Vacuum tube project 7tubes

All design, schemes (circuits) and technical solutions can be reproduced privately for your own use. Publication is only permitted with a copyright notice.
WEB:  7tubes.com   ::  harmotronix.com
All rights reserved © 2017 - 2021 Jürgen Maier, Berlin Germany.

Documentation

User manuals: pdf - Files (En & De)

Circuits  Files (download als Zip)

User manuals: pdf - Files (En & De)

Circuits  Files (download als Zip)

User manuals: pdf - Files (En & De)

Circuits: pdf - Files (download als Zip)

In the picture to the left is the terminal of the 7tubes machine.

7tubes

DOWNLOAD

KEY FEATUREs of the Machine

7tubes

Key features of the headphones tube amplifier:

:: No negative feedback;
:: Controlling of intensity the tubes sound;
:: High slew rate that prevents odd order distortion;
:: Current-on-demand at the output (current output);
:: Measurements at a load of 32 Ohm, Input 0,3 V => Output 0,6 V;

:: Measurements at a load of 310 Ohm, Input 0,3 V => Output 2,2 V;

:: Frequency Response: 10 Hz ... 40 kHz => Diff < 0,5 dB;
:: Dynamic range at 1 kHz is better than 105 dB;
:: Interferences at 50 Hz, 100 Hz, 150 Hz better than -89,3 dB;
:: WIMA capacitors in the signal path;
:: Output stage SRPP on tube ECC99 present high power;
:: For headphones with an impedance of 30 up to 600 Ohms;
:: Modern vacuum tubes of new production: ECC83 + ECC99 x2


Key features of the RIAA tube preamplifier:

:: Input: MM Cartridge (2,5 V.... 7,5 mV RMS);

:: Input impedance: 47 kOhm; 0-100-150-250 pF;

:: Gain: 42 dB at 1 kHz;
:: Output impedance no more than 5 kOhm;

:: Noise at 1000 Hz better than -95 dB;
:: WIMA capacitors in the signal path;
:: Mica capacitors to get the RIAA curve;
:: RIAA curve deviation: less than +/- 0.5 dB
:: Passive filter mode for RIAA equalization;
:: The input stage is based on SRPP design;
:: No negative feedback;
:: Modern vacuum tubes of new production: ECC83 x3 + ECC82


Connections:

:: Headphone: stereo jack 6,3 mm;
:: MM cartridge, RIAA, AUX: RCA cinch gold-plated;

:: Power cold device socket with protective contact;
:: Voltage power 230 Volts, 50/60 Hz;
:: Power consumption: 65 watts around.


Chassis:

:: Front panel: oak;
:: Aluminum housing with dimensions:
:: L x H x B: 470 x 270 x 90 mm around;
:: Fan: Noctua NF-A6x25 FLX; Max. noise emission: 12.9 dB(A);

:: MTBF (Mean Time Between Failures): 150.000 hours;
:: Weight: 5,4 kg around.

inscription                  stock      docs        legal           contact

DOWNLOAD

KEY FEATUREs of the HARMOTRONIX

Key features of the vacuum tube Harmonization Unit:

:: Three modes for adjusting the tubes sound: pure direct  -  smooth  -  warm;

:: Double vacuum triodes used (ECC81 or ECC82, choice);

:: LED VU meter for volume control is available;

:: Input: 0 dBu (0.775 V RMS); Impedance: 50 kOhm;

:: Output: 0 dBu (0.775 V RMS);

:: Output impedance no more than 5 kOhm;

: WIMA capacitors in the signal path;

:: Soft Start System for long life of the tubes.


Key features of the headphones amplifier:

:: TPA6120A2 High Fidelity Headphones Amplifier;

:: High slew rate that prevents odd order distortion;
:: Current-on-demand at the output (current output);
:: Wide range frequency response;

:: For headphones with an impedance of 16 up to 600 Ohms;

:: There are two 6.3 mm & 3.5 mm jacks for connecting headphones;

:: It is possible to use two headphones with different impedances at the same time.


Key features of the RIAA preamp:

:: Ultra low noise ICs (LM4562 or OPA2134 (FET), choice);

:: Input: 5 mV RMS; Impedance: 47 kOhm;

:: Input capacity is set to: 0-100-150-250 pF;
:: Output: 0 dBu (0.775 V RMS);

:: WIMA capacitors in the signal path;

:: Passive filter mode for RIAA equalization;

:: RIAA curve deviation: less than +/- 0.2 dB.


Connections:

:: Headphones: stereo jacks 6.3 mm & 3.5 mm;
:: MM cartridge, RIAA, AUX: RCA cinch gold-plated;

:: Power cold device socket with protective contact;
:: Voltage power 230 Volts, 50/60 Hz;
:: Power consumption: 18 watts around.

DOWNLOAD

In the meantime I am leading other projects into the final phase.

The sale will come later and the documents will appear here.

KEY FEATUREs of Sound Bar MR

:: Modern vacuum tubes of new production:

:: ECC99 x2 + ECC82 x2:
:: SRPP input & SE Output stage design;

:: Output power: 2 channel 2.3 watts each;

:: Input: 0.3 V RMS (-7.8 dBu);

:: Impedance: 47 kOhm;

:: Frequency response and distortion:
:: determines a output transformer.


Supply v2.1:

:: Set with high voltage anode regulator
:: and anode voltage delay about 20 sec.

Supply v2019:
:: Soft start of system (time intervals are around):

:: I. 0-12 sec: filament is preheating with half voltage;
:: II. 12-30 sec: filament is full heating voltage;
:: III. 42 sec: the anode voltage is on;
:: Power consumption: 50 watts around.

SoundBar MR