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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
dev's avatar
dev
832 posts
 
I see what you are doing but no solid state amp that I have tried to date provides the sonic characteristics of what these tube amps can.

I have had Boulder 2050's, Karan 1200,s, MBL 9008's and 9011's, Bryston 28 Squared just to name a few all with the same speakers.

Using these amps with my speakers ya there was bass but know way sounded like it does as with my VAC 450's, not in the same universe. I'm not just saying that because I own them, it's a fact.

F.Y.I. Amount of power isn't everything, it's "The QUALITY" that matters :-)

I think my speakers might possibly be a little less efficient when it comes to this area than your also and when I tried a pair of 300.1 on my speakers just didn't do it.

Heck by the time you deside to buy a pair they will be $100K Ha! Ha!, they are now @ $80K and Kevin continues to get orders so you know he will continue to raise the price.

My pre-amp doesn't have that switch either so our pre's must be the same besides except mine has the built-in phono added.

I just ordered a pair from Sam who had listed on Gon saying;

Siemens and Halske grey plates 7308 E188CC NIB/NOS best of the best!

These grey plates tubes are the best Simens made E188CC/7308 tubes. According to the date code engraved on the metal plates inside the glass, these two tubes were made in 1967 with the same G7/1C date code. They scored 92/104 and 102/92---almost 100% matched! For Simens 7308/E188CC tubes, these are good as you can get.

So we will find out soon enough.

Cables; that's a whole story on it's own.
rgd
656 posts
 
Fp, are you sure about the DNA-500 being 500 w/ch in Class A? If we are talking about the amp made by McCormack I believe it is an Class AB design although I don't know how many watts are in Class A? A buddy of mine owned one a while ago and I don't remember him advising it was all Class A power. If you are speaking of another manufacturer then never mind....
fplanner2010 OP
283 posts
 
Dev- The DNA-500 is the sweetest,most tube-like solid state amp I have ever heard, at any price. I used it in my prior system and am very familiar with how it sounds, especially in the bass area. It is very high quality sound and the rave reviews it received were accurate, IMHO. What I don't know is how it will sound with the VACs, but I suspect it will sound much better than it currently does, as the VR7se's crave power, especially in the less efficient lower bass cabinets, which is what the DNA will be feeding. Ran this past Albert VS last night and he also thought it was a great idea, being familiar with my VACs as well as the McCormack.

Congrats on the tubes - let me know how you like them.

Rgd - I was TOLD by a friend who has had several McCormack amps that mine was all class A. I have a hunch it goes from A to AB at some point, but don't have the manual to confirm where that is. From my standpoint, having heard it extensively several years back, everything I heard sounded like A. In retrospect, I probably should have left out the sound rating comment, since I am *personally* not sure, so as not to unintentionally mislead anyone. Sorry if I caused any confusion by the McCormack "all Class A" comment.
almarg's avatar
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almarg
9,670 posts
 
Steve McCormack as quoted in this review:
The DNA-500 is a Class A/B amplifier that's biased fairly rich. Because I don't have to use extremely high voltages, it runs only warm at idle and I don't need a huge amount of heat sink surface area. If it were pure Class A, I would have had to use a huge heatsink to dissipate all that continuous heat. The heat sink in the DNA-500 is actually quite generous and can handle extreme operating conditions, including very low-impedance speaker loads.
As Steve explains elsewhere in the review, the need for extremely high voltages is avoided by incorporating two amplifier circuits, bridged together, for each signal channel (left and right).

Enjoy!

-- Al
dev's avatar
dev
832 posts
 
Fplanner- yes I look forward to hearing those tubes.

The DNA-500 is an okay amp but really nothing special to me. Your passion speaks volumns, if you feel the 500 is that great why do you have your VAC 300.1's.

I have never heard any solid state period provide the same bass as a top notch tube amp can, once you get the 450's and experience such you will know what I talking about and all will be history.
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