Fender Dlx Rev build- last Q b4 fire-up.

[Sea Chief]

Hmmm.?...

Nothing about changing V5 should have changed the tone of the amp other than the tremolo function. Not saying it didn't happen. Just saying it shouldn't have.

If the weird duding is reduced by changing proximity to other electronics in the room, that could be the whole problem right there. Does it still happen with the guitar unplugged? Did you try placing a shield over the open chassis? And as a last resort, did you try moving the whole rig into another room? It's probably not the trem making the noise.

Unplug the reverb pan output output from the amps reverb pan input. Meaning, remove the plug from the amp, not the pan. Now turn up the reverb knob. Noisy?

Well, something changed significantly- I hope to heck its like that when I turn it on again. The sustain was there, the tone vastly better, the low notes clear. Before the low ntes were muffled slightly and not the character overall it has now. I hope.

Odd.. I did pull most of the small tubes and re-insert mind you, did the same to the ftsw plug numerous times too. Maybe s'thing there sorted it because the ftsw then behaved perfectly. Odd too the reverb has the hum now, as I had that sorted just before(normal hum, no feedback). Its same place it was too in the head, plugs facing front as before.

Anyway I will try the reverb fix and the dud-dud tests if I have time this week. In meantime its very playable.

[JazzP- but just reversing the plugs doesnt make the 9V battery a -9V battery, it just means you got the plugs the wrong way round! (I dont think you can buy a -9V battery.. can you?). So the whole notion of negative voltage is fundamentally meaningless to me: you cant get a negative quantity, or a negative flow of water for eg].

Thanks, Sea Chief.

[Chuck H]

An empty 1lb sack of flour is -1lb of flour. That or it's just an empty sack. In that light you can't have an empty sack of anything, but you CAN have an empty sack of nothing

Ok... All kidding aside. Electricity has polarity. Just like a magnet does. If negative volts can't be reconciled then perhaps neither can a magnets, say, southern polarity. The point is that there aren't actually negative volts (and there's no anti matter, Easter Bunny or Santa Claus. Sorry Trekkie's ) So it's more like that. Not certain why the confusing choice of "positive" and "negative" was applied but for two reasons. One is that the two conditions cancel each other. As in negative voltage negates positive voltage. The other is that any equipment used to detect the state of electricity would have read them opposite on a numerically quantified scale. So, maybe there was a better, less confusing way. Maybe not so much once you see negative voltage on a meter with a "-" in front of it. Besides, without negative voltage how would we bias our Deluxe Reverbs?!?

[Jazz P Bass]

SC, I think you missed the point.

It's all a matter of reference & convenience.

If you have a +12 volt supply and tack on another +12 volt supply you have a total of +24 volts.
With reference to the first +12V ground.

Now suppose you use the mid point of those two supplies as a measurement reference.
You will now have a +12 volt supply AND a -12 volt supply.

There is not any negative anything.
It is all in what your reference point is.

[Tom Phillips]

...It is all in what your reference point is.

...and that's how you end up with things like negative temperature readings.

[Enzo]

And how +14 degrees Fahrenheit is a negative temperature in centigrade. Same temperature, different reference.

[Sea Chief]

And how +14 degrees Fahrenheit is a negative temperature in centigrade. Same temperature, different reference.

I cant cope. my heads gone bananas. b b but -14* is below 0*. Temp I can cope with cos water freezes at 0* (don't) and going onto another scale- the very cheek of it. JazzP's eg is at a reference point +12V, albeit looking left and right.. omg look stop it already.

[Sea Chief]

And how +14 degrees Fahrenheit is a negative temperature in centigrade. Same temperature, different reference.

Is there negative Time-??

There- put that in your pipes and smoke it..

[Sea Chief]

Is there negative Time-??

There- put that in your pipes and smoke it..

.. well yes, if I put a big "-" to the LHS of my clock, I have negative Time!

Christ Im even answering my own posts. I need a lie down.

[g1]

There is always a WRT (with reference to) implied for every voltage measurement. It is assumed to be ground unless stated otherwise. But it does not have to be. The voltage reading is "x volts" with reference to where ever we put the black probe.
One of our old tractors (and many very old cars) has a positive ground. Battery + connects to chassis and the entire electrical system is minus 12 volts.
Birds can land on high voltage wires because they are not referenced to ground. They are at 0 volts with reference to the wire. If you touch them with a wire connected to ground you will electrocute them. This is also why in case of high voltage wires down on the ground you are supposed to either shuffle or hop away.
When they work on extreme high voltage wires, they put guys in suits and charge them up to the same voltage as the wires they are going to work on. Then, when they float them up there, they are at 0 volts with reference to the wires they are to work on.
https://www.youtube.com/watch?v=9tzga6qAaBA

[Jazz P Bass]

Is there negative Time-??..

In a way, yes, there can be "Negative Time".

Say you have an appointment at 5:00.
Traffic is bad, so you show up late. 5:04.

That is negative 4 minutes for the 5:00 appointment.

[g1]

T minus 7 minutes 30 seconds.

[eschertron]

Astronomers use negative time "all the time " when they calculate where a planet or start was thousands, millions, or billions of years ago. And I'm pretty sure in secondary school I was forced to graph trig functions that crossed the Y axis at time zero, so that everything to the left of the Y axis was negative time.

But voltage should be fairly easy to model in real life. Look at a staircase, say there's 8 steps on it. If you're at the bottom, the first step is +1 step up, and each successive step is another +1 step above the one before. So from the reference point of where you are standing at the bottom, the top is +8 steps. Now walk up several steps. From the reference point of where you are standing now, the top is now only +5 or so steps away, and the bottom is -3 steps away.

Also you can toddle on down to the pub and see how many negative steps you have to take to get home!

[Chuck H]

All semantics! There is indeed no such thing as times opposite. Some manifestation of chronology that erases that which has transpired. This is great fun but perhaps only confounds SC's confusion.

[Sea Chief]

In a way, yes, there can be "Negative Time".

Say you have an appointment at 5:00.
Traffic is bad, so you show up late. 5:04.

That is negative 4 minutes for the 5:00 appointment.

Now look you lot..

Ok I will endeavor to re-re-read the explanation posts, but as it is Im just trying to figure out final gremlins so my head is quite full as it is. Gremlins persist (altho even a my £20 receycle-bin squier strat-with-better alnico cheapo pickups in.. sounds absolutely superb! even w'out reverb/ trem! It -will- be one fine amp once sorted..).

The reverb, which I had working w'out any excessive hum/buzz, in exactly the position it is now.. is now producing a ferocious hum/buzz. Worse than ever. Increaces with vol. It remains if I move pan right furthest away I can on a shelf nrby. And nothing Ive done so should not be any different to when it was working y'day w'out noise. Ive put amp into single socket way other side of room- no different.

It buzz/hums when gtr pulled.
It remains when ftsw pulled too.
It buzz/hums in time with the trem pulses, if thats on too with ftsw.

Unbelievable- unfathomable. Thanks alot chaps, SC.

[Chuck H]

So, is the hum on the reverb intermittent? Has it come and gone with no circuit changes to the amp? If this is the case you must have an intermittent open ground. Probably on the connecting cable since that is what gets moved around the most. If you have other shielded RCA cables this is pretty easy to check.