C2-x phono gain:
I've done some testing and have some data.
I fed aux, DAD, and MM inputs with a 1000Hz sine wave at their specified levels and measured Vout @pre-out and rec-out. The input voltages were set with the signal generator loaded by the respective input. The output voltages were unloaded/only DMM across the output. Measured w/Fluke 88 DMM.
(pre-out spec @full volume: 1.5V; rec-out spec .15V)
MM: (2.5mV in)1.426V out (spec 1.5V)
MM w/-10db cut button selected: (7.9mV in) 1.42V out (spec 1.5V)
Aux/DAD: (.150Vin) 1.50V out (1.5Vspec)
Then I tested the output of the Bang & Olufsen 8002/MMC-1 cartridge and the PX-2/AT440MLa cartridge, unloaded/meter direct which probably yields slightly higher than actual output voltages. The first track of Miles Davis "Straight No Chaser" was sampled for avg and peak V.
MMC-1 (spec: 2.12mV@5cM): avg .7mV/2.8mV peak
AT440MLa (spec 4.0mV@5cM): avg 1.4mV/5.2mV peak
CD output w/jazz record, fairly dynamic: avg .35V/.75peak
Tuner, jazz station/calm announcer: avg .27/.50peak.
I'm assuming that normal peak levels=specified input levels, in which case actual input levels are much higher than specd-in the case of CD by a factor of 5! (14db), tuner: 3.3 (10.4db)
This explains why I need to attenuate line inputs to match levels, especially with MMC B&O carts. And my high output Adcom MM VandenHul, although rated at 2.5mV into 47K-higher than the B&O-has less "snot" than the B&O. Neither of these cartridges can fully drive my system to "party" levels. If I select MC and <10db> phono cut, then I can drive the hell out of it, but now the situation is reversed: the MC input is too "hot" compared to line ins (without attenuaters-to solve the imbalance I'm running <10db> attenuaters on tuner and DAD inputs) and the MM is now unusable in that the back panel <10db phono> button affects all phono inputs.
If anyone's interested: MM phono gain is 55db, 45db w/<10db> button selected. (measured) calculated from spec: 55.6db
Line inputs: 20db (measured/specd)
MC, calculated from spec: 83.5db.
Using calculator @ www.muzique.com/schem/gain.htm
phil
ps: Mandak-did the discussion of low-cost carts on VE lead you to the AT440 as well?
I've done some testing and have some data.
I fed aux, DAD, and MM inputs with a 1000Hz sine wave at their specified levels and measured Vout @pre-out and rec-out. The input voltages were set with the signal generator loaded by the respective input. The output voltages were unloaded/only DMM across the output. Measured w/Fluke 88 DMM.
(pre-out spec @full volume: 1.5V; rec-out spec .15V)
MM: (2.5mV in)1.426V out (spec 1.5V)
MM w/-10db cut button selected: (7.9mV in) 1.42V out (spec 1.5V)
Aux/DAD: (.150Vin) 1.50V out (1.5Vspec)
Then I tested the output of the Bang & Olufsen 8002/MMC-1 cartridge and the PX-2/AT440MLa cartridge, unloaded/meter direct which probably yields slightly higher than actual output voltages. The first track of Miles Davis "Straight No Chaser" was sampled for avg and peak V.
MMC-1 (spec: 2.12mV@5cM): avg .7mV/2.8mV peak
AT440MLa (spec 4.0mV@5cM): avg 1.4mV/5.2mV peak
CD output w/jazz record, fairly dynamic: avg .35V/.75peak
Tuner, jazz station/calm announcer: avg .27/.50peak.
I'm assuming that normal peak levels=specified input levels, in which case actual input levels are much higher than specd-in the case of CD by a factor of 5! (14db), tuner: 3.3 (10.4db)
This explains why I need to attenuate line inputs to match levels, especially with MMC B&O carts. And my high output Adcom MM VandenHul, although rated at 2.5mV into 47K-higher than the B&O-has less "snot" than the B&O. Neither of these cartridges can fully drive my system to "party" levels. If I select MC and <10db> phono cut, then I can drive the hell out of it, but now the situation is reversed: the MC input is too "hot" compared to line ins (without attenuaters-to solve the imbalance I'm running <10db> attenuaters on tuner and DAD inputs) and the MM is now unusable in that the back panel <10db phono> button affects all phono inputs.
If anyone's interested: MM phono gain is 55db, 45db w/<10db> button selected. (measured) calculated from spec: 55.6db
Line inputs: 20db (measured/specd)
MC, calculated from spec: 83.5db.
Using calculator @ www.muzique.com/schem/gain.htm
phil
ps: Mandak-did the discussion of low-cost carts on VE lead you to the AT440 as well?
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