Crystal Radio Earphone, High Impedance, 3.5mm

I use this earphone with a crystal radio and also a dual triode 12AT7 vacuum tube regenerative receiver. Both applications require a high impedance earphone or headphone to work properly. This earphone has quality construction and a low price.

The earphones I received work exactly as expected. I was able to complete a radio project with them illustrated at http://www.netzener.net/index.php/8-project-articles/5-3-transistor-short-wave-radio. Whatever product quality issue existed in the past resulting in poor reviews must have been fixed. I ordered two just to be safe and both of mine worked extremely well and have continued to work even with me banging them around. The 1/8" headphone jack is perfect for the project I build. If you have small ear canals, the size of the earphone will be uncomfortable. But you don't really need to jam them in your ear like the typical in-ear dynamic earphone. In my experience they are loud enough to be heard with just a very loose fit.

Got 2 of these and both worked well. Very happy not to have to smack them as is common with these kind of devices. Remember to test them by making some static against something and tap the leads against it, if it clicks they are working and you need to check your connected items for proper function.

Came on time, They represent a good value. I feel they do not have quite the gain or clarity as another earphone I already had, but for this price it is still very compelling This use is for cub scout crystal radios, so it is not quite so exacting.

I ordered 11 of these and when they arrived, I tested all of them with a crystal radio. Two of the eleven were dead. The other nine worked well. Sources on the Internet confirm what I found. It appears that the problem is in the wire connection to the foil diaphragm. I dismantled one of the defective ones and found infinite resistance between the wire and the diaphragm, confirming that the problem is in the wire connection to the diaphragm. If you really need one of these, it is probably better to order two unless you have free shipping. At this point I cannot offer any information on longevity of these units.UPDATE: ordered an additional 20. When they arrived, testing revealed 4 dead. One of the 9 in the original order has now stopped working after just a few minutes of use. You may be better off trying to make your own with a piezo device. I have ordered Mallory Sonalert PT-4175WQ and when it arrives I will make a high impedance earphone from it. Will report back later on comparison. It appears that this is the only commercial source of crystal earphones so if you are not willing to make your own, then this is it.Alternative to this product: just received an order of Mallory Sonalert piezo devices, part number PT-4175WQ from Mouser Electronics (Mouser number 539-PT4175WQ) for $2.08 each plus shipping (I ordered 11). The two wires of the piezo device are soldered to the diaphragm and ceramic disc so they should last a long time, unlike the glued connection used to attach the wire to diaphragm for the Crystal Radio Earphone. I connected the piezo device to my crystal radio and found that I could easily hear the strongest AM station in my area. In fact, to my ear, it seems a little higher in sound volume than the Crystal Radio Earphone. I would suggest this as a superior alternative to the Crystal Radio Earphone offered by AmplifiedParts.

I ordered two of these just in case they were poor in quality. There isn't much to say other than the fact that they don't suck I guess.

Don't buy.I bought 4 of these, but didn't start using them for several months after the purchase (that is, until I needed to replace the one I was using). Two worked for about 10 minutes. Ended up throwing them all away.The phone plugs don't appear to be standard size. They don't seem to make a good contact in the jack. The ear pieces are REALLY BIG, and are uncomfortable in the ear.

I ordered this along with a variable capacitor. Both arrived in just 2 days! Extraordinarily fast shipping, great quality (items are NEW). Great earpiece for DIY crystal sets, shortwave radios, etc. They'll (Amplified Parts) definitely see more orders from me in the future.