Log in
Register
Home
Forums
New posts
Search forums
What's new
Featured content
New posts
New profile posts
Latest activity
News
Members
Current visitors
New profile posts
Search profile posts
Features
Log in
Register
What's new
Search
Search titles only
By:
Search titles only
By:
New posts
Search forums
Menu
Install the app
Install
Reply to thread
Home
Forums
Low Earth Orbit
Lighting & Electrical
Ebtech HumX
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Message
<blockquote data-quote="Jay Barracato" data-source="post: 26415" data-attributes="member: 24"><p>Re: Ebtech HumX</p><p></p><p>Final report-</p><p> </p><p>I am suspecting that I was hearing both ground loop hum and some type of rf interference.</p><p> </p><p>On Friday, the bass amp plugged into the wall with a single cable plugged in (no instrument) had a definite ground loop. This was before any of the rest of the system was plugged in. The Hum X did stop the hum, but I did not leave it in place for the show. As far as I can tell the device can tolerate 6 amps on the ground circuit. To me that means the device will fail by opening and removing the ground before the 15 amp breaker will trip. This seems to be a repeat of what Greg and Bennett have said about this product.</p><p> </p><p>Looking at the building there are 4 actual interconnected structures that have been added at different times. I am not sure if they have a single service or multiple service, but I would hypothesis that if they have multiple services the grounds are at different potentials. A secondary hypothesis is that the performance room is actually next to the service/utility room for the hotel. During the day at setup time I could hear washers/dryers etc. running. I would suspect something may have been dumping to ground back there. This was a fairly basic setup. One power stringer to SL ran one powered speaker, the bass amp, and a couple of fishman aura pedals. A second power stringer to SR ran a second powered speaker, one mix wiz for FOH and a second mix wiz for monitors. I used XLR ground lifts to isolate the ground for the FOH board and powered speakers, and I used the ground lifts on the split to isolate FOH from monitors. In addition, the bass amp was isolated with the ground lift on the DI. Each piece of powered equipment only had 1 path to the same ground through its power supply.</p><p> </p><p>This left a gentle hiss. The best I can describe the sound is like an old guitar tube amp idling once the tubes are starting to degrade. The really odd thing is that the system was silent when set up but as soon as the cables for the stage were plugged in the hiss started. On Friday, by show time the hiss was down to unnoticable (lower than the background sound in the room).</p><p> </p><p>On Saturday, I set up basically the same way except I dug deeper through my cable box and used all the quad cables I could.On Saturday i was setting up later in the day. By time I was setup the hiss was even lower than on Friday.</p><p> </p><p>I am not sure if I can attribute the change from Friday to Saturday just to the change in cables. It may be that the source of both of the noises was reduced or stopped by time I was setup on Sat.</p><p> </p><p>For Fridays show we had more people than they have ever had at one of these events before, and while Saturday started slower, we had a good crowd by the second set and the venue made it's money at the bar. The management is extremely happy with the job the band and I did, and we are already scheduled to be back there basically one weekend a month until Nov. </p><p> </p><p>There is some sort of transmitter as well as a cell tower on a hill about 3 miles form the venue and a small airport about 3 miles in the other direction. Next time I am down there I will look for other closer sources of RF and see if I can figure out where the main power service(s) for the building are.</p></blockquote><p></p>
[QUOTE="Jay Barracato, post: 26415, member: 24"] Re: Ebtech HumX Final report- I am suspecting that I was hearing both ground loop hum and some type of rf interference. On Friday, the bass amp plugged into the wall with a single cable plugged in (no instrument) had a definite ground loop. This was before any of the rest of the system was plugged in. The Hum X did stop the hum, but I did not leave it in place for the show. As far as I can tell the device can tolerate 6 amps on the ground circuit. To me that means the device will fail by opening and removing the ground before the 15 amp breaker will trip. This seems to be a repeat of what Greg and Bennett have said about this product. Looking at the building there are 4 actual interconnected structures that have been added at different times. I am not sure if they have a single service or multiple service, but I would hypothesis that if they have multiple services the grounds are at different potentials. A secondary hypothesis is that the performance room is actually next to the service/utility room for the hotel. During the day at setup time I could hear washers/dryers etc. running. I would suspect something may have been dumping to ground back there. This was a fairly basic setup. One power stringer to SL ran one powered speaker, the bass amp, and a couple of fishman aura pedals. A second power stringer to SR ran a second powered speaker, one mix wiz for FOH and a second mix wiz for monitors. I used XLR ground lifts to isolate the ground for the FOH board and powered speakers, and I used the ground lifts on the split to isolate FOH from monitors. In addition, the bass amp was isolated with the ground lift on the DI. Each piece of powered equipment only had 1 path to the same ground through its power supply. This left a gentle hiss. The best I can describe the sound is like an old guitar tube amp idling once the tubes are starting to degrade. The really odd thing is that the system was silent when set up but as soon as the cables for the stage were plugged in the hiss started. On Friday, by show time the hiss was down to unnoticable (lower than the background sound in the room). On Saturday, I set up basically the same way except I dug deeper through my cable box and used all the quad cables I could.On Saturday i was setting up later in the day. By time I was setup the hiss was even lower than on Friday. I am not sure if I can attribute the change from Friday to Saturday just to the change in cables. It may be that the source of both of the noises was reduced or stopped by time I was setup on Sat. For Fridays show we had more people than they have ever had at one of these events before, and while Saturday started slower, we had a good crowd by the second set and the venue made it's money at the bar. The management is extremely happy with the job the band and I did, and we are already scheduled to be back there basically one weekend a month until Nov. There is some sort of transmitter as well as a cell tower on a hill about 3 miles form the venue and a small airport about 3 miles in the other direction. Next time I am down there I will look for other closer sources of RF and see if I can figure out where the main power service(s) for the building are. [/QUOTE]
Insert quotes…
Verification
Post reply
Home
Forums
Low Earth Orbit
Lighting & Electrical
Ebtech HumX
Top
Bottom
Sign-up
or
log in
to join the discussion today!
