I forgot to ask why you need bass boost:

1) Is it because the speaker is cheap and/or is too small?
2) Is it because the speaker does not have an enclosure so the sound from its rear comes around and cancels bass from its front?
3) Is it because the enclosure is too small?
4) Is it because your signal source reduces its bass?

5) It was in the schematic that I chose and I don't know any better yet

I plan to build my own enclosure around the amplifier once I know it is working.

 

Sayal is an electronics parts and products clearance store chain in Canada. I bought some regulated voltage fairly high current power supplies made by Philips for an obsolete router for only $1.50CAN each.

They sell modern and some obsolete ICs. I bought some of their own bag of LEDs but only half of them worked properly.
All their staff are from India.

 

I haven't heard of them. I was interested until the bit about half the LEDs not working, haha. I usually get my components from Creatron Inc and haven't had any issues so far. I will still take a look. Thanks!

 

I lived near Creation in Agincourt (Asiancourt) 35 years ago, then I moved to Mississauga that's also mostly Asian (and Arab) now.

 

I don't think I have access to this company here in Canada, but this is still a good tip Thanks!

Your local internet provider - if they supply routers, when older models come back, sometimes they come with a brick PS. Or a Cable provider - or maybe a satellite provider. DirecTV units typically have the power supply built right in. I have a few old units laying around. If I wanted I suppose I could salvage the supply out of one of those as well. The point is that there are plenty of power supplies around. Buying something from China means taking a risk that it isn't really what it says it is. I've heard a few horror stories where someone bought something that was - oh, lets say 5 amps - and it couldn't go past 3 amps. Going with a cable provider or satellite provider means you're more likely to get something that is as advertised. Meaning if it says 5 amps then it probably is.

 

Buying something from China means taking a risk that it isn't really what it says it is. I've heard a few horror stories where someone bought something......

My city's electricity utility company distributed many compact fluorescent light bulbs for free to promote their high efficiency. These light bulbs were Chinese. Some of them dripped flaming plastic so they were all recalled and replaced.
They found out that the Chinese manufacturer stole the certification number from a competitor so these light bulbs were never certified to be safe. But I betcha they were cheeeep.

 

See my attachment

Point number 5 in your correction: "The bass boost control is not supposed to be less than 10k"

Is this to suggest I add a 10K resistor in series with the 10K pot?

 

Point number 5 in your correction: "The bass boost control is not supposed to be less than 10k"

Is this to suggest I add a 10K resistor in series with the 10K pot?

The 6dB is such a small amount that you do not need a bass boost control. Replace the 10k pot with a 10k resistor in series with an on-off bass boost switch. Since the bass boost simply reduces the max amount of treble then I think you will leave the bass boost turned off.

 

Thank you!

 

Thanks to everyone who offered advice. Everything went pretty well. Here it is in action, amplifying a really dirty breadboard circuit signal.

https://twitter.com/i/web/status/1223802644122218507

 

A solderless breadboard is a mess of wires all over the place. Each wire is an intermittent connection and an antenna that picks up all kinds of interference.
Your digital squarewaves sound like buzzers. A sinewave makes a smooth tone.

 

LM7809- Refer to the datasheet for specifics. I'll explain some things below the images:



and where to place your capacitors:



First, you need to understand that all datasheets are written by a vendor to make their product look better than other products. As such, their values shown are rarely what is actually possible. In any given data sheet, check the _TEST_ parameters closely as these are the true indicator of what the vendor recommends the component be run at. Maximums are just simply maximum- usually non-simultaneous. Notice that in the test condition, the Io is 500mA... in truth, if you do your thermal calculations, whether or not a heatsink is used, etc, you will be able to find your maximum current to operate the regulator at a given voltage and current, while at the same time keeping it within an acceptable temp range in relation to ambient air.

As shown above, dropout voltage is 2V- So yes, 11V (or more) to get 9V out. So having a 12V wallwart is ideal.

Decoupling capacitors serve several purpose not initially obvious to the novice:

Because the circuit is digital, it's current demands are sometimes faster than what the power-supply can supply- a capacitor fills this niche by filling up and then unloading excess current into a DC environment on demand, keeping your switching energies satisfied in the quantity of energy domain. By the same mechanism, this offers a 'smoothing' effect to ripple to elevate and keep the ripple at a higher level than it might otherwise have.

 

A solderless breadboard is a mess of wires all over the place. Each wire is an intermittent connection and an antenna that picks up all kinds of interference.
Your digital squarewaves sound like buzzers. A sinewave makes a smooth tone.

Thank you. I have only started soldering circuits in the past couple months. Before that I had only experimented with solderless breadboards and so have become familiar with their limitations. I still find it helpful to build solderless breadboard versions of a circuit before trying to solder a more permanent one. Useful as a practice run and a guide while soldering.

And, sometimes, buzzing sounds cool! And I did say it was amplifying a "dirty" breadboard circuit.

 

@BobaMosfet Thank you for your detailed explanation, I appreciate it.

As shown above, dropout voltage is 2V- So yes, 11V (or more) to get 9V out. So having a 12V wallwart is ideal.

Indeed, it was. I am using a 12 V AC to DC adaptor, max current 1.5 amps. My LM7809 seems to like it very well - it's not even getting warm to the touch when operating.

Decoupling capacitors serve several purpose not initially obvious to the novice:

Because the circuit is digital, it's current demands are sometimes faster than what the power-supply can supply

Reading this was a lovely little "a-ha!" moment for me. Most of my circuits experiments have involved capacitors so I am familiar with using them, and generally where they are needed... But I don't think I knew the real reason of why before. Thanks again!

 

A 3-terminal voltage regulator such as LM78xx is an analog servo-feedback control system.

The input side is the raw DC voltage coming in. Smoothing in the input is not critical. Generally, a bulk reservoir capacitor, 10-100μF will work well at low current loads.

The output side is more critical. If the output voltage falls the analog circuit attempts to pump more current into the output in order to supply the desired load at the desired voltage. There is feedback delay in every closed loop control system. If this delay is too short the system will oscillate. If the delay is too long, there is poor regulation and the system oscillates. This is the reason the manufacturer specifies a specific output capacitor such as 0.1μF. Use the capacitor value recommended by the manufacturer. They know a lot more about the performance of their device than we do.

And one more thing. The output capacitor goes between the output pin and ground at the regulator, not at the load (that is a different story).

 

@MrChips Thank you for your detailed explanation! It was easily understandable for me.

I did use both the input and output capacitors recommended by the manufacturer at their respective pins at the regulator. I did end up putting a 100uf capacitor before the voltage regulator that probably isn't necessary, but based on some of the other tips I got here isn't going to hurt anything.


I learned a lot making this and I'm excited to build some more noise making circuits to run through it.

 

@MrChips Thank you for your detailed explanation! It was easily understandable for me.

I did use both the input and output capacitors recommended by the manufacturer at their respective pins at the regulator. I did end up putting a 100uf capacitor before the voltage regulator that probably isn't necessary, but based on some of the other tips I got here isn't going to hurt anything.


I learned a lot making this and I'm excited to build some more noise making circuits to run through it.

More power to you. If you haven't, I suggest you get a copy of this book- it will help you understand a great deal about electronics in a structured way. It may seem basic in some respects (or maybe not, depending on your knowledge level) but it's worth the read--

Title: Understanding Basic Electronics, 1st Ed.
Publisher: The American Radio Relay League
ISBN: 0-87259-398-3

 

@BobaMosfet Cheers! I did take note of this title when you suggested it in another thread. Looking at the Chapter Index the first few chapters will be review before quickly moving to new territory for me. Thank you for the recommendation, I will look into buying a copy soon.