Announcing the new AVA Ultimate 70 Vacuum Tube Amplifier

avahifi · « **Reply #40 on:** 3 Jun 2005, 10:57 am »

After you do order an Ultimate 70 kit and get it up and running then you will have to rationalize why you waited so long.

Frank

rmihai0 · « **Reply #41 on:** 3 Aug 2005, 11:02 pm »

Wow!!! Today I got the Ultimate 70. Wow wow.

I was so wrong being afraid that this little amp will not drive my 83db speakers. So wrong. The Ultimate 70 is just as good (from this perspective) as any 150W solid state amps that I tried before. Don't ask me how this is posible. Ask Mr. Van Alstine the Magician.

Finally an amp that I will never tweak/modify or whatever. I trust Mr. Van Alstine enough not to change even the power cord. Of course - I will replace the tubes sometine down the road.

Regarding the sound quality - I will let you know the next couple of days. I just plug it in 15 min ago.

Thank you very much Frank and many thanks to your team also.

Notre respect.

rmihai0 · « **Reply #42 on:** 14 Aug 2005, 04:31 pm »

Finally, I can review the Ultimate 70.

IS everything I wanted to be and even more. Main characteristiques:
1. "Musical"
2. Involving
3. Sound right/natural
4. Outstanding dynamics and transients
5. Surprises me with its ability of very fast responding to peaks. From a wisper to +20db is moving extremelly fast and natural. Nothing short of incredible.

I love it.

Congratulations Mr. Van Alstine - you did it.

daveshel · « **Reply #43 on:** 12 Nov 2005, 05:47 pm »

Quote from: avahifi

The obvious difference is that the Fet Valve amps are ten times as powerful which is very useful in many applications.

However, a die hard "tube lover" is going to like the U70 better, just because of the intangible "vacuum tube" presentation (without the normal vacuum tube fuzz and obvious colorations).

The U70 does not match the dynamic range or extension of the Fet Valve amps, and probably not quite the same transparency (a bit different kind of transparency?) but it does have this sense of "musica ...

And how would you describe the difference between the U70 and the 170EX?

orthobiz · « **Reply #44 on:** 3 Jan 2006, 04:00 am »

Well, this is what I just bought, hope to someday do the Ultra mod, but it looks like I'll need to cut a hole in it. It's a rack mounted Dyna used in an organ, just couldn't resist how it looked!

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5849692400&rd=1&sspagename=STRK%3AMEWN%3AIT&rd=1

biz

orthobiz · « **Reply #45 on:** 3 Jan 2006, 11:54 am »

I meant "Ultimate" mod, not "Ultra." So much cool stuff going on the AVA site, I can't keep the words straight!

biz

avahifi · « **Reply #46 on:** 3 Jan 2006, 02:50 pm »

Likely you will have to make holes in the Hammond version of the St-70 as the PC card is obviously mounted below the chassis, and I doubt if there is enough "headroom" for the necessary parts mounted on the U70 board (the 47 uf 400V electrolytics are pretty tall).

Frank Van Alstine

skrivis · « **Reply #47 on:** 3 Jan 2006, 04:50 pm »

Quote from: orthobiz

Well, this is what I just bought, hope to someday do the Ultra mod, but it looks like I'll need to cut a hole in it. It's a rack mounted Dyna used in an organ, just couldn't resist how it looked!

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5849692400&rd=1&sspagename=STRK%3AMEWN%3AIT&rd=1

biz

It looks really nice. It would be kind of a shame to cut holes in it.

orthobiz · « **Reply #48 on:** 4 Jan 2006, 01:15 am »

It looks really nice. It would be kind of a shame to cut holes in it. --skrivis

I agree. Am already plotting on buying an uncut base on eBay and somehow stacking it upside down on this one, somehow painting both the same and tucking the PC board underneath. Will have to see when it gets here. Heck, I'll have to see how it sounds unmodified!

biz

skrivis · « **Reply #49 on:** 4 Jan 2006, 03:03 pm »

Quote from: orthobiz

It looks really nice. It would be kind of a shame to cut holes in it. --skrivis

I agree. Am already plotting on buying an uncut base on eBay and somehow stacking it upside down on this one, somehow painting both the same and tucking the PC board underneath. Will have to see when it gets here. Heck, I'll have to see how it sounds unmodified!

biz

You might also be able to make a wooden frame that the amp would sit on top of that would give you more room underneath. That might be less expensive than an unpunched base from ebay.

Sounds like you have a lot of fun ahead of you.

(If you like that kind of thing like I do.)

avahifi · « **Reply #50 on:** 4 Jan 2006, 11:34 pm »

Hey guys, I would not bother cutting holes in an old Hammond St-70 because you cannot find a good working original Dyna St-70 for the Ultimate 70 kit.

We are a lot closer than you might think to a new Ultimate 70 chassis. I have a good customer who turned out to be a sheet metal design whiz and had all the software and has designed a complete new 70 chassis for me just for fun (and a promise of the first completed one we build).

Anyway, the engineering drawings are already at the sheet metal company and they have already given us firm build cost quotes, and all I have to do now is write a PO for a prototype ("one-offs" are expensive, but not as expensive a fixing mistakes in a whole productionrun). I also have to make a few minor changes to the audio board, and a new prototype will be running.

If all goes well a complete new Ultimate 70 will be available in about 2 months and a kit version following as soon as I can write a kit manual.

I think you are going to like it.

Frank Van Alstine

simon wagstaff · « **Reply #51 on:** 29 May 2006, 12:29 pm »

Nothing going on here so I thought I would make a quick post. Just purchased an Ultimate 70 on the used market froma fellow leaving to go overseas. I can't imagine any other reason to sell it.

I have a pair of Inifinity Intermezzo 4.1 with a powered subwoofer. Impedance is rated at 6 ohms so I am not sure if I should use the 4ohm or 8ohm taps. I am currently using the 4 ohm ones.

I have a Denon AVR 3803 that I am using as a pre-pro. I was using a Sony TAE-9000 power ampin bridged BTL mode with 250 watts a side. it is well reviewed and I have used it happily for a while but just started to notice some grain and harshness (upgrade fever)

Well, I cannot believe the difference! it is more like getting a new pair of speakers, not a new amp. Inner detail, midrange bloom, vocals, reverb decay, extended high end, tight bass (remember the subs are driven by an internal 850 watt amp). this amp drives them beautifully. Maybe limited in ultimate volume (87 db sensitivity) but I just don't feel like turning it up. I get more than enough levels out of this amp. I could never understand how Infinity had the balls to charge $7K for these speakers (I got mine on e-bay for $1500) but NOW I understand. Again, WOW!

I am not sure if the Sony was that bad or the 70 is that good. I am guessing a combination of the two.

The problem that I have is matching up the rest of the surround system to the gain of the Ultimate 70 which is about 10 db lower than the solid state stuff used to drive the other channels. I can balance the surround receiver using internal controls but not the analogue output from my SACD DVD-A player. I have found some in line rca jack attenuators that will give me 6db of gain reduction. If that is not enough there are some other ones with 10db of attenuation. I don't care too much if the sound is slightly compromised for the surround and center but any other ideas would be welcomed. Paid $15 at parts express for them.

Also, any sugggestions as to the best tubes for the output stage?

If you are thinking about this amp, don't worry. My system is sounding so good right now it is unbelievable.

thanks Frank!