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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
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hifidream's avatar
hifidream
135 posts
 
Bdp24 you’re right it was the case that he had stopped making them and you could get a kit but he made some tweaks to the design and it looks like he has a new model that is in production on a special order basis. . . I like to keep up with his designs in First Watt. He’s so innovative!

How much fun would it be to sit and listen to all the different designs he has come up with one after another and hear how they differ. Speaking of bi-amping, most of his work in First Watt are for efficient speaker designs and being able to vertically bi-amp them would allow them to be used with a lot more speakers. One can dream. . . 
rodman99999
6,159 posts
 
@georgehifi - Something to consider: (http://www.allegrosound.com/Dahlquist_DQ-LP1_AllegroSound.html) (https://www.hifishark.com/model/dahlquist-dq-lp-1) Lots of ways to upgrade/tweak and still supported by it’s builders(well- some of the guys that worked there, anyway). (http://www.regnar.com/dahlquist-dq-lp1-parts---upgrades.html) Hard to find, ’cause they work great and are still sought after, by many. btw: If you’re interested, PM me and I can send a PDF copy of the manual(no, I don’t still have a DQ-LP1, but- do miss it, sometimes).
georgehifi's avatar
georgehifi
10,312 posts
 
Thanks rodman99999 just another opamp based one though, I have tried a quite a few and in the end was disappointed, then spent the time and built my own discrete active 4th order xover @150hz just for the bass of my Monoliths, It’ just I’ve always wanted Nelson Pass’s B4 as it's discrete also.

Cheers George
rodman99999
6,159 posts
 
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!
bdp24's avatar
bdp24
9,821 posts
 

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.

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