10pcs EE-14 Audio Transformer High Efficiency Audio Isolation Transformers 1300 : 8 Ohm for Voltage Amplification and Power Output

Good components with close matching specs

I needed an isolation circuit that I could connect directly to speaker connections of a bookshelf stereo, without disconnecting said speakers, and attenuate speaker drive signal for the common ground line level input of a separate amp. These tiny audio transformers did the trick. I used the high impedance side of the transformers to parallel the existing speakers while the low impedance sides are supplying common ground, corrected phase line signals to a piggy back amp in a set of active speakers (see attached schematic). The transformers alone attenuate the speaker voltage about 6.2:1 with the 1k line out potentiometer allowing for fine line output attenuation adjustment. This arrangement puts almost no additional load on speaker outputs ie >3kohm impedance at 1kHz. I needed to use the transformers to isolate and phase correct the left and right speaker outputs from the existing dual-supply, push/pull amps to the common ground line input of piggy backed powered speaker system. This circuit also allows the one volume control on the main unit to control volume to piggy backed powered, active speakers as well. The 1kohm pots, once set, are adjusted to balance the additional speakers with original speakers to listeners taste; adjust for max 600mV RMS line level at max listening level. The frequency response of these transformers, tested with sig generator and scope, appears to be almost flat from about 150Hz to 20kHz at line level loads since the cores don't come anywhere near saturation. So if you have a bookshelf stereo, like I do, without a line out connection, try this simple little circuit to amp it up... This circuit, as presented here would be useful for systems of 25W/channel; ie about 15V RMS into 8 ohms... More powerful amps would require series resistors, of appropriate size, on the driven side of the transformers to prevent over-heating/over-loading them.

No cancelan el ruido

Great little transformer for home circuits

Four of the ten transformers have both coils open. Two of the transformers had one coil open. The remaining 600:600 ohm transformers have very poor frequency response. These are a total waste of time and money.

Poor Frequency Response.You will notice telephone quality audio.Suitable for the experimenter but not for high quality audio.Since no audio range is given I will provide one for you:At 100Hz it has a very low output.At 300Hz it comes alive and stays fairly at unity until 100KHz.It then rolls off sharply.No low end.It has a primary resistance of 2.7Ω and secondary of 97.3Ω.You figure out the turns ratio yourself.

I tested every single transformer I got, and they’re averaging out to about 105:5, which is nowhere close to the promised specifications. Save your money and give these a pass.

Word well on a electronic project I'm making a filter system for the oscilloscope, where as can put a signal in a radio and it will filter out all unwanted signal andharmonic.