[tonyptony]

Hi Frank. I'm not sure if this has been discussed, but I'd appreciate your objective assessment of the strengths (and weaknesses, as driven only by comparison) of the DVA Hybrids against the new DVA SETs. I've been very happy with my 600R, and I did hear the SET Monos at AXPONA, which were very nice indeed. But as yet I haven't had the chance of hearing these different topologies in the same system. If, for example, I were to look at the DVA 850 and the DVA SET 600, where does each show its strength? Do they have equal ability to handle complex loads that have tough, low impedance drops? Is either one better at low listening volumes? Why might one choose one, versus the other? Thanks.

[avahifi]

In general, we design and build both solid state and hybrid tube equipment because some potential clients will have nothing to do with solid state equipment and others don't want the task of dealing with vacuum tubes.

Of more interest is that as our design skills improve, the sonic signature of all our equipment, tube, hybrid, and solid state, are converging. We would suggest that if the designs were actually perfect, the sounds would be identical.

We are not there yet, but as I often go from design type to another in final testing in my reference system of all our new equipment we ship, it is really tough to say which are the best.  They are all really good sounding as our clients know.

The balanced mono SET 600 and 850R designs are a bit different. They have musical advantages over their stereo counterparts. Running full differential mode from source to speakers is an advantage as any very low level distortion and noise is eliminated and there is even more isolation between channels. To my ears, this provides an even better three dimensional sound stage and transparency.  Of course this comes at about twice the cost.

The SET 400 compared to a Fet Valve 400R?  The SET solid state design is to me a "high energy" design, capable of resolving the tiny microdynamics and energy of a string instrument amazingly well without grain, glare, or any unnatural brightness. It has an enjoyable "wow factory" from top to bottom and is definitely the choice to perk up the bottom end of any speaker. It probably is not the amplifier for speakers running towards the "detailed" or slightly hot side.  The Fet Valve amps are a bit more relaxed with very engaging and a very slightly warm presentation. The Fet Valve amps do have a vacuum tube front end after all.

In any event, a pair of Vision SET 600 mono amps will outperform our stereo Fet Valve and SET amps, while the DVA Fet Valve 850 mono amps, which are crazy powerful, do best of all.

All our amplifiers are happy into 4 ohm loads and have no issues with 2 ohm loads either, up to the max recommended speaker fuse ratings.  They are just as musical at very low listening levels as at high, but because they don't stress out at high levels, you might want to crank up that volume control to better match live performance sound levels.

Remember too that all new AVA equipment comes with a 30 day satisfaction guarantee so it is hard for you to go wrong choosing our audio equipment.

Frank

[tonyptony]

Thanks Frank. I appreciate your objective descriptions. At this level of performance it's the subtle things (IMO) that will sway selections of the finest gear. Would you say the DVA 850 might not quite reach the same level of low end articulation and clarity compared to the SET 600?

[avahifi]

The DVA 600 balanced mono amps do indeed have extraordinary bass performance.  They play back the range, impact, temper, and transparency of bass string, brass, and drums with shocking clarity and definition.

These amps will make you wonder why you had been missing so much of this part of the music in the past.

Note -- we are two months out right now to build you a new amp(s), preamp, or DAC.  Still swamped from new orders this spring and the onslaught has not turned off for the summer yet.

Frank

[tonyptony]

Thanks Frank. I wish I was closer to your neck of the woods. I'd love to be able to hear both the 600 and the 850!

[simon wagstaff]

Any advantage to a pair of SET 120 monoblocks?

Asking for a friend.

[avahifi]

The SET 120 amplifiers would require our separate external phase inverter bridge circuits to be used as bridged mono amps.

Also, the chassis of these amplifiers is not tooled to support XLR balanced inputs and it would be expensive to try and have these added after the chassis are produced.

So adding the cost of two SET 120 amps plus the phase inverter (which we could probably fit in the Vision Q phono box with some modifications) would be 2 X $899 plus $500 for the phase inverter total about $2300.  This would provide you with somewhat more than 150W per amp.

Since a 225W/Ch stereo SET 400 is just $1999, you are way ahead in performance and cost benefit ratio to just purchase a new Vision SET 400 amplifier as so many of our clients are doing now.

Of course you could use two SET 120 amps as is in a bi-wired system, one amp per channel, with speakers that are bi-wired capabile (one channel for the top and one for the bottom of each speaker).  This would acoustically sum the output to an equivalent 120W per channel.

All winter and spring our business has been running at about triple normal level (Trump economy at work maybe?) and our lead times are long, six weeks or so, but out clients are reporting back the rewards are well worth the wait.

I can report for sure that the Vision SET 400 is the best solid state stereo amp we have ever designed and produced and that it rivals the Fet Valve 400R for absolute musicality.  They are not identical, both are compelling, but the presentation is slightly different, like a couple of different great wines.  You will probably be overjoyed with either design.

Frank

[BobRex]

Of course you could use two SET 120 amps as is in a bi-wired system, one amp per channel, with speakers that are bi-wired capabile (one channel for the top and one for the bottom of each speaker).  This would acoustically sum the output to an equivalent 120W per channel.
Frank

Umm, not to split hairs, but isn't this actually bi-amping?  Using an amplification channel for each driver?  I've always known bi-wiring as being same output channel split between 2 drivers.  In fact, every bi-wire cable I've ever seen is configured that way.

[avahifi]

You are correct.  I meant bi-amping.

Frank

[steverii]

Frank, Can your phase inverter be used to combine two identical mono blocks into a single, very high powered mono amp?

[simon wagstaff]

Frank, I was under the impression that the SET 120 and 400 had similar if not identical sonic signatures? I dont need more power, it is the suggested sonic improvement from the balanced monoblocks that I found potentially appealing. There wouldn't  be much point in going to a stereo SET 400 from a 120 unless I needed more power? There seems to be a sonic benefit to balanced SET 400 monoblocks. The same sonic benefit with lower power and cost is what I would be after.

However, I am super happy with my SET 120.

[avahifi]

Steverii, assuming that the mono amps are already two channel differential designs, they cannot be combined further.

Simon, I have never tried a set up using two SET 120 amps. Using two of them in a bi-amp configuration might be sonically useful if your speakers support this (two sets of linked speaker terminals each that can be unlinked by removing their external jumper links).

 We did this at the RMAF a couple years ago using our DVA 4/2 amp.  We used it in the four channel 60W/ch mode driving a set of Alta Audio amazing big Titanium Hesta speakers in their bi-amp mode.  The results were outstanding.

I assume using two new SET 120 amps would be even better.

Frank

[steverii]

Frank, the amps were built as mono amps from the beginning and are what I believe is called common ground. I don't believe they are differential amplifiers if this makes any difference.

[avahifi]

I would need to know more about your amps to advise you regarding that possibility.

[steverii]

Thanks Frank, I might end up talking to you in the future