I wish to build a bass amp.

[Left_Hand_Strat]

Please note:

I wish to build this amp for enjoyment which also rewards my efforts with something that works and does a task. it is NOT a thread where people say 'don't bother, just buy XYZ... blah blah'. I WANT TO BUILD A AMP. if you are going to suggest a Ready built amp then thanks but no thanks..... sorry but that's how I feel

Now that I have a bass, I would like to build an amp for it.

I would like anywhere upto 50W, not that I would need that, but it makes for a cool build.

I require simple poweramp circuits, I have been studying the LM3886 chip and that seems to be pretty cool. I will need a nice pre amp which can do clean and Distorted tones and a Must for an EQ section, preferably knobs to keep it simple. So EQ would be Bass, Low Mids, High Mids, Treble etc.

I also need a suitable speaker and that always helps in any amp builds.

So what to do from here?

 

[Funkfingers]

Re: I wish to build a bass amp.

In keeping with the OP, the only aspect that I suggest you rethink is the output level. Fifty watts in a bass amp is only going to work on stage if the guitarists use practice amps and the drummer plays with brushes.

In a band context, if you hope to be heard, multiply whatever wattage the guitarists are using by at least three or four.

 

[MojoMonster]

Re: I wish to build a bass amp.

There are plenty of beginner SS amp kits out there that will get you started.
You should have no trouble then scaling that up to 50-100 watts.
Check out Jameco and/or places that cater to the DIY HiFi crowd.

I know I've seen DIY "pedal amps" before. I just can't recall where.

Now, if you're talking about building a *tube* amp, that's an entirely other thing and you'd be better off starting with a simple Champ-style kit.

Good luck.

 

[Left_Hand_Strat]

Re: I wish to build a bass amp.

In keeping with the OP, the only aspect that I suggest you rethink is the output level. Fifty watts in a bass amp is only going to work on stage if the guitarists use practice amps and the drummer plays with brushes.

In a band context, if you hope to be heard, multiply whatever wattage the guitarists are using by at least three or four.

Agreed, but its more of a house amp and practice amp for the moment, when I need a gigging rig then yeah I will buy some hugeass wattage motherf***in' piece of kit like, IDK a trace elliot or sumthin'

There are plenty of beginner SS amp kits out there that will get you started.
You should have no trouble then scaling that up to 50-100 watts.
Check out Jameco and/or places that cater to the DIY HiFi crowd.

I know I've seen DIY "pedal amps" before. I just can't recall where.

Now, if you're talking about building a *tube* amp, that's an entirely other thing and you'd be better off starting with a simple Champ-style kit.

Good luck.

Cheers bro!

I know the DIY Pedal haunts especially for total scratchbuild stuff.

I do not wish to go near tubes or tube projects until I have gained enough electrical knowledge about tubes etc. I know how lethal they are. Plus my dad is a trained electrician working as an electro mechanical engineer on forklifts. Imagine the headlines.... 'Electricians son electrocuted to death'

 

[MojoMonster]

Re: I wish to build a bass amp.

Ok, I found the place I was thinking of.
Beavis Audio Research.

It's a guy named Dano from the BYOC boards I first encountered several years ago.

His site has been pretty dormant for a couple of years, but it looks like he's updating it again.
Dig around, he's got some awesome stuff.

His "cigarette amp".

 

[GoldenVulture]

Re: I wish to build a bass amp.

That LM is really not suitable, it's made for HiFi devices.

Device Uses

• Component stereo
• Compact stereo
• Self-powered speakers
• Surround-sound amplifiers
• High-end stereo TVs

Also it's a pre-made module that you tack a few control components on the outside.
If you really want to build an amp, how about something like this circuit.
- http://www.redcircuits.com/Page158.htm -

[ Power Amp section ]

It's not a kit, parts would be readily available as there fairly common types of transistors. I use Vero Board for making circuit boards for "projects " if I'm starting from scratch.

You could probably find a kit using similar Transistors if you wanted one. I made up a kit similar to this circuit some years back for a mate. It went into his practice amp that had died, a little combo unit with one 12" speaker. He used it for his Bass.

 

[Left_Hand_Strat]

Re: I wish to build a bass amp.

cheers GV that site is great, Just went through the page you linked and to be honest.... might be worth my just building that amp and then using bass speakers???

 

[GoldenVulture]

Re: I wish to build a bass amp.

cheers GV that site is great, Just went through the page you linked and to be honest.... might be worth my just building that amp and then using bass speakers???

That would help you target what your trying to get out of the amp. There's quite a range of possibilitys with bass speakers and configurations.
I figure your trying to keep costs down, something like a 100 Watt 12 " would suffice. Don't forget that the amp will peak out above 70 Watts.
You need headroom in your speaker(s).

Power Amplifier Technical data:

Output power (1KHz sinewave):45 Watt RMS into 8 Ohms - 69W RMS into 4 OhmsSensitivity:0.81V RMS input for 45W outputFrequency response @ 1W RMS:15Hz to 23KHz -0.2dBTotal harmonic distortion @ 1KHz:1W 0.008% 20W 0.008% 45W 0.016%Total harmonic distortion @10KHz:1W 0.01% 20W 0.015% 45W 0.025% Unconditionally stable on capacitive loads

 

[Left_Hand_Strat]

Re: I wish to build a bass amp.

I would use 8 ohm as the standard out. I'm tempted to build the amp as a separate head and cab??? then I could always make 2 cabs with 1x12 100w speaker in each, make a stack in the future if I ever felt like it?

 

[trevorus]

Re: I wish to build a bass amp.

If you happen to be interested in tube stuff at all, there are some kits out there that could be had for about the same cost as building a SS setup.

 

[Left_Hand_Strat]

Re: I wish to build a bass amp.

If you happen to be interested in tube stuff at all, there are some kits out there that could be had for about the same cost as building a SS setup.

Definitely a contemplation, however, as much as tubes are exciting, I feel i should wait until I have more electrical experience.

thinking about it I wonder how much this amp will cost me to build???

I give £20 for all the little caps and all that shizzle, most expensive thing will be the tranny and the speaker.....

 

[trevorus]

Re: I wish to build a bass amp.

Don't forget the chassis to build it in, proper heat sink for the power section, cabinet if you want it to last. I would do a small head and 110 cab or something of the sort.

 

[Left_Hand_Strat]

Re: I wish to build a bass amp.

Don't forget the chassis to build it in, proper heat sink for the power section, cabinet if you want it to last. I would do a small head and 110 cab or something of the sort.

I'm good at getting 'reclaimed' wood.... normally involves several skip dumpsters at midnight!!! :laugh2:

I would do head and cab, makes maintenance easier too.

 

[Left_Hand_Strat]

Re: I wish to build a bass amp.

Also forgot to ask, Should I also have a couple of cooling fans in the case? if so I need to power them somehow.

 

[trevorus]

Re: I wish to build a bass amp.

Also forgot to ask, Should I also have a couple of cooling fans in the case? if so I need to power them somehow.

Depends on the thermal requirements of the circuit. Some amps can handle it, some can't. A big heat sink can possibly take care of it by convection alone.

 

[Left_Hand_Strat]

Re: I wish to build a bass amp.

Yeah but whrring fans would be cool

 

[GoldenVulture]

Re: I wish to build a bass amp.

Yeah but whrring fans would be cool

And can be noisy. Heat sinks are the way to go .

Something like this for the output TR's usually suffices for TO3 type transistors and heat dissipation. They don't cost much. have you an electronics parts shop/s to get such things from ?

 

[Left_Hand_Strat]

Re: I wish to build a bass amp.

And can be noisy. Heat sinks are the way to go .

Something like this for the output TR's usually suffices for TO3 type transistors and heat dissipation. They don't cost much. have you an electronics parts shop/s to get such things from ?

git a Maplin store and three electrical wholesalers near to me! if they don't have it, then Ebay does! :biglaugh:

 

[Left_Hand_Strat]

Re: I wish to build a bass amp.

how would I connect the pre amp to the power amp in that 70w red circuit link GV posted? only ask because when I look at the schematic the pre amp only has one output line and the input of the power amp has two....

 

[GoldenVulture]

Re: I wish to build a bass amp.

how would I connect the pre amp to the power amp in that 70w red circuit link GV posted? only ask because when I look at the schematic the pre amp only has one output line and the input of the power amp has two....

One of those input terminals is ground. You connect the preamp ground to the power amp ground. If it's all on one board that would happen when all the grounds are connected.

P5 [out]to C1. The grounds are other connection.