Free major Ultimate 70 amplifier upgrade.

simon wagstaff · « **Reply #40 on:** 15 Jun 2009, 11:42 am »

Well, I am no expert but I would check the solder traces and make sure there are no shorts anywhere. It is a little tricky as the wires are close together and the solder can run.

simon wagstaff · « **Reply #41 on:** 15 Jun 2009, 11:53 am »

More time with this last night. Amazing how little details POP out and I still think the biggest difference is in the cymbal "splash" area. the reverb decay goes all the way down to silence.

Listened to Andreas Vollenweider "Caverna Magica". this is an album I have listened to literally 100's of times. I heard things I haven't heard before. it is like a 3-dimensional bubble of sound is being projected by my Infinity IM 4.1. I have to give another plug for how good this combo is. some poor fellow is selling a set on E-bay for 900 bucks opening bid and no bites last time I checked. For less than two grand you can really find audio heaven.
I just ordered some KT77 tubes, not the Gold Lion but J and J or something but were 85 bucks for a match quad and though I would give them a try, seeing as how I am in the market for tubes.....

Wayner · « **Reply #42 on:** 15 Jun 2009, 01:20 pm »

I 100% agree with you simon. That was the first thing I noticed (cymbal crash) and the reverb. I also love Andreas Vollenweider (great minds think alike) and I really can hear the sound envelope or "bubble" your talking about. It's holographic, audio speaking and If you have the album White Winds by Andreas Vollenweider, you will be further amazed. Freidmann's Indian Summer is also a hoot. All is on vinyl, of course.

I lucked out with Andreas Vollenweider. One day I was on the internet on Acoustic Sounds website and was looking for some albums and did a search on Andreas Vollenweider (who also has a new album out) and found 4 used ones for $15 each. I bought all 4: Dancing with the Lion, Book of Roses, Caverna Magica and Behind the Wall. I had Down to the Moon and White Winds.

For those of you who have no idea who this guy is, he's from Switzerland, plays a harp and has an orchestra behind him. All of the music is instrumental, and are some of the finest "audiophile" recordings avalible on vinyl, on the CBS lable (not Columbia). Who ever was the recording engineer(s) for Vollenweider's albums were absolutely masters at their craft. I simply couldn't part with my collection, in fact in my mind, it is priceless.

Wayner

simon wagstaff · « **Reply #43 on:** 15 Jun 2009, 01:29 pm »

"Great minds think alike"

"Caverna Magica" was my first one of his albums and it is the standard for me. A lot of them sort of sound alike. I listened to some of "Red Rose" or whatever, that is supposed to be a 24 bt dithered down and the whole time I was just thinking "I would rather listen to Caverna Magica

there is a DVD out with great surround sound though.

I still can't get over how a little wire switching seems to have transformed things. what happened, did Frank just wake up in the middle of the night exclaiming "Eureka" or did somebody miswire it and find the change?

My guess is the latter...

Hope the other fellow finds the problem.

It has been a while since I have felt like this, can't wait for the work day to finish so I can go discover some more music.

Wayner · « **Reply #44 on:** 15 Jun 2009, 01:44 pm »

Frank is in the process of tooling the U70 up and going into production. Hopefully some of you guys will place some orders. I know they have been pooring over all of the circuits and asking themselves questions on all of the existing design. I'm pretty sure they looked at that and wondered to themselves if the then current way was the best way, and tried the new wiring scheme and found the improvement. The old circuit wasn't "wrong", it was just a different wiring scheme. With my experience as an electrical designer, I know there is about 10 different ways to wire up things and not really anyone of them is "wrong", it's just that some ways may be better then others.

Wayner

avahifi · « **Reply #45 on:** 15 Jun 2009, 02:29 pm »

First of all be careful with JJ output tubes, either the EL34s or KT77s. We got some of each of these with smaller than spec pin diameters that did not fit snugly into the sockets. This can cause intermittent or iratic operation.

I understand that this issue has been subsequently fixed by JJ, but if you get loose fitting tubes, return them for ones that do make good contact with the socket pins. These tubes are just fine if they have the correct pin diameters for a good solid fit.

Regarding the rewiring effort resulting in blown fuses and a lighting up 5AR4 tube, you have almost certainly miswired the project. Look for solder bridges or wires going to the wrong places.

Regards,

Frank Van Alstine

Art_Chicago · « **Reply #46 on:** 15 Jun 2009, 03:08 pm »

Frank,

Would one Ultimate 70 be enough to drive ST's with the T-8 preamp? The room is 20x16x17. Thanks,
Art

simon wagstaff · « **Reply #47 on:** 15 Jun 2009, 03:31 pm »

Frank,

thanks for the input, I am aware of the issue with the pins, it was mentioned on the web site where I bought them from, stating that it had been taken care of. Fer sure if I have any doubts, back they go.

thanks again for the upgrade on my U70. really, really nice.

turkey · « **Reply #48 on:** 15 Jun 2009, 03:40 pm »

Quote from: Art_Chicago on 15 Jun 2009, 03:08 pm

Frank,

Would one Ultimate 70 be enough to drive ST's with the T-8 preamp? The room is 20x16x17. Thanks,
Art

You might want to check with this person and see what they think too.

http://www.audiocircle.com/index.php?topic=68902.msg639167#msg639167

Art_Chicago · « **Reply #49 on:** 15 Jun 2009, 04:24 pm »

thanks, I did.

tgp06 · « **Reply #50 on:** 15 Jun 2009, 04:57 pm »

Art_Chicago,
My setup is temporarily in a smaller (15'x13.5'x8') room, but I previously had them in a 27'x15'x8' room and the STs filled the room fine with a single U70 (pre wiring change)-more volume than I could take! The STs final home will be a 28'x15.5'x10' room and there is little to no doubt the single (post wiring change) U70 will be plenty. Heard a single (post change) U70 driving HT3s and was frankly amazed by the bass extension/control and overall transparency. Would never have believed it could drive HT3s that competently. The T-8/U70/ST combination should be great.

Art_Chicago · « **Reply #51 on:** 15 Jun 2009, 05:39 pm »

tgp06,
thanks, man, great input!
Frank should offer you a position in his sales department, unless you possess it now...

simon wagstaff · « **Reply #52 on:** 15 Jun 2009, 05:42 pm »

I'll take that position too!! Really, the U70 is quite the nice amp now, I liked it before, I like it better now. Can't wait to get the KT77 tubes in it and see what that does.

Will the new U70 that Frank is developing be identical to the current configuration or will there be differences?

avahifi · « **Reply #53 on:** 15 Jun 2009, 05:57 pm »

The updated U70 will drive Songtowers just fine, thank you, probably all the amp you will ever need for them. - - - Assuming you don't mind a little extra heat in the room during the summer and the fact that you will have to test and replace tubes now and then. You will need an inexpensive volt meter to set the bias current (easy to do) and to make an occasional "health check" on the amplifier.

The all vacuum tube amp is not for you if you must depend upon local service for simple issues like tube replacement. You really need to learn to do this yourself. We will help you if you call us of course. 651-330-9871

The "new" vaccum tube amplifier is a bit more refined yet and unfortunately will cost a lot more than the U70 kit plus a good original Dyna St-70 amp, but musically it will be well worth it.

Regards,

Frank Van Alstine

simon wagstaff · « **Reply #54 on:** 15 Jun 2009, 05:59 pm »

HI Frank,

thanks for the information. Will the new U70 be different enough that if I want to set up a bridged set up (not that I am thinking of that) I would need to get 2 of them and sell my current u70?

avahifi · « **Reply #55 on:** 15 Jun 2009, 07:22 pm »

No problem with this, you will be able to use one Dyna based chassis U70 and one new AVA chassis unit just fine. We are playing with a bit bigger power transformer for the new one that gives us 40 watts per channel in the standard stereo mode.

I am using a pair bridged right now driving my Salk HT3s and they provide plenty of power for this application in my room.

Regards,

Frank

hotroady · « **Reply #56 on:** 16 Jun 2009, 03:25 am »

Quote from: avahifi on 15 Jun 2009, 07:22 pm

No problem with this, you will be able to use one Dyna based chassis U70 and one new AVA chassis unit just fine. We are playing with a bit bigger power transformer for the new one that gives us 40 watts per channel in the standard stereo mode.

I am using a pair bridged right now driving my Salk HT3s and they provide plenty of power for this application in my room.

Regards,

Frank

I can attest to them having enough power cuz, Frank let me listen to them with his DAC in circuit, today.

hotroady · « **Reply #57 on:** 16 Jun 2009, 03:58 am »

I agree, this is a major sonic improvement. I did this about 3am, and thought I was slick, tipping it on it's side. Well..I got solder drip trace on the circuit board. Don't be lazy like me...take out the tubes and turn it upside down! Brought it over Frank's(about 5 miles). He graciously took a look, then cleaned the now discolored joint area(mild arcing). To my great relief, it survived! I'm real interested in the new power supply transformer..man ST-70's always suffered in that department. Imagine a batch of changes coming on supply side coming forth to optimize. This update is the sort of thing I've been hunting for, kind explains why I had to do it, when I seen it on the net at 2:00 am. Will give a further assessment later, I have to listen NOW.

hotroady · « **Reply #58 on:** 16 Jun 2009, 09:14 pm »

I also changed tubes in this swap....I've been watching bias drift and change in relationship to each other. Wondering if splitting the one lead to two...each going to separate, individual red may resolve this. Has anyone else noticed this?

Wayner · « **Reply #59 on:** 16 Jun 2009, 10:32 pm »

The bias will drift. Perhaps more on new tubes? Frank would know better. I wouldn't get too hung up on it. I set mine every couple of days and it usually drifts to a lower bias voltage.

Wayner