An interview with – Sergio Hamernik of Mercury Magnetics

VG: Tell us a little about the background of Mercury Magnetics?

Sergio Hamernik: Although Mercury was founded in 1954 it was around 1980 that we fully recommitted ourselves to designing and building transformers specifically for tube-based electric guitar amplification.

Most of us know that by the late 1970s the audio electronics world was going solid-state. Although it now seems absurd, back then tube-based amplification was being abandoned. We were amongst a relatively small group of hold-outs. We were also acutely aware that if someone didn’t step in to preserve the technology that decades of know-how (not to mention the essence of tone) would be lost forever.

We put out the word about Mercury’s mission and immediately began to work directly with a select number of top players and amp designers who were like-minded.

VG: Who came knocking?

Sergio Hamernik: We were surprised that much of the early interest came from British artists. They had the resources and seemed to understand the transformer connection to great-sounding amps. But it didn’t take long for the word to spread. Soon artists from all over the world were bringing us transformers from their most prized amps to study and clone. The feedback from this period set the pace for Mercury and we haven’t strayed since.

Today Mercury’s friends and customers include pretty much the entire upper echelon of professional players and recording studios. In the builder community our friends range from the legendary Alexander Dumble and Ken Fischer, to passionate enthusiasts building amps on their kitchen tables. I’ve always been amazed at the caliber of talent we’ve attracted and the level of interest in our goals.

VG: How did Mercury determine which transformer designs had superior tone? 

Sergio Hamernik: Think of what we’re doing as transformer archeology — not unlike opening ancient scrolls for the first time. Over the years we’ve unearthed some real sonic treasures!

Artists and amp collectors continue to bring us transformers from their most coveted amps to analyze, restore, duplicate or upgrade. They’re hard-won converts because they’ve all tried other replacements only to discover that the magic was gone.

By tradition, transformers have always been hap-hazard and inconsistent in design and build quality. Many of these amps were the freaks, factory prototypes, or often with one-of-a-kind transformers that just blew everything else away.

These are the transformers we have always been most interested in studying. Unfortunately, when it came to analysis, we discovered that the conventional methods only gave us a piece of the puzzle. Mercury had to devise its own proprietary methods of determining what made these outstanding transformers sound so amazing. Their “recipes” if you will.

… if someone didn’t step in to preserve the technology that decades of accumulated knowledge (not to mention the essence of tone) would be lost forever.”

It can take up to a week to properly analyze a single transformer. Aside from the need to catalog and replicate these gems, we’ve tackled these projects for other important reasons. What makes a great-sounding transformer tick is no longer mysterious. Prior to our research the engineering community did not fully comprehend the characteristics of a good electric guitar amp transformer. We’ve used this hard-won knowledge to look beyond the confines of conventional engineering to find the previously undiscovered rules behind the most desired electric guitar amp tones.

VG: If a transformer dies will a replacement change my tone? 

Sergio Hamernik: Until Mercury got involved if your transformer tanked there was a good chance that your sound would be lost forever. An amp tech could spend a lifetime fiddling around with caps, resistors and tubes and never find your sound again. The missing component in the equation was the transformers.

Oddly enough, duplicating build quality so that each and every transformer of a particular model, or period, sounds exactly the same had been a struggle in the past. Traditional manufacturing methods have always produced inconsistent-sounding transformers. Literally no two had the same sound. This only makes sense when you realize that few were aware of the transformer connection with tone. This also explains why the average amp tech uses random and generic transformers. They just didn’t know any better. The ability to buy an identical replacement transformer, or an upgrade for that matter, is a major breakthrough in amp tone — there’s no doubt about it.

There’s also a side benefit to consistent build quality that some players and amp techs are just beginning to discover. Mercury catalogs many design variations for all the popular amps. This means that you can easily and reliably experiment with the tone-enhancing qualities of other transformer designs and amp configurations.

VG: Why are transformer magnetics so vital to guitar amp sound?

Sergio Hamernik: Once you understand that generic “by the book” transformers can actually neuter your tone — the battle is over. Your choice in transformers opens the door to MAJOR tonal possibilities.

When you listen to all the different tube amps made over the years, it’s brutally obvious that the really bad-sounding variations had junky transformers (even though they were usually within design spec). We know this because when you simply replace the stock transformers with quality units they come alive.

There’s a curious phenomena associated with cheap magnetics — they tend to make an amp fatiguing to the ear — uninspiring to play or listen to. Boring, actually. With tonally dull transformers you just can’t get the other components to sound as they should. And the fun doesn’t stop there—inferior transformers result in amps that are unreliable, have a tendency to overheat, etc. You can easily identify them by their uninteresting, thin-sounding and harmonically anemic tone. Unless one is stone deaf, the sonic superiority of quality magnetics is obvious.

 “Once you understand that ‘by the book’ transformers can actually neuter your tone — the battle is over.”

It’s important to understand that the pioneers of the electric guitar amplifier and most of the techs that followed were self-taught. It only makes sense that much of what they came up with were results from happy accidents. But despite their trial-and-error methods with tubes, speakers, and other components, many of them misunderstood the role of the amp’s magnetics (transformers) as it relates to electric guitar tone.

Over the years there’s been an overwhelming number of hit-n-miss transformer designs used in guitar amps — even within specific models. Mercury has had the benefit of the rear-view-mirror, looking back over time, discovering what sounded great and what didn’t.

Mercury’s holistic approach has taught us that the unique nature of the amplifier seldom lends itself to just one ideal set of transformers. Can you imagine that for the Bassman sound alone Mercury inventories over 2,000 transformer combinations? The differences may be slight, but we cover just about every conceivable tonal and configuration variation for that model amp — factory, mod or custom built. And that’s just one amp line out of hundreds — Mercury’s growing library is approaching every amp ever made (including the odd-balls!), from 1948 to 2006!

Our current library consists of hundreds of unique transformer designs and their variants. Aside from vintage, we also have our enhanced next-generation Axiom designs. They incorporate many of the discoveries we’ve developed for even better-sounding, more inspirational amps.

VG: I understand Mercury has three separate electric guitar amp transformer lines? 

Sergio Hamernik: Everything we do has evolved from the real needs, wants and requests of our user base. Mercury’s products are all logical extensions of each other, but there are actually four separate offerings.

Mercury Vintage — our one-off service where we repair or restore otherwise valuable, usually vintage transformers. There are no modifications or enhancements added. These one-off restorations are ordered by players who are aware that their original (and valuable!) transformers are expiring but want to continue using the amp because they love its tone.

ToneClones are tonal duplicates of best-of-breed vintage amps. We have hundreds of designs and every one of them is from a stellar-sounding original. Indeed, it was our customers who helped to invent the ToneClone line. If you want to make your vintage-style amp sound as close as possible to the best-sounding amp of a specific period — you need to hear our ToneClone series transformers.

The Axiom series is a totally new concept in tube-based amp transformer design. They marry the best of the vintage-era and Mercury’s breakthrough discoveries. Axiom-ized amps give you more tonal “bloom” — vintage-sounding but more, a lot more. There’s a growing group of boutique amp builders, as well as tech-savvy players, that have been working with them. Of all the raves and testimonials we receive daily, the most emotional are those by our Axiom users. I’m particularly proud of the Axiom series because we believe they represent the future of tube-based amp designs.

And finally, custom transformer designs. Non-disclosure agreements prevent us from discussing our clients, but there are quite a few boutique as well as major brand manufactured amps out there with our custom designs in them.

Think of what we’re doing as transformer archeology — not unlike opening ancient scrolls for the first time. Over the years we’ve unearthed some real treasures!

All of our products are built like no other transformers in the world. We may be the only manufacturer who uses custom-formulated, American-made materials. Every single transformer is handmade, hand-tuned and tested by us before it leaves Mercury. Our proprietary processes and expertise are unique. We design and make every one of our transformers here in California — no work is farmed out to other countries.

VG: Where do we go from here? 

Sergio Hamernik: Our work is fascinating, and as our advertising reflects, we’re having a good time doing it. But we wouldn’t have gone through all the drama of creating these exceptional-sounding transformers if it wasn’t for the support and encouragement we’ve received from so many brilliant artists and passionate players. Their passion has fueled our drive.

We view Mercury is a catalyst — reintroducing what inspirational, non-fatiguing real tone is all about. We’re also confident that we’ve also raised the bar for the “old” guys who long for the tone they grew up with. Can you imagine playing modern equipment that sounds even better than you remember it did back then? It was transformer and tube-based sound that originally turned the world onto electric guitar tone — the tonal qualities you feel more than just hear. At Mercury we believe that transformers are the last key to the tonal puzzle.


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