Help please with hooking up my nearly complete amp's - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Solid State Talk all about solid state amplification.

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
Thread Tools Search this Thread
Old 25th September 2001, 11:32 AM   #1
Im a novice to electronics, but I purchased some full-range, bi-amplifeid "plate" amplifiers that I want to hook up to my speaker project. They came out of some powered Alesis loudspeakers.

Basically, I have this question: On the back of the AC plug recepticle, there is a metal prong with a "ground" symbol below it. Where do I attach this ground to? The metal of the amp itself, or..?

I cannot recieve support from the mfg. with this question.
Other than that, the only other connection of question is that the leads from the amp to go to the speaker drivers are not labeled as +/-...does it matter, as long as I kep the scheme consistant?

Also, I tried running the amps (made music) for three minutes without connecting this ground wire. I turned them off because I smelled a faint electronics burning smell from the power supply. Wasnt sure if this was just a normal break-in smell or overheating, but nothing appeared to blow. Any damage likely as a result of not grounding the AC plug recepticle itself?

I appreciate any help,
  Edit/Delete Message Reply With Quote
Old 25th September 2001, 06:10 PM   #2
The one and only
Nelson Pass's Avatar
Join Date: Mar 2001
Probably had nothing to do with the grounding, and
there's a good chance that it's just the "new amp smell".

I would recommend attaching the AC earth ground pin to
the heat sink through a power thermistor, such as
the Digikey # KC006L-ND. You can of course make the
connection directly, but the thermistor gives some
ground loop reduction while offering protection from
AC primary leakage.
  Reply With Quote
Old 26th September 2001, 07:33 AM   #3
Question Grounding required, or optional then?

Hey Thanks Nelson!

Well I wasn't expecting to get help from someone like you. Is it required* electrically that I make some type of ground connection from the AC, or will it just improve things sonically?

(I know I should start studying up on this stuff on my own.)

BTW, here are the specs on my amp: Does this change the Digikey part# you would recommend to me?

Low Frequency Driver: 6.5" non-woven carbon fiber with Santoprene surround and dual magnet shielded configuration

High Frequency Driver: 1" silk dome with medium viscosity ferrofluid coolant and dual magnet shielded configuration

Crossover: 1500Hz, 8th-order, 48dB/octave filters

Input Impedance: 20k_ balanced, 10k_ unbalanced

LF Filter: 2nd order, "optimal Q" high pass, +1dB boost@50Hz

LF Amplifier: 75 watts, 8_ load

LF Amp Distortion:less than 0.03% thd @ 30w
lf amp slew rate:<>19V/µsec

LF Amp S/N Ratio: >110dB, ref. 60W @ 8_, A-wtg., 1kHz

HF Amplifier: 25 watts, 4_ load

HF Amp Distortion:less than 0.06% thd @ rated power

lf amp slew rate less than 9V/µsec

HF Amp S/N Ratio: >112dB @ rated output

Frequency Range: 38 Hz - 23.5 kHz (-10dB point)

Connectors: Combination XLR-1/4" jack with input level control

Dimensions: (WxHxD) 8.5"x15"x9.75" (381mm x 216mm x 248mm)

Weight: 19.5 lbs. (8.9kg) each.

  Reply With Quote
Old 26th September 2001, 07:51 AM   #4
Question PS

Heres what someone recommended in order to determine the polarity of unmarked speaker taps on an amplifier. Does it sound like a good approach, or is it even necessary to do this at all?

Seeing these aren't marked and 1 is + from the amp the other will be at chassis ground. Why not just take a DMM or better yet a speaker and test them back to chassis ground. One should show ac present and the other nothing? in other words hook 1 wire from the amp to the + teminal on the driver, then from the drivers - terminal run a wire to chassis ground. then swap one wire from the amp at a time. This should tell you very quickly which is which.

  Reply With Quote
Old 26th September 2001, 12:09 PM   #5
Super is offline Super  United States
diyAudio Member
Join Date: May 2001
Location: Connecticut
Send a message via AIM to Super
For every driver I've handled, the + has been on the right, and the - on the left. Not sure if this holds true in your case though, but its more than likely.

Also, this connection DOES matter. If not connected properly, your output will suffer dramatically, particularly in the bass region. There are few exceptions to this, although the connections are reversed sometimes in subwoofers, for push/pull alignments.
  Reply With Quote
Old 26th September 2001, 04:37 PM   #6
diyAudio Member
Join Date: Feb 2001
Location: Columbia, SC
Are you trying to determine the polarity of the connections for a driver or for an amp?
If it's a driver, hook a battery (something like a 6 or 9 volt will do) to the terminals. One polarity will cause the cone to jump backwards, the other forwards. When the driver jumps forwards, the + terminal of the battery is connected to the + terminal of the driver.
If it's an amp that you're trying to determine the polarity of, don't even turn it on. For most amplifier topologies the - terminal will be connected to ground. Simply use a meter to check continuity from the output terminals to a known ground. (You may have to pull the cover to get to a clean ground, as paint doesn't conduct well, and you won't want to scratch off the paint to get to bare metal. Ditto for anodized aluminum.)

  Reply With Quote


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
hooking up my subs this way or that way skooter Car Audio 2 18th December 2007 05:53 PM
help with hooking up transformer to IEC and psu Joseph0 Solid State 0 19th August 2005 05:57 AM
Help hooking up a uP tobias_svensk Digital Source 0 15th May 2005 12:42 AM
Hooking up a third sub??? brock24 Subwoofers 2 9th March 2005 02:02 AM

New To Site? Need Help?

All times are GMT. The time now is 09:31 PM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2