300B / 205D Push-Pull Monaural Power Amplifier

Soft and powerful sound quality.
Excellent panoramic feeling by monaural construction.
Penetrable sound quality by transformer drive.
You can enjoy the sound quality of both 300B and 205D.




Input terminal RCA input (unbalanced) x 1
Output terminal Speaker output : 4 ohm to 8 ohm, standard 6 ohm
Maximum output power
6 ohm load
20W with 300B class A2 push-pull operation
12W with FullMusic 205D/n classAB2 push-pull operation
Frequency Response 10Hz to 50KHz (-3dB)
Gain 26dB
Noise 0.6 mV or less (no correction), 0.1 mV or less (JIS A correction)
Dimensions (1 unit) Width 17cm, height 22cm, depth 39cm
AC Power Requirements
(1 unit)
110-120Volts, 50-60Hz or
220-240Volts, 50-60Hz.(Choose at the order.)

Price for 1 set ( 2 units )
US$ 2,300 with 300B
US$ 2,800 with FullMusic 205D/n

This Amplifie is Make-to-order product.
It takes about 1.5 months from order to shipment.

Inquiries and orders : softone@nifty.ne.jp

205D used for this amplifier
We strongly recommend FullMusic 205D/n used for this amplifier.
We do not conduct the operation test with other 205D, we do not guarantee the operation with other 205D.
The output tube socket of this amplifier is UX 4 pin same as 300 B. It is not small UV of WE205D.
Only 205D with UX 4 pin socket foot can be used. WE205D can not be used.

FullMusic 205D/n
It is a 205D compatible tube with UX 4 pin socket foot and mesh plate.
Initially FullMusic 206D/n has a 4.5V 1.2A power saving filament.
but in the latest version it has 4.5V 1.6A filament same as the original WE205D
It became specification more like the original.
The latest version is used with this amplifier.


Front Side When 300B is installed
Side When 205D/n is installed FullMusic 205D/n mesh plate
@Full view of the filament operation
Rear Internal

Circuit diagram

Measurement result

Inquiries and orders : softone@nifty.ne.jp