Let me say, first of all, that I was extremely pleased to be asked to write a formal review of this charming VST plugin effect. Of the many plugins I have encountered in my visits to the KVR website, the SoftAmp 3OD clearly rates as one of the best. More officially described as a vacuum triode stage simulator, I believe more VST users would know it in its common name as a "preamp tube sim." And although adding analogue-styled sounds of tube and tape warmth and saturation to our digital recordings these days is in vogue and all the rage, a device of this type is probably more in demand primarily by players of instruments, the guitar being first and foremost, followed by keyboardists and drummers. The need is for some degree of overdrive and tube warmth, which is most often added up front in the signal chain to colour the sound of the instrument or further signal amplification that follows. In this role the SoftAmp 3OD is superb. As one of the many guitarists who record using today's digital audio workstations, I am constantly on the hunt for the better overdrive device, and over the years I have tested and used almost all of them with varying degrees of success. I can honestly state that this one has quickly become one of my favourites. The main reason for this is that it truly does sound more like the real preamp tubes used in the preamp stage of practically every guitar amplifier ever made, but more on this shortly. This year's designers' contest, the Developers Challenge 2012 had the most offerings of any year so far I believe, some 55 in total, and there were several new ones that were simply irresistible, including several new synthesizers, a bundle of new presets for popular softsynths, and effects devices, this one included. I eagerly downloaded my selected half dozen and put them through my standard tests. It is all too common for some in each D.C. contest to come with an assortment of bugs both large and small. The SoftAmp 3OD was no exception, featuring an annoying clicking sound when changing some of its settings and also displaying a bit of odd behavior in two of my host programmes. I commented about the discovered bugs, was quickly located and contacted by AXP, its creator, and this is how my involvement with the plugin began. A few fast releases later and I'm happy to report that all issues have been corrected, based on my further testing of the device. Since then also I have had more time to really listen to the plugin, as I've been going through the many possible sounds and settings offered by adjusting its rather simple controls. Those of you with some knowledge of preamp tubes will quickly recognize the three 'tubes' used as the most common to tube amps, each capable of a different output level, the 12AX7 being the highest and most-used in the V1 socket of amps. What's nice about SoftAmp 3OD is that it also offers simulation of three different plate voltages to 'feed' the chosen tube, as well as a choice of three different capacitors. These features alone would be more than enough for a tube sim saturator or overdrive, but AXP goes on to include a 16X oversampling (can come in handy for more extreme, higher gain settings), a normalisation control, and a graph on the far right. So, what about the sound of this plugin? Well, having a fair amount of experience using the real thing -- tubes in many classic designs of tube guitar amps -- I can tell you that this unit sounds practically identical to the preamp of an amp for each grade of tube it includes and from lower levels all the way up to the woollier highest gain settings. Especially on the higher gain settings, this device can benefit from some EQ in the signal chain and following immediately after it. Try to imagine it for what it is or sounds like -- the preamp stage of a very good tube amp but without a tone stack with treble, bass and middle controls included. Note that on the lower, more subtle gain settings, much more like what would be used merely to create analogue warmth on a track, adding EQ may be unnecessary. I already have a folder of VSTs that are designed specifically for saturation. My purpose in using the SoftAmp 3OD is to add one more stage of overdrive gain before sending the signal into a full-blown modern amp sim. Even though the guitar amp sim I use these days is one of the very best, if not the best indeed, it's a common problem we guitarists often encounter: In our efforts to produce the massively overdriven modern electric guitar sound, including particularly those players in the heavy metal camp, we find that most of today's amp sims need one more good and solid stage of gain to push the amp 'over the top.' Here is where the 3OD really shines. All the way from just a touch of extra overdrive on up to my previous description, this plugin does perhaps the finest job of it that I have yet heard or experienced. This is the kind of plugin I believe most guitarists -- and probably many keyboardists and synth players, too -- will call a real 'keeper.' It is that good. In fact, since this VST was perfected in its latest 1.0.4 release, I have removed a couple of the better clones of the famous 'green' overdrive and deleted them. I'll be using the 3OD instead for my professional work. This SoftAmp 3OD probably deserves a full 10 rating; however, I reserve that grade for VST/VSTi creations that are sure to last for a century or more as forever freeware classics, such as Ichiro Toda's Synth1, Fuzzpile's Oatmeal and Magnus at smartelectronix with the Ambience reverb. The SoftAmp 3OD easily attains to a 9.
Can you provide a more detailed description? Does it happen when Cubase scans the VST plugins on start, or when you do it manually from the Devices->Plugin Information menu? What do you do to make it reappear?
Really sexy sound, the only downside is the delay because I have to route a signal through two channels if I want to mix the dry signal into the wet signal because adjusting the dry/wet knob in the mixer in my DAW just gives me phasing from the delay.
I still route it through two channels though it's totally worth it on my drums to make the kick into this earthquake fart sound.
That's a really interesting one. There are two places where the delay could be introduced. One is the cathode capacitor, but that's inherent to the modeled circuit and shouldn't cause any problems (try the 22uF setting just in case). The other one is the oversampling. It will introduce 8 sample delay. You can try to turn off oversampling and see if it helps (button in the upper part of the UI). Unless you drive the tube very hard you can get away without oversampling.
I will check if there are no other glitches with delays and get back to you shortly.
Now it comes to my mind that a delay-compensated dry/wet mix know could be handy.
Ok, I think I've got something. The nastiest phase interaction comes from the fact that it's an _inverting_ triode stage. I've kept it as is in the model but nothing is keeping me from changing it to non-inverting.
Cathode cap indeed introduces some phase shifting and will attenuate some frequencies when output is mixed with dry signal.
Oversampling severely affects the phase, so dry/wet mixing is not possible with oversampling in the current implementation. After DC-12 is finished I will add mix control in the future version that will be phase-corrected. As a positive side effect it will make the transfer function plot in oversampled mode a bit more meaningful as well.
I'm going to fix the invertion and release an updated version soon.