Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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

Quiet PA amps
Quiet PA amps
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 27th September 2019, 12:02 AM   #41
Soldermizer is offline Soldermizer  United States
diyAudio Member
 
Soldermizer's Avatar
 
Join Date: Feb 2012
Location: Tamper, FL, USA
Ha ha ha Behringer in a studio!!! (I can laugh...) I own 5 Behringer units for my home stereo and they probably cost less than what goes into an engineer's nose on one busy night
__________________
Ibid.
  Reply With Quote
Old 17th February 2020, 10:35 AM   #42
kipman725 is offline kipman725  United Kingdom
diyAudio Member
 
kipman725's Avatar
 
Join Date: Jun 2007
Location: Warrington
Send a message via MSN to kipman725
So I have a Yamaha P7000S now and can confirm in home usage the fans don't even spin. Mine had been gigged (very bashed outside) but there was very little dust inside the case so I would presume that even at 'war' volume the fans don't run very fast. Its unloaded clip point is 100Vrms/200Vrms bridged so I think real world it may be more powerful than an inuke6000 which hits ~95V. I'm a bit overloaded but I hope to bench test both amps next month.

I also have a crown CTS4200 in which at idle the fan does not spin (it defiantly has a working fan as it momentarily spins on startup). However googling this amp shows people fan swapping on it to make it quieter, so there may be a firmware difference between earlier an later productions of this amp. The fan is controlled using a buck converter running from a PIC microcontroller which takes in temp sensor data from all over the amp so its a bit opaque as to what would actualy turn on the fans. This will also be bench tested so I will have a better idea soon as to what the fan behavior is.
  Reply With Quote
Old 17th February 2020, 08:32 PM   #43
mpa is offline mpa  United Kingdom
diyAudio Member
 
Join Date: Mar 2010
Quote:
Originally Posted by Soldermizer View Post
Ha ha ha Behringer in a studio!!! (I can laugh...) I own 5 Behringer units for my home stereo and they probably cost less than what goes into an engineer's nose on one busy night
This made me laugh out loud as I know it's true 😄

Take a look at some Chevin amps, the fans are very quiet at normal listening levels. Or MC2 and replace the fans with Noctua.
  Reply With Quote
Old 20th February 2020, 11:03 AM   #44
kipman725 is offline kipman725  United Kingdom
diyAudio Member
 
kipman725's Avatar
 
Join Date: Jun 2007
Location: Warrington
Send a message via MSN to kipman725
I did some testing on my CTS4200 and the fan noise is very dependent on load. For light load on a single channel it does not spin, however running a single channel at full power into 4R the amp quickly turns into a jet engine and thermally limits after a couple of minutes. Clipping point for a single channel into 4R is 40Vrms giving 400W, clip lights only illuminate under heavy clipping.
  Reply With Quote
Old 25th February 2020, 03:16 PM   #45
1hiep0 is offline 1hiep0  United States
diyAudio Member
 
Join Date: Dec 2013
Location: San Diego
Quote:
Originally Posted by kipman725 View Post
I hope to bench test both amps next month.
Hi kipman725, am curious to see the result as I have the Yamaha p7000s. thanks
  Reply With Quote
Old 10th March 2020, 10:13 PM   #46
kipman725 is offline kipman725  United Kingdom
diyAudio Member
 
kipman725's Avatar
 
Join Date: Jun 2007
Location: Warrington
Send a message via MSN to kipman725
Default Crown CTS4200 tests

Here are some super basic tests on the CTS4200. Test condition is just CH1 loaded with a 4ohm test load.

1) 50Hz CEA-2010 waveform with gain adjusted such that waveform is just beginning to clip. 108Vpp, 363W/4R.

2) 20Hz tone burst at end of 100 cycles (5s), I wish I could show the full burst but my scope has tiny memory. Its a quite clipped but that me not bothering to set the gain exactly correct. Basically this is the same at the start and end of the 5s burst. The fan did not turn on doing these bursts, it only turns on when the output is run at this level for longer time periods.

This is an amplifier with a switch mode supply and class AB bipolar amplifier so these results are to be expected as the power supply is regulated and a single amp channel is insufficient to force it out of regulation. The spec for this amp claims 270W/4R for a single driven channel at 0.1% THD, it would seem to be more than capable of meeting this spec.

The bigger amps are going to need me to borrow a high voltage differential probe.
Attached Images
File Type: png CTS4200_4ohm_CEA2010_50Hz.png (12.8 KB, 156 views)
File Type: png End_100cycles_20Hz.png (12.8 KB, 153 views)

Last edited by kipman725; 10th March 2020 at 10:20 PM.
  Reply With Quote
Old 12th March 2020, 06:37 PM   #47
kipman725 is offline kipman725  United Kingdom
diyAudio Member
 
kipman725's Avatar
 
Join Date: Jun 2007
Location: Warrington
Send a message via MSN to kipman725
Default P7000s test results

Here are the test results for the P7000s. Unfortunately repeated 20Hz sine wave bursts appears to have damaged* it when bridged into 4 ohms (the one burst rating in the manual made me curious).

1 channel / 50Hz CEA-2010 / 4 ohm = 179.7 Vpp = 1008 W
1 channel / 20Hz sine at end of 100 cycles / 200 Vpp = 1250 W
Bridged / 50Hz CEA-2010 / 4 ohm = 324 Vpp = 3280 W

I used the maths function to make a pseudo differential probe for the bridged burst result so the individual traces will have ground noise on them that's canceled in the maths trace.

So quite a good amp for getting a lot of power into 8 ohms (probably around 2 kW but I don't have a load to test this) or 2*1kW into 4 ohms.

*Took the top off to start fixing it and it now powers up again so presumably some kind of protection was triggered, still don't bridge it into 4ohms...
Attached Images
File Type: png P7000S_Bridge_4ohm_CEA2010_50hz.png (15.8 KB, 139 views)
File Type: png P7000S_One_CHan_4ohm_CEA2010_50Hz.png (10.5 KB, 139 views)
File Type: png P7000S_ONE_CHAN_End_100cycles_20Hz.png (10.2 KB, 139 views)

Last edited by kipman725; 12th March 2020 at 06:53 PM.
  Reply With Quote
Old 15th March 2020, 01:53 AM   #48
conanski is online now conanski  Canada
diyAudio Member
 
Join Date: Mar 2013
Quote:
Originally Posted by kipman725 View Post
Here are the test results for the P7000s.
So quite a good amp for getting a lot of power into 8 ohms (probably around 2 kW but I don't have a load to test this) or 2*1kW into 4 ohms.
That is how I use my copies... feeding individual 4ohm sub drivers and they do a great job with it. FWIW it's long been my understanding that these were never designed for bridged 4 ohm operation, the documents and advertising also suggest that is the case.
  Reply With Quote
Old 15th March 2020, 01:43 PM   #49
kipman725 is offline kipman725  United Kingdom
diyAudio Member
 
kipman725's Avatar
 
Join Date: Jun 2007
Location: Warrington
Send a message via MSN to kipman725
Yes but there is the one pulsed power rating in the manual that made me curious. Another interesting thing about the p7000s is that when you push it to clipping the whole case starts rattling, the magnetic feilds must be savage.
  Reply With Quote
Old 16th March 2020, 01:28 AM   #50
conanski is online now conanski  Canada
diyAudio Member
 
Join Date: Mar 2013
That is interesting, I haven't experienced that with these Yamahas because the only time I have pushed them that hard is with speakers attached so any noise generated gets drowned out, but I have experienced that phenomena with other large PA amps so I don't think it is unique.
  Reply With Quote

Reply


Quiet PA ampsHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
It was quiet... too quiet. (Email issues) d to the g Wild Burro Audio 15 2nd March 2018 01:58 PM
SSE very quiet adrianbaugh Tubelab 33 12th August 2014 12:05 AM
How quiet is dead quiet? pchw Tubes / Valves 36 22nd November 2007 04:36 AM
Quiet here, isn't it? pinkmouse The Lounge 24 8th February 2005 08:29 PM
Too quiet! grataku Everything Else 14 14th February 2003 04:39 PM


New To Site? Need Help?

All times are GMT. The time now is 11:45 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Copyright ©1999-2020 diyAudio
Wiki