VAC owners, sound off

My last ditch-resort (prob just confirming the unfortunate known) is to put in a call to Kevin Hayes and go over some specs. Plan on doing that today. If that goes as expected, I'll put this VAC up on the 'gon and use the $ to get something that hopefully synergizes better.

The VAC has an even lower output impedence than the AH. One of the lower ones i've seen in fact @ 350. Based on that you'd think it would mate fine with my amp rated at 55k input.

I have a Vac amp, which does have a high gain. I believe
38, as opposed to many other tube amps, which are closer
to 30. I only open my V-C to around 9:00 ot 1/4 turn,
which is loud. The manufacturer of my preamp said not to
worry about this because the type of volume control he uses
in his preamps do not change in sound no matter what level
you are playing. FWIW, I also heard a VAC Ren sig 2 on a
VAC amp, and I believe this sound was also loud at around
1/4 turm. My pramp is not a VAC, but does have 20 db of gain, the VAC's I know are higher gain as well. Not sure of the spec. I guess even though VAC amps have the higher
than average gain, Kevin still uses a fair amount of gain in his preamps. When I heard a VAC amp at a dealers recently, he was using the VTL pre. Again, a higher gain pre paired w/ the Vac amps. Regardless, I do feel it would be better to open up the V-C a bit more and/or have smaller step increments on it as well. Just my related experience, hope it helps. It does seem like a synergy issue may be involved though. You may want to call Kevin,
and let him know your amps specs, and then your amp manufacturer, and let him know the preamps specs.

Thanks Tvad. You're an asset here.

Did you mention Audio Horizons in particular because you think it will better suit my needs or because they are a company with a 30 day? (or both)

don't know if that contributed to the issue in this case, but gain was exactly as you described -- loud at about a quarter way or less on the dial. Is there a spec to determine if gain on a pre will match up well with your amp?

I surmised the same thing. Outside of impedance matching, is there any other specs to check between pre and amp for compatibility before rolling the dice?

So I figure I'll just tack onto this thread rather then start a new one. After listening to the pre for about 2 weeks I think I've adjusted to the sound. My impression is that it's, in a word, unremarkable? I find the mids and bass light and lacking. Vocals -- which I think any good pre should do well, are also light and even sound a little boxy and compressed. Presentation is also bit flat. Basically the sound lacks dimensionality and fullness.

Reason I bring these observations up is they seem to fly in the face of the overwhelming kudos to the VAC sound. I'm not hearing it, or at least what I'm hearing isn't what I believe so many people would be raving about.

I do have the unit on brass cones into brass feet, underneath of which are iso-node pods. I do this primarily because the shelves on my custom rack are natural wood and not 100% flat, and the cones are height-adjustable. While the cones also help tighten focus, I do notice that they lighten the mids and bass to a degree (the iso-nodes help counteract that). But I tried the unit on its own feet, with only a slight improvement.

Maybe I'm looking for the wrong things? I listen to hard and classic rock, electronica, some solo acoustic. Maybe this pre sounds better with different music styles. Maybe there's a system dis-synergy. Don't know. At this point I'm ready to put it back up for sale, but thought I'd try here beforehand to see if anyone has any thoughts or troubleshooting ideas.

Glad you got the RCA Cleartops, they are excellent overall, and do remain a comparative bargain. I agree that Andy at VTS is beyond reproach, and I have also had good luck with Brent Jesse Recordings for NOS.

Happy for you ! Amperexes in the 12au7 spot will bring you back some extension in the highs, decay maybe or maybe not. In my preamp, it did but it is a more subtle difference than changing the 12AX7 tubes. Remember to wait at least 50 hrs of running the new tubes in order to hear the best of them.

You say the preamp has a little less decay than with the original tubes. This means it is there somewhere but hidden since you heard it before. You have more bass and weight, obviously your hearing is rebalancing itself. You might just hear your decay back once you are accustomed to it.

Have trials with your speakers positionning and have a look at your acoustics. Don't forget to check your electronics isolation to vibration. Better quality electronics are more sensible to the surroundings. Doesn't cost anything and most of the time does a lot.

Have fun !

An update. Put the PS on some 1.5" butcher block, and that on a glass shelf off the floor. I honestly don't know if that made a difference vs just being on the floor. Whatever it was, it was subtle. I also reversed polarity at the amp, and that did seem to help things, though it wasn't quite the 'a ha' moment I was hoping for. The biggest difference? swapping out the stock Sovtek 12au7's and Chinese 12ax7's for a pair of black plate GE 5751's and RCA clear tops. Big difference. MUCH better bass and weight, dimensionality seems to have increased as well. Though I think the highs are a bit less extended with less decay. At any rate, the musicality has increased, which is what I was really missing.

A big shout out to Andr who turned me on to Joes lore and conversed w/me via email. Because of the tube hunt, I also met and did business with a wonderful tube seller here on the gon -- Aztubes. A relative newcomer here, but an honest, knowledgeable and helpful tube seller with reasonable prices and fast shipping. A class act and highly recommended.

I have owned 2 fine pieces of audio gear by VAC. The Avatar SE and I presently own and use heavily the PA 100/100 amp. I have many high end pieces over the years but none seem to have both the mixture of elegance and sound quality that these pieces exhibit. You cannot do yourself wrong with VAC gear.

Keep listening to the music, Richard.

So in a general question, what's the deal with inversing polarity? Why do some manufacturers do it and not others? What's the advantage?
Tholt (Threads | Answers)

It's a simpler/shorter circuit with only one gain stage that is cost effective for the price/perf ratio. My Renaissance does not invert but it costs more as well.

Thanks Andr, don't know if you got my PM but you just answered my questions.

we-252 is the seller's name. Regardless, I appreciate all the "Beware of Ebay!" signs you guys threw up. My last tube purchases have been from either equipment manufacturers directly, or from agon.

Hello Tholt,

As told in a previous post, I strongly recommend you have a look at "Joe's tube lore" for good advices on 12au7 and 12AX7 tubes. I went through it and tried many of its recommendations with my Standard LE. Worth it. Just type it on Google and you will fall in Audio Asylum where it is based.

Now, the VAC tubes that come with the unit are....hmmm very so so. Flat, dull and no punch.They will give you a bad impression of your unit, period !

IMHO, Joe's....recommends RCA Clear top 12 in the 12AU7 spot and Amperex Bugle Boy. The RCA'S are very good overall performers and easy to get at a reasonable price. Got a couple of pairs myself and strongly recommend you choose those as a starter. Can't go wrong with those. The Bugle Boys are scarce and expensive. I've got Valvo ones supposedly made in the same factory, at the same time, for a fair price. I love those for the better dynamics and openness.

As for the 12AX7, there is a lot of choice and tried many combinations. My preferred ones are the 5751 like Joe's recommend. I love both the GE JG5751WA and the Sylvania JHS-5751 or Gold Brand. I prefer the GE for rock because of their slightly recessed soundstage with its better detailing of electric guitar. Bass and drums are tight and slammy with this one. I prefer the Sylvanias for Jazz, soft rock and ambient. Very warm and lush mids one with voices very upfront.

GE'S are common on Ebay and Sylvanias quite expensive but damn their worth it.

Good luck !

At this point I'm stoked to reverse polarity and see what happens, tube rolling may be a moot point. Thanks for the tips and troubleshooting all. Let you know what happens. If it is the 'a ha' moment, I'll be one very happy puppy.

Appreciate the tips on tube buying on ebay and such. I was going to go through a dealer called we-252 who runs a store called FantasticTubes, if anyone is familiar with them. Great feedback and a Power seller.

So in a general question, what's the deal with inversing polarity? Why do some manufacturers do it and not others? What's the advantage?

The VAC selected tubes are excellent IMO but if you must play with NOS then Andy at VTS is the one. You want the lowest noise and best matched tubes possible. Andy has never let me down in that regard.

There is no better NOS seller than Vintage Tube Services. Brent Jesse Recordings is also very good. I agree with Swampwalker, you don't know what your doing, stick with VERY reliable and known sources.

tholt- be VERY careful buying tubes on "flea-bay". If you don't have ready access to a tester and a return guarantee, I would avoid it. I would estimate that 50% of the NOS tubes i bought there (before I had a tester) barely make minimum good and more than 25% did not even test that high. So maybe a 1 in 4 chance of getting a tube that is even close to NOS. And then there is the counterfeit problem. I'm sure there are exceptions, and YMMV. As for me, I'm sticking to tube sellers on on 'Gon as well as the better known internet sellers like Vintage Tube Services and Upscale Audio.

Tholt, you will be in for a pleasant surprise now, after you compensate for the phase and provide better support for the PS. You'll be jamming tonight!

Tholt, I tried spikes between the PS and the platform and didn't like the results. Currently it sits on the Mapleshade platform on its own feet. The Mapleshade is spiked to the bottom shelf of a Polycrystal rack. I don't like the Polycrsytal rack BTW.

The butcher block should thin out the mids and give you better top end extension. The bass may be a bit unpredictable. Have fun experimenting.

Rhjazz -- just reading over the manual again -- output does state its inverting.

Rhjazz - 2 things I never would have thought about. PS is sitting on hardwood floor. I'll try getting it off that. I actualy have some butcher block I could use. Did you attach the spikes to the PS, or underneath the wood block? Secondly, I don't recall reading anywhere in the manual about phase inversion. Ill double check.

The tubes in the pre are standard VAC issue (they even have the VAC logo on them). The previous owner said they were fairly new, and from talking to Kevin the 12ax7's are Chinese and the 12au7's are Sylvania (not sure which kind). I read up a little on Joe's Tube Lore (found the site people have been citing for years) which started me on a tube hunt. Found some Amperex 12au7's and some GE 5751 (supposedly better then 12ax7) on ebay that I'm thinking about.

Tholt, what is the power supply sitting on? The material it sits on will definitely make a big difference in the sound. I've tried MDF, solid oak, solid cherry, granite, butcher block, and the best is the Mapleshade solid maple platform with brass spikes. The second best was the MDF. Also, I think the VAC standard preamp inverts phase so you will need to reverse the connections at your speakers.

I don't know what type tubes are in your Vac...but I have had good luck with d-getter Amperex tubes. Owning Vac amps... I would agree that your preamp should resolve very well....the bass is excellant on my amplifiers.

Well, I received the pre and have had a couple nights to listen to it. It is a Standard that was upgraded to LE status. I'll give a summary of my equip and listening habits, then give some very brief impressions.

It is receiving source material from a Musical Fidelity a308cr upsampling player via analog unbalanced RCA. It is feeding a NS LM3886 chip-based amplifier, the Jaton Operetta also unbalanced. That is feeding Usher 6381 3-way towers -- 87db@8 ohms. My music preferences are solidly rooted in hard rock, and a bit of techno, though i do enjoy acoustic guitar/vocals male and female as well. No jazz, no classical.

The preamp it replaced was a Rogue Audio Metis. Comparatively, differences were interestingly not that extreme, I'd say they were more subtle. What I can tell is that the VAC seems to have a flatter frequency curve and perhaps more neutrality then the Metis. I'm still getting a handle on explaining sound in technical and oft-used audio terms. It also seems to resolve better. What I miss, though, is the mid-bass and bass I got with the Metis. That's why I say it seems to have a more neutral tone -- mids seem to be pushed more, bass seems to have receded a tad.

Has anyone experimented with tubes in a Standard before, and perhaps have either tube recommendations to try that have a bit of warmth and/or extension, or just in general what they thought of my impressions vs their own? Just curious.

Not much to add here but another vote for VAC. I have a PA100/100 amp and Standard MKII preamp (must be an upgrade 'cause it says LE on the chassis but MKII on the box and has no external powersupply) Anyway, totally reliable so far.
I have taken the pre to several audio get-togethers and it has always sounded fabulous with whatever it's been hooked up to. Also at my place it has powered several amps, each wonderfully.
While I really like my VAC amp, my gut tells me that my pre is the more special of the two.
I don't think impedence matching will ever be an issue because VAC pres have the reputation to be able to drive anything.
Very satisfied.

-Mike

Let's us know whay you think once you get a chance to spend time with it. By the way, I don't own VAC, but have heard there equipment many times and was always very satisfied with the sound of their gear. You should be happy with unit, VAC is good stuff, no doubt.

I confirmed impedance compatibility from Kevin Haynes when I spoke with him, so all good there.

I also got the 'welcome to the family' line from Haynes. Nice guy, coupled with reputation and the love you guys obviously have, i'm looking forward to trying the VAC.

thanks

Tholt, Tvad's comments on impedance matching are critical for many reasons, and usually more of an issue when dealling with a tube preamp. Now if you are also planning on using tube amp it becomes less likely you have a problem. I think trying VAC is a very good idea, a 9 year old VAC remains and will always be good piece of equipment well worth exploring. Now if you want a warmer, "tubier" sound there are other choices and not driven by the necessity of "newer technologies" - good/great preamps have been made for quite a while.

and i didn't either (mean disrespect). it is after all, the absolute truth. you have to try. my point is it goes w/o saying. More to the point, that my questions (and i think anyone's with simple curiosity about components) are leading up to if we actually want to try 'X' out in our systems, or if "X' will even work from a technical standpoint.

And for the record, i plan on doing just that.

Hi Tholt. The most useless thing anyone can say comes from those who give you an opinion on a piece of equipment they have not heard and guaranteeing it will be right for you. Slightly less useless are opinions coming from those with a limited range of equipment they have real experience with, and then telling you how wonderful the piece they happen to own is, with very little comparative listening but a real gungho recommendation on what they do own and with no knowledge of your preferences or system context. Ultimately, "you have to try", might very well be the best advice anyone can give you and the most honest - since we all hear differently and look for different things. The answer to your original question was answered pretty well. It sounds like VAC might very well work for you - but you will never know till you try it - that's just the way it works, and the next step if what you have heard about VAC here has made you interested in pursuing it further.

Tvad, if only all heads were as cool as yours... But of course, the passion and the chest banging are all part of the game, esp when we can all hide behind a screen name and yell a little. It's all good and part of the fun until it just gets stupid.

Thanks for the sound explainer on VAC's. Answered a lot, primarily that the modern technology question wasn't necessarily the right question to ask. Got it.

Of course ultimately it always boils down to 'try it in your system and find out.' And of course that's the most useless thing anyone can say. Like, really? That's all i have to do? What am I wasting time asking questions for? Nah, I found tons of information that i didn't know -- info i trust -- in one day from over 20 posts. i feel better. And hey, hope everyone here had a good T-day. I truly appreciate you taking the time from it to give me your thoughts.

Tholt,
Also, keep in mind, whatever vintage VAC preamp you are looking at, make sure that its output impedance matches well with the input impedance of your amp/s. This is a very important parameter to match up front in helping you to make your decision.

Like someone said earlier, you would have a hard time finding a better way to spend $1,500 for a good preamp. Whether you like it or not, I would think you would though, you just have to try it. Now if you can describe a type of sound you like like lets say warm and smooth, versus fast and detailed just as a general orientation we might be able to direct you to some options. But if I had $1,500 to spend, that VAC looks mighty good to me.

I own a bit of VAC gear, find it to be of exceptional build quality and in the event it were not, Kevin has been absolutely terrific to work with.

The guys are right, VAC gear has it's own sound that you will need to hear and spend some time with in your own system to make the best determination for yourself. However, I believe your intent was to ask about reliability and relelvance of older VAC pre's. Not a worry in either case is my opinion. I will own these pieces the rest of my life.

Tholt- I stand by everything I said - Tvad just explained above in more detail pretty much exactly what I was driving at. In other words, you need to hear it for yourself and all the questions in the world are no substitute for your own ears in your own system.

I meant no offense - we always appreciate good questions and you did ask a good one, which was answered by several, including myself. You attitude needs some work, though, as do your manners.

I will never sell my VAC's....they are that good....buy it.