SiALM Audio Level Meter

The SiTubes ALM is an audio level meter, packaged in a standard octal tube envelope.

It integrates a peak-responding full-wave rectifier circuit to display audio power level.  It provides a 128-segment bar graph on an OLED display, with several programmable scaling and legend options.

The ALM can be powered from an AC or DC voltage, and the power supply input is completely isolated from the signal input.  This allows the ALM to be powered from any available supply, such as a 6.3V AC filament circuit, even if it is floating with respect to the signal input.

For more details, please download the full ALM datasheet (PDF file).

 

Video of the ALM in action!

 

SiDPM Digital "Panel" Meter

The SiTubes DPM is a digital "panel" meter packaged in a standard octal tube envelope.

It measures a DC input voltage from 0 to 2V full-scale.  Several selectable legends (V, mA, A, etc.) can be selected by an external programming resistor.  It is particularly useful to measure supply voltages (such as plate voltage) and tube bias levels (normally plate current) in tube amplifiers.

The DPM can be powered from an AC or DC voltage.  The power input is isolated from the measurement input, so floating measurements can be made up to 1500V above or below the power input.  This allows high-side current measurements - for example, sensing plate current directly at the tube plate -  or the ability to be powered from a supply that is not referred to ground.

For more details, please download the full DPM datasheet (PDF file).

 

SiFWR Full-Wave Rectifier

The SiTubes FWR is an octal solid-state rectifier tube replacement. 

Employing 1200V Silicon Carbide Schottky rectifiers, it can directly replace full-wave rectifier tubes like the 5U4, 5AR4, and other tubes with similar pinouts.

For more details, please download the full FWR datasheet (PDF file).

 

SiTDR Time Delay Relay

The SiTubes TDR is a time delay relay, capable of controling AC or DC voltages.  It is available in two versions:  The TDR-HV can switch voltages up to 1000V (DC or peak AC) at up to 0.9A, and the TDR-LV can switch voltages up to 60V at load currents up to 6.5A.

The TDR-HV is well suited for delaying the application of B+ voltage in directly-heated tube circuits.

The delay time is programmable from zero up to 256 seconds using an external programming resistor.

The TDR is packaged in a standard octal tube envelope, and can replace standard octal glass delay relays.

For more details, please download the full TDR datasheet (PDF file).

 

SiBRX Bridge Rectifier

The SiTubes BRX is a simple bridge rectifier packaged in a standard octal tube envelope.  The BRX-HV uses Silicon Carbide Schottky rectifiers rated at 1200V, 1A; the BRX-LV is rated at 100V, 10A.

The BRX-HV is useful in B+ power supply circuits using bridge or hybrid bridge (tube plus solid-state) rectifier circuits.  The BRX-LV can be used to generate DC supplies for filament supplies.

For more details, please download the full BRX datasheet (PDF file).

SiLPF Low-Power Isolated DC Filament Supply

The SiTubes LPF is an isolated flyback power supply intended to be used as a DC filament or heater supply.  It operates from an AC or DC voltage, and generates 1V - 7VDC output at 5 watts or 1.6A (whichever is greater).

The output of the LPF is galvanically isolated from the input, and can float up to 1500V above or below the input.  This allows it to power DHT filaments that need to operate at DC bias, while powered from a standard heater supply.

For more details, please download the full LPF datasheet (PDF file).