211 A2 Amplifier

211 tube amplifiers have always delivered a nominal 12 to 20 watts in Class A operation and gained acceptance for this service. As a means to deliver more power from the 211 tube, we at Electra-Print Audio have updated the traditional design using Class A2 operation delivering easily over 40 watts due to higher swing high voltage music power. The purpose of the design is to operate a less expensive, easily obtained popular tube, in a practical and acceptable high powered circuit.

Circuit Description

View our Tech Blog to find a full description of this unique amplifier design. Power supply and amplifier stages are fully covered.

Schematics

Click on the links below to see the schematics:

211 A2 Amplifier Schematic

211 A2 Power Supply Schematic

Resulting operational features:

a] No feedback on a very high voltage swing results in extremely good amplitude linearity. No global feedback giving greater dynamics to the music. b] High frequency has low distortion due to electrostatic shielded partial silver secondaries. c] Headroom over 10 watt listening level is over 400%. d] Not a feature but note worthy, is the 20 Hz higher distortion due to output transformer core mass limit to practicality. This will exist on all SE amplifiers to some degree as core mass used. e] Our Electra-Print amplifier design emphasizes the most important things found in recorded music including, detail, dynamics and presence.

Parts we can supply:

Amplifer Transformer prices:

Part	Price	Note
211ESE10K	$382.75	SE, PSSS Secondary, 6 Ohms, Electrostatic Shield
A2LD-7	$137.50	Common Mode Driver

Power Supply Transformer prices:

Part	Price	Note
211 Pwr	$319.00	M6 Laminations
3030	$37.50	HV Filter Choke
FC3.5A	$26.50	Filament Choke, 3.5 Amp