Hi to all the good folks of DIY Audio.
Looking for my first set of powered monitors and I was led to the Yamaha HS8 by a friend and also biased towards it as it uses the LM3886 IC onboard. However, I find the schematic confusing... Can anyone shed some light on what the row of njm4558 opamps are doing? (top right of schematic Page 42)
I can't spot how they're connected, or what they would be doing there.
I'm also interested in where the LM3886's Pin 3 (output) goes on both the HF and LF amps. It's a little confusing to someone who has done only chipamp, Jaycar and Altronics builds of the gainclone. I'm used to seeing Thiele/Zobel networks and capacitors for DC blocking, but that's about it.
There's a lot of extra stuff in this design I don't understand, but would like to!
I'm sure others are interested too, as it's a pretty popular monitor these days after taking over from the passive Yamaha NS-10M.
I'm looking to rule out any DSP in the Yamaha HS8 as so many other powered monitors now seem to have, that's why I'm looking and asking here, what these other parts of the circuit do. Some sort of crossover/filter network for splitting HF and LF obviously, but something else too? I wonder... I'm just not that knowledgeable on the complexities beyond simple gainclone builds and I'm wondering if some readers here can tune me in on what it all means.
As it seems to have disappeared from the internet, I've hosted the Yamaha HS8/7/5 service manual and the amp's schematic can be seen on page 42 & 43.
Any thoughts appreciated in advance.
Cheers!
Looking for my first set of powered monitors and I was led to the Yamaha HS8 by a friend and also biased towards it as it uses the LM3886 IC onboard. However, I find the schematic confusing... Can anyone shed some light on what the row of njm4558 opamps are doing? (top right of schematic Page 42)
I can't spot how they're connected, or what they would be doing there.
I'm also interested in where the LM3886's Pin 3 (output) goes on both the HF and LF amps. It's a little confusing to someone who has done only chipamp, Jaycar and Altronics builds of the gainclone. I'm used to seeing Thiele/Zobel networks and capacitors for DC blocking, but that's about it.
There's a lot of extra stuff in this design I don't understand, but would like to!
I'm sure others are interested too, as it's a pretty popular monitor these days after taking over from the passive Yamaha NS-10M.
I'm looking to rule out any DSP in the Yamaha HS8 as so many other powered monitors now seem to have, that's why I'm looking and asking here, what these other parts of the circuit do. Some sort of crossover/filter network for splitting HF and LF obviously, but something else too? I wonder... I'm just not that knowledgeable on the complexities beyond simple gainclone builds and I'm wondering if some readers here can tune me in on what it all means.
As it seems to have disappeared from the internet, I've hosted the Yamaha HS8/7/5 service manual and the amp's schematic can be seen on page 42 & 43.
Any thoughts appreciated in advance.
Cheers!
Thanks for the service manual.
In the SM is the block diagram which gives a good guide to the overall operation of the circuit.
The details of the power amp sections are covered in standard opamp theory....there are plenty of resources online, Google is your friend.
That should get you started, any specific questions, just ask.
Dan.
In the SM is the block diagram which gives a good guide to the overall operation of the circuit.
The details of the power amp sections are covered in standard opamp theory....there are plenty of resources online, Google is your friend.
That should get you started, any specific questions, just ask.
Dan.
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