After the release of the first Hot Mod V2 in 2019, our new tube plug-in device was an immediate hit, but we still wanted and appreciated the feedback we received from customers. Our work wasn’t done. In fact, it was through our customers’ collective feedback that led us to refine the circuit further with the introduction of our Hot Mod V2 Evo (a.k.a. The Evolution) we offer today. Knowing what musicians want from their tube amplifiers – whether it’s a particular type of tone or how an amp feels/responds – is invaluable. We are a small, but fiercely customer-focused company. With that said we were very surprised with ONE particular use-case request for our mods that we received time and time again. More on this in just a moment so we can first provide background context.

Initially our Hot Mod V2, just like the original Soldano Hot Mod offered in the late 1980s, was designed for medium-gain amplifier models like the Marshall (JMP and JCM 800) 2203 or 2204 Master Volume series. And this made perfect sense as our mods work similarly by adding an additional tube stage for more gain and tone-shaping characteristics to extend the entire range of the preamp control. Adding an extra tube is what many famous modders did in the ‘80s to produce and create what were the quintessential hot-rodded Marshall amplifiers of the day. Marshall Super Lead and Master Volume series amps were the most commonly modded platform and as such it made sense that they would also remain the ideal application for our Hot Mod V2.

Now back to the present: over time while offering the Hot Mod V2, we started to receive inquiries about the potential use of it with higher-gain amplifiers. Mesa amps, Friedman amps, Soldano amps, and more. Now of course we had NOT tested or validated these higher-gain applications for compatibility, nor had we honestly planned to.

My own personal thought, which I also shared with Dave Friedman of Friedman Amplification was, “Why would anyone NEED more gain using these mods with an already higher-gain amp?” And he and I both agreed on this point. But apparently there remained people who still wanted to use our mods for his and other high-gain amps.

The requests continued until one day I decided to explore it further and consider giving the customers what they wanted. I must first acknowledge Dave Friedman and thank him as he was very helpful sharing info about compatibility with his designs so we would know which versions of our mods would work within his amplifiers. We sent him a couple of early units as well so he would be intimately familiar with what we were doing.

Honestly, I still didn’t think much about it at the time as far as why people wanted to add the mods into their higher-gain amps. But I just figured it was just a niche thing and if it gave people the results they wanted, then by all means have at it. We’re customer-focused after all.

So we validated our mods with Friedman amps and as time passed, word spread and more customers came and bought units. I decided maybe I was missing something here. People were raving about these, so I needed to check this all out for myself.

I purchased a Friedman Runt 20, which was one of the more popular amps to use our mods with, plugged in and then after a few moments, I GOT it. Wow…I was in fact more excited about the mod in this new application than I had been with the Marshall Studio Series 20-watt heads. Using the mod, I was now able to dial BACK the preamp gain control instead of running it too high and the net result was that I was now achieving all the sustain I wanted, while still having extremely articulate note definition. And as a bonus and due in part to the use of DC heaters by Friedman, the amps stayed noticeably quiet even with the added gain.

When the mod was out of the amp and I turned up the preamp gain high on the stock Runt to compare, there was definitely a point where it went beyond its sweet spot and started to feel a bit less defined. And this is no surprise as the further that ANY preamp gain dial is turned up on an amp, the more it will tend to lose some of its definition and in worst case, feel flubby. A famous example of this is the Mesa Rectifier series of amps, where excessive preamp gain control use will certainly loosen the amp substantially.

So now by using our plug-in mod, the results were clear and it was a lightbulb moment. If we keep the preamp gain set lower on the amp for those corresponding early gain stages, the amp will remain very articulate. But then there won’t be enough sustain. So then we can fix that by adding back in that sustain using our mod which is inserted downstream in the amp circuit past those early gain stages. So that’s the idea – the amp gets improved note articulation and definition and sustain all in one package. All pure tube circuit integrated beautifully.

So just as our customers were raving about this application, I was also really enjoying the newfound feel and extra flexibility. And of course if I still wanted a traditional highly-compressed sound, I could still do that by turning up the preamp gain as before – but now I simply had more overall range and choice!

I wanted to sanity-check my thinking so I discussed the topic with our Hot Mod V2 co-designer Andy Marshall of THD Electronics. As he explained to me, his own preference was always to design his amps in such a way to where his choice of gain sent to each tube stage was a moderate amount, never wanting to excessively max out the available gain in each stage or over compress the signal. In fact, this is also the approach used by Mike Soldano with his famous Soldano SLO amp. Although Mike would deploy many more gain stages within his amplifiers compared to THD amps, making the SLO a much higher-gain amplifier, they both sought out a certain type of response that emphasized low noise, and a higher degree of note articulation.

All this led me to think that the Hot Mod V2 and what evolved into the Hot Mod V2 Evo and George Lynch custom Mr. Scary mod, are indeed more than “just adding more gain” devices. It’s about enabling a way to get the best of the hot-rodded type high gain sounds and sustain without becoming overly compressed or lose too much definition. It’s a way to expand an amp’s capabilities from what’s otherwise available in our beloved vacuum tube amps. And if you still want to add back in the compression, you’ve got plenty on tap by increasing the preamp gain control even further for those times you DO want “more gain.”

When thinking about my use of boost pedals on my classic Marshalls, even on a mid-gain amp like a JCM 800 2203/2204, running the gain control past about 7 never sounded that good to me. So I’d always run a boost pedal up front to push for more gain rather than turning up the gain to 10 and then boosting. And this is where a pedal like a Tube Screamer became the go-to norm, since it also boosts and “pushes” the front end for higher overall tube compression, while also taking away some low-end flub that would otherwise be excessive in the signal path. It’s a classic approach and has its own character and feel.

I certainly no longer scoff at the idea of using our mods in higher-gain amps as I did initially. In fact, we’ve recently validated our standard-wire mods to work with the famous two-channel Mesa Dual-and-Triple Rectifier amps. These are well known to become too loose when the gain controls are pushed too far clockwise. For my own use with the mod inserted, I was able to reduce my own Dual Rectifier’s preamp gain to 9 o’clock. The result? Perfect percussive high gain that sounded and felt fantastic – and very natural.

Similarly, I tried the mod in a Marshall JCM 2000 DSL 100 (check video below!) and achieved similar results. It’s really been nice to have the option to play with the new range of sweet spots in gain and positively impact an amp’s feel and dynamic control using our mods. Keep checking out our compatibility list as we will continue to work with manufacturers and designers to keep the list updated as we validate additional amplifiers.

At the end of the day, we’re thrilled that our customers have fueled these new applications for the mods. And as I always tell everyone who inquires, there is nothing wrong with using a pedal to boost! I do so myself and have quite a collection of stomp boxes. But with that said, there’s also something very special about getting the gain by using a pure-tube device that’s been integrated inside the amp. But no matter what you do and use, if it inspires you or your playing in some shape or form, that’s really what is most important and what it’s all about.

Have fun and enjoy the music!

David Szabados