JE Labs Full Function Preamp
Phono: 2x 6SL7s, Linestage: 2x 6SN7s
and 2x 76s
choke input power supply with GZ34 as a rectifier
Battery-biased for 6SL7s, precision resistors where applicable
Built for Paul Folbrecht
Completed on 4/22/09
TAL JE Labs full-function preamp is one of the best, and best-valued, pieces of audio gear I've ever owned. It is very
quiet, and dynamic, and very lively. It does not sound like any typical small-tube preamp or even octal pre in my experience
- the 76 tube (or else the circuit) simply sounds very, very 'present', intimate, and lively. At the price for a full-function
pre it is quite a steal." - Paul Folbrecht
Built on two separate chassis - power supply and preamp. The choke
input power supply is rectified by GZ34. Keeping these two separate seems to keep things quiet. The preamp has two sections:
phono and linestage. The phono section has cascaded 6SL7s with a passive RIAA equalization. The linestage has a 76 coupled
to a 6SN7, exactly like the preamp stage in JEL 2A3dx and 300Bdx.
All gold-plated RCAs. Note the nickel plated 4-pin connector originally
used for CB radios. It gives a solid connection, properly secured by top screw. Those FT multi-section caps are my personal
favorite. They are a bit pricey, but well worth it.
This is where this preamp shines. It's PS is big enough to power
a 2A3 SET amp. The heaters are rectified and regulated (those Nichicon 10,000uF 16V are audio grade). Note that the voltage
divider that lifts the heater voltage around 80 VDC above ground is NOT grounded here. Instead, it should be grounded at the
The linestage armed with Russian oil tanks. The same
preamp stage is found in JEL 2A3dx and 300Bdx circuits. Love those Art Deco 76 tubes!
Got wires? The phono stage consists cascaded 6SL7s with a passive
RIAA circuit. The tubes are all battery biased. The current through them keeps them charged up automatically.
I really like this preamp. The linestage is very transparent and
the phono stage is very natural sounding. I listened to some records through my La Scalas today and found myself really enjoying
the mellow sound coming out of those horns. It's a good circuit that can sound very expensive if supplemented with good