I have dubbed this unit the Altec Blue RH84! It is an excellent sounding, little amp, that has amazing sound quality equal to Decware at less than half the price! Operating in Single Ended Class A with ultra short signal path for minimal alteration of the sound. And the sound quality is still developing as it has about 10 hours of total playing time.For your consideration, I present my latest tube amplifier project; An RH84 v2 in Altec Blue, which is a SINGLE ENDED EL84 stereo tube amplifier using a single EL84 per channel (brand new Russian 6p14p) with a General Electric 5965 (a milspec 12at7) driver tube. The design is by Alex Kittic and has been copied by thousands of DIY'ers all over the world. The unique aspect of this design is the use of "local feedback" vs. "global negative feedback" that is used in almost all other audio amplifiers. The use of local fb bypasses many of the ills of "global negative feedback" which requires compensation networks to reduce phase problems. This and an excellent sounding tube combination makes for an superb sounding single ended amplifer. This is the sixth RH84 amp that I have built and they all sound excellent, but truthfully, I think this might be the best sounding one. If you have not heard a Single Ended tube amp you are in for a treat. The only issue is the need for some efficient speakers like JBL or Altec Lansing, or Klipsch. For this build, a Motorola console amplifier from the 1960s with their superb quality output and power transformers were used. Only the chassis, power and output transformers are reused. All other parts are brand new top quality capacitors, resistors, wires, etc. Price is 360.00 for 1 amplifier. This amp has all new matched parts in both channels for the ultimate in lifelike sound quality. The very important coupling caps are legendary Mullard mustards. This gives a sound that is detailed yet smooth and sweet but very dynamic. Output power from a class A el84 is about 5 watts, but what a glorious sounding 5 watts. But even so, this is a very strong 5 watts and that can drive my JBL L112 speakers loud enough to send my wife outside! Find out why those who have heard a single ended tube amp on efficient speakers never go back to any other type of amplifier. You have read all the hype the only way to know is to experience it for yourself. You don't need to spend big bucks on single ended triode amps with 300B tubes to hear the difference. Indeed, one of my SE EL84 amps that was sold to a fellow in San Francisco, sounded better than his 300B amp to he and his audio friends. This amp is completely hard wired point to point for best sonics and audiophile quality sound and better reliability. All components are new. 5 way speaker binding posts, IEC type power socket with fuse, on/off switch, rubber feet. Special attention was lavished on the power supply which is one of the reasons for this amps outstanding sound. In technical terms most power supplies for audio amps are simply capacitor input. High End amps will use an inductor after the capacitor and only an audio fanatic will use an additional inductor and capacitor. Thus the power supply is now CLCLC or capacitor/choke/capacitor/choke/capacitor input. First the AC is rectified with a vintage mil-spec JAN CG 5Y3GT for super reliable operation. Then the all important first capacitor is a Solen 22uf x 400 film cap for lightning quick dynamics. The all important inductor is a vintage Freed twin choke also ex-military for utmost reliability. Between the 2 chokes is a 50uf x 400v Nichicon followed by another choke section then the final filter is a paralleled pair of Nichicon 180uf x 400volts. This combination reduces any power supply ripple to negligible levels which is born out by its absolutely dead quiet operation. Even with my JBL L112 speakers and my ear right next to the cone I hear no tube noise or hum at all.
The B+ for the driver tube has also been highly upgraded with a high inductance choke (the little one between the driver tube and power tubes) and a 25uf film cap. This combination of components is unheard of in an amp like this. The result of all this attention to the power supply is a very dynamic sound, with deep bass, sparkling highs, and outstanding "headroom" on loud passages. This amp also has excellent detail retrieval. On Dire Straight's classic album "Brothers in Arms" in the cut , "money for nothing", Stings' vocals appear in the background slightly off center in the most realistic manner. Please check out the photo of the underside showing the high quality components used and the 14 gauge solid copper ground bus. The amp is super quiet with no extraneous sounds emanating from the speakers which makes it an excellent partner for horn type speakers. You have not heard audiophile sound until you have heard a single ended tube amp. These amps have the ability to transport you into the music. Your recordings will sound like they never have, with heretofore, unheard of elements coming to the fore. The kick drum is thumping in your gut, cymbals have that metallic bite and reverberation and the vocalist sounds like she is standing in your room for a personal concert! In other words each element in the sound track has its own space. Truly, audiophile quality amplification at a beer budget price.
Don't let its small size fool you as the saying goes, great things come in small packages Thank you, for reading the complete text and visiting my sale. Please remember that this amp is sold strictly as is. Caution is required as tubes are hot and there is no bottom cover to the amplifier. Just remember if you are into headbanging, window rattling, neighbors phoning the police, loudness, this amp is definitely not your cup of tea. But if you are looking for a great sounding little amp for your den or bedroom this will make a Bose sound like pocket transistor radio in comparison and probably cost less and have a better resale value. Although this amp is built to extremely high standards and with the utmost of care it is sold strictly as is. Thank you very much for reading my ad.
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