GlassWare Audio Design
Thanks for supporting the Tube CAD JournalIn Stock! 6H30 in an octal envelope. Perfect for octal headphone amplifiers.
Product Description
The 6H30PI is the octal version of the 6H30 twin triode. The sad situation for an octal partisan like myself is that 9-pin twin triodes greatly outnumber octal twin triodes. The only real choices for octal twins are the 6AS7, 6BL7, 6BX7, 6SL7, 6SN7, 6SU7, 12SL7, 12SN7, 12SX7, 5691, 5692, 6080, 6082, B65, and ECC32. In contrast, the list of 9-pin twin triodes is too long to list.
Some of these 9-pin tubes are dirt cheap and sound great in an Aikido line amplifier, such as the 6BQ7 at less than $2. Other 9-pin triodes can cost $300 each and also sound great, such as the cinch-waist 6922s from the Amperex. But beyond price range, 9-pins tubes offer many more choices in terms of gain and output impedance. Therefore, considering the spare pickings with octal tubes, the 6H30Pi is truly a welcome addition, particularly as it fills in a notch in the present lineup.
How's that ?
When driving low-impedance headphones or long lines of high-capacitance cables, the 6SN7 type triode just doesn't cut it. Okay, but don't the 6BL7 and 6BX7 already fill that bill? No, not really. Here's why: the following table shows the results for all five triodes at 100V cathode-to-plate voltage and 0V grid-to-cathode voltage.
Tube____Vh______Ih_______Ik_______rp_____mu_______Zo 6AS7.......6.3V.........2.5A.........562mA.......167..........4.3...............32 6BL7.......6.3V........1.5A..........33.7mA......2110........17.2............116 6BX7.......6.3V........1.5A..........86mA.........860.........12.2..............65 6H30Pi....6.3V........0.825A......112mA.......714.........18.5..............37 6SN7.......6.3V........0.6A.........10.8mA.......7320........23.5.............299
Notice that for the 6H30Pi's heater current increase of only 225mA we get a nearly tenfold decrease in output impedance over the 6SN7 in a cathode-follower configuration. Also note that the only other triode that beats the 6H30Pi is the 6AS7, but at the cost of nearly three times the heater current and much too high an idle current and far less linearity.
Now imagine an Aikido headphone amplifier with a 6SN7 input tube and a 6H30Pi output tube and a pair of Sennheiser HD650s and a big smile on your face and a green tint to your friend's faces.
Some of these 9-pin tubes are dirt cheap and sound great in an Aikido line amplifier, such as the 6BQ7 at less than $2. Other 9-pin triodes can cost $300 each and also sound great, such as the cinch-waist 6922s from the Amperex. But beyond price range, 9-pins tubes offer many more choices in terms of gain and output impedance. Therefore, considering the spare pickings with octal tubes, the 6H30Pi is truly a welcome addition, particularly as it fills in a notch in the present lineup.
How's that ?
When driving low-impedance headphones or long lines of high-capacitance cables, the 6SN7 type triode just doesn't cut it. Okay, but don't the 6BL7 and 6BX7 already fill that bill? No, not really. Here's why: the following table shows the results for all five triodes at 100V cathode-to-plate voltage and 0V grid-to-cathode voltage.
Tube____Vh______Ih_______Ik_______rp_____mu_______Zo 6AS7.......6.3V.........2.5A.........562mA.......167..........4.3...............32 6BL7.......6.3V........1.5A..........33.7mA......2110........17.2............116 6BX7.......6.3V........1.5A..........86mA.........860.........12.2..............65 6H30Pi....6.3V........0.825A......112mA.......714.........18.5..............37 6SN7.......6.3V........0.6A.........10.8mA.......7320........23.5.............299
Notice that for the 6H30Pi's heater current increase of only 225mA we get a nearly tenfold decrease in output impedance over the 6SN7 in a cathode-follower configuration. Also note that the only other triode that beats the 6H30Pi is the 6AS7, but at the cost of nearly three times the heater current and much too high an idle current and far less linearity.
Now imagine an Aikido headphone amplifier with a 6SN7 input tube and a 6H30Pi output tube and a pair of Sennheiser HD650s and a big smile on your face and a green tint to your friend's faces.
