Analog Engineering Phono Tape Preamp tube stage

Quite Possibly the greatest phono stage ever made! Available in RIAA, IEC,and NAB. Whether you want to play Reel to Reel Tape from your Tape Heads or Records from your turntable we have the right preamp for the job. We feel this product is so great that we offer an unconditional return policy. If for any reason you feel this is not better than anything you have ever heard it just return it for a full refund excluding shipping. Here is more info on this lovely beast:
Preamp Circuit:

The phono preamp uses three triodes per channel: one half of two 6N1P-EB type tubes for gain, and one half of a 12BH7 for cathode follower output. The 6N1P is a current production Russian tube; its high performance specs and sound quality have made it a favorite alternative to pricey NOS valves.

The RIAA equalization is split; the first EQ constant is implemented between the two 6N1P gain stages, and the second EQ constant between the second gain stage and the cathode follower. The cathode follower is direct coupled, with an output impedance of roughly 500 ohms, so the circuit can easily drive long interconnects.

Constant Current Sources (CCS) are used for loads on all the tubes, and LEDs are used within the CCS for cathode bias. The LEDs are selected for their low noise, dynamic impedance, and RF stability in the circuit.

If you’re not an engineer, don’t worry if this all sounds complicated. The simple result of the circuit is rich, smooth, detailed analog sound in all its glory.

Power Supply:

The power supply has been designed to minimize noise and exhibit extreme stability. It all starts with a high-performance torroidal power transformer.
The 6V heater circuit powers the 6N1P tubes, and is exceptionally quiet. The circuit is rectified with Schottky diodes, and feeds a choke input filter for an extra degree of common mode noise rejection. Capacitive bypasses around each heater eliminate any remnants of VHF hash.

The 12V heater circuit is rectified with Schottky diodes, and employs an RC (Resistor-Capacitor) filter. The 12V heaters are bypassed in the same manner as the 6V heaters.

The high voltage is rectified with SiC Schottky diodes, and is well-filtered with a three-stage RC network. This filter supplies two shunt regulators, providing dual mono regulated power for the preamp.

What does all this tech talk mean to you, the listener? An inky, blacker-than-black background, from which music leaps out with astonishing clarity.

Layout and Lead Dress:

Since layout and lead dress are vital in analog circuits, a great deal of attention was given to the placement of key components. No detail has been spared. Signal leads are kept very short, to minimize both magnetic loop area and capacitance to other wiring. On the signal return loop, ground connections all return to a low impedance ground plane.

Grid stopper resistors are used on each vacuum tube grid, to damp any resonance associated with grid capacitance and lead inductance.

High current heater wiring is elevated from the circuit board on heavy gauge shielded twisted pair wire.

Experienced craftsmen assemble each preamp by hand with loving pride. We treat every unit as if it were going to be hooked up to our own system.

and the reviews? read this!

http://www.sixmoons.com/audioreviews/analogengineering/208.html

After developing the AE-2008, Mike went to work on phono preamplifiers. "I auditioned many phono preamps to compliment these two turntables but was never completely satisfied with most. I felt I could do better so in 2005 I decided to design and build my own. This would be the genesis of my third product, The Phono Preamp, which uses a split passive RIAA circuit as the basis and is designed by none other than Paul Joppa. The gain triodes are Russian 6N1Ps with C4S (Camille Constant Current Source) loads. The output is fed into a C4S'd 12BH7 running as a cathode follower and the whole thing is shunt regulated by a hybrid 5687 regulator, which is in turn loaded with C4Ss. The DC heater supply is heavily filtered, including some chokes."

Mike's phono preamp can also be configured for use with reel-to-reel tape decks. Guess what he named that version? What else, The Tape Head Preamp. While based on the RIAA phono preamp, the stock RIAA equalization network is then reconfigured to be a passive NAB equalization network but the rest of the preamp circuit and power supply details remain the same. Mike uses The Tape Head Preamp with a modified Technics RS-1500 at home.