GETTING DEEPER INTO GM 70 TERRITORY
Interview with Lukasz Fikus regarding Lampizator GM 70 amplifiers. Few of late night tube galore glowing after the text below.
Why Lampizator amplifier?
When I started thinking about adding an amplifier to my line of DAC products about a year ago, honestly I had no idea what I am entering. Well, not exactly the gates of hell, but something like a lite version of that.
First I had to take strategic decision - what people expect from us and wether it is doable or not.
"My customers" and I mean by that the people who bought the DAC before, are kind of a similar group, a microeconomist would call that a market segment. They came to me only after burning their fingers by buying the wrong gear. They wanted something different and they all DO CARE about the music. They are not just hi-fi snobs. I visited tens of homes of my customers and I saw their equipment and only few had speakers or amps that I really liked. Since I am not in the speaker business, I thought that my customers will react very well to a no-nonsens amplifier at reasonable price.
I chose monoblock approach simply because if I want to use all the large parts and overspecified components - there is no room in one box. So that decision was a no brainer.
"My customers" and I mean by that the people who bought the DAC before, are kind of a similar group, a microeconomist would call that a market segment. They came to me only after burning their fingers by buying the wrong gear. They wanted something different and they all DO CARE about the music. They are not just hi-fi snobs. I visited tens of homes of my customers and I saw their equipment and only few had speakers or amps that I really liked. Since I am not in the speaker business, I thought that my customers will react very well to a no-nonsens amplifier at reasonable price.
Why mono blocks?
I chose monoblock approach simply because if I want to use all the large parts and overspecified components - there is no room in one box. So that decision was a no brainer.
Why tubes and not solid state?
I choose tubes because I believe that in the amplifier world it is much easier to make a tube amp that meets my performance criteria than a transistor amp. I know of good transistor amps out there but they are too costly and difficult to make. And my middle name is not Mister Transistor. So the second decision was a no brainer either.
Why triode?
I have very long experience with push pull amps based on 6c33c triodes. My first thoughts were to make these, but again - my dream was a SET amp, so there is much more fun in fulfilling my dream than in making a me-too, another 6c33c push pull amp.
Aristocracy of triodes?
I tried to read about the SET from the aristocracy range of big triodes - 805, 845, 211 and GM70. It turns out there isn't so much written about them. US market was really dominated by foreigners - BAT, LAMM, VTL, Manley - all Europeans who made it there. 99 % of US market is push pull, again - BAT, VTL, Manley, Lamm. In Europe - things were much "smaller" and 300B is almost like a limit of whats available. Russia does not exist on the wider World arena, and Japan is almost exclusively associated with Kondo and Ongaku. You just can't escape from Ongaku. So my last criteria for the new plan became "A monoblock tube amp, with the royal triode SET but NOT another Ongaku clone."
And why GM70 exactly?
And so it started. I chose GM70 because it is simply to good not to use. It is larger than the western cousins, it is so robust that it seems indestructible (unlike the fragile 6c33c). There is plenty of them and the supply will not dry out in our lifetime. There is little competition for "consuming" the NOS supplies because almost no other manufacturer uses them. It seems to be the Queen of DIY triodes, but not of the industry.
What is difficult in creating such amp ?
First, it is hard to make decisions before trying the real implementation, so only the experience and gut feeling guided me in making preliminary design and decisions. Life is simply too short to try every transformer, tube and capacitor. Nobody can do this. It is difficult to "think" and work with 1000 Volts. Especially DC. Not everybody knows that DC is 10 times more dangerous than AC. Everybody probably got kicked by 220 V from the wall once in their life and had survived. Short of taking a bath with the hairdryer - AC220 is not lethal. 30 V DC is considered lethal voltage in safety regulations. It is an interesting aspect of todays industry that we have no more parts for high voltages. Since the end of tube era in the early 70's there are less and less parts for 500 V not to mention 1 kV or more. Last industry that needed high voltage was TV CRT glass tube display industry and it is gone too. So one has to be very concerned with sourcing parts that withstand 1 kV DC, even wires. Fortunately the military industry in Soviet block produced those parts by millions (and fortunately - never used it). Many people ask why I did not use the GM70 at its full power - with 2kV on the supply. The answer is simple - it would cost 5 times more to build such amp only to get 7 watts more, on top of the 23 W that I provide, of which we are using 2-3 Watts in everyday listening. Or 1 Watt in case of alnico speakers (like my own). So this decision was very easy to make.
One of the hardest things in the whole process was investment in the inventory. Every custom made part has to be ordered in quantity, usually they laugh at me when I order 10 aluminum parts like the top plate or something like that. The metalwork industry LOVES quantity and those metals cost a lot of money. Once the CNC cutting is done - the design is written in stone almost literally. That happens before we even hear the first prototype, and the payments are already due. So yes, thats hard for a small company.
Having said that, THE most difficult and dangerous - from the business point of view - part of the process was definitely to avoid the risk of warranty claims. It costs so much to ship a palette of 75 kg back and forth that it is not even funny. So in the first batch stage as well as for the future, it is the most important to avoid unnecessary returns. We took the careful approach and we were selling the amps in the radius of 100 km from the factory - here in Warsaw. Knocking on wood - there was not a single failure in the first batch of 12 pairs in the first year. When we gained self confidence, we loosened up the restrictions to all Poland. Again - another batch of 8 pairs and no failure. To design with this level of reliability while working in the completely new territory it is both hard and expensive. I had to overspecify the parts to the degree when it was almost embarrassing. All parameters have to have double overhead, and another 50 % to sleep well plus their own military 100% safety margin. It got to the point that I got so confident of the parts overspecification (in terms of current, voltage, wattage, temperature and life expectancy) that if someone would call and say that the part in the amps got burned - I would simply say that he is wrong and it did not. I am not implying of course that something will not fail eventually, but I just describe my general mindset about it. Even space shuttle failed a number of times but all things being equal - for us it is like building a space shuttle by hand.
The sound: it is simply a result of everything we did well. We did not "design" the sound. It just happened when the amp was finished. All the decisions summed up to a very transparent amp. You do properly the transformers, the power supply, filtration, grounding, chokes, caps, wires, military resistors, point to point wiring - and the beast pays back with clean sound. Turn the volume up - still clean, turn it more - walls shaking, live concert in the room - still clean. It gives a certain enjoyment to have this huge power. Like having a car with big engine. Press the pedal to the metal and the car effortlessly takes you to 200 kmph. We don't drive like that every day but it is so nice to have. I was particularly worried that I will get in the end a "tubey" sound, nice, warm and rounded. I hate it when people associate tubes with that. Like in my DACs - there is absolutely NOTHING tubey as far as the sound is concerned. I am not a nostalgic kind of guy and I don't fetish tubes. I just think they do what other technology can only struggle with.
I tested the amps against two main benchmarks: Verdier 845 monos and BAT VK-75. I am not ashamed of any of those two fabulous amps. I think that my customers really appreciate their purchase - they own something they never ever dreamed of owning, because the price of well established triode monos is usually very high. Out of reach for most normal middle class people. We struggle with rent, taxes, car repairs and kids in school. Now that the amps are available for export as well, they may end up in countries where people can afford much more costly stuff. But even there they are a minority, the vast majority of audiophiles would never go above 3000 Euro mark, unless they found something REALLY SPECIAL. Then some of them could stretch a little and go for 4 or even 5K. Those are the people I want to target. And for most of them it will be the last amp they own. And then they can leave them in their will to their kids.
What were the hardest things?
One of the hardest things in the whole process was investment in the inventory. Every custom made part has to be ordered in quantity, usually they laugh at me when I order 10 aluminum parts like the top plate or something like that. The metalwork industry LOVES quantity and those metals cost a lot of money. Once the CNC cutting is done - the design is written in stone almost literally. That happens before we even hear the first prototype, and the payments are already due. So yes, thats hard for a small company.
Having said that, THE most difficult and dangerous - from the business point of view - part of the process was definitely to avoid the risk of warranty claims. It costs so much to ship a palette of 75 kg back and forth that it is not even funny. So in the first batch stage as well as for the future, it is the most important to avoid unnecessary returns. We took the careful approach and we were selling the amps in the radius of 100 km from the factory - here in Warsaw. Knocking on wood - there was not a single failure in the first batch of 12 pairs in the first year. When we gained self confidence, we loosened up the restrictions to all Poland. Again - another batch of 8 pairs and no failure. To design with this level of reliability while working in the completely new territory it is both hard and expensive. I had to overspecify the parts to the degree when it was almost embarrassing. All parameters have to have double overhead, and another 50 % to sleep well plus their own military 100% safety margin. It got to the point that I got so confident of the parts overspecification (in terms of current, voltage, wattage, temperature and life expectancy) that if someone would call and say that the part in the amps got burned - I would simply say that he is wrong and it did not. I am not implying of course that something will not fail eventually, but I just describe my general mindset about it. Even space shuttle failed a number of times but all things being equal - for us it is like building a space shuttle by hand.
Your view on the sound outcome?
The sound: it is simply a result of everything we did well. We did not "design" the sound. It just happened when the amp was finished. All the decisions summed up to a very transparent amp. You do properly the transformers, the power supply, filtration, grounding, chokes, caps, wires, military resistors, point to point wiring - and the beast pays back with clean sound. Turn the volume up - still clean, turn it more - walls shaking, live concert in the room - still clean. It gives a certain enjoyment to have this huge power. Like having a car with big engine. Press the pedal to the metal and the car effortlessly takes you to 200 kmph. We don't drive like that every day but it is so nice to have. I was particularly worried that I will get in the end a "tubey" sound, nice, warm and rounded. I hate it when people associate tubes with that. Like in my DACs - there is absolutely NOTHING tubey as far as the sound is concerned. I am not a nostalgic kind of guy and I don't fetish tubes. I just think they do what other technology can only struggle with.
What were your testing references?
I tested the amps against two main benchmarks: Verdier 845 monos and BAT VK-75. I am not ashamed of any of those two fabulous amps. I think that my customers really appreciate their purchase - they own something they never ever dreamed of owning, because the price of well established triode monos is usually very high. Out of reach for most normal middle class people. We struggle with rent, taxes, car repairs and kids in school. Now that the amps are available for export as well, they may end up in countries where people can afford much more costly stuff. But even there they are a minority, the vast majority of audiophiles would never go above 3000 Euro mark, unless they found something REALLY SPECIAL. Then some of them could stretch a little and go for 4 or even 5K. Those are the people I want to target. And for most of them it will be the last amp they own. And then they can leave them in their will to their kids.
Matej Isak. Mono and Stereo ultra high end audio magazine. All rights reserved. 2006-2013. www.monoandstereo.com. ..:: None of the original text, pictures, that were taken by me, links or my original files can be re-printed or used in any way without prior permission! ::..