Amplification Help/Suggestions Please

[vertigo]

Hey guys,

I'm a new member here and just posted my intro in the new members section. I'm here because.. well I'm in love with my MLs. But also because I need help figuring out a proper amp for my Vistas.

We have the following set up:

Center: Motif
Left/Right: Vista
Left/Right Rear: Fresco I
Sub: PolkAudio DSW MicroPro 2000

As of this moment they're being powered by a Pioneer Elite VSX 32.

I'm looking to drive the front stage with either the Emotiva XPA-3 or just the Vistas with the Rotel RB-1572.

I've read great things about the Emotiva brand and I was all set to pull the trigger on the XPA-3 when I found out about Class D amps while researching the Pioneer Elite VSX 32.

I'm leaning toward the Rotel simply because of the size and I like the concept of a class D amp.

Does anyone have any experience with any of these? Any other brands maybe in the price range that may be better for the money?

Thanks so much in advance for your help.

Yes that tiny tv up there is a Sony 52in

 

[eknuds01]

Are you planning on using your Pioneer receiver as the pre-amp to go along with the Rotel?

I happen to like Rotel gear. When I first getting into this hobby, I had a receiver and then I wanted to upgrade to separate components. Rotel and NAD were at the top of the list - great value.

I decided to go with used equipment (lighter on the wallet). I wound up with a Sunfire amp. It sounds like the Rotel is more than up to the task when it comes to powering your speakers.

The question is: do you like Class D amps because of the technology, or the way they sound?

If you are looking to drop $1300 on the amp, you could probably do a lot better on the used market with the same amount of money.

Erik

 

[vertigo]

Are you planning on using your Pioneer receiver as the pre-amp to go along with the Rotel?

I happen to like Rotel gear. When I first getting into this hobby, I had a receiver and then I wanted to upgrade to separate components. Rotel and NAD were at the top of the list - great value.

I decided to go with used equipment (lighter on the wallet). I wound up with a Sunfire amp. It sounds like the Rotel is more than up to the task when it comes to powering your speakers.

The question is: do you like Class D amps because of the technology, or the way they sound?

If you are looking to drop $1300 on the amp, you could probably do a lot better on the used market with the same amount of money.

Erik

Thanks for the reply!

Yes I am planning on using the Pioneer as a pre amp. I'm interested in the class D amps mostly because of the tech. The size of the unit is definitely something I'm interested in as well as the actual power consumption.
I don't have access to either of the amps and buying something that powers my speakers to make sound without hearing it is a bit uncomfortable.

That's honestly why I'm here to see if anyone can shed some light and guide me since I will be making this decision "blind".

I would like to know *IF* there's actually a difference in sound. From my understanding amps are designed to be clear of distortion and should not change the sound of the signal. That is to say home theater amps. I'm sure tube amps in a guitar situation do something completely different to color the instrument.

Having said that I'm sure not all amp designs are created equal and there may be a difference in sound. I would be interested in picking up a used amp. I've been looking at audiogon but have a hard time finding anything other than equipment aimed at guys who pay 30K for HDMI cables. (God forbid a 1 or a 0 comes through distorted).

 

[Rich]

There is a huge difference in sound between different amps, even between different solid state amps. The differences are due to variations in circuit design, as well as quality of the components. Buying an amp without first auditioning it is basically like rolling a dice to make the decision. You may like what you get and you may not. Getting opinions of others can be useful, but ultimately you are relying on their subjective opinions, based on their experience with their systems in their rooms. None of which is necessarily applicable to you.

That being said, if you want opinions, there are plenty of threads on this forum regarding amps that go well with Martin Logans. The search feature is your friend. Certain names continue to come up on a regular basis, and Sunfire is one of those that is renowned as some of the best sound for the money. Class D amps have their proponents and their detractors. I have heard them sound great with some gear and not-so-great with other gear. I'm not sure how many people on the forum are using them with ML's. I would encourage you to try your best to audition a potential amp with a pair of ML's to get an idea if the sound is what you are looking for. Otherwise, you may want to buy used, so at least if you decide you don't like it, that way you don't lose so much money when you try to resell it. Good luck with your search.

 

[eknuds01]

As Rich stated there is indeed a difference in sound. You are at the stage where you are 'graduating' from the mass market receiver technology to higher quality components (such as the Rotel).

At this moment, for the money you are willing to spend, this is where you will see a huge improvement. After you break into separate components and each time you make another jump (to something better, say) it will require even more money. At some point you reach a financial threshold where the improvement does not justify the cost (diminishing returns as some call it).

Depending on where you live it may not be practical to audition equipment, but I would think there would be at least a handful of stores in the Seattle area.

Having said that, I bought a my amp without listening to it and am happy with the purchase. I did the same with the pre-amp I have as well (although I listened to a similar model in two different logan setups).

You may want to listen to other amps by different manufacturers - something other than the class D stuff to make a comparison. If you really like class D amps, you can even consider Outlaw (might be cheaper than the Rotel). I suggest putting the sound quality ahead of the technology.

You are taking a risk by not listening to the amp(s) beforehand, but I think you will find some difference, or improvement, going from the receiver to the Rotel.

Are you opposed to buying used stuff? Like I said before, you may be able to get a much better audio research, CJ, BAT, VTL, Pass, Sunfire, etc for $1300. Also those are very respected brands and if you end up hating the sound, you can likely turn around and sell it down the line.

Erik

 

[vertigo]

Class D amps have their proponents and their detractors. I have heard them sound great with some gear and not-so-great with other gear. I'm not sure how many people on the forum are using them with ML's. I would encourage you to try your best to audition a potential amp with a pair of ML's to get an idea if the sound is what you are looking for. Otherwise, you may want to buy used, so at least if you decide you don't like it, that way you don't lose so much money when you try to resell it. Good luck with your search.

Part of the reason I'm interested in the class D is the technology but also because it's my understanding that the Vantage woofer is powered by a class D amp as well.

You are right I need to get over to Magnolia and listen to see if I can even tell the difference. Afterall, as you've pointed out I'm the one who has to live with it.

Erik -

I'm definitely interested in the used market! I have been scanning Audiogon for quite some time.

Thanks for listing out the brands I should be looking at. I'm definitely going to be doing some reading.

The Sunfire TGA-7201 definitely seems awesome. Priced new it's out of my range. I'm just not interested in 400 watts x 7 @ 4ohms. I do feel like being a 7 channel amp I'd be wasting it on a 5.1. Unless that is, the amp shares power and some of it leaves more overhead for the fronts.

This is I guess where my confusion comes in. I was under the impression that if I just powered the Vistas with a separate for stereo use that would be enough for music and in a home theater application it would relieve enough strain from my receiver to give enough love to the Motif and the Frescos.

 

[Rich]

The Sunfire TGA-7201 definitely seems awesome. Priced new it's out of my range. I'm just not interested in 400 watts x 7 @ 4ohms. I do feel like being a 7 channel amp I'd be wasting it on a 5.1. Unless that is, the amp shares power and some of it leaves more overhead for the fronts.

This is I guess where my confusion comes in. I was under the impression that if I just powered the Vistas with a separate for stereo use that would be enough for music and in a home theater application it would relieve enough strain from my receiver to give enough love to the Motif and the Frescos.

Consider that if you got a 7 channel amp, you could use four channels to bi-amp your Vistas (that's 200 watts for each woofer and 200 watts for each panel -- plenty of power for those babies) and that would still leave three channels available to power your center and surrounds for home theater use.

 

[Gordon Gray]

Hi Vertigo,

I will underscore what Rich and Eric have previously stated. For better or worse (I trust for the better) you've purchased speakers that will clearly allow you to hear differences between different amplifiers and different technologies thereof.

Forget about Class whatever and trust what you hear in your room. The goal is to connect with the sonic presentation of your system, be it listening to a CD or watching a movie. As Rich said, no one can tell you what's right.

It's a great journey and I hope you enjoy the ride.

GG

 

[vertigo]

Consider that if you got a 7 channel amp, you could use four channels to bi-amp your Vistas (that's 200 watts for each woofer and 200 watts for each panel -- plenty of power for those babies) and that would still leave three channels available to power your center and surrounds for home theater use.

The Vista owners manual clearly states you cannot use active bi-amplification

Active Bi-Amplification
We do not recommend active bi-amplification of Vista.
The internal crossover can not be bypassed. This connection
method seriously degrades the Vista’s performance.

Otherwise I'd be all over it. Seeing as how the woofer is powered this makes sense

Gordon -

Thanks for hitting the point home. I guess I just never thought that an amp would make that much difference in the acoustics. I figured a watt is a watt. I guess I better go to listen to a bunch of amps at Magnolia and see if I can figure out what sounds better to me.

Any thoughts on where to start and where I should finish?

 

[Spike]

On the subject of bi-amplification

The Vista owners manual clearly states you cannot use active bi-amplification
Otherwise I'd be all over it. Seeing as how the woofer is powered this makes sense

Rich suggested bi-amplification, not "active" bi-amplification. The manual clearly states that "passive" bi-amplification is okay.

Spike

 

[Rich]

Rich suggested bi-amplification, not "active" bi-amplification. The manual clearly states that "passive" bi-amplification is okay.

Spike

Correct. You can passively biamp, using the speaker's own internal crossover. You just split the signal coming out of each channel of your preamp with a Y-splitter cable, and send it to two different amp channels for each speaker. You then take each of those amp channels, and send one speaker cable to the woofer binding posts, and one speaker cable to the ESL panel binding posts on each speaker. Your speaker's internal crossover takes it from there.

Using an amp that provides 200 watts per channel, this would provide 200 watts of power to the woofer and 200 watts of power to the ESL panel of each speaker, for a total of 400 wpc to each speaker. The Vista is more than capable of handling this power, and I expect you will see a huge performance boost from it. This basically powers your Vista similarly to the Vantage. The only difference being the Vantage has the 200 watt amp for its woofer in the speaker itself.

Seeing as how the woofer is powered this makes sense

This is incorrect. The Vista does not have an internally-powered woofer. As mentioned above, that would be the Vantage, and the speakers above the Vantage. Passive biamplification, using the Vista's internal crossover, is a perfectly acceptable means of powering these speakers, and will provide a huge performance improvement over using a single 200 wpc amp channel to power them.

 

[Satch]

Hi vertigo,

What Rich said.

I have Vistas in my second system running bi-amp from a Pioneer Elite VSX-91TXH. The panels are run from the Front Left and Front Right. The woofers are run from the Back Left and Back Right. That's two sets of cables. I removed the jumper plates that were on the Vistas.

The Pioneer puts out 110 wpc @ 8 ohms. This set up sounds pretty good in my office. I also picked up a Velodyne sub at a Pawn shop for $50.00. But if I keep this set up, I'd find a used Sunfire Theater Grand from AudioGon for under $2k.

Satch

 

[vertigo]

Learning So Much

Wow so much to read and learn thanks for the information.

I read an article a while before setting up my speakers on bi-amplification and the article basically stated active bi-amplification is the "only" form of bi-amplification ...everything else utilizing the internal crossover is just really bi-wiring. Well I guess I must have just used that definition when I read through what Rich said. But after hearing what you guys are saying I think it's worth a shot. I'm going to try using the passive bi-amplification on the Vistas today with my Receiver after work and see if I notice any improvement.

Is it true that the internal crossover can be responsible for losing up to 3db meaning you pretty much lose the benefit of doubling the power?

Can't wait to try this out! :bowdown:

 

[vertigo]

Question

Am I really going to gain much on the Vistas by passive bi-amping if I have my receiver set to cross over to the subwoofer at 80?

 

[robertawillisjr]

I think ML uses three terms:
Biwiring, Passive Biamping and Active Biamping.

 

[eknuds01]

I suppose there are many advantages to bi-amping. Some like to actively bi-amp because they can set the crossover at whatever they want and they have more control over where and how the signal is divided up.

Another advantage is that you are allieviating the amplifier from having to power both the woofer and panel at the same time (from one channel, say). In your case, you are using multiple channels to drive the high and low frequencies.

Will this make a substantial audible difference? Hard to say as it is always subjective.

Down the line you may want to mix solid state and analog electronics with bi-amplification.

Erik

 

[Rich]

I read an article a while before setting up my speakers on bi-amplification and the article basically stated active bi-amplification is the "only" form of bi-amplification ...everything else utilizing the internal crossover is just really bi-wiring.

Well, I can see why you thought that then. Basically, that article is wrong. If you are using two amp channels to power one speaker, that is, by definition, bi-amplification. Since you are still using the internal crossover, it is "passive" bi-amplification. If you split the wires coming off of one amp channel and had one set going to the woofers and one set going to the panels, that would be bi-wiring.

Am I really going to gain much on the Vistas by passive bi-amping if I have my receiver set to cross over to the subwoofer at 80?

All I can say is that I saw a huge performance jump when going from a single amp to bi-amplification using two amps on my Ascents. Your mileage may vary, depending on your own system, implementation, and listening habits. Obviously, ML thinks it is a good idea, since they specifically incorporate it in most of their higher end speakers.

 

[vertigo]

Thanks Rich!

I was looking at it from a completely different mindset. I was thinking "well if woofer is powered and I can't use an active bi-amp set up so am I really going to gain anything".

Now that I know the woofer isn't powered I can definitely see a bit more use for the passive bi-amping. It would make sense that if I feed the woofer around 110w @ 8ohm from my receiver and the panel it's own 110w @ 8ohm meaning really about 220 @ 4ohms it should in theory react a bit better at least when playing it loud.

I guess this passive bi-amping may end up working out a bit better with electrostats than a typical floorstanding speaker with tweeters since tweets only use what about 5% of the overall wattage going in and stats are way more current hungry.

I wish I could try it out right after work but I'm stuck going out to dinner.

I'm still going to keep my expectations low so that if there is a difference I'll be pleasantly surprised. ...that and I still want power from a separate!

 

[Spike]

I was looking at it from a completely different mindset. I was thinking "well if woofer is powered and I can't use an active bi-amp set up so am I really going to gain anything".

On the contrary, if the woofer is already powered (ala Summit or Vantage), you're already half-way to bi-amping. All you need in this case is an amp to drive the panels The supplied internal amplifier is handling the bass for you without you seeing them!

I guess this passive bi-amping may end up working out a bit better with electrostats than a typical floorstanding speaker with tweeters since tweets only use what about 5% of the overall wattage going in and stats are way more current hungry.

Be careful here since the power section of most receivers are not designed with driving sub 1-ohm load. You might get harsh, metallic sound due to the receiver going into clipping at the high-frequencies. This characteristic is not indicative of what bi-amp can offer.

Spike

 

[vertigo]

Got Home Early

So got home early... cut up some left over wire and did the passive bi-amplification, turned the bi-amp feature on in the receiver settings and reran MCACC.

Some observations:

Do I think that someone is going to ask "hey wow that sounds great is it bi-amped?" No.

Do I think that when my girlfriend comes home turns on the music she's going to say "Hey this sounds different did you do something to the speakers?" No.

Do I think that if I explained to her what I did she would listen harder and pick out what I'm hearing? Probably.

What am I hearing? Well there's no audible difference to me in 5.1 HT application (just threw in the new Batman BD).

In direct stereo just with the bi-amped Vistas. I can tell there's a bit more clarity. I'm able to pick out the instruments a wee-bit better. So I guess you can say it's not as muddy but that may be an overstatement since it wasn't ever muddy. So I'll say there is a bit of a difference not one that anyone will pick up if their ear isn't already used to the sound a specific system makes.

So I guess I can end this experiment by saying yes there is a bit of a clarity thing going on but it's definitely hit the wall of diminishing returns.

Big bad 500 watts per channel amp here I come!!! :rocker: