VAC Sig Ren MK2a Headscratcher


I am thinking about adding a solid-state amp (DNA-500) to my system to drive the bass cabinets of my VR-7se's. Currently I have 1 set of balanced outs going to 2 VAC 300.1s that are each driving a VR-7se speaker full range. The other set is driving my subwoofer.

If I disconnect the sub and hook up the 500 to these balanced outputs from the pre, with the 500 speaker outputs going to the bass cabinets of the VR-7se's, will this work? Only problem I can see is that both modules of each speaker will be receiving a full range signal, but only using a portion of it depending upon the drivers. Balancing will be a snap as the volume control will control the 500, with the attentuating knobs on the VACs available to balance the rest of the speaker to the bass.

Will I be doing any damage this way? Is there a better way to do this w/o complicating things with crossovers, etc? Does what I'm proposing make sense? The 7's love power and I had the DNA-500 sitting in a closet.... Seems like this way I can get the best of both worlds, with about 750w going to each bass unit and 300 VAC tube watts (50w+/- Class A) going to each mid/tweet/super-tweet module. On paper, seems like a great idea, BUT...Before I go very far down this path, I'd really like to get some feedback and answers to these questions above.

Thanks in advance for any light you can shine in the tunnel.. :-)

BTW- just replaced noisy Dragon 6dj8 pre driver tubes with Seimens NOS 7308's - quieter(obviously), better imaging, bigger soundstage, more air and a bit tighter bass - after 1 hour!! Will only get better - more expensive but worth it IMHO. YMMV.
fplanner2010
Al- Thanks for clarifying on the DNA-500 - I feel a bit embarrassed to have caused this mess-up.

Dev-
Kevin talked to me about the 300 for over a solid year before I would even give the 300.1 an audition. I was THAT happy with the DNA-500. It is quite a bit more than an "okay amp", at least to me, all who have reviewed it and most who have owned it. It also obviously depends on the system it is in and what it is driving. It is very far from just "raw power", which is why I'm so excited about trying this little experiment.

I have never heard better midrange than the VACs produce and have come to really like the VAC "sound". The fact that I may be able to free up my VAC amps to only have to drive the glorious midrange and highs with 300 tube watts per speaker is something I really look forward to trying. The sound should be magical with ridiculous headroom :-)

In addition, the ability to finally drive the bass enclosures of my 7se's like they were made to be driven means I should no longer need my sub(except maybe for movies). Since the 500 is only driving the bass enclosures, there could be an enhanced positive effect there as well. The 7se's spec down to 18hz, which is probably more visceral and felt, rather than heard - can't wait to find out!!

I'm visiting Kevin in May - will hear the 450's if he's got a pair handy. Everyone I have talked to who has heard the 450's raves about them - I've yet to hear them. Quite honestly, I REALLY like my 300.1s, and may like them a whole lot more if my little experiment goes the way I hope it does. Thanks for your responses and enjoy the tubes!! :-)
... the ability to finally drive the bass enclosures of my 7se's like they were made to be driven means I should no longer need my sub (except maybe for movies).
I suspect that if you connect the sub you would be connecting it to your Integra processor, and using the preamp's cinema (home theater bypass) mode. If, however, you ever find yourself wanting to connect the sub via its speaker-level inputs, an important point to keep in mind is that the sub's negative speaker-level input terminals must not be connected to the negative output terminals of any of the amplifiers.

Since the DNA-500 is fully balanced, and the 300.1's are being operated in bridged mono mode, all of their negative output terminals have full-range, full amplitude signals on them, rather than being grounded. Connecting the sub's negative input terminals, which presumably are grounded, to the negative output terminals of the amps risks shorting those output signals to ground (depending on the internal grounding configurations of the sub and the amp), and causing damage.

If you want to connect the sub to the outputs of the DNA-500, either of the negative input terminals of the sub should be connected to a circuit ground point on the amp. Chances are that a chassis screw is such a point. That could be verified by using a multimeter to check for continuity between the screw and the ground sleeve of one of its rca input connectors, or between the screw and pin 1 of an xlr connector (while nothing else is connected to the amp).

If you want to connect the sub to the outputs of the 300.1's, since there are two of them one of the negative input terminals of the sub should be connected to a circuit ground point on the preamp.

The two negative speaker-level input terminals of the sub are most probably connected together in the sub, so only one of them would need to be connected externally. The positive speaker-level input terminals of the sub would be connected to the positive output terminals of the amp.

Regards,
-- Al
Hi Fplanner- no worries it's just a discussion of agree to disagree which is okay and nothing else meant by my replies.

Let us know how it works out for you.

Visiting Kevin to hear the 450's, don't think that's going to pan out, reason I mention such is becuase someone else whom I know was wanting to do such but was referred by Kevin to best go to a dealers or someones place.

Even doing is far from being ideal, if they just happened to have the identical speakers you have that would be amazing but what's the chance of that happening, slim to non.

I know of a guy who has two pairs of 450's and is bi-amping his speakers, absolutely crazy but has me wondering what my speakers would sound like.

Never ending journey.
Al- YIKES!!! Now I'm scared to turn anything on!! Just kidding - thanks for the heads up and insightful analysis.

Dev-
No problems. Already on other business near Kevin, so a visit to VAC is a no-brainer. I know its long odds they would have a pair of 450's to listen to, but you never know.

Bi-amping with 450's sounds like your next step. Its in effect somewhat similar to what I hope to be doing with the DNA-500 and my 300.1s. OF course I realize its nowhere near the same - hopefully yours would sound better :-)

What are your speakers again?