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Hi Brian or Russ. I have hooked up one IVY III on top of two Buffalo 3se. The phase is shifted on one channel because its dual mono setup. But i reversed it with twisted siver wire between the boards. Altered R1-R4 to 374 ohm 0.1% metal films, couldn't get 375ohm. Im also planning to add a set of Ventus EZ and driving left and right IVY channel and Ventus EZ separate with one Placid BP for each channel and one for the Ballsie stage. How mutch current draw is there? And how mutch should i shunt with the three Placid BPs for each section? Also is this config correct?  Best regards, Peter Hoppman.
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Greetings Peter. Congrats on your dual mono BIII SE! Just for future reference this thread had specifics for proper wiring and halving R1 to R4 values on the IVY III in a dual mono setup. http://www.twistedpearau...E-setup---Dual-Mono.aspxThe schematic shows 750 Ohm resistors for R1-R4 so shouldn't they be 325 Ohm? The values may have changed. I'm just going by the Ivy III schematic listed on the Ivy page. This is what the wiring should look like. This was a picture someone else posted, I just changed the colors for proper polarity (Red positive). "Half value" points to R1 and R4. It should have also included R2 and R3.  Just shunt 50mA for each PS. You are using three to power Ivy? Edited by user Wednesday, September 11, 2013 1:10:59 AM(UTC)
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Thanks SCompRacer.
Yes thats exactly how i wired it.
When i look in the thread i get a bit confused when i se what Russ wrote "Yes you can use a single IVY the same way you use a single Legato, but I would reduce R1-R4 by half."
Thats just what i have done.
Standard is 750ohm. For one board in stereo mode and half of that is 375ohm. So how do you get 325ohm?
Also if you look in the Buffalo III/IIISE DAC Integration Guide Revision 2.1.2.
You can se on page 23. Deviding 3000 with the amount of paralleld channels.
For one board in mono thats 8 channels and 3000/8=375ohm.
Its correct that im using 3 Placid BPs to Power the board.
Im going to shunt 50ma overhead for each section as you suggested.
Best regards,
Peter Hoppman.
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The exact value of the resistor isn't as important as that they match each other very closely. The change in signal amplitude will not be large enough (between the values being discussed) to change the performance of the circuit greatly.
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Your math is better. Sorry bout that. ;) |
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It's all good SCompRacer. I often get my values wrong because i have a tendency to mix up numbers when i read them. Thats why i check all my stuff as carefully as i can, learnd it the hard way.  And Brian. This is the resistor type i used to set the gain R1-R4. Product Range: WELWYN - RC55 Series Resistance: 374ohm Power Rating: 250mW Resistance Tolerance: ± 0.1% Resistor Case Style: Axial Leaded Resistor Element Material: Metal Film Temperature Coefficient: ± 15ppm/°C Voltage Rating: 200V I hope this resistor accuracy is sufficient?  Best regards, Peter Hoppman.
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Hi Brian or Russ. Ok. Now i got some problems. Ordered and installed a pair of Ventus EZ on the balanced outputs for headphones (Sennheiser HD650 600ohms). Im also going to use them as outputs to a poweramp. Driving IVY + Ventus left and right side with a separate Placid HD BP. Shunting with 50ma extra on each channel. I have zero DC offset and all seems fine. But the output is to low. Close or the same as driving the headphones without the ventus. And direct from the IVY (not jumpering the output resistors). Its like the Ventus EZ makes no differense. I measured the current shunted with and without the ventus connected on one channel. The difference was about 25ma. Thats a bit low i Think??? I replaced the gain resistor on the IVY as i described above with 374ohms. And that should be right according to the guide. Now i increased them to 750ohm (standard). But thats for 4 channels and not for eight like i use for left and right. The output volume increased. But after 50% volume and more the sound sounds flat and all bass and dynamic is lost. I sounds strained. Surely how mutch gain can i increase? If thats the problem at all, but it sound strage? I also need to have consumer audio output standard on the balanced outputs for the poweramp. I have used different digital soureces also, but it makes no difference. The Buffalos and the IVY is wired as the image above. The headphone jack is a Neutrik NJ3FP6C-BAG. And is wired like the image i got from another post http://www.twistedpearau...ffset-in-Ventus-EZ.aspx. Exept that im using only one IVY in dual mono. I have no clue what to do? Please, i hope someone got some suggestions? astro888 attached the following image(s):  Ventus EZ.png (242kb) downloaded 17 time(s).You cannot view/download attachments. Try to login or register.
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Ventus EZ does not add gain, just current (as provided). You can increase it's gain if needed.
It sounds like you are running out of current at higher listening levels. Try increasing the shunt current for the VentusEZ and see if that improves the higher-level performance.
You can also monitor the rail voltages at higher output levels and see if they are drooping (fluctuating) at all.
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Hi Brian. Thanks for the advise but it diden't work.  I increased the shunt current, so im shunting 100ma overhead on each channel. Also mesured the rail voltage at min and max volume and there is no voltage fluctuating. Still sounds stained and lacks dynamics and bass over 50% volume. What can i do now? Shuld i replace the 750ohm gain resistors on the IVY back to 374ohm. So i get consumer level balanced output. Beacause of the eight paralleled dac outputs on each cannel? And trying to raise the gain on the ventus ez? And if so how do i raise it, there is no manual for it? Maby you have some other suggestions? Best regards, Peter Hoppman.
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Yes, definitely - the gain is too high for dual mono. You should divide it in half. Use 374R or 357R there instead of the 750R. What you are hearing is that stage clipping badly. Edited by user Thursday, September 26, 2013 3:52:19 PM(UTC)
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Thanks Russ.
Swapped the 750ohms back to 374ohms on the IVY.
Now the output from the ventus ez sounds mutch better but im back to square one.
Cause the output to the headphones is to low.
Can i add gain in the ventus ez to boost the volume by changing values on some resistors?
And what values should i change to, need like 25-30% more volume?
Best regards,
Peter Hoppman
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If you want more gain out of the IVY-III swap out the 180R at R13-R16 with ~374R. That will get you a 6db boost. It was only the front end that was clipping. :) Cheers! Russ Edited by user Friday, September 27, 2013 12:15:33 AM(UTC)
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