The new "My Ref" Rev C thread

[AndrewT]

Originally Posted by SRMcGee

Sorry for what may be a particularly dumb question

don't apologise. No question is dumb.

This is a very good question.

What will the circuit try to do if the 3886 part enters mute mode?
Could the opamp survive this loading. Could it be operated outside of specification.
Will the 3886 mute function work as a mute when it is operated as a current source?

[regiregi22]

Originally Posted by SRMcGee

Folks:

Sorry for what may be a particularly dumb question, but is there a simple way to implement a mute function with the MyRef RevC?

Thank you,
Scott

Yep, just look at the datasheet for the "mute" pin. It should be tied to -v through a 33k res or so. Just place a switch in there, so when it is "open", it will get muted.

[troystg]

I may be mistaken, but I think Mauro originally stated that the mute function could NOT be used in this implementation...

[regiregi22]

Originally Posted by troystg

I may be mistaken, but I think Mauro originally stated that the mute function could NOT be used in this implementation...

mmmmm something about it comes to my mind. Something about being nested in the LM318 feedback loop and the mute function causing some instabilities.
Anybody out there with better memory?

[AndrewT]

Originally Posted by AndrewT

What will the circuit try to do if the 3886 part enters mute mode?
Could the opamp survive this loading. Could it be operated outside of specification.
Will the 3886 mute function work as a mute when it is operated as a current source?

Originally Posted by regiregi22

look at the datasheet for the "mute" pin. ............... Just place a switch in there, so when it is "open", it will get muted.

Originally Posted by regiregi22

Something about being nested in the LM318 feedback loop and the mute function causing some instabilities.

Regi,
do you read?
Read again the expanded three questions following SRMcGee post.

[regiregi22]

My apologies Andrew, I was at work, where the forum is seen like a crap. Login doesnt work well, website doesnt reload properly...I couldnt read your post.

Now I understand why it cannot be implemented, closer to what I had in mind. Thank you.

Sorry for that again, regards

Regi

[SRMcGee]

Folks:

Okay, since it appears that I cannot exploit the mute function on the MyRef RevC LM3886, perhaps a relay can be used. Does it make any sonic difference where a "mute" relay is used in the circuit? This project involves a Pedja Rogic buffer, Lightspeed attenuator and the MyRef RevC, and the relay could be placed before or after any of these stages.

Regards,
Scott

[AndrewT]

Hi,
you could place an input mute activated by loss of mains power on any of the inputs.
I would be tempted to put one on the front end of MyRevC and also put one on the input to the pre-amp. But only if the source can drive the muted circuit without damage.

Have you read the threads talking about the LDRs and what happens when they are powered down?

As an aside.
The same MyRevC input muting relay could also be activated on detection of excessive output DC. Just in case it is a preceding source that has gone faulty.

[SRMcGee]

Andrew:

Man, you're quick! I had read the LDR threads but must have missed the discussion regarding what happens when they power down -- thank you for the pointer. I'll take another look.

Much appreciated!

Regards,
Scott

[regiregi22]

Why not forcing the protection relay to kick in? I have added a switch to the MyRef_C protection circuit schematic. Anybody see anything wrong with that?

Will it correctly work?