PyleHome Audio Power Amplifier System with Bluetooth - 2X120W Mini Dual Channel Mixer Sound Stereo Receiver Box w/ RCA, AUX, Mic Input, For Amplified Speakers, PA, Theater, Studio Use - PTA4

I'm using this amplifier primarily for a cassette deck connected to powered speakers, as the speakers couldn't get very loud with the RCA cable straight from the deck. Bought one of these as open box for $30 and it has been the perfect boost to the sound that I needed.Unlike the newer model of it, this unit has volume dB meters, and there are several inputs for flexibility and potentially connecting multiple devices. Three RCA inputs, an RCA output labeled Recording, one 3.5mm aux input, a 1/4" microphone input, and finally, a 1/4" headphones output. I'm using that last option to connect to my powered speakers with an adapter to 3.5mm. I have Bluetooth capability with my powered speakers, and that already played quite loudly, so I haven't tested Bluetooth functionality on the amplifier.Newer models seem to reduce the number of corded input options and took away the volume meters, so that's why I stuck with this older model. One downside to this model is it does not come with remote, something I was aware of, but I'm happy using the tactile knob. What I do find strange is the knobs have a tactile middle-position where you'd assume they should be pointing straight up, but they're actually tilted a bit when they fall into that middle-position notch.My only grievance is now with my cassette deck as the meters on it read higher, or even max out during playback using the amplifier. I found this odd since my setup is deck -> amplifier -> speakers, and I didn't expect the deck would be affected. The deck doesn't have an output adjustment, but it's only for recording that I need to care about the levels on the deck, and I do have an adjustment knob for input recording level.Making up for the deck meters now being too sensitive, the PTA4 amplifier has its own volume meters, and those seem to work well during playback, though the amplifier's volume control has to be balanced with the volume control on the powered speakers to get the right dB readings. If you set a low volume on the speakers, you can crank up the amplifier volume dial and max out the amp's meters with ease. With the speakers set to a very high volume, you can also keep the amplifier volume very low to the point where the meters won't light up.Without powered speakers, I assume you'd need a deck with output level control to be able to "calibrate" the amp's level meter to match the deck, if the accuracy of these meters is important to you. I haven't yet tested non-powered-speakers to see how high or low those meters register when connected through speaker wire. If you're using a device where you can set the volume at the source, such as powered speakers or a mobile phone, then don't even worry about that.

This is a great little stereo amplifier with 3 RCA inputs for Aux 1, Aux2 and CD. There's also a high impedance microphone input (1/4" jack) and a spare Aux input (1/8" jack) on the front panel. The front panel controls are Input Select, Balance, Treble, Bass, Master Volume and a mic input level volume. Outputs are L & R speaker terminals, Record out (flat) and Phones. There are switches for Mixing the mic with main program material, a Pager setting for the mic, a On/Off power switch and a voltage selector (110/240). It's very well built, solid and looks high quality. Listening tests on quality speakers (JR149s) plus passive sub woofer sounds to me exactly as good as my normal home HiFi on different types of program material. It's subjective but honestly, I couldn't tell the difference so sounds great.Now for some technical stuff. As I have a digital scope & a sig generator I measured the frequency response into a resistive load (8 ohms) and it was as advertised (in linear region ie: no distortion). I ran a 1KHz square wave at several different levels (short of clipping) and the unit showed no signs of ringing or instability which is very good. Then for the not so good..... The unit is advertised as being able to source 2 x 120 watts into a 4 ohm load. My measurements showed using a 200Hz and 1KHz sine wave that just below the onset of clipping it would provide 18.4v peak into 8 ohms and 15.2v peak into 4 ohms which translates into 21 watts RMS into 8 ohms and 29 watts RMS into 4 ohms per channel. So in reality my unit provides 2x30 RMS watts into 4 ohm and NOT the 2x120 watts as advertised.Some manufacturers provide misleading power info by advertising PEAK instantaneous output power without stating that it's not true RMS power which is the only power that counts. Peak power divided by 4 equates to RMS power. You can't really say it's dishonest advertising so buyer beware!!So in summary, this is a superb high quality and versatile home stereo amp at an incredible price. Mine provides 21 watts RMS per channel into 8 ohms (which most home speakers are) and should provide years of listening pleasure at reasonable volumes.