Amp vs preamp question

Matching amp to speakers and speakers to room is most important to get right first. Cost to accomplish this is secondary. Larger rooms will generally cost more to get right.

Once you have this planned out, a pre-amp to match can be determined. You need to consider what kind and how many input sources the pre-amp must handle.

Tell us something about the speakers and room you are working with first and then it should be possible to offer some useful suggestions.

Also, knowing you overall budget for both amp and pre would help.

I have the thiel cs 3.7
Room size 18X18

Thanks

Question:
Where should more money be placed, into the preamp or the amp?

Preamp. hands down. Period.

that is not to say the amp is of no consequence. Not at all. I've found out personally, that if a chain of priorities is in place, the sound begins with the source. So the source should be as good a one as a person can afford. Following that philosophy, the preamp/controler should be on par or better than the source. This should, and I do mean should, keep the signal intefgrity on a very high level.

An amplifier that receives a fine signal will sound better than one which does not. To assist the amp in doing it's job, the front end needs to be as good as one can get and a little more... well, that's my approach anyhow.

the speakers and amp combo are about a matter all their own... and usually the speakers will narrow the field of amps best suited to them by their eff and impedance curves.

I've never heard great speakers sound great with the stuff in front of them being just so so. On the other hand, I've heard great sounds coming out of moderately priced speakers with great front ends.

It's all about the signal and keeping it as pure as is possible... as it gets magnified along the way.

I must say if I had to decide between the two.,I would say that the Pre-amp has much more to do with altering ( good or bad ) the sound of your system....

Each piece contributes to the sound.

The engineering principle of bottle necking comes into play when "tuning" your system. Basically, this means you make sure the part furthest downstream is not "bottle necking" or limiting performance. Once this part is tuned, then move to the next piece upstream.

Unfortunately, if you do not make sure the amp can drive the speaks properly in you listening environment first, you will have a bottleneck downstream and not be able to get the most out of your expensive upstream electronics no matter how much money you throw into them.

I agree with most of the points above. I have found on an absolute basis the preamp has a larger effect on the overall sound of a system than an amp (this is obviously a generalization).

That said, Mapman's right in that if your amp won't drive your speakers properly the rest really doesn't matter. And since most Thiel speakers are demanding and quite picky when it comes to amps it's probably particularly important in your case to get the amp right first, then find a preamp that synergizes well with your sound preferences and the amp itself. I'd follow that strategy and let the costs fall where they may.

Best of luck.

I have to agree with Mapman here. Especially with Thiel's. Thiel's are more demanding of appropriate, quality amplification than most speakers. BTW, I've been using Thiels for 20 years.

The amp is more important than the preamp, and vice-versa.

Seriously, my experience generally supports Mapman's statement, but within a range of amps that accomplish that optimum combo, the choice of preamp will give a profound, perhaps more significant improvement.

btw - I spent about the same on both in my system.

" the choice of preamp will give a profound, perhaps more significant improvement."

I agree the impact of pre-amp will be profound.

How exactly does one best go about chosing which pre-amp will be best at this point though?

square rooms gives grey sound
rectangular rooms give color sound, to my ears.
= grey vs. color = diferent harmonics.

no matter if the speaker and amp are the best, the room can make them sound ugly.

power also , needs balance, big room needs power.

but, electronically speaking,
speakers, amp & cables are more important than pre-amp.
the best pre can only perform as good as your speakers or amp.
the weak link its your best.

I see no inconsistency in most of the arguments above. I'm in the "garbage in, garbage out" camp. So I view the pre-amp as being more important than the amp. This presumes, however, all other things being equal. The amp has to mate well with the speakers and the system has to be tuned for the room, or vice versa. So if you have an amp that is suited for the speakers, and if your room acoustics are good, then all things are equal and a preamp upgrade should do more for you than an amp upgrade.

Thank you very much for your help
I am thinking about BAT vk 51se preamp and Rogue Audio Zeus Amp

Can you give me some more advice?

The Thiel 3.7's drop to 2.8 Ohms, very few tube amps are at their most comfortable operating into such a load.

I'm not a Thiel guru, but it sounds like tube amps are not a good match to the Thiels due to difficult load.

You might be better off going SS on the amp and tubes on the pre-amp, if that's the sound you like. The SS amp should double power to 4 and 2 ohms as discussed above due to the load.

I'm sure others may have some specific suggestions regarding what works good with Thiels. If it were me, I'd consider some of the better Musical Fidelity amps of perhaps something Class D, like Bel Canto or Rowland maybe.

A Friend of a friend of mine owns the 7 series Thiels, and has put in place several differring amps, as is my understanding. Krell, Ayre, BAT, and I think a Classe. I'm pretty sure a few Tube amps as well. Last I heard he liked both the BAT vk500 and an Ayre, (the model escapes me now).

I feel as I said above, the speakers will narrow the field by it's own demands.

Impedance curve, efficiency, and freq range. With thiels, I'd venture that SS power would be by far the safer bet for an amp with Theils in the picture. Overall.

There likely are tube amps which will satisfy too.... depending again, on what it is you are looking for ultimately.

The BAT vk51SE is a solid preamp. Great build and some flexibility, and great support. Lots of tubes though... but with SE & XLR output, that should allow a greater field of amps to select from. Keeping built in sysnergy in mind, a pretty safe bet I'd say would be to go BAT amp too.

Given BAT's rep for power resivoirs if a vk51 is likely to be your preamp choice, you could do worse than adding a BAT SS amp. I sure wish I had my VK 500 still.

Whatever the pick... good luck.

If you are asking that question, buy an integrated. :)

Douglas Schroeder has a good point.

You want to be sure what you buy synergizes well. If you are not sure what will, an integrated would be a safe bet. Just make sure the amp can drive the speakers adequately.

Another option is trial and error. Buy used and don't overpay if that is the way you want to go, then if something doesn't work out you can sell and buy something else without taking a loss (who needs more of those these days)?

Very few integrateds have the power, especially into sub 3 Ohm loads, to get the most out of the Thiels.

IMO - Amp/Speakers matching first.
Finding preamp that will complement the amp/speakers synergistic qualities is the trick. Transparency is the goal and prefered coloration - just like salt & pepper- to ones own taste. Gamma of features, ease of use, cosmetics, value - all, just iceing on the cake.
At the end, your system is or will be as good as your weakest link. Speaker>amp>pre>source>rest is my own general rule.

Unsound, good point. If he's driving the Thiels to high levels in an 18x18 room, he's got more problems than amp power; he'll be working on hearing loss. 4 Ohm nominal impedance, 90dB sensitivity. He'll be fine. I have used integrateds (i.e. Pathos Classic One MkIII, Eastern Electric M520, Dussun V8i) at moderate listening levels with less efficient speakers and they all have worked perfectly.

Now, if he wants to blow the walls out... that's a different story. Most audiophiles I know do play their gear louder than I do, so take that into consideration.

True, he can get more power with separates, but likely more cost and potentially more mismatches in gear. It's a trade off. He may want to stick with a one brand solution then.

1) A solid state amp that doubles output as speaker impedance is halved is a necessity for the Thiel speakers. MAYBE a Wolcott tube amp would work...maybe.

2) Impedance matching between preamp and amp is critical. The BAT preamp has a fairly high output impedance that limits the number of solid state amps that will match properly. Obviously, a BAT solid state amp would work well.

3) The same requirements as stated in point number 1 above apply to any integrated amp being considered. You can cross tube integrated amps off your list.

The direct answer to your question is that the amp is most important in the respect that it must match properly with your speakers. No preamp will fix a poor amp/speaker match. Next, once you have a good amp/speaker match, the preamp must match the amp in respect to impedance. A marginal impedance match between the preamp and amp will result in rolled off bass and possibly rolled off highs...despite an excellent amp/speaker match.

Bottom line...I'd recommend a good solid state integrated amplifier that doubles output as speaker impedance is halved: Pass Labs, Gryphon, Bryston...maybe even a Portal Audio Panache.

Perhaps the term “high” needs some definition… My vk5i total output imp was 800 ohms, 400 per phase… the vk32 has an output imp total of 600 and the Rex is 200 per phase or 400. .. I’m figuring the VK 51 is in there somewhere between 400 & 800 ohms total..

Unless I read an article reviewing the CJ 350 Premiere solid state amp in error, one of the two mainstays, either Mr. Conrad, or Mr. Johnson said a ratio of 10:1 is sufficient for preamp to amp matching. So if the preamp in question has an output imp of say 1000 ohms total, then the amps input imp needs to be 10,000 ohms or better…. Many amps, even the modest input impedances of Spectral amps, would meet that criteria.

My single ended thor output impedance is I think 400. it’s driven every amp I’ve connected to it with eease. 60wpc tube amps, 250wpc SS amps, 100 wpc SS etc… in to speakers with low impedances of 1.8 ohms, 4, 6, and 8ohms. With eff ratings from as low as 85 db!

So what’s a high impedance output for an active preamp??? 1100 ohms? 1500?

All the BAT amps I just looked at have input impedances of 90K +. Tube or SS.

I doubt seriously you’ll run into trouble in that preamp > amp, regard.

BTW none of the BAT amps double down in their power outputs… they just have enormous power reserves. Other’s use negative feedback to ehlp out there.

…and let’s face it… exactly when will one need to have an amp which produces 500 wpc… or 600, or 1000 wpc?

90% of the music is made in the first 20wpc anyways.

It will all come down to what your aim is for driving your loudspeakers. Wanna peel paint? Produce live rock and roll shows?

I’ve got a pair of 87db, 4 ohm speakers which drop to 2 ohms… I can run them easily with a pair of 120 wpc tube amps… very well….. or with a 150 wpc SS stereo amp too! Even with my SS HT receiver which questionably put out 110wpc!

Kevin Hayes of VAC told me once he runs many of his amps on a pair of Thiel 2.6s…. even his 30wpc SET amp! Check the specs on some of the VAC amps which are very well regarded, and you will notice they don’t double power with halved impedances.

This deal ain’t that hard. A quality amp will do well…. And here’s a thought…. Call thiel and ask them what amps on your short list they would recommend.

Usually, its the bass at lower to moderate volumes that suffers driving speakers with difficult loads with amps that are not up to the task.

IF you're willing to live with that for some other aspect of a particular amps sound, then I guess you will be fine, but you may not be getting everything that your speakers are capable of delivering at lower to moderate volume.

In my case, I replaced a 360w/ch Carver amp that did not come close to doubling output with impedance with a ~100w.ch Musical Fidelity that does.

The Carver went louder and sounded fine at higher volumes, but the bass and dynamics were noticeably missing at lower volumes. The Musical Fidelity does not go as loud, and the sound is dynamic and balanced now at the volumes I more typically listen at.

09-27-08: Blindjim
...one of the two mainstays, either Mr. Conrad, or Mr. Johnson said a ratio of 10:1 is sufficient for preamp to amp matching. So if the preamp in question has an output imp of say 1000 ohms total, then the amps input imp needs to be 10,000 ohms or better…

My experience trying several tube preamps with Pass Labs solid state amps tells me the ratio rule-of-thumb is a only useful as a general guideline, and may not apply in the real world.

Recently, I tried an ARC REf 3 preamp (600 ohms) with Pass Labs XA-60.5 (30kOhms)...a ratio of 50:1. The match was not ideal. Not bad, but not ideal.

If one reads Stereopile's measurements section of their preamp reviews, one learns that output impedance changes with load. For example, the Audio Research Reference 3 has an output impedance spec of 600 ohms balanced, but in J. Atkinson's test of the preamp it's output impedance rose to 1437 ohms at 20Hz. This would indicate an early bass roll-off when used with some solid state amplifiers, and indeed when I tried the Ref3 in my system with the Pass Labs amps the bass was lacking some depth and control.

Atkinson wrote about the Reference 3:
"The output impedance was also to spec., at 635 ohms balanced and 326 ohms unbalanced in the treble and midrange, but rose to 1437 ohms and 625 ohms, respectively, at 20Hz."

So, the moral of the story is that output impedance specifications are only part of the tale. Test measurements are another part of the tale. Listening to the actual combination completes the tale.

Regarding VAC amps, it may be true that Kevin runs some of them on Thiel 2.6 speakers, but my experience with the 160wpc VAC Musicbloc monoblocks on Silverline Sonata III (5 ohm minimum impedance) was that the VAC amps produced an unbalanced sound lacking bass depth and definition, leading to an overall "tipped-up" presentation due to the lower power output into the lower impedance frequency region (bass) relative to the higher impedance frequency regions.

I absolutely agree that total WPC is not the most important criteria. However, the impedance issue is crucial, IMO.

Just curious about these impedence matching observations - BTW Tvad, I think your observations are good - how often do folks feel that impedence matching issues, which might be only marginal, if extant, are exacerbated by improper selection of long IC runs from pre-amp to amp.

For instance, using the same components and either 1, 2, or 5 mter IC's the sound doesn't differ much, perhaps a tad with the 5 meter cable, but not enuf to matter (to me). But put in an 8 meter IC of the same brand and type and the roll off is marked and not just in the bass.

Is it possible that much of which is charged to the consequences of impedence mis-matching might be laid at the foot of IC mis-matching as well? Seperaately and concurrently?

Just a thought............

I have to (mostly) agree with Tvad, here. The 10 to 1 ratio is only a guideline and there are many respected voices that disagree. Though a bit off topic, other considerations re: pre to power amp matching include output and input sensitivity, the potential for DC leakage and how it is tolerated, and single ended vs. balanced operation. And let's not forget sonic synergy.
If one reads through the archives here on Audiogon, one will find that some are satified will fairly low powered amps on their Thiels, but more often than not, those who have tried various quality amplifiers, find that the higher powered ones work best. While the majority of music played doesn't usually require gobs of power, the balance can suck up huge amounts very rapidly. With the Thiel's, I think the cost of appropriate high quality ss amplification can be a bit dear and the cost of high powered tube amplification can quickly come cost prohibitive. SS amps seem to offer a better value with Thiels(!). IMHO, ss amps sound best when they are not run into their limits... with ss amps, having some headroom is advisable.
BTW, I certainly hope that Ledenhheim doesn't have an "18 X 18" room!

Tvad
.... it never ceases to amaze me how much minutia compells some folks.

naturally there is more to preamp matching to amplifiers than simple impedance figures.... and just 'whose' figures should we use? Those claimed by the makers, or those claimed by the second party testers?

But I still hold to the "plug one in" notion. Despite Tvads notes, he admits he did just that in practice... as he's 'plugged in' several lately by my count alone. Tubed and Solid state as well.

The numbers alone, don’t tell the whole story sometimes.

Damping too, along with power reservoirs/storage account for something too. But as so much inference was being placed on impedance matching I felt compelled to throw that CJ bit in . IMO it might ought to be 100:1…. But my exp says there are exceptions to this rule.

BTW consistency doesn't seem a commonality in Silverline products from time to time... apparently either.

it's all just time well wasted, casting about this rhetorical note and system building philosophy back and forth here... the proofs in the pudding... if it were otherwise... we'd all go out and get the exact right amp the very first time as we or some of us do ijn fact 'know' by the numbers only which amp will work best.

Right?

You ask 50 audiophiles a question, you’re very likely to get 55 answers!

it's not a numbers game folks. you have to try some out for yourself. that's what most folks here did and do... so I'll just hang onto the more practical approach of just bust a move and throw something in there!

Ledinhhien

Some amps will surely surprise you, and some will (as Tvad pointed out via his own exp) be disappointing... despite their reps and numbers.

Ask the maker of the ??? item for some direction. That's a gooder place to start IMHO.

Look at what others with similar speakers are using in the virtual systems listings.

I’ve found scant little if any, perfection in this world and attempting to acquire it is a waste of time and energy…. Most quality amps will be capable of providing a good power source and no one here can say for you, just what that should be… but you… well and your wallet.

I’m sure, given the expense of the CS3.7s, you’ll acquire a commensurate amp…. But going back to the initial Q… I’ll always put more money into a preamp than into an amp… as a rule ‘cause you can’t make up for what you lost early on, downstream. You can only cover it up.

The impedance numbers help narrow down the possibilities, so one isn't just throwing something into a system to hear how it works. Personally, I believe the test measurements are considerably more valuable than manufacturer's impedance numbers because the test measurements tell the whole story. I didn't pay much attention to them until the past year, but I've learned to appreciate their value.

If you consider this minutia, then so be it.

After trying four different amps on the Silverline speakers, I ended up buying (and keeping) the amps that were initially recommended to me by the owner of Silverline. They are a perfect match. Go figure. It was during this period of trying amps that I finally appreciated the importance of doubling power output as speaker impedance is halved. The amps that did this all sounded best (better tonal balance which eliminated the "tipped-up" sound created by amps that did not double power output).

It doesn't mean one has to spend lots of money on an amp. One of the best amp/speaker matches I found was with amps that sell used for less than $4k/pair (the brand was one of Silverline's suggestions).

Amp/speaker match is everything, IMO. That's my tune and I'm stickin' to it.

Tvad

"Amp/speaker match is everything, IMO. That's my tune and I'm stickin' to it."

Now theres a real stretch.

So from this point going forward, you know exactly which amp, preamp, and loudspeakers to get simply from the numbers, huh?

Good for you.

Personally I feel there's more to it than simple claimed figures. They serve only as some sort of guideline and not the end all be all. That would make things far too simple.

...and simple is not the way of the audiophile! We're complicated folk.

Grant, I ain't taking you or any other party here to task... the deal however is always the same thing though. Eventually. Even with all the 'numbers' being in place in all areas, one still has other considerations. Style. Size. Price. One lump or two? and then there's that oh, yeah, sound aspect.

You and I both know now, that makers' specs are sometimes as subjective as are our own preffs. Now and then their figures get tweaked to be more attractive, or are figured out in differening ways.

True enough, by and large, their usually close to actual, though.

the numbers which matter most to me apart fomr the necessary ones, are size, weight, and price, and not always in that order.

Go by the numbers or go by your ears... I will always prefer the latter.

My name is blindjim.... and I approve this message.

Without the "numbers" the quest might be endless and terribly expensive. The numbers don't neccssarily provide the ultimate answer, but they can sure get you there quicker. I'm in complete agreement with Tvad here.

The numbers are just guidelines to help narrow the search and get you there quicker. After that, its largely subjective...a matter of taste.

I'd consider some of the more powerful Class D amps with the Thiels to get them fully fleshed out at reasonable cost from what I'm reading.

09-27-08: Blindjim
So from this point going forward, you know exactly which amp, preamp, and loudspeakers to get simply from the numbers, huh?

Blindjim, you either have not read my posts carefully, or you're selectively leaving out details.

Please don't do that. It's not fair to those who don't read all the posts.

For interested readers, I have explained my process in detail in my posts above. Please read them for the full account.

Mapman
...agreed!

Tvad
...same here.