Diy bass amp.

LeftHandStrat · 26th August 2012, 03:02 PM

Hi all, I posted a similar topic in the Chip amps section and was advised by a fellow member to ask here for advice also.

I wish to make a bass amp as this will increase my knowledge on electrical stuff and also give me something usable at the end of the process.

I am looking to build a practice amp, no more that 50W in power, simply because it is for the house and maybe the odd garage jam, nothing more.

I have been thinking heavily about a LM3886 power amp section as this chip can provide 50W of power. I wish to steer clear of tubes as I wish to gain some more knowledge before undertaking a tube project.

The amp needs to be able to do clean and distorted sounds, if I need to use a pedal then I do not mind as I can probably mod something or muster up a pedal specifically for the job. It does need an eq section in there and I would prefer a basic 3 or 4 pots (Bass, Mids, treble or bass, low mids, high mids and treble).

The circuits won't necessarily be simple and I do realise this, but the simpler they are the better, I work by the KISS principle as taught to me by my dad and granddad so keeping things simple is in my brain

in terms of tones I need a good varierty but I want that rip roaring lemmy tone as well, so i need to factor that in (although i am not rich enough for a ricky and a marshall!)

If you have any words of wisdom or ideas, I would love to read through them

many thanks,

Bruce

Minion · 26th August 2012, 04:31 PM

Well I don"t know how simple it would be but you would start with a basic adjustable gain stage going into a 3 or 4 band active EQ stage then into a LM3886 Power amp stage , you could add a couple diodes at the output of the gain stage to give you a fuzz bass effect .....

If you wanted something simpler you could skip the EQ stage and add an FX loop and use an outboard EQ pedal or rack EQ ......

Cheers

LeftHandStrat · 26th August 2012, 04:42 PM

The effects loop is a cool idea and I will keep it in mind but for the minute the on board active eq would be better for me.

cheers.

Minion · 26th August 2012, 10:54 PM

Well here is a 3 band active controll I have used for a guitar amp that also sounds good for bass but you will need a gain stage/buffer before it .....

Printer2 · 26th August 2012, 11:30 PM

How about something like this?

Ginger

Passinwind · 27th August 2012, 03:33 AM

You might consider this one too. I gigged on bass with the preamp section quite happily for a few years, and the power amp part is also available already built if you don't feel up to doing it yourself. Lots of Fender vibe, if that appeals.

Struth · 13th September 2012, 04:53 AM

Hi Guys

Lemmy's sound is predicated on a clipped output stage and some EQing ahead of it. He sets the bass and treble down a bit and cranks the mids.

Doing this in solid-state is pretty simple. The above suggestions for making a clippable gain stage using diodes is an easy start and allows you to get the sound without actually clipping the 50W output chip. EQ after the distortion stage will let you make the tone as crisp or fat as you want. You can build the whole preamp with three opamps, if you buffer the output of the diode stage into the EQ.

If you wanted to keep it really simple, you could do the first stage with variable gain and diode clipping, then a simple Tube-screamer style EQ stage with a single tone control, and a final volume before the PA. Just two opamps.

Since opamps have so much gain, you could also do a single opamp variable gain stage with built-in clipping into a passive EQ, volume and PA.

Opamps are pretty forgiving and can be made to sound however you wish. Fortunately with electronics you can use any path to get to your goal.

Have fun
Kevin O'Connor

LeftHandStrat · 13th September 2012, 07:32 PM

Hey,

Even though three opamps sounds a little more complex, it does give me the EQ options I wanted.

Which chips would I use with that? and is there a schematic for a similar circuit or the same circuit as the one you are referring to?

cheers

sreten · 08:44 PM

Hi,

Hifi amplifiers have nothing much to do with musical amplifiers, as any
perusal of hifi amplifiers versus musical amplifiers will quickly prove.

Lots of tricks used in musical amplifiers and the only way to learn is
studying (and emulating) the schematics of other musical amplifiers.

rgds, sreten.

Look up TinaTi, an excellent free emulator.

FWIW I'd simply buy a good sounding small used bass amplifier.
In my case I learned more analysing what it did and how it
worked and how to fix it, than I would have done "designing"
my own bass amplifier, which would have cost a lot more,
and TBH a lot worse, reinventing the wheel is not good.

A used Ampeg BA112 would be a very good idea.

LeftHandStrat · 13th September 2012, 08:30 PM

Cheers! Looks like a lot of schematics need looking up lol

26th August 2012, 03:02 PM	#1
LeftHandStrat diyAudio Member Join Date: Aug 2012	Diy bass amp. Hi all, I posted a similar topic in the Chip amps section and was advised by a fellow member to ask here for advice also. I wish to make a bass amp as this will increase my knowledge on electrical stuff and also give me something usable at the end of the process. I am looking to build a practice amp, no more that 50W in power, simply because it is for the house and maybe the odd garage jam, nothing more. I have been thinking heavily about a LM3886 power amp section as this chip can provide 50W of power. I wish to steer clear of tubes as I wish to gain some more knowledge before undertaking a tube project. The amp needs to be able to do clean and distorted sounds, if I need to use a pedal then I do not mind as I can probably mod something or muster up a pedal specifically for the job. It does need an eq section in there and I would prefer a basic 3 or 4 pots (Bass, Mids, treble or bass, low mids, high mids and treble). The circuits won't necessarily be simple and I do realise this, but the simpler they are the better, I work by the KISS principle as taught to me by my dad and granddad so keeping things simple is in my brain in terms of tones I need a good varierty but I want that rip roaring lemmy tone as well, so i need to factor that in (although i am not rich enough for a ricky and a marshall!) If you have any words of wisdom or ideas, I would love to read through them many thanks, Bruce

13th September 2012, 08:19 PM	#9
sreten diyAudio Member Join Date: Nov 2003 Location: Brighton UK	Hi, Hifi amplifiers have nothing much to do with musical amplifiers, as any perusal of hifi amplifiers versus musical amplifiers will quickly prove. Lots of tricks used in musical amplifiers and the only way to learn is studying (and emulating) the schematics of other musical amplifiers. rgds, sreten. Look up TinaTi, an excellent free emulator. FWIW I'd simply buy a good sounding small used bass amplifier. In my case I learned more analysing what it did and how it worked and how to fix it, than I would have done "designing" my own bass amplifier, which would have cost a lot more, and TBH a lot worse, reinventing the wheel is not good. A used Ampeg BA112 would be a very good idea. __________________ There is nothing so practical as a really good theory - Ludwig Boltzmann When your only tool is a hammer, every problem looks like a nail - Abraham Maslow Last edited by sreten; 13th September 2012 at 08:44 PM.

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26th August 2012, 04:31 PM	#2
Minion diyAudio Member Join Date: May 2006	Well I don"t know how simple it would be but you would start with a basic adjustable gain stage going into a 3 or 4 band active EQ stage then into a LM3886 Power amp stage , you could add a couple diodes at the output of the gain stage to give you a fuzz bass effect ..... If you wanted something simpler you could skip the EQ stage and add an FX loop and use an outboard EQ pedal or rack EQ ...... Cheers

26th August 2012, 04:42 PM	#3
LeftHandStrat diyAudio Member Join Date: Aug 2012	The effects loop is a cool idea and I will keep it in mind but for the minute the on board active eq would be better for me. cheers.

26th August 2012, 10:54 PM	#4
Minion diyAudio Member Join Date: May 2006	Well here is a 3 band active controll I have used for a guitar amp that also sounds good for bass but you will need a gain stage/buffer before it .....

26th August 2012, 11:30 PM	#5
Printer2 diyAudio Member Join Date: Apr 2010	How about something like this? Ginger

27th August 2012, 03:33 AM	#6
Passinwind diyAudio Member Join Date: Dec 2005 Location: Columbia River Gorge, Washington	You might consider this one too. I gigged on bass with the preamp section quite happily for a few years, and the power amp part is also available already built if you don't feel up to doing it yourself. Lots of Fender vibe, if that appeals.

13th September 2012, 04:53 AM	#7
Struth diyAudio Member Join Date: Aug 2012 Location: books at londonpower.com	Hi Guys Lemmy's sound is predicated on a clipped output stage and some EQing ahead of it. He sets the bass and treble down a bit and cranks the mids. Doing this in solid-state is pretty simple. The above suggestions for making a clippable gain stage using diodes is an easy start and allows you to get the sound without actually clipping the 50W output chip. EQ after the distortion stage will let you make the tone as crisp or fat as you want. You can build the whole preamp with three opamps, if you buffer the output of the diode stage into the EQ. If you wanted to keep it really simple, you could do the first stage with variable gain and diode clipping, then a simple Tube-screamer style EQ stage with a single tone control, and a final volume before the PA. Just two opamps. Since opamps have so much gain, you could also do a single opamp variable gain stage with built-in clipping into a passive EQ, volume and PA. Opamps are pretty forgiving and can be made to sound however you wish. Fortunately with electronics you can use any path to get to your goal. Have fun Kevin O'Connor

13th September 2012, 07:32 PM	#8
LeftHandStrat diyAudio Member Join Date: Aug 2012	Hey, Even though three opamps sounds a little more complex, it does give me the EQ options I wanted. Which chips would I use with that? and is there a schematic for a similar circuit or the same circuit as the one you are referring to? cheers

13th September 2012, 08:30 PM	#10
LeftHandStrat diyAudio Member Join Date: Aug 2012	Cheers! Looks like a lot of schematics need looking up lol