I am looking for a bit of troubleshooting advice, please.
While happily playing my Geco Audio MM Phono Stage, and loving the sound,
I also this week completed my build of the Geco Audio MC PS.
This afternoon I put it in a box with RCA sockets, and hooked it up to the
15-0-15 30VA transformer that powers the MM PS.
I fitted a MC cartridge that I know is good to the SME arm on my Thorens TD125, and
put Oscar Peterson on my platter.
Bated breath, as they say.
Well, it plays, and on both channels.
But the sound is very, very soft.
Nothing until the amp's volume is on 3 o'clock, and quite soft at 5 0'clock (max volume).
I tried it both with the MM Phono Stage also connected, and with only the MC Phono Stage connected to the transformer.
The MM Phono Stage works perfectly while the MC Phono Stage is connected.
I measure 15VAC coming in at the MC pcb, and -15.08VDC on pin 4 of the LME49720 opamp and +14.96VDC on pin 8.
(Is this opamp correct?)
Given the above information, and the pictures below, what should I look at / check and correct, please?
Thanks, Johan.
While happily playing my Geco Audio MM Phono Stage, and loving the sound,
I also this week completed my build of the Geco Audio MC PS.
This afternoon I put it in a box with RCA sockets, and hooked it up to the
15-0-15 30VA transformer that powers the MM PS.
I fitted a MC cartridge that I know is good to the SME arm on my Thorens TD125, and
put Oscar Peterson on my platter.
Bated breath, as they say.
Well, it plays, and on both channels.
But the sound is very, very soft.
Nothing until the amp's volume is on 3 o'clock, and quite soft at 5 0'clock (max volume).
I tried it both with the MM Phono Stage also connected, and with only the MC Phono Stage connected to the transformer.
The MM Phono Stage works perfectly while the MC Phono Stage is connected.
I measure 15VAC coming in at the MC pcb, and -15.08VDC on pin 4 of the LME49720 opamp and +14.96VDC on pin 8.
(Is this opamp correct?)
Given the above information, and the pictures below, what should I look at / check and correct, please?
Thanks, Johan.
