2X 6S45P-E; 2.0 Watts / Channel

Copyright 2005-2007  Grandpa's Basement Audio
All Rights Reserved.
Here is a Single Stage Single Ended Triode Stereo Amplifier professionally built around the 6S45P-E Triode as an Homage / Tribute to the MIG-25 Interceptor that flew these phenomenal tubes in its Smerch (Tornado) Radar System.

At a time when the West had gone completely solid state, the Soviets were still perfecting the state of the art in vacuum tube technology - the tubes in this amp were still in Military use as late as 1988!   The Smerch Radar System was designed to perform during and after a Nuclear Doomsday, and may well have been one of the most rugged, indestructible set of electronics ever built!  Thanks to its vacuum tube amplifier, this Radar was immune to Radiation and any Electronic Countermeasures the US could throw at it.  It is  rumored that on the ground, this Radar System would stun or kill rabbits around the airfields out to 300 yards. 

Mounted in the supersonic MIG-25, this Radar system completed a highly capable Interceptor Platform designed to duke it out with th US and  NATO for air-superiority in WWIII. 

I started this project with a goal to build an amplifier that looked like it could have just been pulled out of an avionics bay on a fighter aircraft.

The heavy gauge steel chassis measures 6 in X 13 in X 5in high.  The overall shape gives the amp a solid brick-like heft.  Exposed stainless socket head and tri-y fasteners (bonded down no less!) complete the look with nice military / industrial undertones.  The stainless rack lift mounts not only look good, but are great for lugging this beast around.

In keeping with the Soviet Mentality, everything electrical is overbuilt, under-rated and bomb-proof.    Recessed gold plated RCA connectors feed the dual amplifier assemblies via twisted shielded pairs of heavy gauge silver wire.   Internal Components are all top quality; Vishay Dale and Holco Resistors; ELNA and Marcon capacitors.  A new dual coil toroidal power transformer with solid state bridge rectification feeds two monstrous 390mf Marcon Capacitors rated at 450V/105C.  Between the caps is a NOS Westinghouse choke that kills any hash trying to ride the line.  B+ voltage is a mere 218 volts.  Considering that these tubes can be run in excess of 400 volts, you could listen to this thing from now until you pass it on to your kids and it will still be clicking along like new. All grounds are central routed to a star ground.  A grounded binding post (located directly behind the inputs) is provided to ground the input device to an equipotential with the amplifier if desired.   The air-gapped output transformers are oversized for excellent bass response, and are copper shielded.  Output connectors for 8 ohm speakers are new gold plated binding posts.  The tubes are cathode biased, with the external US Military Surplus Paper-in-oil 0.22mf dual section capacitor playing the roll of  bypass capacitor for each channel.  The controls are stupid simple: One is the power(Off/On), the other acts as a standby/impedance selector.  In the central position the amp is in standby mode.  Flip it to the left and the output trannys are loaded at 5K ohms for a very clean sound.  Flip it to the right and they drop to 3.5K ohms - kinda like turning on the afterbuner.for some more rip.  Instead of a fuse like every piece of junk made today, there is an Honest-to-God circuit breaker that can be accessed under the amp.  Finishing touches include a titanium rear control panel, and a Nice MIG logo badge on the front.  Lastly, the amp is completely sterile.  No control labels, no numbers, no nothin' - just like the real gear fielded by the Soviets.  Instead there is only a small removable card with the control schematic on it. Remove the card, and it is hard for the enemy or spies to figure out how to work the darned thing - might work just as well around roommates or nosy friends.   
Includes a new matched pair of NOS 6S45P-E tubes from the Soviet  Reflektor Plant.  Both date from the early ‘80s and are the much sought after ‘Chrome Dome' military version.  Matching for both is within 1%. 

Maximum power output in the ‘clean' setting is right at 1.6 watts per channel from 18Hz out to 25Khz (+/-1dB); more than enough power for an office or study with speakers at least 94 dB efficient.  Flipped to the ‘hot' impedance setting you can get just over 2.0 watts.

How does it sound you ask?  Absolutely magical.  Power it up, and the first thing you will notice is that the amp is dead quiet with absolutely no hum or microphonics - partially due to good internal shielding, but mostly a tribute to Soviet vacuum tube technology that was still advancing the state of the art 20 years after we had completely abandoned it in here in the west.   The 6S45P-E is the Soviet analogue to the Western Electric WE-437 and Telefunken EC-8010, both of which have reached almost cult status (and prices). The sound can only be described as clean, crisp, and dead accurate. Try to imagine a very clean solid state amp, but without the trademark harshness (some would say hatefulness) and edginess.   Even though the amp is single ended with the associated second order harmonic coloration (or imaging, or whatever you want to call it), you can listen to this amp for days and days without your ears getting tired - music comes through fast and accurate without any buttery soupiness, but still open and airy without a hard edge.  The inputs aren't picky about what you feed them - plug in your Ipod, CD Player or even your old 8-Track; any line or headphone level input will do. 

This amp was built with the Aviation buff in mind, and to fit in with the decor of any home, office or study, while providing phenomenal sound that is easy to listen to day in and day out.  And as with all my custom work, it is a one off piece - there will never be another one made like this again.    

Sold on Ebay:  $825