taking the gain pots out of the "mix" - diyAudio
Go Back   Home > Forums > Live Sound > PA Systems

PA Systems A forum for discussion of all parts of a sound reinforcement or DJ system: loudspeakers, mixers (desks) etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 21st April 2013, 09:35 PM   #1
diyAudio Member
 
Join Date: May 2012
Location: Ardmore, PA
Default taking the gain pots out of the "mix"

I run the music elective program as artist in residence at Wyncote Academy. Most private schools have no music budget so I bought a cheap Technical Pro TA1250 power amp and then removed the gain pots and changed the inputs to 1/4 inch. I was getting drop outs with the RCAs. The amp was set up for mono bridging so I eliminated that when I bypassed the PCB that made such bridging possible. So far no problem. All the class equipment is run into a Behringer MX802A so that source is how I set the power amp response. I eliminated the gain pots on the front because the LD students felt (while I was busy in another room) they could boost the level. Best decision I have made. Yes, they could blow the amp and speakers via the Behringer but they haven't caught on to that possibility. I HATE gain pots on stereo power amps. They needn't be there. Any challenges? John Poole wyncoteacademy.org/
  Reply With Quote
Old 21st April 2013, 10:13 PM   #2
expert in tautology
diyAudio Member
 
bear's Avatar
 
Join Date: Apr 2002
Location: New York State USA
buy a behringer compressor limiter put it in a place where the students can't muck with it, and set it so that no matter what knobs are twiddled before it that the amp can't be clipped, or driven so hard that the speakers can be damaged.

the good part is that the behringer unit that does this is probably under $100 new...

_-_-
__________________
_-_-bear
http://www.bearlabs.com -- Btw, I don't actually know anything, FYI -- [...2SJ74 Toshiba bogus asian parts - beware! ]
  Reply With Quote
Old 21st April 2013, 10:24 PM   #3
diyAudio Member
 
Join Date: May 2012
Location: Ardmore, PA
Thanks, I just remind them if they clip the speakers then that is it! I can bring in some combs with wax paper for group kazooing. What was happening was even though I set the gain pots at max they would twist them further and so gone they were! The speakers are surprisingly resilient. Cheap Stageworks S12CDH. I have them facing up from the floor on 5 inch risers. Once the compression horn fell off the plastic bevel and into the box. Hell, they still sounded fine and we are driving two electronic drum sets and synths. Maybe I just got lucky with those speakers from Sam Ash. I prefer not to use limiters or compressors for class. On a gig that is a different story. John Poole
  Reply With Quote
Old 21st April 2013, 11:27 PM   #4
expert in tautology
diyAudio Member
 
bear's Avatar
 
Join Date: Apr 2002
Location: New York State USA
as you wish sir...
__________________
_-_-bear
http://www.bearlabs.com -- Btw, I don't actually know anything, FYI -- [...2SJ74 Toshiba bogus asian parts - beware! ]
  Reply With Quote
Old 25th April 2013, 02:02 PM   #5
JMFahey is offline JMFahey  Argentina
diyAudio Member
 
JMFahey's Avatar
 
Join Date: Mar 2009
Location: Buenos Aires - Argentina
I would think than an unattended class is worse than any gig

There's the old story about the USS Missouri, where Japan's surrender was signed in 1945, which tells that it survived Pacific War battles against the Japanese Navy, Kamikaze attacks, etc .... and was all but destroyed by visiting schoolkids
Click the image to open in full size.
  Reply With Quote
Old 25th April 2013, 04:51 PM   #6
diyAudio Member
 
Join Date: May 2012
Location: Ardmore, PA
Thanks for the sympathy but the gig isn't too bad at times. I've learned a little about piezo transducer swap outs, keybed sensor replacement, cables, jacks, plugs etc which has come in useful in servicing my own personal gear.
Your comment about the battleship's travails reminded me of Pablo Picasso's contrary experience that children or animals running amok in his studio never harmed anything but when an adult visited they would end up breaking or damaging something.

Last edited by dinnerpianist; 25th April 2013 at 04:57 PM.
  Reply With Quote
Old 27th April 2013, 04:09 PM   #7
diyAudio Member
 
Join Date: Mar 2013
Quote:
Originally Posted by dinnerpianist View Post
I run the music elective program as artist in residence at Wyncote Academy. Most private schools have no music budget so I bought a cheap Technical Pro TA1250 power amp and then removed the gain pots and changed the inputs to 1/4 inch. The amp was set up for mono bridging so I eliminated that when I bypassed the PCB that made such bridging possible. I eliminated the gain pots on the front because the LD students felt (while I was busy in another room) they could boost the level. Best decision I have made. I HATE gain pots on stereo power amps. They needn't be there.
I don't understand what you are trying to achieve here. You work at an educational institution so I would have thought the goal was to educate the students about audio principles and the correct way to operate and utilize all the features of professional sound equipment. But instead you expose them to modified gear that they will likely never see again and when they have to use that gear they will have no idea how to do it correctly.
  Reply With Quote
Old 27th April 2013, 09:46 PM   #8
diyAudio Member
 
indianajo's Avatar
 
Join Date: Jan 2010
Location: Jeffersonville, Indiana USA
I would think music education at the middle school level would be more about the music, not the equipment. I was lucky enough to hear "Hall of the Mountain King" over a 6" diameter 16 mm film projector speaker in 5th grade, which helped me to decide to study bassoon. (Great choice, super lead parts!). Of the kids in that class, I was the only one that made All State Band 7 years later, so music education is not of great importance for everybody subjected to it.
This system sounds as if the music would be much more realistic.
Kids learn weird things from their contemporaries. Blowing out the woofers is a fun game for 20 year olds with a car boomer system and too much pocket money from living at home, but is a one time event (not very musical) on a school budget.
__________________
Dynakit ST70, ST120, PAS2,Hammond H182(2 ea),H112,A100,10-82TC,Peavey CS800S,1.3K, SP2-XT's, T-300 HF Proj's, Steinway console, Herald RA88a mixer, Wurlitzer 4500, 4300

Last edited by indianajo; 27th April 2013 at 09:54 PM.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
"The Mix" Magazine DIY Series MaxiMoo Instruments and Amps 7 5th October 2013 06:13 PM
WTB Alps Black or Panasonic "for Audio" pots sjs Swap Meet 1 11th April 2013 05:33 PM
Are these 2 motorized Pots (ALPS) "compatible" electrically-wise? jdec Solid State 1 30th March 2011 04:41 PM
Taking a "bite" out of a tweeter bostarob Multi-Way 13 13th April 2003 04:25 PM
Quality pots with "notches" at 12 o clock? massappeal129 Parts 5 3rd April 2003 09:14 PM


New To Site? Need Help?

All times are GMT. The time now is 06:09 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2