More gain = more transistors.

 

I bought these devices on Amazon. Does Mouser or Digikey have better prices than Amazon? Are there other companies you can suggest that have lower prices than Amazon?

The thing about buying components from Amazon is that you're probably not buying from an authorized reseller. You could get lucky and find someone selling genuine parts and not knowing what they were actually worth, or you could be buying from a disreputable source that doesn't know or care where the parts came from or whether they're authentic.

Amazon, eBay, AliExpress, and the like are full of disreputable sources. When I buy electronic components from any of them, I'm not surprised if I get counterfeit product.

I learned that Amazon is a source of counterfeit parts when I bought an ignition switch for my BMW. The part that I received had the BMW emblem on it, but it was the wrong switch. When I informed the seller, I was told that they could send me the correct part, but they had to scrape the BMW logo off because it wasn't an OEM part.

My first order from AliExpress was for some 64GB Micro SD cards. They looked enough like Sandisk that I assumed that it was a Chinese manufacturer for Sandisk that had decided to compete with their customer. It turns out they were hacked 8GB cards. It took me months to get my money back.

 

I use Seeed Studio.

Bob

 

Thank you. Can you suggest any companies that do a good job of making pcb boards in China?

Use oshpark, I despise China mfg.
It's not much more expensive, has free shipping (often makes up the difference in price), is always high quality enig finish. My only complaint is the boards are purple....

Digikey or mouser would be my recommendation for cheap parts. You know your getting the real deal, and to be honest they're usually cheapest.
I have bought some stuff from Tayda before, seems good, but it really isn't all that cheaper. Is clearly lower quality and shipping sucks. Both time and cost.

 

Possibly more gain from the amplifer. Other than that I am satisfied with the lm386 amplifier.

The datasheet for the LM386 shows that its simple gain is 20 times. It shows by adding a 10uF capacitor between pin 1 and pin 8 the gain is increased to 200 times.

 

I bought these devices on Amazon. Does Mouser or Digikey have better prices than Amazon? Are there other companies you can suggest that have lower prices than Amazon?

Prices are constantly in flux so you need to check several sources whenever you buy--

Digikey
Mouser
Arrow
Allied Electronics
Jameco

etc.

Just to name a few. There are hundreds of suppliers-- I source parts from nearly a hundred around the world including many on alibaba.

 

Thank you. Can you suggest any companies that do a good job of making pcb boards in China?

For price: AliExpress China, slow delivery (if at all, have lost several shipments)

For speed: Arrow, free overnight delivery on most parts and reasonable prices (cheaper than Amazon in most cases) Arrow probably hates me when I order onesies and twosies of caps, resistors, chips, xstors, etc. which is weekly or even daily. Seems like I always need a part not in my inventory.

Amazon is not too bad for finding parts, then shop around. Ebay, Ali, Arrow, etc. I don't use DigiKey, Mouser, Jameco, etc. very often anymore (or at all)

 

Rohm -

https://www.rohm.com/products/audio-video/audio-amplifiers


Regards, Dana.

 

I am looking for a npn or pnp transistor substitute for the Lm 386 amplifier chip which powers a 8 ohm 1/2 watt speaker.
The reason that I want to make this switch is for cost, easier to solder to pref board, and less time to assemble and solder.

The lm386 is a good amplifer, however I want to reproduce the amplifier circuit using transistors, preferbly less that 2 transistors.

Thanks

I love the simple transistor amplifier design by Rick Andersen. Low power but works.

https://web.archive.org/web/20180815215057/http://www.ke3ij.com/amp.htm

I replaced the 2N3904's with 2N4401's and the 2N3906's with 2N4403's. Sounded pretty good, actually. Not much power but all I needed was about quarter watt or so.

Here is a screen shot of the schematic:



As Rick says in his web page about this amp, you can lop off the first stage if you wish if the extra gain is not needed.

Rick's website used to be available at http://www.ke3ij.com. Now all that is there is a placeholder website. :-( You can still view Rick's archived website at https://archive.org.

 

ok thanks

Just to cover my bases, What other 8 pin amplifiers are equivalent to the LM386.
I am interested in persuing other options if possible for experimental purposes.

Try TDA7052. For a stereo audio amp IC, try TDA2822. The TDA2822, however, comes in a 16 pin package. Sorry.

 

Digikey or mouser would be my recommendation for cheap parts. You know your getting the real deal, and to be honest they're usually cheapest.

I've found Digikey to be on the high side for most things. For that reason, I haven't bought anything from them for decades. They do have a large selection...

I usually buy from Jameco, Newark, or Mouser. Jameco will price match down to their cost, but I've rarely been able to take advantage of that; they either already had the lowest price, or they didn't carry the part.

I'll make purchases of things I had been planning to buy, but had no immediate need for, when I get notification of some clearance sale, free shipping promotion, or a coupon (usually 20% off from Jameco).

 

Since money grows on trees that I can reach and my government pays me to be retired then I do not save a few pennies buying good electronic parts. I also do not buy obsolete junk from "over there".

 

Since money grows on trees that I can reach and my government pays me to be retired then I do not save a few pennies buying good electronic parts. I also do not buy obsolete junk from "over there".

Have to sympathize with you on trying to avoid cheap parts that don't work right or at all. On the other hand, I do occasionally buy cheap parts in bulk on ebay from sellers in Asia. Sometimes the price is too good to pass up, especially if I want to buy 20, 50, or 100 pieces to keep in my "parts bin" for later use. When I buy in smaller quantities, I use choose a well-known USA-based vendor, such as Mouser, Digi-Key, Jameco, Newark, et cetera, because the cost is not that much greater than buying internationally and waiting weeks for parts to arrive.

It's weird. Sometimes parts from the well-known electronics supply companies (Mouser, Digi-Key, and Newark) have prices similar to what is available in ebay. I find that obsolete parts that I can't get from the big electronics sellers are sometimes still available on ebay. Whether some parts I buy on ebay are counterfeit or not, that I don't know. If the part works and seems to meet the published specs in its datasheet, I just don't worry about it. I don't use electronic parts for mission-critical purposes, like repairing medical equipment or airplanes, so if a part works, that is all I need.

Everybody's needs are different.

Here is a strange problem. You know those handy trim pot adjusters, the ones that have the blade on one end that is surrounded by a plastic ring to keep it from slipping off the pot? The kind that have a clips on them so you can wear them in your breast pocket? I can't seem to find those cheaply anywhere, not even on ebay. There are the genuine Bourns kind that you can get at Mouser for about $1.39 each. I wanted to use these in a weekend hobby workshop class. So I need one for each student. With 10 students, that's $13.90 just for one tool. Now THAT seems like a perfect tool for a cheap knock-off for 10 cents each on ebay. You used to be able to get them as free, "take one", "logo" items from local electronics parts stores, when there were local electronics parts stores. I sense a business opportunity here. I need to pitch the idea to factory in China on "madeinchina.com".

 

trim pot adjusters, the ones that have the blade on one end that is surrounded by a plastic ring to keep it from slipping off the pot? The kind that have a clips on them so you can wear them in your breast pocket? I can't seem to find those cheaply anywhere, not even on ebay. There are the genuine Bourns kind that you can get at Mouser for about $1.39 each.

You can never have too many pot adjusters. I got a bunch from my Father-In-Law. He accumulated them while working as a technician. I collected a few when I was an R&D tech, but not that many. The Bourns ones on the right were from my existing stash:

 

Lately I found that TME.eu has much better prices than Mouser or Arrow, either for low quantities or larger for production.

My main provider now.

Regarding the amp circuit, I 'd prefer a chip even if it cost more than a discrete circuit. Time, effort and the possibility something not done right... Consider how many more soldering will be needed. Not for me anymore. Too old for that.

Ioannis

 

Use oshpark, I despise China mfg.
It's not much more expensive, has free shipping (often makes up the difference in price), is always high quality enig finish. My only complaint is the boards are purple....
I will 2nd that. OSHpark is a reliable, fast and low cost maker of custom PC boards. There are several free or low cost design programs available on the web but the downside is it takes time to learn them.

 

When Texas Instruments bought National Semi a few years ago then their quantity of audio amplifier ICs increased a lot. Have a look at them all.

 

Lately I found that TME.eu has much better prices
Ioannis

I like the prices, but the 10USD shipping kills the deal for me. Unless it's a large order. Thanks for the heads up and I will bookmark it.

 

I am looking for a npn or pnp transistor substitute for the Lm 386 amplifier chip which powers a 8 ohm 1/2 watt speaker.
The reason that I want to make this switch is for cost, easier to solder to pref board, and less time to assemble and solder.

The lm386 is a good amplifer, however I want to reproduce the amplifier circuit using transistors, preferbly less that 2 transistors.

Thanks

Try 2N2491, 2N441, ECG105, ELM105, 2N3315, 2N2081, HEP231