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Hi all,
question:
Having a 4 channel LM3886 amp; would it be oke to use the IVY balanced output to directly bridge two LM3886 amps?
Gerard
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Sure, as long as you understand how to wire it, you will be fine.
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If i am not mistaken + to + of one amp. - to + of other amp GND to GND both amps. and load between each out (not ground) of amp. where the + of the speaker is connected to the amp with + input. 
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Rank: Advanced Member
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great!
can do some balanced bridged testing/listening now before Sympatico comes available.
thanks
Gerard
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hi,
My setup is usb/mux/opus/jt with the ivy at the end.When trying to connect a bridged (4 lm3886) on the ivy's balanced out i get a lot distortion on both channels. SE output on the Ivy is oke. when i tap the balanced output between JT and Ivy everthing is oke too. My guess is there's something wrong with the Ivy. Checked the Ivy for obvious (stupid) mistakes but all parts and soldering seem to be oke. The Ivy is set up for Opus as per manual. Playing the 4 channel LM 3886 bridged tapped from JT is oke, but would like to know whats wrong with the Ivy distorting the sound on both channels.
Gerard
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When using IVY you will need to set it up for voltage input and plan for the 750R output impedance of the JT.
I would set the IVY up with R1-4 as 680 or 750R
Do not use any feedback or filter caps.
Cheers!
Russ
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Rank: Advanced Member
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Thanks for quick reply. as i tap from Jt now and SE from Ivy is working too. Would there be any benefit to follow your suggestion or would my present setup be same? or other option (as i use SE only for driving headphone) place IVY between Opus and JT and throw in a stereo pot to controle the headphone out ? to be more concrete.....is the IVY doing anything beneficial to the sound or is using balanced out straight from Opus (with JT in between) same or better? R1-R4 are now 2k as per manual for opus. I could desolder them and replace with 680R or 750R, but if above options are same, i go for that. The original idea to put IVY at the end of the line was to control both balanced and SE volume with JT. Never realised there was a impedance mismatch Gerard Edited by user Saturday, April 3, 2010 3:50:03 PM(UTC)
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If you have an Opus with a WM8741 I would not use the JT at all, and use a volumite with the output of the opus direct to the IVY.
If you want the JT I would put it after the Opus and before the IVY.
When using the JT with the IVY you have to add the 750ohm output impedance to the input series resistance.
The simplest thing to do is to use jumpers at R5-8 and then use 750R at R1-4.
That's I what I would try if you want to stick with the JT.
Cheers!
Russ
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