Hi,
Trying to figure out the 'Neon bulb balancing trick' used on EMI Altecs. You guys have pulled through so far for me, hopefully this wont be very hard to find an answer to.
The UA175 and EMI/Altec both had plate balance on the 6BC8, but the EMI used a neon bulb to create a ticking that was canceled out when perfectly balanced.
Here is a more through explanation by someone on GS:
"As i understand from "Recording The Beatles", the Balance was a way to synchronize the two amplifiers in the "push/pull" design of the RS124. it was done with a neon Bulb that was wired to the circuit, when the technician pushed the momentary switch (the one you called balance button) the bulb would create a repetitive low frequency "ticking" sound. the sound was sent through both amplifiers. since one was in reverse phase the two amplifiers would null if they were perfectly balanced.
but if you could hear the " tickling" noise you knew the amplifiers were not properly balance. in that case you could adjust the amplifiers balance with the screw hole in the upper left corner above the balance. "
Anyone have an electrical explanation, or know any similar applications I can look at to see exactly how this was implemented?
Thanks!
Trying to figure out the 'Neon bulb balancing trick' used on EMI Altecs. You guys have pulled through so far for me, hopefully this wont be very hard to find an answer to.
The UA175 and EMI/Altec both had plate balance on the 6BC8, but the EMI used a neon bulb to create a ticking that was canceled out when perfectly balanced.
Here is a more through explanation by someone on GS:
"As i understand from "Recording The Beatles", the Balance was a way to synchronize the two amplifiers in the "push/pull" design of the RS124. it was done with a neon Bulb that was wired to the circuit, when the technician pushed the momentary switch (the one you called balance button) the bulb would create a repetitive low frequency "ticking" sound. the sound was sent through both amplifiers. since one was in reverse phase the two amplifiers would null if they were perfectly balanced.
but if you could hear the " tickling" noise you knew the amplifiers were not properly balance. in that case you could adjust the amplifiers balance with the screw hole in the upper left corner above the balance. "
Anyone have an electrical explanation, or know any similar applications I can look at to see exactly how this was implemented?
Thanks!
