I have sort of an odd question here .

[catnine]

I played my champ build to see how it sounded . Then I always discharge the filter caps using a jumper with a 100K ohm resister in it . I go from each cap through the jumper to ground .

Well I had the alligator clip of the jumper on the 3rd filter cap before I had the other end grounded and the OT speaker jack tip is right there and the alligator clip for second touched the positive side of the 3rd filter cap to the speaker jack tip . I heard a slight pop though the speaker . Not loud just a quiet pop. so basically I sent 300 odd VDC through either or both speaker and the secondary of the OT to chassis ground . The amp was of course off and the power plug un-plugged .

I know the primary of the OT handles B+ VDC but what can this do to the secondary?

[theunrulychef]

The amp still sounds fine? If it sounds ok, then it's ok.

When bleeding, you only need to go from ground to the main reservoir cap since all the other caps are attached via resistors - they'll all bleed out just fine. Everyone's got their own ritual / method, but when I'm in a chassis, I keep the resistor/jumper clipped to ground. When I turn the amp off to dig in, I just connect the other end to the reservoir & leave it while I work. Then I pull it off B+ to test out the amp again (and back & forth every time).

Hope this helps,
Jay in Philly

[catnine]

Originally Posted by theunrulychef

The amp still sounds fine? If it sounds ok, then it's ok.

When bleeding, you only need to go from ground to the main reservoir cap since all the other caps are attached via resistors - they'll all bleed out just fine. Everyone's got their own ritual / method, but when I'm in a chassis, I keep the resistor/jumper clipped to ground. When I turn the amp off to dig in, I just connect the other end to the reservoir & leave it while I work. Then I pull it off B+ to test out the amp again (and back & forth every time).

Hope this helps,
Jay in Philly

The amp still works and is still quiet as before . I changed the 30 uf resevoir cap back to a 47UF and added a 47 ohm 5 watt resister in series with pin 8 on the the 5Y3 rect tube and the B+ juction and this happened after that .

I did play through the amp after but at low levels and high levels but it's difficult to tell because even at 6 on the vol I was picking very light and was in the living room instead of the bedroom and at 6 I did a few hard pick attacks and it seemed ok but it's louder in the bedroom and it's late so i really can't test it out fully until tomarrow .

In fact to be honest I drained the caps a few times just to check things out and it's just possible I did drain the caps because I usually start with the resevoir cap and I have checked voltage at the caps after draining and they always show a few volts . I paniced and for some reason I would think there would be a much louder pop if I applied 300+ VDC to the speaker tip . Now after it happened I just can't remember . I did play it a bit on 2 and the bass and treble work and when I turn up the vol to full up I can hear the amp react.

[theunrulychef]

Ok, sounds like it's ok. Even with full discharge through the speaker & into the OT, I wouldn't be surprised if everything was fine. I'd be more concerned about popping the speaker than doing any damage to the OT from something like that.

Hope it's sounding good

[Enzo]

Think about this. Even if your cap was charged fully, or you know, now that I think about it, even if the amp is powered, your discharge cap is 100k. The secondary winding has extremely low resistance - a lot lower than its impedance rating. But let's use 8 ohms anyway.

I will use 400v, because why not? The 100k resistor and the 8 ohm speaker would form a voltage divider. SO to get the voktage actually applied to the speaker, we'd set up the divider. The speaker would see 8ohms divided by 8 + 100,000 ohms, so 8/100,008. Roughly 8 hundredthousandths of the 400v.

8/100,008 = 0.00008

0.00008 x 400v = 0.032v

Your speaker saw 32 millivolts. That was your little pop.


Now since the winding resistance was even lower, so would be the actual voltage. I leave it to others to determine if some inductive kick could have occurred, though I doubt it.

So the bottom line is that even if you connected your 100k discharging resistor to the speaker jack while the amp was on, it wouldn;t hurt anything. other than your pride maybe.

Of course if you were using a 100 OHM discharging resistor, that would change things. Your pop would be a lot louder. A nice 100 watt pulse.