I received my Krivo Electromagnetic Pickup a few days ago. It was recommended in an amplification thread here on Talkbass. The electromagnetic pickup allows you to be loud, without feedback, when you need to be "stupid loud". I have a recurring gig where I have to broadcast across a very large retention pond, and my piezo system wasn't cutting it (more on that later, I have a High Pass Filter coming, which is supposed to help reduce feedback and facilitate high volume. this may render the electro magnetic pickup irrelevent, let's see). So, here is my review of the Krivo Electromagnetic pickup. I got it used off eBay. It is also available from Krivo Humbucking Magnetic Upright Bass Pickup (new smaller model, includes free Jack Mount) at Gollihur Music - Double Bass, Upright Bass, String Bass Specialists Components It comes with an allen wrench for adjusting pole pieces, a piece of Velcro-like material for affixing the pickup to the end of the bridge, the pickup and its attached wire and 1/4" output jack, and a clip for attaching the output jack to the tailpiece of the bass. Installation. Installation is not really easy. You have to take the G string off, and then thread what appeared to be a plastic clip that comes with the Krivo, at the ball end of the string. Re-thread the string through the tailpiece, and the clip will flatten against the tailpiece. I had a piece of felt on the ball end of my instrument, so that went closest to the tailpiece. You slide the 1/4" output jack into the resulting, round clip after you install it on the G string and tune it to pitch. The output jack points downward, into which you put your 1/4" cable to your amp (not included). You can easily slide the output jack, a tubular thing, in and out of the clip for those times you want to remove the entire pickup system. Then you cut a piece of really industrial, strong velcro-like material into the shape of the end of the fingerboard, and stick it on the end of the fingerboard. Press it on really hard and then let it sit for a few hours. The pickup then adheres to the velcro-like material with its own, mated material. It is very strong, not like regular Velcro. My bass is a 1/4 size, so the pole pieces did not line up with the strings. I chose to make the E string pole piece line up exactly with the E string, as I heard from Gollihur Music that string would not amplify as well as the other strings (this they say, is only true for Hellicores). The pole pieces, therefore, were offset from the actual strings on the A, D, and G strings. But this did not seem to matter eventually... Amplification and Feedback. This was the hard part. As Gollihur says on their site, with Hellicore hybrid strings like I use, all the strings but the E string are very loud. The E-string, at first, with my volume on my Ampeg BA-110 combo amp on maximum, barely sounded amplified and lacked definition. I used the 0 Db input jack on the Ampeg BA-110 and it was still too quiet for my liking. I am sure it would have disappeared in the mix. At this point, I was disappointed I'd have to return the pickup. But after about 20 minutes of fiddling, I fixed the uneven volume between the strings by angling the treble side of the pickup far away from the G-string. This of course made the E-string end of the pickup very high, and close to the E string. I also raised the pole piece for the E string. This evened out the volume so it was consistent across the four strings. This did reduce the overall volume of the system, but not to the point it made the pickup useless -- it was still much louder than my unamplified bass. I am a bit concerned about this, but I think it's nothing that a more powerful amplifier (I have a couple) or PA can't fix. Gollihur indicates other strings (like Corelli's) don't have this problem with the Krivo. Note that you have to have strings with a metal core for this pickup to work. On a good note, there was no feedback whatsoever! Tailpiece Room I have a Pure preamp that goes wtih my K&K Double Twin piezo pickup that is stuck to my bridge. The preamp goes on the underside of the tailpiece, held on by two velcro straps -- one of which loops through the string slots in the tailpiece. Happily, the Krivo output jack clip and the Pure preamp did not conflict with each other in terms of position or space. I did make sure the Krivo output jack clip extends on the outside of the tailpiece to make room for the Pure preamp. Space issues for the two systems was not an issue at all, and did not interfere with the 2, 1/4 cables that go in and out of the Pure preamp in that area (not related to the Krivo). Tone The tone does sound a bit electric bassish, but not entirely. The G string was the most like an electric bass, but only because that particular string doesn't growl like my E, A, and D strings on this particular bass. The E, A, and D strings sounded reasonably close to the acoustic sound, but not as close as my K&K Double Twin piezo system does. But it still carried the significant growl that my action, technique, and setup provide from my instrument. I was actually happy with the sound given what I'd heard about the loss of upright bass tone you get with electromagnetic pickups. I had absolutely no feedback whatsoever with my volume on 11 (to quote Spinal Tap)! (Mission accomplished!). Suggested Improvements 1. With the Hellicore strings I use, and the uneven volume for the E string, I wish it was a divided pickup with some trim pots or little volume controls for each string. 2. I also wish it was easier to install the output jack clip at the tailpiece -- as someone new to upright bass, I was nervous about taking off the G-string, as I thought it might topple over the bridge, especially when I had to also loosen the D string and move it off the nut to get my G-string on and off properly. Fortunately nothing happened, but I thought a number of times what a hassle it was. I am glad I only have one upright bass and won't have to move the pickup and output jack clip between instruments. 3. I think a longer pole piece for the E string was in order. When I was fiddling with positioning the pole pieces, I had one position I thought would work, but it meant really adjusting the E string pole piece outwards. It fell out of the pickup because it was too short. So I had to angle the pickup low on the G-string to high on the E-string, as I said earlier, to get the E -string pole piece close enough to the E string for volume balance. 4. The pickup needs to come with a note telling you where to get the installation manual. I wasn't sure how to install the output jack clip until I did a search online and found the site, and its PDF file for installation. Here is the manual: http://krivopickups.com/wp-content/uploads/2016/02/Krivo-2016-Bass-manual-1.pdf Summary Overall, I give it a 4/5. Pros: Good tone, preserves most of the upright bass sound, loud, no feedback, looks handmade and rustic, which is cool on a raw instrument like the upright. Cons: Tough to install the output jack clip, and the low E volume is too low with Hellicore strings, and requires a lot of tweaking that reduces the volume of the whole system. But it can still make your instrument really loud. I will not be returning the pickup, as I now have another tool in my arsenal as I get more and more experience amplifying the upright on various gigs. This ranges from music festivals with hundreds and hundreds of people, to quiet networking gigs. This pickup gives me confidence that I can be ready for any situation that requires loudness, or even modest amplification, without feedback. This of course, is until I learn how to play loudly enough to go solely piezo with a High Pass Filter, which I understand is a technique thing which develops over time. In the short term, this pickup facilitates my goal of gigging as soon as possible for motivation reasons. Looking forward to my next "stupid loud" gig in three weeks!!!