OSD Audio SMC21 Stereo to Mono Converter – Gold-Plated RCA Connections and 1:1 Ratio Audio Transformer

I have a single Adam studio speaker which I needed to use as mono. I read Y connector I was using was a risk to damaging the speaker. This small device provides pure mono output and provides a clear feed to the speaker. The Y connector was dull compared to it. In sum, an inexpensive solution to receiving pure mono. Highly recommended,

I was looking for this exact thing when I found it. I did not "know" such a thing existed, but, logic suggested it should. It is the perfect solution for summing 2-channel/stereo line level outputs to a single channel/mono signal. It is superior and more electrically correct than using a Y cable which could cause damage to outputs. It also is better than the software mono you can create from modern DAWs, IMO.

Used this to combine a stereo RCA signal from a receiver elsewhere in the house to mono for ceiling speakers in my basement and garage. Works well and didn’t introduce any noise.

I purchased this because of the description - it says 1:1 ratio Audio transformer as a stereo to mono converter. It also says it is a ground loop isolator. Well, it didnt isolate ground loops. I called the product manager at OSD and he confirmed that it did not isolate ground loops, but it was a 1:1 transformer. So I initiated a return, but then decided to take it apart, thinking that to isolate ground, all one needed to do was cut the ground from the output transformer winding. The problem is that there is a rivet that prevents one from opening the case up. So I broke the rivet, thinking that if I broke the ground, then it would do what I wanted and I would keep it. Well, surprise, there is NO transformer. All there is are 2 resistors to combine the left and right channels together. When a company misrepresents (lies) about their product on their web site (not amazon's) and makes it hard for one to find out the truth, they are not to be trusted. I would strongly recommend not buying any product from OSD. I am really upset, especially since I cannot return the item and their own product support misinformed me.

Nothing fancy about this device. Looks and operates exactly as it should. As another reviewer noticed: it does not use a transformer to achieve the result, but it works great. Recommended.