Crack w/o speedball transients

jimvibe · 1558

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Offline jimvibe

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on: July 13, 2015, 09:20:11 AM
I have built my Crack without speedball yet and it's totally awesome. I was curious how turn on/off transients look like, so I took a couple of oscilloscope measurements. One through 330Ohm resistor, the other without. These transients look pretty good, I would think this can't harm hd800s. One thing that has to be noted is that the turn on transient happens 10s after the switch is flipped and lasts for 5 seconds. The turn off transient happens instantly and also lasts 5 seconds. So to be careful you have to wait for at least 20 seconds before plugging the headphones in when turning on and 5-10 seconds when turning off. Here are the measurements if anyone is interested.




Offline Paul Birkeland

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Reply #1 on: July 13, 2015, 01:40:27 PM
These transients look pretty good, I would think this can't harm hd800s.

So to be careful you have to wait for at least 20 seconds before plugging the headphones in when turning on and 5-10 seconds when turning off.
Headphones and the loading resistors on the output of the amp severely suppress these transients.  There isn't really any need to unplug your headphones when turning on or off your Crack (I've had my HD-800's for almost 6 years now, and I never do). 

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline jimvibe

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Reply #2 on: July 13, 2015, 06:04:26 PM
It's probably worth mentioning that if you try to turn on Crack if it has been turned off for less than 30 seconds you could get a transient of 10v and that's 1/3W into hd800s. So if you turn it off let it rest for a minute or too before turning on again.