The op amps are only in circuit below the crossover point. There's just one capacitor(I used polypropylene) between the preamp and mains(notwithstanding the extra connections/cabling). I wasn't using a preamp at the last, but a Placette Passive Linestage, in which I installed the high-pass cap, to eliminate the extra connections(bypassed the DQ-LP1, etc). It doesn't get much more transparent. Happy listening!
Bi amp pros out there I could use some help! First time Bi Amping...
Just picked up a BAT vk 200 for the bass and using my Pass Aleph 5 for the mids and tweets. Ive never played around with bi amping so I apologize in advance for any lame questions My speakers are Dunlavy SC3's original 5.5 nominal load. The pass is 90 wpc at 4 Ohm and the BAT is 200 wpc at 4 ohm so Im guessing around 75 wpc off the Pass Amp and 150 plus with the Bat Amp. My pre amp is a Aleph P and Im running the Single ended through a XLR adaptor (cause the Bat is Balanced inputs only) and the pass Aleph 5 off the XLR outputs of the pre and inputs of the Pass amp. The PASS Pre Amp manual says there is a 6db differential between the RCA and XLR outputs two and both can be driven at the same time. So the RCA is 9db and the XLR is 15 db. Gain is within 2db on each amp. So whats the best way to do this? Get a custom XLR "Y" connector and drive both off the XLR output of the pre? Or is there a way better way to get the magic? This is past my "WORLD" Map and experience so Id thought Id ask for the smart people for advice.
Thank you in advance!
-ALLGOOD
Thank you in advance!
-ALLGOOD
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I just (in the past week) sold my DQ-LP1. I at one time used it as rodman suggests, for just the 3rd-order low-pass filter, installing a capacitor on the input jacks of my power amp for high-pass filtering, THE way to do it if a 1st-order filter (6dB/octave) is steep enough for your needs. You CAN use the DQ-LP1 to do the same, but you need to match the replaceable-cap value to the input impedance of the power amp anyway, so you may as well do it inside the amp, and save yourself the cost (and potential sonic penalty) of an extra pair of interconnects. The B4 is MUCH more versatile than the DQ-LP1, providing 1st/2nd/3rd/4th-order filters---both high-pass and low-pass, in 25Hz increments from 25Hz to 3200Hz., and level controls for either (but not both) filter, for bi-amp balancing. As George said, fully discrete, no opamps or ic’s. Cute little bugger, but single-ended only. If you need balanced, you must go up to the Pass x/o, which is a lot more dough. |
As George said, fully discrete, no opamps or ic’sOr coupling caps, "best coupling cap is no coupling cap" Cute little bugger, but single-ended only.Nothing wrong with that, no need for balanced unless your doing 10mt interconnects. And many source outputs and poweramp inputs have "pseudo" balanced anyway. They are just SE with a balanced opamp in the path for the xlr connection. So the SE will actually sound better in these circumstances, as your not sending the signal via the xlr opamp with SE output/inputs Cheers George |
Right you are George, but some power amps (for instance my Music Reference RM-200 Mk.2) have (true) balanced inputs (created by Modjeski with discrete components, no opamps or transformers. He's a very clever designer) only, and some pre-amps have (true) balanced outputs only (Atma-Sphere's, for example). I'm sure the Pass x/o provides benefits over the First Watt B4 other than balanced outputs, but that to me is academic. I don't have the $ for the Pass! |
If interconnects are shielded and kept to a reasonable length, I believe there are no "sonic" advantages for XLR over SE. But there is a real "sonic advantage" for SE over "pseudo XLR" as as I mentioned before (about balanced op-amps in the signal path with "pseudo XLR"). Lampizators view on it. http://www.lampizator.eu/LAMPIZATOR/Balancedornot.html Stereophiles 4 page article on it. https://www.stereophile.com/features/335/index.html Cheers George |
Yes George, and we all owe Ralph Karsten a debt of gratitude for bringing to our attention (mine anyway) the matter of the AES standard for balanced connections---which wires get soldered to which XLR pins. Of course, if your "balanced" output is called that only because it is on XLR jacks (the output being in no way truly balanced), the balanced cable won’t get you any benefits anyway. And learning that some gear is made with its’ pseudo-balanced and single-ended outputs wired together shocked me. How lame! I’m sure Ralph will have a counter-argument to that of Martin Colloms in the Stereophile article! |
FTR: In my experience, it is MORE common to see XLR sockets on unbalanced INPUTS than on XLR outputs. I’ve seen both professional (Yamaha) and consumer (Parasound) amps with this "feature. " The Parasound A23 for instance, but not the A21. It’s basically convenience, to allow pro cables to work, but it defeats the noise cancelling properties of a balanced transmission, and accomplished by grounding the (-) pin at the socket. Best, E |