[ricmon]

OK here’s the deal: 
Recently I had some problems with my system.

http://www.audiocircle.com/index.php?topic=41010.msg365797#msg365797

After the previous incident on the night of June 11 I was partying with a friend who likes to come over and listen to music with me.  That night I was pushing the amp kind of hard when all of a sudden the tube in the left channel gave off a bright flash.  The amp died and so did 2 more tweeters.  At this point I decided to deal with AVA privately off line to remedy the problem.  I sent Frank my 550 EXR, TR7, a pair of my interconnects and one of my speakers cables.  Why?  Because when I spoke with Frank on the phone prior to sending him my gear he made me feel as if I had been using my amp/preamp in something other than a simple 2 channel setup.  After receiving my 550 and TR7 Frank performed a bench test and informed me that I had the wrong tubes in the line section (12AU’s instead of 12ATX’s).  The tubes were replaced and the pre amp returned.  He also told me that I should switch interconnects because the one’s I am using are of a high capacitance.  OK.
 In the mean time I decided to upgrade the 550 to Ultra instead of repairing the EXR.  After examining the damaged 550 Frank informed me that the amp had the wrong fuses installed.  Funny I only remember replacing the fuse in only one of the channels.  Some time back in 2004.  However the amp was upgraded and retuned the first week of August.

Now last night I tuned on my system to perform my prelisting warm up.  I do this by playing the system at a very low volume playing a CD.  The volume is so low that you can not hear it over the TV that’s a few rooms away.  When I return to my listing room to start my musical journey for the night.  NO FUCKING SOUND!!!!!!!!.   The worst part though is having to listen to my girl friend say “you seem to be having a lot of problems from that stuff.  Maybe you should think about getting rid of it”   or “ for all that money, I don’t know honey”.  From her perspective AVA gear is not worth the hassle.  So to recap 5 tweeters, preamp bench test ,tube replacement  $794.00 bucks latter and no sound.  The problem this time is the preamp.  I pulled out my backup pre only to hear this time from my girl friend “it’s singing again”.  I’ll get in touch with Frank about this as soon as I come to terms with the fact that Mr. Murphy lives in my house.  I wonder what it’s going to cost this time?

[martyo]

Bummer ricmon. Tubes and fuses and their types and values are significant components of the gear. Why don't you just call him. Any time I've called, he's answered the phone.

[ricmon]

Bummer ricmon. Tubes and fuses and their types and values are significant components of the gear. Why don't you just call him. Any time I've called, he's answered the phone.

I will when I calm down 

[mcullinan]

First.. how did you end up with the wrong tubes in there?
Also do you think you are getting some kind of power surges in your home? Everything is blowing up!
Mike

[ricmon]

First.. how did you end up with the wrong tubes in there?
Also do you think you are getting some kind of power surges in your home? Everything is blowing up!
Mike

Amps are relatively immune from power line conditions.  The tube are technically not wrong.  The preamp does not have to be biased and Frank has mentioned that we can tube roll all we want with the preamp.  Also everything is not blowing up.  I have other electrical gear and the amp, TT, my other system (seperate amp/pream combo) is just fine.  What has happen here is really not an analysis or condemnation but we on this board lavish our manufactures with all sorts of praise.  I am a long time AVA owner ( I started with a 350hc t0 350EX to 550 EXR a TR7 and noe an 550 Ultra) and not have had any problems in the past.  But this recent round of failures is just to much to bear.

[mcullinan]

Well I hope he is treating you well. I was thinking of purchasing an UltraDac, but not if my system is put in jeapardy.

On a side note I had similiar issues with my Nuforce 9 amps when I first purchased them. The shut off after 2 hours (had to be sent in to get a software update), then one day one poofed into a cloud of smoke, who knows why, sent in x2--> fixed. Then I upgraded to the V2 SE board and upgrade and havent had any problems. Let me just say that these amps are amazing! But it was frustrating waiting  to get them fixed the first 2 times

Mike

[ricmon]

Well I hope he is treating you well. I was thinking of purchasing an UltraDac, but not if my system is put in jeapardy.

On a side note I had similiar issues with my Nuforce 9 amps when I first purchased them. The shut off after 2 hours (had to be sent in to get a software update), then one day one poofed into a cloud of smoke, who knows why, sent in x2--> fixed. Then I upgraded to the V2 SE board and upgrade and havent had any problems. Let me just say that these amps are amazing! But it was frustrating waiting  to get them fixed the first 2 times

Mike

I feel your pain Bro    However there is some solace to know that other have been similarly frustrated.  Of course I'll give Frank a call and work it out.  (i sounds like a jilted lover who whats to make up)

[ricmon]

Well I hope he is treating you well. I was thinking of purchasing an UltraDac, but not if my system is put in jeapardy.

Huh?  Don't the problems enumerated here sound rather customer specific to you? (What's with all the wrong fuses and tubes?) (And how loud do you have to be playing music to keep blowing tweeters?  Do you have hearing loss or something?)

Again the tubes are not the wrong tubes.  And the preamp failed last night playing very low per my first post.  I don't abuse my equipment and one should at least be able to have some fun with the volume cranked up with out the risk of damaging attached equipment.  And the point of all this is for us AVA owners to provide our manufacture with some feed back.  I know for a fact that the preamp just quit.

[mcullinan]

I listen at moderate levels, but sometimes I like to perform a concert in my living room at ear bleeding levels and havent run into any problems.. Except for the bleeding ear thing. 
Mike

[avahifi]

Just some interesting things about this issue the customer did not mention.

The last time the amplifier was sent here, it arrived with 25 amp speaker fuses  slightly larger than enough to light the White House Christmas Tree.  The speakers in use are 90 dB efficient, should not require anything bigger than a 3 amp quick blow fuse ever.

Preamp line section arrived with 12AX7 tubes installed in line section 12AT7 locations.  We salvaged them for phono used but probably should not have, they might have been overstressed due to inappropriate application by user.

These very efficient speakers should go very very very loud on 100 watts, blowing main amp speaker fuses with 300 watt per channel amp kind of sounds a bit like overkill to us, and probaby to the tweeters too (kind of a pun).

Now, questions, would like information, rather than rants.  Both channels down on preamp or just one channel?  All sources, just one source?  Pilot lamp lighting up?  Was the preamp fuse checked? Any background sound from preamp, or dead silence.  Check tubes in preamp?  Lots we can do to help troubleshoot with data rather than just complaints.

Regards,

Frank Van Alstine

[ricmon]

I don't abuse my equipment and one should at least be able to have some fun with the volume cranked up with out the risk of damaging attached equipment.

Unless of course the volume level in question risks damaging attached equipment, I suppose.  Someone might see that you keep blowing tweeters and suspect that you're abusing your equipment.  I mean, they wouldn't be crazy for wondering.  Every speaker has limits.  Not saying you are, but nobody can tell how much fun you like to have can they.  Saying "I should be able to play it as loud as I want" doesn't tell anybody anything, if valuable customer feedback is your goal.  If my volume knob goes much past 10 o'clock it's too loud for comfortable listening, for me.  Does that mean I don't like to have fun?  Or just that I'm not gonna be opening up a night club in my home anytime?  Just wondering...

And the point of all this is for us AVA owners to provide our manufacture with some feed back.  I know for a fact that the preamp just quit.

Probably a blown fuse...?

You mat be right about the fuse but you have missed quote me I said "one should at least be able to have some fun with the volume cranked up with out the risk of damaging attached equipment ".  However, I don't play the blazing thing so loud like having the volume turned passed the 2:00 o'clock position.  In my room that's plenty loud.  And yes my gaol is not to open a night club but some times I do like to simulate a good performance in the room.

[ricmon]

Just some interesting things about this issue the customer did not mention.

The last time the amplifier was sent here, it arrived with 25 amp speaker fuses  slightly larger than enough to light the White House Christmas Tree.  The speakers in use are 90 dB efficient, should not require anything bigger than a 3 amp quick blow fuse ever.

Preamp line section arrived with 12AX7 tubes installed in line section 12AT7 locations.  We salvaged them for phono used but probably should not have, they might have been overstressed due to inappropriate application by user.

These very efficient speakers should go very very very loud on 100 watts, blowing main amp speaker fuses with 300 watt per channel amp kind of sounds a bit like overkill to us, and probaby to the tweeters too (kind of a pun).

Now, questions, would like information, rather than rants.  Both channels down on preamp or just one channel?  All sources, just one source?  Pilot lamp lighting up?  Was the preamp fuse checked? Any background sound from preamp, or dead silence.  Check tubes in preamp?  Lots we can do to help troubleshoot with data rather than just complaints.

Regards,

Frank Van Alstine

Not ranting just trying to have a open conversation about my experience.  As you will note my tone is not one of condemnation.  I love my AVA equipment.  Just frustrated.

[martyo]

Hey ricmon: Just a comment about your tweeters, I understand your preamp is the issue now. I know nothing of the Lipinski's so I researched them like I do whenever people bring up gear (especially speakers) I'm not familiar with. They seem to be relatively efficient and are rated at 4 ohms. That puts your 550 at 500 watts rms, that's a lotta juice for those 1" tweets. Just making an observation. I've already been accused of not listening correctly right here in this same circle, I like to crank it too. I saw Bela Fleck a couple of weeks ago and it was pretty powerful and very dynamic. Not as loud as the Dead were or the String Cheese. But at home I like to try to recreate what I heard live, sometimes it comes close, which is what it is all about for me. Everybody has their preferences, just letting you know where I come from. But it does seem to me that you do have alot of juice there for those little tweeters.

And your concern about that girlfriends impression, oh, never mind.

[mcullinan]

They are very efficient at 90 and wow thats a hell of a lot o watts brother... a sexy amount almost, a my pants are off amount... um let me stop before obsceneness occurs.

My watts are smaller than your watts btw... Though Im planning on a Viagra power cord to supplement.
Jesus I think Im sik.
Mike

[ricmon]

However, I don't play the blazing thing so loud like having the volume turned passed the 2:00 o'clock position.  In my room that's plenty loud. And yes my gaol is not to open a night club but some times I do like to simulate a good performance in the room.

2:00? I don't know what the gain on the older AVA preamps is, but...that's Guantanamo levels where I live.  For your sake I hope it's a very large room.

This is usually with lp's which require a little more gain to achieve the same db levels as cd.

[bpape]

Just doin the math here real quick - even assuming you're PEAKING at 250 watts, that's 117db!  Not trying to beat a dead horse but I really don't think those tweets will take that (nor will your ears for long).  I like to crank it up and listen as much as the next guy but that's seriously loud.  I suspect that at 2:00, you're peaking even higher than that.  It's a credit to the amp that it's staying clean enough that you're not popping tweets more often.

Edit:  You posted while I was typing.  I certainly hope with an LP there is a rumble filter engaged.  That kind of db with a turntable - all it takes is one good warp on the record to make the amp try to do a 6hz or so tone and seriously clip the amp.

Bryan

[martyo]

My speakers are supposed to handle 1000 watts rms. They routinely took all of the 750 Carver watts rms I had with my old amp. The 250 Van Alstine watts I now have "light up" my speakers more.
Volume knob: usually 10:30-11:00. Sometimes on fairly compressed source material it's gotten to 12:00. My old super pas 3i was a different story 2:30-3:00.

Hope it's something simple,and you're up and running for the weekend.

[mcullinan]

I barely get mine past the 12 oclock position before it gets uncomfortable..... my preamp knob that is...
Though I could turn down my DAC output, but then it doesnt sound as good.
Mike

[ricmon]

Just doin the math here real quick - even assuming you're PEAKING at 250 watts, that's 117db!  Not trying to beat a dead horse but I really don't think those tweets will take that (nor will your ears for long).  I like to crank it up and listen as much as the next guy but that's seriously loud.  I suspect that at 2:00, you're peaking even higher than that.  It's a credit to the amp that it's staying clean enough that you're not popping tweets more often.

Edit:  You posted while I was typing.  I certainly hope with an LP there is a rumble filter engaged.  That kind of db with a turntable - all it takes is one good warp on the record to make the amp try to do a 6hz or so tone and seriously clip the amp.

Bryan

Seriously guys.  My system sounds seriously good.  The tt is very well isolated and I get some serious base along with tons of resolution.  I sit about ten feet away from the speakers and just have a good time listening to music.  Some of my lp's and cd's just don't sound good too loud so all listening is not done a loud levels.  I suspect like most of you I like to crank it up some but never an never ending distortion filled onslaught of noise.  Also I got in touch with Lipinski Sound about this as well.  And guess what?  They swear that they drive their speakers pass any level that I do and have not had any problems.  Also Lipinski recommended I use an even more powerful amp if I insist on listening at elevated levels. It was at this point he suggested I buy one of their amps. 

http://www.lipinskistore.com/store/product_info.php?products_id=43&osCsid=a245ebef28464457532bdc4e2d616bf4 

But that ain't happening.  Besides one of the characteristics I like about the 550 Ultra is that it's more enjoyable at lower listening levels than my EXR. 

[gjs_cds]

I move that we bring some sanity into this discussion.

The speaker sells itself as a D'Appolito design using a low order crossover.  Traditionally, D'Appolito designs use odd order networks for improved sonic dispersion.  Thus, its relatively safe to assume that the “low order” crossover is a 1st order XO (6 dB slope); the manufacturer states that the crossover point is 2KHz.  Right off the bat, alarms are flashing...

The manufacture is probably thinking that they can get away with a first order crossover and a low 2KHz Fc because the tweeter's Fs is 500 Hz.  (Assuming that they're using the Vifa XT25TG30-04 ... which appears to be a very safe assumption.)

http://www.madisound.com/catalog/PDF/vifa/xt25tg30-04e.pdf?osCsid=5c05457adaec721cbdab747b8ac2764c
Life for this little guy begins to get a little hairy around 800 Hz.  This makes the MINIMUM suggested Fc around 1.6KHz w/ a 2nd order XO.  So an Fc @ 2KHz using a 1st order XO is problematic, right out of the box.  Sure the manufacturer will not agree with me, but that does nothing to change the indisputable math and physics that are involved. 

Provided that users of this speaker recognize that this design is not intended to produce rock-concert levels of intensity, the speaker manufacturer might be able to get away with this design.

However, if one looks at the specs of that tweeter, it's apparent that the frequency response only begins to flatten out around 1KHz, making a 2KHz Fc really only wise if a minimum 2nd order XO.  (12 dB slope).  Even order slopes would mess up phasing (not the end of the world, but potentially a design hassle), so a 3rd order XO may have been a better choice relative for reliability in high SPL use. 

In short, this speaker design is inadequate for high intensity levels; and it's no surprise that tweeters are being blown if a user sets the volume to concert-level intensity.  I predict that tweeters will continue to be blown if the behavior doesn’t change.  (The gear may have nothing to do with it.)  Further, a 550 amp (rated at 250 watts @ 8 ohms) is entirely inappropriate for a 90 dB efficiency speaker @ 4 ohms.  (Thereby putting the AvaHifi amp functionally in the 400 to 500 watts range @ 4 ohms, I'm estimating.)  That flushing sound is the emptying of a wallet. 

I can't speak to the Frank's hardware in this situation.  It seems that there’s been some poorly chosen modifications by the owner, but I can’t really comment on that.  I've had to have both my AVA pieces repaired at one point or another, and I never "mod", nor have I ever had to repair any other audio gear in my life.  But there is sufficient evidence suggesting that the blown tweeters are user abuse coupled with a poor XO design relative to high SLP use.  Let's give credit where credit is due.  If one wants concert level SPL, then one should get speakers that are designed as such.  And with that said, it seems entirely possible that tube swapping (without proper biasing) and fuse exchanging may just have something to do with these AVA "reliability" problems...

And please don't even get me started by stating that one hears "resolution" at an estimated 117 dB, especially given the radiating area of a two (7-inch) woofer system.