ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: 1 [2]  All   Go Down

Author Topic: Best way to do a transfer function of an amplifier output?  (Read 6209 times)

Art Welter

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2199
  • Santa Fe, New Mexico
Re: Best way to do a transfer function of an amplifier output?
« Reply #10 on: October 23, 2018, 06:18:15 PM »

Next time I'll probably just get some oil-filled electric radiators and put a few in parallel.

Chris,

Since I already had them, used to do that, but it took 5 heaters to do a 2 ohm load, since those 1500 watt 120V heaters were about 9.6 ohms. Dragging 5 heaters to the shop was too much work, and could only test one side at two ohms.
Then I found that wrapping baling wire around a brick worked quite well, and is even cheaper than Mark W's solution, but does have some heat safety issues  ;)
IIRC, using a  8"x 3" x 2.25" brick and 16 gauge steel baling wire at about 1/4" spacing came out to 4 ohms.

Art
Logged

Mark Wilkinson

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1104
Re: Best way to do a transfer function of an amplifier output?
« Reply #11 on: October 23, 2018, 08:02:04 PM »


IIRC, using a  8"x 3" x 2.25" brick and 16 gauge steel baling wire at about 1/4" spacing came out to 4 ohms.

Art

 ;D

Did peeing on the bricks increase thermal capacity ? Lol
Logged

Art Welter

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2199
  • Santa Fe, New Mexico
Re: Best way to do a transfer function of an amplifier output?
« Reply #12 on: October 24, 2018, 01:12:58 AM »

;D

Did peeing on the bricks increase thermal capacity ? Lol
Yes, but changes the impedance too much for repeatable and reliable measurements.
Stinks like hell, too.
Logged

Frank Koenig

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1318
  • Palo Alto, CA USA
Re: Best way to do a transfer function of an amplifier output?
« Reply #13 on: October 24, 2018, 11:50:22 AM »

I've mentioned this trick before but this sounds like a good place to mention it again. You can arrange the load resistor as a voltage divider so that you can hook a speaker to the tap and hear, at a pleasant level, what the amp sounds like when it's killing itself. Since the attenuation is high the source resistance seen by the speaker is low, and all is hunky-dory. -F







Logged
"Nature abhors a vacuum tube." -- John Pierce, Bell Labs

ProSoundWeb Community

Re: Best way to do a transfer function of an amplifier output?
« Reply #13 on: October 24, 2018, 11:50:22 AM »


Pages: 1 [2]  All   Go Up
 



Site Hosted By Ashdown Technologies, Inc.

Page created in 0.033 seconds with 21 queries.