[tblewy]

I plan to use it to drive my NHT 3.3's I also have an old st70 that I built as a teen and it has problems etc. I'm a retired field engineer and former Navy electronics tech,. So I can do mods etc.I hope the  440 will be a good match for my 3.3's any thoughts and where should I look for help with my old ST70.

[ArthurDent]

Greetings & Welcome to AC tblewy     I've seen a number of folks post sources for updates/mods to the venerable ST70, I'm sure many will chime in. My suggestion would be chat with Frank VA, can't go wrong with his input, and his Ultravalve is based on that unit. Enjoy your 'new' Omega 3 440.

[JerryM]

Quite awesome; please follow up with your listening impressions once the ol' gal has had a chance to warm up.
Also - Welcome to AudioCircle, tblewy. 

[Nick B]

Welcome to AC and the AVA club. Just bought my first AVA product recently... .a SET 120 Control Amp and it’s a wonderful amp. Pls keep us posted as to how that ST 70 turns out.

[orthobiz]

My buddy sent his ST70 to me a few years ago. I sent it to Frank for an AVA rebuild/update. He apologized that it had some pitting that couldn't be buffed out and posited that it spent time in a humid salt water environment. Dead on: My buddy had it in his garage in Marblehead, MA for over 40 years!

My daughter has it now. AVA did a fantastic job.

Paul

[tblewy]

OK it actually arrived Friday. I was running an old  B&K ST-202+ (also a Van Alstine design?) rated 200w into 8 ohms and 300w into 4ohms which sounded better with my NHT 3.3 speakers (nominal 6ohms, low 4.3 ohms)
which sounded better coupled with my crown XLS-2500 driving the speakers built in sub-woofers when set for 150hz low pass. The top end appeared to open up quite a bit but I wasn't totally happy somehow mainly because I couldn't really adjust levels properly (I run my Gustard x12 dac directly to them from my Microsoft w10 XMOS computer(which contains my huge cd library)  outputs usually and use an Emotiva PT-100 preamp/dac for all other inputs separating the Gustard/Emotiva outputs to the amps with a simple A to B stereo switch and splitters.

So I hooked up the Newer Van Alstine Omega 3 440 by it self in hope that it would properly blend all frequencies with the same weight and sound purer from top to bottom. I was worried that the amp might not have the low frequency control of the 775w per channel ratting of the crown or that the mid to top end wouldn't be able to benefit from having the low frequency driver chore (4.3ohms) removed (as the ST-202+ did)

It appears that it handles the load very evenly across the whole spectrum including the 4.3 ohms. I have had many different amps driving the NHT 3.3 (which I found to be better sounding than a Wilson Watt Puppy back in the 90's but having less spouse approval  unless your room is large) The Crown did a great job itself but started lagging after a couple of years and was sent in for repair but found to be in spec by an authorized shop. It and the B&K sound similar but so far I think the newer Van Alstine is a lever above and I'm very glad I bought it. It sounds more neutral and a little brighter than the B&K but definitely has more clarity and is better overall. But he Crown/B&K combo is no slouch and is likely to sound just as good with better control as using a modern AVR's preouts with built in balancing capabilities to smooth out the overall response more properly than my strictly stereo system is capable of.

I still have some experiments to do with it( like trying it with the Crown) and I'll hopefully do that with a friend who also owns 3.3s later this week. I will add any worthwhile impressions to this post then.

[tblewy]

Well my buddy isn't getting here till Friday so I just hooked up my Crown XLS-25000 myself setting it up as two channel low pass at 150 HZ and running it the highest effective gain I could, with the Van Alstine going directly to the higher frequency speakers through  splitters
The Omega 3 440 was really nice by itself but opened up even more ,to my ears, and I think I'll end up running it in combo. Ken kantor (the main designer of the NHT 3.3s had told me that it would benefit me to remove the shorting strap between the high and low speaker inputs and use two amps (He suggested a NHT sub-woofer amp naturally) but I already owned the XLS. He said using two amps took stress off of both of them and the resulting lack of driver/amp conflict was very desirable
The upper range does sounds a bit clearer and more open  and the bass is actually deeper and louder but seems to be pretty well matched to the higher frequency curve too. NHT stated that the subs crossover point was 100HZ but their sub-woofer manual said to set it to 150hz due to roll-off. I suspect that a XLS-1500 or  1000 would work just as well given their abundance of power.
 Many speaker have the same capability, to divide the bass driver from the upper drivers,I wonder what any of you, and especially Frank think about using that option? I really don't like having that 150HZ going through the Omega into space driving nothing. Is that  actually cause for concern and if so what  could I do about it(maybe a simple pair of  RC filters connected to the Omega inputs)?
I will report again on this if my friend and I have any more insights Friday.


 

[tblewy]

Well my buddy finally got here and we tested the Omega 3 440 and H&K st202+ amps A to B
Both amps sound better with the XLS-2500 running the 3.3's built in sub-woofers but the Val Alstine
sounds better and indeed much better in comparison as a stand alones. The difference running them with the XLS is determinable with the  Omega having an edge. I bought some Harrison 100HZ high pass filters and they appeared to distort the upper range a little bit. Since it appears that the 3.3's mid and high crossovers do a good job by themselves I'm sending them back.

We didn't see any phase issues and the XLS amp was set for its highest gain and to us appeared to work seamlessly  together with both amps.

As I said before the Van Alstine worked so well as a stand alone that I was actually surprised that it got even
better when re-leaved of sub-woofer duty.
My friend took the 202+ home with him and is going to set it up with his Denon AVR and an XLS-1500 and the same NHT 3.3 speakers. Hopefully his advantage in being able to calibrate the overall outputs with the Denon's internal calibration output and a microphone will up his results somewhat. I wonder if its better for him to use his sub-outs or just set the XLS up for low pass at 150 hz and use splitters from the pre-outs as suggested by NHT before modern avr's?