.com/index.php?topic=2483.0;topicseen

**Little Rebel** full PDF on that page,, under my post.

Never built it but member *newbiediy* has a link to a sound clip which sounded good to my ears. :tu:
Phil.
Title: Re: Preamp for 3w amp
Post by: J M Fahey on February 21, 2012, 12:59:11 PM
The most powerful 9V powered amp is the TBA820 , bit it´s also the most complex :(
And you´ll need to make your own board.

The popular lm386 is so because of its simplicity (can work with only 2 external parts) but also the least powerful/efficient.
No "free lunch" here!!

Use the Velleman kit, which solves most problems, specially the PCB, just don´t think it has 3 watts.
Anyway, with a good speaker, 1 W is enough to have Family/Neighbours problems, believe me. :(
You can get a good speaker cheap at EBay, Craigslist or local ads: *many* guys buy a "better" speaker (an expensive Eminence or Celestion, 65 to 150 U$) and sell the "old" one (which usually is made by Eminence anyway and is very good) pulled from their Peavey or Fender for $15 or 20.
Title: Re: Preamp for 3w amp
Post by: tylerfronheiser on February 23, 2012, 02:39:03 AM
Thanks for the replies, I think I'm gonna look more into the little rebel. That might be easier and cheaper then what i was trying to do considering its my first amp.
Title: Re: Preamp for 3w amp
Post by: J M Fahey on February 23, 2012, 03:49:58 AM
Good.
And it´s a complete project, preamp and all.
Not to forget the killer sound. ;)
Title: Re: Preamp for 3w amp
Post by: joecool85 on February 23, 2012, 08:08:48 AM
Quote from: J M Fahey on February 23, 2012, 03:49:58 AM
Good.
And it´s a complete project, preamp and all.
Not to forget the killer sound. ;)

It's also an easy build, always a plus :-)
Title: Re: Preamp for 3w amp
Post by: newbiediy on March 02, 2012, 02:25:59 AM
Thanks phatt, J M Fahey, and joecool85 for mentioning my build.  <3)

It's quite an easy project, as it's my 3rd build after Little Gem and Ruby. Make a switchable jfet input buffer before the preamp for better clean sound, like the first schematic shown here: http://www.muzique.com/lab/buffers.htm.

If you want loudness, use low wattage speaker. If you want better sound, use a real guitar speaker cabinet like  Fahey suggested in my thread. :dbtu:

You won't regret building it. Nice and cheap. I love it. <3) <3)