Can any pre-amp be mod for HT bypass?

disneyjoe7

The title pretty much sums it up.


Electrically how are these pre doing it?

unc2701

Yes. You put a switch on it just before the pre-out RCA's. In one position it takes the output from the pre; in the other position it take the output directly from the HT-bypass input.

Modding an integrated is a little more involved.

disneyjoe7

Could a relay be used also, I figured a 4PDT may do the tick. This way it's auto bypassed if off, for HT mode. Cool or NO NO?

unc2701

I'd prefer a switch, but there's no reason a relay wouldn't work. Also, all the grounds are usually tied, so a DPDT will work. I've traced some bad channel seperation back to the grounds being tied, but it's a lot of work to swap out all the switches to have twice as many poles to do the ground switching, too.

disneyjoe7

With a DPDT switch or relay, are you splitting both out and input to them self vs. to original circuit?

unc2701

OK, with a DPDT, I was assuming that you'd have a dedicated HT bypass input that could not be run through the pre.

With 4PDT, you could disconnect one of the inputs from the pre and route it straight to the output.

disneyjoe7

Ok I see your point, but I considered doing this to a pre which doesn't have a HT input using an existing input for such propose.


But I don't think that is an issue also, as I found my AVR will not give me a fixed level output from the tape outputs. I was trying to use the AVR for the dac as two sources are digital inputs. As this didn't work out, your idea with the DPDT would work also. I thought most pre had a HT bypass as it seems very popular, but I don't see a lot listed as such used that is. I could see playing with a "Cheap" pre but would have an issue modding a Nice pre. I'm just playing with the pre idea, with my HT / 2 channel setup.