Consonance M400S Push-Pull Vacuum Tube Power Amp – PAIR





Consonance M400S Push-Pull Vacuum Tube Power Amp

Consonance M400S EL34 Monoblock 40w Push-Pull Vacuum Tube Power Amp

To purchase contact us for a discounted shipping quote@ (763) 575-7447 or

For your consideration; a pair of beautifully hand-crafted mono blocks. Do your research and read the reviews.  These amps are silky smooth killers.  They are hard to find, and this pair are in excellent condition. They come with new Mullard and Telefunken Black Diamond tubes, the original Electro Harmonix tubes, a digital multimeter to adjust the bias, and upgraded power cords.  Also included are the original inner and outer shipping boxes and the owner’s manual. 

Here’s some more info:

M400S are mono blocks featuring a completely hand crafted chassis. It has a simple design, is easy to use, and offers outstanding headroom performance. There is a toggle switch on each monoblock towards the front. It is labeled Ultralinear toward the front and Triode towards the rear. Triode mode reduces the output to about 22 watts instead of 40 but tightens the bass end somewhat and gives sweeter, more “tubelike” midrange reproduction. The Ultralinear mode was an invention of David Hafler and Herbert Keroes in l951. It uses tetrodes or pentodes and special taps on the output transformer. These taps are connected to the screen grids of the tubes, causing them to be driven with part of the output signal. This lowers distortion and is seen on amps using only certain power tubes, of which the EL34 is one.


Control Functions: Power on/off toggle at rear
Inputs: RCA left & right
Output Impedance: 4 or 8 ohms, user selectable
Output Power at 1 kHz for less than 1%THD: 40 x 2
Bandwidth at -3dB: 6Hz to 60Hz
Signal to Noise: 90 dB
Input interfaces: 1 group (RCA)
Input impedance: 100k
Power consumption: 90w x 2
Tubes: EL34 x 4; 6922 x 2; 6189 x 2

Return Policy

All units are sold with a 90 day warranty period in which you can exchange them for full the purchase price (less any shipping charges) towards any other unit we have in stock.  Any unit which proves to be defective within ten days of delivery can be exchanged for the same model or a suitable replacement. In the event a replacement unit is not available, we will refund the purchase price. We will pay the shipping costs for replacement merchandise. Any non-defective merchandise returned for credit will be subject to a 15% restocking charge, with the buyer paying all shipping charges. Please call us at (763) 575-7447 for a return authorization number. No returns will be accepted without a valid return authorization number.

Equipment must be repacked exactly as it was packaged when it was originally shipped to you; all packing materials intact double boxed, etc., in order to avoid shipping damage. Equipment initially returned as defective, where the defect cannot be verified, will incur a 15% restocking charge.