Above is the catalog insert for the BTO, probably the most sought after Garnet amplifier. Most likely due to the fact that only about 300 were made during a three year time span, the heads fetch 'silly money' in the U.S. of A, while the cabinets don't. This is a crying shame because the cabinet came optionally in a 4X12" set-up with 70-watt Marsland speakers 'featuring' Alnico V magnets. Can you say "but-tah"? I own a 4X12" BTO cabinet and it is the smoothest sounding bass cabinet I have ever heard. Getting back to the head, four EL34's with a high voltage supply easily gave 150 watts of output power (before clipping) into a standard cabinet with three 15" speakers (Model R260D) or two 15" speakers and one horn (Model L260D, as shown above). Greg Leskiw (who replaced Randy Bachman in The Guess Who) insisted on JBL's for the 15" speakers in his BTO cabinets, making this amplifier/cabinet LOUD! There are many slight variations in the construction of the head, which include;

• The original chassis mounts 'upside down' on the top of the cabinet (as shown above; think Fender) while the later version chassis mounts on the bottom (think Marshall).
• Brass trunk corners were used on all earlier Garnet amplifiers, including the BTO's. Chrome corners equals 1970's amplifiers.
• The 'Stinger' was a 6AN8 on a few of the earliest BTO's, followed by a 6AU6 and finally the much more seen 6JW8. FYI; The 'Stinger' is NOT the same as a 'Herzog'. The 'Tremolo' on some models may also use a 6AU6 and have a 'swing' that is to die for! This is because the voltage gain of a 6AU6 (pentode) is much higher that the triode section of either the 6AN8 or 6JW8. This gives HUGE depth to the 'Tremolo'.
• The original silk-screened 'Garnet' EL34's are Siemens tubes! Gar is also one of only two manufacturers I know (the other being Traynor) that used an EL34 in a way that promotes tube reliability, but still I definitely wouldn't put anything but a top-notch EL34 in this amplifier, unless you are prepared to seriously modify the screen and bias supply.
• There was a 'Bass' version available, that would give any Ampeg SVT a serious run for its' money! These are identified by the bass clefs attached to the head and cabinet. The BTO 600 put out a clean 225 watts RMS with six EL34's.