Jetcity RV3B12 3-Pack Analog Vacuum Tube By Roberts Retrovalve - Blue

The vendor timely delivered the product.I've had a a chance to experiment with these Retrovalves in three different guitar amplifiers. I've also been able to move them around into different pre-amp positions. They sound better in some applications than in others. They typically do not challenge the best 12AX7s or 5751s for tone in V1 stages, but they are fine down the line in a pre-amp with cascading gain stages. Some amps take well to them as phase inverters. You just have to experiment and see what they do best for your amp.It is an interesting product that has its place, but I'm not going to use them in my primary tone generating stages over a GE, RCA or some other premium 12AX7 or 5751.

UPDATED5stars!!! Brilliant idea, so glad they made them, essential to my gear now. They add a great little gain boost that sounds very analog when mixed with real triodes, and they never die. Just wonderful.4 because the it will take years to see how they hold up. But really great so far. It seems odd diodes for triodes, but it really helps add gain in a very analog way. The blues and yellows work as advertised as well. BIG RECOMEND

I think these are really important devices for tube amps.I was mostly excited to use these in V1 preamp positions for driving power tubes into saturation. This way you know your preamp wont be microphonic or unreliable. I really like the way it sounds in V1 of my tube amp.A side effect I did not expect was an opening up of tone. Normally my amp seems very mid heavy. I've never been able to dial in much of a scooped mids tone to emulate Fenders. With this, I'm able to do it! Placebo effect? perhaps....another great application is for touring. These would be reliable during the course of a tour. No more tracking down amp techs in unfamiliar towns.I think these could also be good in phase inverter positions, tube buffered effects loops, reverb, trem.I love tubes and hope they can continue to be manufactured forever. by reducing bound to fail components like preamp tubes, we make our amp more reliable and easier to troubleshoot. Middle road FTW!

These products work as advertised. I used all three in my AC30CC2's preamp section (which has 3x 12AX7s), and the results were fantastic. I recorded an A/B comparison with 12AX7s and then the RetroValves (Blue), and I must have spent a half hour going back and forth between the tracks trying to convince myself I could hear a difference, but it was so very subtle I honestly could not tell. I previously had Tung-Sol 12AX7s in my amp, which are by no means "bottom shelf", and so dollar-for-dollar, I say these RetroValves are a real winner.If you take a look at the picture, you can tell that the Blue RetroValves did in fact have a "cooling" effect. There is (to my estimation) a good -6 dB signal reduction based on the charts, and so what this has done for my AC30 has made my channel volume knobs more linear than exponential (by this I mean, 12AX7s have a tendency to go from "zero to sixty" without so much wiggle room in between). This is a good thing for AC30's, which run hot as they are, because the RetroValves have made my control knobs less jumpy and dramatic and a lot smoother instead... which has made it easier to find "sweet spots". So, the Blue RetroValves to my estimation is closer to a 12AT7.This would have been a 5-star review with a couple exceptions: 1) I haven't had the RetroValves long enough to really say anything to their endurance (although the product itself seemed very well constructed), and 2) they DID NOT WORK in my Behringer VT999 Vintage Tube Monster pedal. I'm guessing it has something to do with the operating voltage requirements for the pedal, but I was hoping to also be able to use the RetroValve in one other capacity.

Replaced the first three tubes in my Triple Rectifier with these. I thought my amp sounded killer before, these pushed it over the edge! I plan on getting 3 more to put in my Randall V2 when I get it back from the tech. They sounds way better than even my NOS RFT, Sylvania and GE tubes.

Great way to hot rod your tube amp.

I have 3 of the amber or standard gain tubes. I have a Carvin Belair amp that I use them in. (immaterial I know) I had issues with some slight microphonic, ghosting, feedback whatever you want to call the resonant sound that most tube combo amps (I've had several do this) produce when certain chords or notes are played. It is a minor to major annoyance, depending on your volume and environment. I bought these elsewhere cheaper. I experimented with position, V1 or V2 depending on your preamp setup. As soon as I installed these the extraneous noises disappeared completely. You have no idea how happy a guy/gal is to play through a tube amp that is almost dead quiet with no other noises produced than what you intend. If you play loud and high gain stuff, I don't think these will make much difference. If you play clean at moderate levels these are worth every nickel. They change your 12ax7 tube sound slightly but change them around with your clean/gain/inverter positions to find what YOU like the best. You will be pleasantly suprised at how these tighten up your gain sound and don't ruin your clean sound. Get the 'cocktail set' if you want to experiment. These will probably never die and are covered with a lifetime warranty (yea, right) but they are cool to the touch so that has to mean less heat load and stress on you power tubes and xformer. I say get 'em and experiment, you will not regret your purchase, especially when you factor in the longevity factor.