VAC Sig Ren MK2a Headscratcher

What you are describing is a conventional passive bi-amp arrangement. It won't do any damage. The crossover circuits in each of the two sections of the speaker will filter out frequencies that should not be applied to the corresponding drivers, just as they do in your present configuration.

I believe that your preamp has a transformer coupled output, which results in a low output impedance across the entire audible frequency range. If so, there won't be any impedance compatibility issues driving the DNA-500's relatively low input impedance (10K iirc).

Given that, the major question as I see it is how coherently the sonics of the two different amplifiers will match. But since you already have the McCormack amp, there would be nothing lost in giving it a try.

Obviously, when you do this any connections that presently exist between the two sections of each speaker, either directly or through bi-wire cables, should be removed.

Regards,
-- Al

Thanks Al - you are correct about the transformer coupled output stage. I think/hope the sonic signatures between the amps will be more similar than not. If I can cable this properly, I'm hoping to achieve several orders of magnitude in sonic improvement, since the VAC's will be loafing and headroom should increase tremendously as well. Hopefully....:-). Thanks again.

Hi Fplanner2010,

if you got a pair of Vac's Statement 450's you would not have to worry about this Ha! Ha!

Very interesting what you posted above in relation to the tubes in your Vac, are those the only ones you have changed.

Do you have the stock fuses or did you go with ...

I'm at the stage now to try some different things such as tubes, fuses, power cords etc.

I'm truly enjoying my current set-up but when I read from other owners such as your self really peaks my interest specially when the cost of trying really is not too costly.

Where did you get you Seimens NOS 7308 tubes

Hi Dev-

Still stock fuses. Actually, it was thinking about the 450's that led me to my present plan! The DNA-500 I already own and is 500w of Class A into 8 ohms, 900w at 4. As you know, the first 50+w of the 300.1's is also class A. The VR-7se's thrive on lots of power and with only the 300's, are barely breaking a sweat. Time to see what they can REALLY DO!!

In effect, I will have MORE POWER THAN YOU, all class A, without killing my budget on the 450's. It should take away a lot of that "450 envy" you keep reminding me I have.. :-) (sorry - couldn't resist.. :-))

My preamp does not have the 6/12v switch, so I am limited to tubes of the 6dj8 line. I can't reveal my tube source yet until I get a backup pair - I'm sure you understand.. :-). I'm also sure there are better tubes for this application than what I got - its all about personal preference, what you are willing to spend, how much research you do, and what sound you are looking for. You really won't know until you start experimenting. I really wanted to try the 8416's, but was not able to due to the lack of the above switch. I just got very lucky in that I really like the first pair of 6v I tried in my system.

As you know, it is very easy to go nuts trying different tubes, fuses, etc. At this point, I am going to focus on the bigger picture of incorporating the DNA-500. As my friend Art mentioned this am, I may also need a buffer or in-line attenuator if the power of the DNA overwhelms the VACs. I will deal with that if it becomes an issue. The DNA is probably 1 of the best SS amps I could try to mate with the VACs, so I am glad I didn't sell it when it came out of my system several years ago.

I'm pretty sure I can reduce the cable quality, as long as silver prevails, in the chain from VAC pre to DNA to bass modules. I'm not sure I would hear the difference between $200. cables and $2500. cables for this bass-type chain. Thoughts?