Vintage 6SL7 Phono Stage (MM / MC)
Tavish Design’s Vintage 6SL7 Phono Stage is a passively-equalized, two-gain-stage design using the 6SL7GT octal dual triode, a vacuum tube first introduced (by RCA) in 1941. Although miniature vacuum tubes (like the 12AX7) later became more popular in consumer equipment because of their smaller physical size, the 6SL7GT remained a favorite of many audiophiles for its linearity and low noise. Our Vintage Phono Stage was inspired by the current availability of several high quality 6SL7GT tubes, including the Sovtek 6H9C/6SL7GT, the JJ 6SL7, and the Tung Sol Reissue 6SL7GT, all of which are offered with the Vintage Phono Stage.
The Vintage 6SL7 Phono Stage shares the same basic circuit topology as our Classic Phono Stage. This passively-equalized, two-gain-stage circuit topology has remained popular for many decades. The reason for its endurance is simple: with appropriate updates, it is very difficult to beat without going to elaborate multi-tube circuits. In fact, this simple phono stage outperforms many (if not most) high-end products.
Our update of this classic circuit includes optimized RIAA equalization that makes the circuit less sensitive to variations between tubes, as well as a relay-selected JFET pre-preamplifier for low-output moving coil cartridges. It retains the excellent linearity and extremely high overload margin inherent to high-voltage vacuum tube circuits.
Our design also includes linear, regulated high-voltage and heater supplies for low noise and low operating drift. The 210 volt supply rail operates the tubes in their intended range - we don’t starve the tubes by operating them at low voltages. And, we completely avoid the use of switching power supplies. The unit is powered from an external AC wall transformer, using a small internal step-up transformer for the high voltage supply. This puts the larger, high-current transformer outside (and well away from) the enclosure. A sophisticated circuit board design with multiple ground domains eliminates coupled noise. As a result, the Vintage 6SL7 Phono has exceptionally low noise and hum for a tube phono stage, in a compact and low-cost package.
The 6SL7GT has been a favorite audiophile preamplifier tube for decades, and the Vintage 6SL7 Phono Stage puts it to best use in a modern update of a classic circuit. It’s not your grandfather’s phono stage - it offers high-end sound and performance, and exceptional value.
In addition to the assembled unit, the blank printed circuit board (with no components) is also available, for experienced DIYers. We no longer offer the complete kit. We suggest downloading the Assembly and Setup Manual before ordering the circuit board, to be sure you are comfortable with the assembly process.
The assembled version is available with either Sovtek 6H9C/6SL7GT tubes, JJ 6SL7 tubes, or Tung Sol Reissue 6SL7GT tubes – please select when ordering. Both the JJ and the Tung Sol Reissue versions ship with a selected low-noise input tube.
- Designed to accommodate any cartridge (Moving Magnet, High-Output Moving Coil, or Low-Output Moving Coil) with an output of approximately 0.25 mV or more
- Gain: 41 dB Moving Magnet, 61 dB or 53 dB Moving Coil (switch selected)
- RIAA equalization accuracy ±0.5 dB, 25Hz – 20kHz
- Signal-to-noise, moving magnet (MM) input: >79 dBA, ref 5 mV @ 1 kHz
- Signal-to-noise, moving coil (MC) input, 53 dB gain: >79 dBA, ref 1.25 mV @ 1kHz
- Signal-to-noise, moving coil (MC) input, 61 dB gain: >76 dBA, ref 0.5 mV @ 1 kHz
- Reference output level: 560 mV RMS (-2.8 dBu)
- Total harmonic distortion <0.02% at reference output level into 22k ohms, 1kHz
- Output level for 1% THD: >14 VRMS into 22k ohms, 1 kHz (28dB overload margin)
- Adjustable cartridge loading on both MM and MC inputs
- Linear regulated high voltage and heater supplies (No Switching Power Supplies)
- OMRON low-signal relays for MM/MC selection and output muting
- 14 gauge powder-coated aluminum chassis
- Tube complement: 6SL7GT (x3) (MM input has an all vacuum tube signal path)
- Transistor complement (for MC preamp): 2SK209 (x2) Toshiba low-noise audio n-channel JFET, MMBFJ270 (x2) p-channel JFET
- Easy kit assembly with hum-free, single circuit board design
- Power Consumption: 18W, 120V, 60Hz using an 18VAC wall transformer
- Size: 9” wide, 6” deep, 1.5” high (4” high to top of tubes)
- Weight: 3.5 lbs. including wall transformer (6 lbs. shipping weight)
- Made in U.S.A.
- 6 year limited warranty