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LampizatOr Amplifier GM70 Mono DHT SET

After years with the DAC it was time for LampizatOr  to introduce an amp. I thought that this introduction would re-define the price point for owning the real deal SET mono amps. Amps that sound as good as 5 figure amps on the market at less than half price. We are aiming at people who would normally buy a stereo 300B amp, but from us they get not only monos instead of  stereo integrated, not only 22 WPC instead of 8, but also the super cool super mean looks of the GM 70 triode.

All our know how, experience, passion and resources went into this creation. Not to mention all our reputation at stakes.

We are extremely proud of the amplifier - we managed to realize 101% of our plan and we managed to stay within our budget without making any compromise at all. Everything we though was important - is there.

As of December 22nd 2012 the new improved production batch has seen the light of day and there are many significant improvements over the prototype batch, namely: new improved top plate and layout of all parts, new super powerful rectifier for GM70, new signal capacitors  and new analog meter. Also the main power transformer has been upgraded to famous OGONOWSKI high-end type. Mains transformers also covers now 110 V countries.

Hand made, custom order, high end equipment with vacuum tubes.

Interview about the amps :

LINK http://www.monoandstereo.com/2013/07/interview-with-lukasz-fikus-about.html

AMP Review link HERE

The amplifier is the muscle of the music system, if the DAC is the brain and heart.  During the years with Lampizator DAC we realized, that customers need an amplifier, and they are very concerned that a decent tube amp cost in 5 figures Euro.   I believe that this amplifier offers terrific value: surely it is not cheap, it is hardly pocket change but it is the lowest price for which a decent amplifier can be built from parts that were not stolen or found in the garbage, but actually purchased with an invoice. There are no miracles - if someone offers cheaper power amps of similar class - he is either selling them under cost to get rid of them or using children slave labor in far away camps. Or simply the technology has too many compromises like underpowered transformers with aluminum windings, underrated voltage specs, undersized caps. Such amps will last a year at best.

I offer good price because the amps share half of their parts with the lampizator DAC - the front panel, the caps, sockets, small tubes, all input and driver circuits and supplies. (the amps have part count of 330 ! )

The amplifier employs only the most radically “kosher” circuit features like:

1. • Single ended triode operation from input to output
   

2. • Pure Class A
   

3. • Zero feedback, neither local nor global
   

4. • Zero solid state parts in audio circuits
   

5. • Unregulated and over specified supplies
   

6. • Separate transformers for each task (four in total per side)
   

7. • Short signal path - from RCA to pot - 2 inches of silver wire, same  from pot to first  tube, same from the first to the second tube and a hop across one capacitor to main tube without additional wiring.
   

8. • Power tube bias current is monitored on analog needle meter
   

9. • No need for triode matching as the bias is set manually.
   

10. • There is a possibility to compensate aging drift on power tubes
    

11. • Pre-heating operation mode for tube (and for electricity saving)
    

12. • All tubes will be available forever in plentiful supply (only circa 100 USD per pair of  graphite GM70, 50 USD for all other tubes)
    

13. • Pots can be bypassed completely by toggle switch for the “power amp” operation  mode.

The amp is built around simple concept: to make it “as well made as sanely possible”. Without Gucci crazy stuff but otherwise - without compromise. 

The power tube is the best I know of (except the insanely unavailable original WE211)

The power supply has oversized transformer, one separate transformer for every task - one for GM70, one for small tubes and one for all heaters.

The small tubes have choke supply, and separate PSU for every half of the two triodes. The schematics is the best I know of. 

GM70 has its own huge choke as well. 

Signal "path" is super short - 6 inches in total. 

All parts are very good, over-specified, used well under their limits and so on. 

Bias is adjustable by user.

And whats most important - the output transformer and power transformer  are of first class  - the famous OGONOWSKI type - on Tango - Tamura level,  but without the Ongaku silver windings. It is my own design to build the power AC transformer around the core which is used for output transformers (so the transformer quality is one big notch higher than any power transformer normally available).

I decided to use very well tried schematics - 80 % is my Lampizator DAC scheme plus the power tube circuit .

The amp sounds VERY powerful, with strong bass, pure trebles, scary close mids, deep 3-d soundstage - all I wish for and more.

I hope there is nothing that can fail, even after 30 years of service.

THE AMP DURING PRODUCTION:

GM70 on the right, 845 on the left. The GM70 is MUCH larger inside.

READ THE AMP EARLY DAYS CREATION STORY HERE

ORDERING FORM

Specification of GM70 version:

1. • Single Ended triode mono block integrated amp (no need for a preamp)
   

2. • Rectifier tube 5C3S - the giant coke bottle dual diode. (It supplies the small   tube section)
   

3. • dimensions WHD : 450 x 140 (250 with tubes) x 500 mm
   

4. • weight: net 29 kg per each mono before packing (33 kg packed)
   

5. • Gross shipping weight of a pair: 77 kg (170 lbs)
   

6. • Power: 22 WPC single ended class A
   

7. • Power consumption: 180 WPC on idle,
   

8. • 95 W on pre-heating (per each block)
   

9. • Power Tube: GM70 triode, graphite type
   

10. • Driver: White-6N6P (at 30 mA) - NOS
    

11. • Input tube ECC40 Mullard  - NOS
    

12. • Input impedance: 90 K
    

13. • Output impedance (speakers recommended) 8 Ohm
    

14. • Output transformer: OGONOWSKI / Lampizator 
    

15. • High Voltage transformer: Ogonowski (using audio output transformer  core )
    

16. • Biasing: manual (with exposed pot and meter)
    

17. • Volume: Stepped input ladder switch (24 SMD resistor pairs)
    

18. • Power transformers total capacity: 700 VA. 4 transformers in total per side
    

19. • Anode supply: 900 V DC
    

20. • Available front colors: black or silver (top always silver)
    

21. • Input socket topology: one RCA SE (second input possible)
    

22. • Biasing range: -60 to -140 V DC (covers both copper and graphite GM70s
    

23. • Signal Caps: Soviet military PIO. NO Duelunds or Jupiters or Jensens or
    

   V- Caps - sorry. There are technical reasons for this.

About GM70 power triode tube:

The GM70 is one of the biggest triodes ever used in Audio applications. It is a Soviet response to 845 tube which it resembles visually but in fact the GM70 is much larger. It’s plate is 42 % larger in area and the whole guts of GM70 are much more substantial. 

It has directly heated wolfram thoriated cathode (whatever that means)

It has a hair rising specification of 125 W continuous power and 150 W peak. All that at 1500 Volts on the anode. It is like HEMI engine or Audi W10 diesel.

We run the GM70 at 80 Watts continuous (90 mA at 900 V DC).