Transcendent Sound       Vacuum Tube Audio Amp Kits

The Sub Buddy

Something Different  

Full Kit without Tubes- $599, With Tubes $699

A universal audio product that can improve any system.  Here’s what it can do:

◆  It’s an adjustable high pass filter for driving a main speaker amp.

◆  It’s a high current, low impedance buffer for superior driving of interconnect cables.

◆  It has an isolated, adjustable output for driving a subwoofer amp.

◆  It’s a headphone amplifier

◆  It’s a noiseless, unity gain, master volume control for directly connecting a signal source to your amplifiers.

◆  Better than a passive preamp.  Drives long cables.


Subwoofers are very common, but integrating them into a sound system can be very tricky.  Often times the result is overpowering, boomy bass.  The Sub Buddy provides a means for a seamless transition between the sub woofer and main speakers.

There are two convenient controls that are used to mate the subwoofer to the main speakers.  One is a volume control that drives the sub- woofer amp. Music tracks with excessive bass can be tamed without having to crawl on the floor to adjust the subwoofer amp level.  The second control is the high pass filter for the main speakers.  The higher that control is set, the less bass the main speakers contribute to the sound.  It is often detrimental to set the crossover frequency for the sub the same as the main speakers.  The high pass filter allows different frequencies be used which dramatically improves subwoofer integration.

The high pass filter improves the performance of speakers when used with a subwoofer.  By rolling off the lowest frequencies, the loudspeaker is relieved of massive cone excursions which reduces distortion and smearing in the midrange and treble.  Stock frequencies are: FLAT, 50 HZ, 70 HZ, 100 HZ, 150 HZ, and 220 HZ.  Rolloff is a gentle, but effective 6 dB/octave.  The FLAT setting allows comparisons with no rolloff and also let’s the Sub Buddy function as a dual amp driver with independently adjustable outputs.  The Sub Buddy is customizable.  By changing the timing capacitors, any rolloff frequency can be set.  For example, by making the capacitors ten times smaller, each rolloff frequency will be be ten times higher.            

It has been discovered that high current output greatly improves sound quality by properly driving interconnect cable capacitance.  The longer the cable, the greater the improvement, but substantial gains will be attained with cables of three feet in length.  The sound is clearer with more detail and presence.  The Class A high current tubes will add a layer of richness to the sound.  This is especially beneficial for use with solid state amps.  The Sub Buddy’s outputs can provide up to 20 mA RMS of drive current into a 30 ohm load.  Long interconnect cables are no longer a problem.     

The Sub Buddy will provide 15 milliwatts into headphones with an impedance of 32 ohms.  That is enough power to produce moderately loud levels but not be uncomfortably loud.  Output increases with rising impedance and it can make 40 milliwatts into 100 ohms for better performance.  

Controls are simple but versatile.  The MASTER VOLUME adjusts the volume of both outputs.  The SUBWOOFER VOLUME allows the subwoofer output to be further adjusted independently.  Once the volume is set as desired, the subwoofer can be easily adjusted, up or down, from the front panel.  The SUBWOOFER VOLUME also sets the volume of the headphone output.  By setting the SUBWOOFER at

12 o:clock and then adjusting the MASTER for desired volume, the SUBWOOFER control can be adjusted up or down as desired.    

Many systems have a sufficiently strong signal source and gain that an active preamp is unnecessary.  These systems are good candidates for use with a passive preamp.  The Sub Buddy is an ideal choice for such systems as it has no gain, and the high current drive will greatly improve the sound by better driving cable capacitance.  Passive preamps, by their inherit nature, insert a high impedance into the signal path which greatly chokes off the supply of current.  Replacing a passive preamp with a Sub Buddy will reveal detail you never thought existed.  

The Sub Buddy can also be used with an active preamp.  It can be directly connected to a phono preamp on a pure vinyl system.  It has been designed to sit on top of our Grounded Grid Preamp.

The Sub Buddy also contains a 10 second time delay mute circuit.  This protects your speakers and amps from any transients and noises when equipment powers up or down.  The entire system can be safely energized simultaneously.  



Harmonic distortion measures less than .08% at one volt and is mostly second and third order.

Noise spectra shows only a tiny bit of noise at 2o microvolts. The noise below 20 Hz is room rumble being picked up by the tubes and is inaudible.  The Sub Buddy is noiseless.  

On left:  The 10 kHz square wave at 4 volts peak tp peak to perfect.

On right:  The 100 kHz square wave shows a rise time of 0.8 microseconds.  Man that's fast!

Tubes used:

Two- 6H30pi

One- ECC99

Output impedance:  65 ohms

Bandwidth: Flat from 10 Hz to 300 kHz

Voltage:  120 or 230-240V, 50 to 60 Hz

Footprint: 10 by 15 inches.

Weight: 10 pounds.