My_Ref Fremen Edition RC - Build thread

[Marra]

What to look for?

[bcmbob]

Could that also indicate a weak or defective relay ?

[AndrewT]

measure the output offset.
Remember when the relay is triggered you must measure to the Main Audio Ground, not the isolated ground connection that has been broken by the open relay.

[badrisuper]

I had the same problem like relay clicking on and off again and again in one channel, later identified I shorted out one channels speaker channel? Will it cause this problem? I had both boards singing in one speaker terminal and from another terminal the relay click on and off.

Badri

[AndrewT]

with the chipamp protection active, the chip may be switching ON/OFF. That might trigger the relay detection circuit.

[ClaveFremen]

Originally Posted by bcmbob

Tom, You belong on this thread as much as anyone. The FE is, as I'm sure Dario would acknowledge, an extension of all the work and contributions from a whole lot of folks like yourself.
(...)
Hoping to get you and the other "Old Dudes" onboard - hands-on soon.

Absolutely!

Originally Posted by lehmanhill

Dario reminded me that I needed to check orientation. To be honest, I hadn't thought to do that, although I should have. As always happens, I managed to pick the wrong orientation for both the ZN and the True Copper. Of course, I had the right orientation for the K71, so I am batting 1000.
(...)
In the end, both the TC and K71 beat the ZN for clarity and image in my system.

I'm happy you found same results.

Originally Posted by Marra

Thanks for the reply Dario.
(...)
The LM318 was changed and unfortunately I don't have any spares of the bc639/640's.

You're welcome.

You should try to replace those transistors, you can use easy to find BD139-16/BD 140-16 in place of BC639/BC640.

It's easy to damage them while measuring.

Originally Posted by madisonears

If your relay clicks repeatedly or not at all, you most likely have other problems.

Originally Posted by AndrewT

that sounds like DC detection and intermittent triggering of the relay to protect the speaker output.

Absolutely

Originally Posted by badrisuper

I had both boards singing in one speaker terminal and from another terminal the relay click on and off.

H Badri,

so both channels are working if connected (one at a time) with the same speaker terminals?

[badrisuper]

Originally Posted by ClaveFremen

H Badri,

so both channels are working if connected (one at a time) with the same speaker terminals?

Yes, Dario, will be completing it this weekend. Sings well.

Badri

[Marra]

The saga continues.My friend suggested I replace/resolder D1 which was slightly of square which I did this evening and having powered up all voltages appear ok and there is 4.3mv offset and 14.58v across the relay diode.It has been sat on the workbench/dining table for the past 30/40 mins without anything untoward happening.I think it might be good to go

[lehmanhill]

Marra,

Great news. Here is hoping for stable operation and sweet, sweet sounds.

Jac

[ClaveFremen]