-

Jump to content



Sign up for a free account!

Signing up for an account is fast and free. As a member you can join in the conversation, enter contests and you won't get the popup ads that guests get. Click here to create your free account.

Photo

Hafler circuit


This topic has been archived. This means that you cannot reply to this topic.
5 replies to this topic

#1 of 6 John Meringolo

John Meringolo

    Agent

  • 40 posts
  • Join Date: Jan 19 2002

Posted September 20 2002 - 12:54 PM

anyone out there long enough to know what the "hafler circuit" is or where one can be located?

#2 of 6 ThomasW

ThomasW

    Screenwriter

  • 2,282 posts
  • Join Date: Nov 06 1999

Posted September 20 2002 - 05:13 PM

If you're referring to the ambient recovery circuit it's pretty easy

Left front + to Left rear +
Right front + to Right rear+

jumper between the left and right rear - terminals.

HERE'S more info

The main problem with it is that it's difficult to balance the output levels. The old DynaQuad box used a 50 watt stereo L-pad that burned out after while.

I had friends that made line level devices (same circuit) and then ran the output to power amps. That works ok if the amps have input level controls.

#3 of 6 Greg Monfort

Greg Monfort

    Supporting Actor

  • 884 posts
  • Join Date: May 30 2000

Posted September 20 2002 - 07:57 PM

The main problem with it is that it's difficult to balance the output levels. The old DynaQuad box used a 50 watt stereo L-pad that burned out after while.
=====
I had good luck with this the one time I tried it:

Tie the center channel (-) to a variable pot (0-nominal speaker impedance) to the LF and RF (-) jumper, and the CC's (+) to the LR (-) and RR (-) jumper. Once the pot is dialed in, replace it with a sufficiently high wattage resistor.

Note that the speakers must all be the same nominal impedance and that the amp must use a common ground for left and right channel speakers.

GM
Loud Is Beautiful, If It's Clean

#4 of 6 Manuel Delaflor

Manuel Delaflor

    Supporting Actor

  • 660 posts
  • Join Date: May 25 2001

Posted September 21 2002 - 01:49 AM

John

You can always point your browser to Dynaco This box is an evolution of the original Dynaco Quadaptor (Hafler design which I still own by the way and it works flawlesly) and it appears to have a somehow improved circuity.
Here was my gear info... Now is on my profile, in case you want to know

#5 of 6 ThomasW

ThomasW

    Screenwriter

  • 2,282 posts
  • Join Date: Nov 06 1999

Posted September 21 2002 - 05:42 AM

I used the several of the DynaQuad boxes in the late 70's/early 80's. Always ended up burning out the L-pad.

Maybe I was was just too heavy handed in my younger days Posted Image

#6 of 6 John Meringolo

John Meringolo

    Agent

  • 40 posts
  • Join Date: Jan 19 2002

Posted September 21 2002 - 10:36 PM

Wiring the circuit on the speaker level side DOES put very high loads on the amp! Iam looking for a circuit that does this on the pre-amp side.btw check this I found:
US Patent No. 5,386,473
Passive Surround Sound Circuit
Issued: January 31, 1995
Inventor: Robert W. Harrison, Cortland, NY