Questions about my new [used] Van Alstine gear.

Merle · « **on:** 9 Sep 2003, 12:25 pm »

I've received my Omega III SL preamp and Omega III 260 amp and got to listen to them together for the first time last night. When I first hooked everything up, the sound was bad, very distorted. I checked all the connections, everything seemed fine. Finally, I switched the input selector on the preamp back and forth and the distortion disappered. Maybe I should take the cover off and clean all the switches with some electronics cleaner? The seller told me the preamp was not used in the last year, maybe it was just dusty? Next issue. I had been using a Monster Cable power bar to hook up all my componets. With the AVA gear, I decided to hook the pre & amp into the wall, using the inputs on the preamp to plug in sources. I listened for an hour or two this way, and again, frankly, the sound was not very good. In a nutshell, no tone. To me, tone is everything. If gear brings out the true tone of an instrument, everything else tends to fall into place. Getting discourged, I decided to put the Monster Cable power strip back in. I plugged everything into it. Preamp/Amp/CDP. Now it gets weird. Everything sounded great. The tonal color was there in it's full glory! Space, air, depth, everything that was missing before. Now I'm really confused. It seems to me the gear should sound much better plugged into the wall. Maybe it was plugging the CDP [Rega Planet] into the outlet on the preamp was a no-no? Next question. Power. This is my first "high power" amp. I've always had amps in the 50 to 100wpc range. This one puts out 130. I thought it would be louder. This might be a feature of the AVA preamp. It will go loud, but I really need to twist the wick on the preamp. [speakers are Paradigm 20v.3's, an easy speaker load] This is not a complaint, rather an observation. I'm used to preamp that tend to have a "powerband" set at around 8 to 10 o'clock on the dial. The AVA preamp seems to want to function from around 9 to 3 o'clock. Is this normal with AVA gear? When I got everything working and started to figure out the quirks of the AVA gear, I have to say I am very impressed with the sound. I've only got a couple hours where it was sounding right but it was most promising. I believe you need to live with an amp for months before you really start to get a feel for what it will and won't do right. AVA states that cable and interconnects are not that important provided they are of good quality. I'm using Audioquest CV-4 speaker wire and AQ Coral interconnects. Is there any cables users have found to mate well with AVA gear? I want this to be the last amp set I own for quite some time and I want to make sure I get the best out of them. Sorry to ramble on so.

Stampeder · « **Reply #1 on:** 9 Sep 2003, 07:44 pm »

Try your amp directly in to the wall outlet instead of the power strip. If the strip has any filtering it MIGHT be limiting current which is bad for the amp. Most people who use line conditioning don't run their amps thru it.

avahifi_lj · « **Reply #2 on:** 9 Sep 2003, 08:59 pm »

Hi:

If you have a noisy input switch I recommend using DeoxIT from Caig (contact cleaner). Spray a quick burst into the switch and cycle the switch 100+ times. You can also try cycling the switch without a cleaner to see if it helps, generally it does.

In reading you question I assume you tried to plug all of the components into the three AC jacks on the back of the preamp. The preamp AC jacks are for low power devices, such as a turntable, DAC, etc. Do not try and plug in the power amp into the preamp as you will most likely starve the power amp of AC power. In my home configuration I plug only the CD player and turntable into the preamp. The power amp plugs directly in the wall outlet. If you are going to use a power strip I suggest that you still plug the power amp directly into the AC outlet.

Regarding the power of the amp verses the volume. Having a lot of wattage does not necessarily mean that the volume will be extremely loud. For example an OmegaStar 440 and an OmegaStar 260 have the same exact audio characteristics. The only difference is the amount of reserve capacity (220W per channel verses 130W) in the larger amp. The extra capacity helps the amp in dealing with difficult situations such as a very load passage. The volume controls we use in the preamps are typically slower reacting in the lower settings (audio taper). In addition, the Omega III series of preamps were designed to perform as you have noticed with the sound opening up starting at the 9:00 position. It's pretty normal to have the indicator on the know pointed to the 11:00 position. The actual position of the indicator can be changed by changing the alignment of the knob using the two set screws opposite the white indicator.

Thanks for your interest the AVA products!

Larry Jenkins
Audio by Van Alstine

avahifi · « **Reply #3 on:** 9 Sep 2003, 09:23 pm »

In general it is nice to have a big power amplifier on a completely separate circuit from the rest of the equipment. The power amp can modulate the AC line (putting a bit of the music signal back on the line) which then can be passed on to the other components as an unwanted feedback loop (how it behaves, who knows). The way to preclude that is to put the amp on its own AC circuit, certainly not plugged into an AC outlet on the preamp.

The position of the volume control when it "gets loud" is simply a factor of the taper of the control, the gain of the equipment, the gain of the room, and the recorded level of the source material, so many variables. In general it would be nice to be able to use most of the rotation of the control so we set our controls and gain characteristics that way. If it got too loud at 10 o'clock, for example, you would be wasting more than half ot the control capability. Manufacturers of lower grade consumer equipment often waste half the rotation of the volume pot so it does get "too loud" at partial rotation. The uneducated user thinks that is because it has "more power" than a unit where there is more useful control rotation. Actually, it simply a cheep sales trick. You can easily set up the control so that a 10 watt amp will sound louder than a 1000 watt amp at one quarter control rotation (within the power limits of the smaller amp). Its simply what kind of a control taper you choose.

Frank Van Alstine

Merle · « **Reply #4 on:** 10 Sep 2003, 01:18 pm »

I had never tried plugging the amp into the preamp, just the cd player. I now have the amp plugged into the wall [as oppossed to the power strip] with the preamp / cdp & tuner plugged into the powerstrip. All sounds very well. I did spray the selector switch with some electronic cleaner I had from RS. No more distortion. In fact, it sounds great! And, I really like the range the volume pot allows. I was just not used to a preamp with such a wide "powerband". I'm hopefull these are the amps I'll grow old with. Wish me luck and thanks for the replies!