I had to send the first one back as my first impression was awe, very clever, high quality and well constructed. But upon hook up, was not too impressed by the total performance. Most EQ's offer 6db's (+ or-) per spectrum. On the the 60hz knob, I cannot tell a difference, the 120hz is when it starts to work; I'm guessing + or - 3db is all it does from 120hz to 6khz, has no effect on the 16khz knob. when I got the replacement, it was only slightly better. no patch cords included. I need more of a performance. Very well built, has a balance control (?) but not a level control which is greatly missed. Has the AC adaptor. This EQ comes up lacking. Behringer's is WAY better.

The bypass does not work. 1/3 volume of hazy music is heard when the bypass is pressed. But, the equalizer is very effective on re-toning the sound & this is what I bought this for. Additionally, it's well built; the knobs turn nice and smoothly. The balance control works well too. All in all, this is really a bargain to add to your system & overall it does not disappoint. Plus it's fun to use.

Yo me considero muy especial en la calidad de sonido ( a nivel de audiofilo sin exagerar) y me es grato comentar que el funcionamiento de este equalizador es muy bueno, lo conecté a mi sistema entre mi DAC wiim, y mi amplificador Cambridge ( 100 w por canal reales) al cual esta conectadas unas torres polk audio ES55; sonando también un subwoofer Athena de 10 pulgadas y 150 w reales, en especial yo buscaba un poco mas de presencia de bajo en determinados géneros de música y mas presencia de medios y voces en otros géneros y me funcionó muy bien. los botones no vienen iluminados, las perillas son un poco duras, solo ilumina un led en rojo cuando se enciende el equalizador. El sonido es limpio, sin afectaciones de ruidos ni adicionales en estáticas; cabe destacar que todo mi sistema esta conectado con cablería especial, blindada y de 100% cobre ( tal cual buscando calidad de sonido.).

Doesn't seem to add any measurable noise by ear at least. It does have some good control and works well, has a nice metal case. The potentiometers and the orientation of the knobs are kind of weird where the center detents line up. Had to pull a few knobs to try and line up the center line but a few are still off the line no matter where you put the knob. But overall it seems like some decent quality for the low price. The 2 different sets of pass-throughs are nice as I can use one channel for the dac and another for the switch box that all my analog stuff comes through. Definitely adds to my budget system.

This is a very good equalizer. Be careful of a HUGE user error that I made! I did not realize that the knob on the far right was a balance control, and since I had it turned to the right, one of the stereo channels was not working (or so it seemed). I had shut off the left channel without realizing it. Stupid me.The amount of band separation is great, allowing me to fine tune the audio. I use this to clean up the audio from my Android device via a Bluetooth receiver. The receiver goes into the EQ, and then into my stereo amp. Great way to get rid of the "flat" sound that is delivered from the various streaming services. I now get better bass and treble, and can tone down the mid-range.One drawback of this type of device is that by having knobs for each frequency band, you cannot see exactly how you have each range adjusted, which you can do with sliders. However, the only EQ devices with sliders that I found were mostly "rack" systems (who does this anymore?) So, if you want to tweak different audio types or music sources, you will need to look closely at the mark on each knob to see your +/- db adjustment level. Again, for the price of this device, that is acceptable. It does really improve the quality of digital music sources that have been "dumbed down" or flat.I would HIGHLY recommend this to anyone who is looking to improve the sound from their devices. You can feed audio out from an Echo device, either using a mini-plug to an RCA adaptor cord, or through any inexpensive Bluetooth receiver that you can find on Amazon. If you have an external amplifier to drive your speakers, you will be a much happier music listener.

Good things come to those who wait. After a long journey from China the equalizer finally made it home. The equalizer does make tangible changes in the sound of the amplifier it is hooked to , which is a Yamaha rs202. Not putting the rs202 down, but " barefooted" , which simply means with no equalizer, the rs202, at least my particular one, lacked in the middle to upper frequencies. I knew bass was adequate as is in my case, so only the last 3 nobs are above flat. I already knew I didn't need lower frequency increase.It is obvious the equalizer is a preamp. It uses that preamp to effect changes in the amplifier input. All nobs do increase or decrease tonal quality, and I wanted them to be capable of doing so. As previously stated, only the upper frequency ,last 3 nobs are above flat.I have found what I call " Cyberspace ", or " virtual equalizers in android phones and mp3 apps " weird out " and are inferior to an actual, material equalizer, and that even on a flagship samsung. I have never experienced a " Cyberspace " or " virtual equalizer that actually allows " normal " equalizer tone , frequency response adjustments unless they " like " the equalizer adjustments. If " Cyberspace " and " virtual equalizers don't " like " where someone sets them they are weird out and are more than basically worthless. They are worthless unless they are set to very limited overall settings that the Cyberspace and virtual equalizers like to be set.This tangible, material equalizer made of matter is not like that. It will do what the user wants without weirding out. In other words it is my experience that a material, tangible equalizer is superior to phone and specifically android equalizers in Cyberspace and virtual equalizers that don't exist in the world of matter. In order to effect change by phone streaming requires " hardwiring " by a usb to rca plugs adapter. It will not eq phone streaming by Bluetooth because it's not in the line inputs and outputs to do so. Usb c to rca male patch cords are inexpensive and abundantly available. They work.Concerning this particular equalizer, not only do I not regret this product and purchase, but I am glad I did it.Shipping speed is slow because the product was not in a warehouse in the United States. It shipped individually from China.I finally got it. It has been welcomed home, and initially is functioning correctly.The rs202 Yamaha is not a high end 2 channel amplifier, so it needed an equalizer/ preamp to help it output a sound with more " presence " and treble.This equalizer has caused it to do that.It was worth the wait of getting it from an origin Shipping source in China instead of the United States. It took longer to get it than usual, but it was worth the wait.As previously stated, there is no hum , or any other sound negatives about it. If it adds distortion, it is less than detectable by my good ears. I have good hearing and I don't hear any distortion at all because of the equalizer. What I hear is better presence and treble, which is what I needed. This product is good, and Irecommended It based on my particular experience so far. I just got it today. 5 stars.