to look

At first there were only vacuum triodes

A double

vacuum triode


Mica capacitors

The theme of tube sound is currently mainly gossip and fairy tales. The miraculous excitement at the supernatural level of human perception is not discussed here. There are also no comments on the connection cables made of oxygen-free copper or pure silver for several hundred dollars - such cases are simply a waste of money.

However, this phenomenon of tube sound exists in nature and has had an impact on me every day for several years: At home, three devices coexist peacefully and complement each other. Each device implements its concept in different ways. You can see how they are arranged inside.

SoundBar MR

The quasi-open speaker system contains

the 2x 2.3-watts tube triode SE amplifier

TV SoundBar MR
TV SoundBar MR
Chassis Tang Band W5-2143: 5 inch, full range design, bamboo fiber paper cone with durable structured santoprene, very low THD ( 2nd and 3rd harmonic distortion)
Darckside
Darckside
The back wall should allow the speaker to "breathe" freely and easily. This is the prerequisite for natural sound.
View from above
View from above
Inner workings, all inner surfaces are covered with bitumen mastic.
Supply, earthing, fuse
Supply, earthing, fuse
Toroidal transformer, choke and high frequency power filter, soft start system of amplifier, protective earthing, thermal fuse 110 degrees C.

click to expand

Important design features, without which you should not even expect a decent result.


The inner surface of the body is covered with bitumen mastic to absorb the low-frequency vibrations and resonances of the walls.

The amount and size of the holes in the back panel affect the height of the 3rd harmonic in the audio spectrum. This could spoil all of your efforts.


This is extremely important: low mechanical quality factor (Qm, one of Thiele/Small Parameter) thus the mechanical damping of the driver. This is required for correct control of the diaphragm at low frequencies.

Harmotronix

It is a composition of fine tube technology with the best components from the world of solid state

Harmotronix face
Harmotronix face
Standard Enclosures from Hammond (inch: 17 x 10 x 2); the front panel is self-designed and handmade.
Harmotronix interior
Harmotronix interior
Tube harmonize unit and RIAA preamp + headphone amp in aluminum case.
Harmotronix interior
Harmotronix interior
Supply, two toroidal transformers, HF filter
Harmotronix interior
Harmotronix interior
Tube harmonize unit and RIAA preamp + headphone amp, cover is off

click to expand

This device is currently permanently connected before a solid state (IC & transistors) system to ennoble the sound.


The output of the headphones amplifier has two sockets:
6.3 mm and 3.5 mm.

It is possible to connect two pairs of headphones to enjoy the music together at the same time.


It is intended to set an independent basic signal level for each channel. Sometimes this is useful if the left and right ears have different sensitivities. Or a sound track has a skew center.



Hear how the tubes sound

7 tubes

Here is the empirical finding of our older colleagues and modern knowledge to design human hearing

7tubes face
7tubes face
Standard Enclosures from Hammond (inch: 17 x 10 x 2); front panel is self-designed and handmade.
7tubes: Terminal
7tubes: Terminal
Headphones Output Jack 6.3mm, AUX & RIAA
7tubes interior
7tubes interior
Main unit: 7 double vacuum triodes, supply section with air equipment.
7tubes interior
7tubes interior
Main unit: 7 double vacuum triodes: 4x ECC83, ECC82, 2x ECC99.
7tubes interior
7tubes interior
Fan: Noctua NF-A6x25 FLX; Max. noise emission: 12.9 dB(A); MTBF (Mean Time Between Failures): 150.000 hours
Main unit with the vacuum tubes
Main unit with the vacuum tubes
This is just a sample implementation, the unit is before assembly
Main unit bottom
Main unit bottom
This is just a sample implementation, the unit is before assembly
Bottom level
Bottom level
You can see the opening for adjusting the input capacitance.
Side view
Side view
Size inch: 17 x 10 x 2; (470x270x90mm around)
Backside
Backside
Two filament compensation potentiometers and power switch can be seen.

click to expand

This device has seven double vacuum triodes.

Four triodes shape the RIAA preamplifier.

The RIAA curve is executed by passive filtering of mica capacitors. No negative feedback.


The  headphones amplifier is a transformerless cascade according to SRPP technology and with my modifications.

Again, no negative feedback is used.


There is a natural spectral composition that is physiological to our hearing conform. So it happened in nature that the vacuum triodes make this sound.

Hear how the tubes sound