This is just an area I can blab on about stuff without it using up bandwidth in the threads 
Hopefully someone will find it interesting or useful.
Tony.
Hopefully someone will find it interesting or useful. Tony.
The reason my amp has turn on delay....
Posted 6th September 2009 at 12:44 PM by wintermute
Updated 25th November 2009 at 12:08 PM by wintermute (added to amplifiers category)
Updated 25th November 2009 at 12:08 PM by wintermute (added to amplifiers category)
Well I drilled some holes and wired up the new RCA's on the back of my amp, so now I can switch between direct input (bypassing the preamp) and the normal integrated path. Works nicely and I suspect that the slightly soft top end was actually due to the preamp as the sound seems a bit crisper now on the direct input.
However.... when I switch from direct to via the preamp, or vice versa I get a big thump from the speakers
I can avoid if I switch the speakers off but it is not particularly family friendly, especially since I have a 21 month old who will love to switch the switch on and off 
So I'm not sure if it is switch contact bounce or perhaps just switch on thump (the fact that there is no thump at all when switching to the off position leads me to belive it is more like a switch on thump), but it is rather anoying. Puts a bit of a damper on an otherwise successful mod. The switch is a center off type, I might have to get a three pole double throw switch and wire the third pole into the switch on delay circuit (controls relays on the output). Oh well, first impression is that it sounds nicer, but unless I can get a splitter for the inputs (and wire up to both the pre and the bypass simultaneously) and switch between the two I guess I won't really know. I think one thing is clear though and that is that the hum has dropped a lot. It's still there (and not when the switch is in the off position) but it is a lot less. Looks like I'll have to increase that resistor on the earth loop breaker from 10 to 18 ohms afterall...
Tony.
However.... when I switch from direct to via the preamp, or vice versa I get a big thump from the speakers
I can avoid if I switch the speakers off but it is not particularly family friendly, especially since I have a 21 month old who will love to switch the switch on and off So I'm not sure if it is switch contact bounce or perhaps just switch on thump (the fact that there is no thump at all when switching to the off position leads me to belive it is more like a switch on thump), but it is rather anoying. Puts a bit of a damper on an otherwise successful mod. The switch is a center off type, I might have to get a three pole double throw switch and wire the third pole into the switch on delay circuit (controls relays on the output). Oh well, first impression is that it sounds nicer, but unless I can get a splitter for the inputs (and wire up to both the pre and the bypass simultaneously) and switch between the two I guess I won't really know. I think one thing is clear though and that is that the hum has dropped a lot. It's still there (and not when the switch is in the off position) but it is a lot less. Looks like I'll have to increase that resistor on the earth loop breaker from 10 to 18 ohms afterall...
Tony.
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