Amp Questions - 1.2TLs

nacam

Well, after some testing I think my 1.2TL's are ready to rock. I had one that was making a buzzing sound at certian frequencies and found that one of the internal cabinet braces had come unglued. U fixed that and they are sounding (as far as I know) as good as they should. Another issue I fixed is that one of the MW's was completely disconnected.

Now I am thinking I am going to upgrade my Yamaha P-2200 to drive them. Many over the year have used this amp to power studio monitors. It does have some decent power (200w continuous/channel @ 8ohms) but it's old and I have been hesetant to have it drive these past 100 watts (from the meters). One option is to have it sent in to have it checked and re-conditioned or purchase a new amp all together.

I have been doing some research and have been looking at some options. Most if you prefer Carver from whar I can see but I am interested in learning more as to what to look for in an amp than just someone telling be "Buy the Carver ****".

Ovbiously I can understand some of the specifications on an amp (bandwidth capability is one I can understand) but it get's confusing as all amp manufacturers measure things differently. For example my P-2200's power rating:

200 Watts continuous average sine wave power into
8 ohms with less than 0.05% THD, (Total Harmonic
Distortion), over a bandwidth of 20Hz to 20kHz,
both channels driven.
230 Watts continuous average sine wave power into
8 ohms with less than 0.05% THD, at 1 kHz, both
channels driven.

I can sort of gather what this means but what is this amp producing "realistically" at full power? For a new amp, what rating should I be looking for in something new to get a minimum of 300 watts into each of these monsters?

Damping factor was another rating I was reading about. My P-2200 has a damping factor of >300 from 20hz-1khz. From what I have been reading this (in general) is an amps capability to control the drivers (ok, that's the dummbed downed version). This factorr keeps the bass tight an keeps the drivers from "ringing" (moving back and forth) after a hit of power from a kick drum signal for example. Is this right? Question - what damping factor should I be looking for? I have seen amps that go up to >5000 from 20hz - 100hz @ 8 ohms. Is this really needed? Is the more control the better for the 1.2's given their design?

I have been looking more in the "professional" realm of power amps (Crown, QSC).

Any help in determining what would be best in terms of specifications would be appreciated!

Thanks in advance:
Nacam

gdb

Just my opinion but.....steer clear of pro amps, they as a rule don't have the refined sound of home stereo equipment. One way to get higher power is to buy two of the same amp and bi-amp with them. I am a Carver fan but they bring a lot more money than other decent brands like Adcom etc. I'm not sure if the amp linked below is common ground or not but it would definitely give you all the power you'd need.:)

http://cgi.ebay.com/CARVER-TFM-75-amp-owned-by-Bob-Seger_W0QQitemZ230358047630QQcmdZViewItemQQptZVintage_Electronics_R2?hash=item35a268db8e&_trksid=p3286.c0.m14&_trkparms=65%3A1%7C66%3A2%7C39%3A1%7C293%3A1%7C294%3A50

AudioGenics

you bring up an interesting topic
professional amplifiers compared to home high fidelity amplifiers.

I'll probably should start a new thread.....

thsmith

I too am a fan of carvers. My TFM-45 is in ROllands hands for a full service.

He just serviced a TFM-55x that will most likely be on the FM once I get the 45 back.

My advice on any of the TFMs is try to buy one that has been serviced recently. It makes no sence to pay going price for one that will need servicing.

What I like about Rollands service over others is he brings it back to better than new.

F1nut

Most if you prefer Carver from what I can see

Hardly.

I'd say Adcom gets the most recommendations along with the other usual suspects, Rotel and NAD.

All will work, but there are much better choices. Specs can help guide you, but they will not tell you what the amp sounds like or if it will have synergy with the rest of your gear. Pro amps, just forget about them.

So, what is the rest of your gear and how much money are you looking to spend?

Ron Temple

You get alot of Carver recs here, because they are fairly easy to find and are relatively inexpensive. I like the way they sound in comparison to amps I've heard, but many don't.

nacam

F1nut wrote: »

Hardly.

I'd say Adcom gets the most recommendations along with the other usual suspects, Rotel and NAD.

All will work, but there are much better choices. Specs can help guide you, but they will not tell you what the amp sounds like or if it will have synergy with the rest of your gear. Pro amps, just forget about them.

So, what is the rest of your gear and how much money are you looking to spend?

Well the TL1.2's are downstairs as part of my home studio setup. "She" would never allow such monsters to be part of the decor upstairs so I had to settle for a pair of B&W DM603's for the living room.

My signal path would be mostly coming from purley digital sources like MP3(yuck), ripped CD's, and tracked audio usually at high sample rates (92khz, 24-bit). From the computer I am going into an RME Fireface 800, then out of the D/A's balanced line ins of a Mackie mixing board then balanced out to (for now) my Yamaha P-2200, then out to the 1.2s (no processing in between). It's doing the job, but I am a little afraid to throw more than 75-100 watts from the Yamaha to the Polks due to it's age. I've been waiting too long (24 years) to get my hands on a pair of these to fry them with an amp I got for free.

My plan was to run a pair a balanced lines to the amp across the room to the amp driving them to cut down on the powered speaker wire length which is why I am sort of looking for something with balanced (XLR) ins, but not a show stopper. I put in an inquiry for a locally used Rotel RB985 MK2 which I could use the 4 channels to Bi-Amp these at 4 ohms correct? It's rated at 100Wx5 continous @ 8 ohms. Would this work?

Sorry for the noob questions. Just want to get the most out of these beauties!

Cheers;
Nacam

snow

Since you asked My oppinion is this..... for the most bang for the buck get a Sunfire 300 X 2 I have had Adcom's Carver's Proton's Marantz"s a Bedini 250wpc class A amp and several more various brands running my 1.2tl's and the Sunfire 300 has been the best of them all. It doesnt break a sweat no matter how hard I push it, very dynamic sounding more on the neutral side of warm sounding but not sterile.



REGARDS SNOW

thuffman03

I have heard a set of SDA SRS's with a pair of Carver TFM 35's and they sounded wonderful.

Most common ground amps should do fine though. But since I am Carver bias I would go that route. One TFM 35 might be fine but I have not had the pleasure of heaing that model so...my recomendation should be added to someone who has had a set.

beemer

Don't let 'em tell you a pro amp can't make those 1.2's sound good. Get yourself a QSC PLX 3402 used and never look back. Tight, fast and clean. I have 1.2tl's and this woke them up. The speakers came with a pair of 200W/ch Denon POA 2200's. A single PLX 3402 won that contest hands down.

Pace, rhythm, timing all improved. Damping factor of the PLX is greater then 500. You are spot on about your thoughts on damping factor. Any amp can move a cone speaker.

I have since sold the Denons. I have a pair of 3402's that are not going anywhere soon.

Last but not least.....the 3402 is common ground. No problem with the SDA cable.

Best,

Paul

F1nut

Damping factor of the PLX is greater then 500. You are spot on about your thoughts on damping factor.

Actually no, not spot on. There is such a thing as having too much damping and IMO, 500 is way too much. I had an amp at one time that boasted a damping factor of 1000. It sucked at controlling the drivers. Then there's things like tube amps with a damping factor of 10 that control drivers perfectly. It's really a spec with little value.

BTW, it's easy to better those Denon amps.

nacam

One more question would be

Bi Amping these:

This involves simply removing the jumpers on the HF/LF terminals and hooking them up to seperate amps right?

Does this drop the ohm load the amp sees to 4 or something lower?

Cheers;
Nacam

concealer404

There's a Hafler XL600 here in Indy for a relatively decent price, if you want ridiculous power.

nacam

I picked up that Rotel RB-985 MK2 tonight. The price was right and it is in MINT condition. It's claims are 5x100W @ 8 ohms. I fully tested it before purchasing it and it was clear as a bell. The guy I bought it from had no problems hooking it up to his very expensive looking speakers (didn't catch the brand and didn't ask but they were strange looking, side firing subs, twin 3" mids and ribbon tweeters) and cranked it up testing all 5 channels. In his other room he had some Totem Mani2 Signatures which he was also selling so his mains must be his pride and joy. Planning on using 4 of the 5 channels to bi-amp my 1.2's. Without thinking before I bought it, does anyone know if this amp is "common ground" or not?

Keeping my fingers crossed......

beemer

F1nut wrote: »

Actually no, not spot on. There is such a thing as having too much damping and IMO, 500 is way too much. I had an amp at one time that boasted a damping factor of 1000. It sucked at controlling the drivers. Then there's things like tube amps with a damping factor of 10 that control drivers perfectly. It's really a spec with little value.

BTW, it's easy to better those Denon amps.

Hello F1nut:

We'll have to agree to disagree then. In my world damping factor is critical. I hate to touch on the darling of the Polkie world Carver amps however in listening tests here the QSC's also outperformed several different Carver offerings that shall go unnamed as not to offend. IMHO, my Crown Macro-Tech 5000VZ can take the 1.2tl's to an even higher level of control than the 3402, and the Crown has a damping factor of greater the 1000.

As to tube amps......I have a McIntosh MC2000 here that does a wonderful job on Infinity IRS-Beta mid/hi panels. I would not consider using it on 1.2TL's or as a LF amp for the Infinities. I have heard relatively few tube amps that I would consider viable contenders for woofer control.

I speak only from actual experience with every item I recommend from my own use and ownership.

It's truly wonderful that there is so much variety out there for our ears to choose from. Choose wisely.

Best,

Paul

F1nut

Well, you can agree to disagree all you want, but the facts are not in your favor.

A damping factor of 10 is more than adequate to control any driver(s) and in fact it is a myth that a low damping factor, say 10, has any bearing on the control of the driver(s) verses a really high damping factor of say 500. If the damping factor is less than 10, then there may be some concerns, but even that depends on a multitude of variables of which I won't get into right now.

Now, those amps that claim really high damping factors also have to own the fact that they can only do so by applying huge amounts of negative feedback and lots of negative feedback means greater phase shift issues and the greater the phase shift issues, the greater the distortion and greater distortion results in less detail. Hence my comment that there is such a thing as having too much damping.

You should seriously reconsider using your Mac amp with your SDA's. You may be pleasantly surprised.

beemer

F1nut wrote: »

Well, you can agree to disagree all you want, but the facts are not in your favor.

A damping factor of 10 is more than adequate to control any driver(s) and in fact it is a myth that a low damping factor, say 10, has any bearing on the control of the driver(s) verses a really high damping factor of say 500. If the damping factor is less than 10, then there may be some concerns, but even that depends on a multitude of variables of which I won't get into right now.

Now, those amps that claim really high damping factors also have to own the fact that they can only do so by applying huge amounts of negative feedback and lots of negative feedback means greater phase shift issues and the greater the phase shift issues, the greater the distortion and greater distortion results in less detail. Hence my comment that there is such a thing as having too much damping.

You should seriously reconsider using your Mac amp with your SDA's. You may be pleasantly surprised.

Once again my listening impressions do not align with yours. I find amplifiers without sufficient control over woofers to be quite dull. Pace, rhythm and timing come into play as well. The QSC's nor the Crowns lack detail. According to your thoughts I should reconsider every amp I own, including additional amplifiers from Levinson, Krell and Classe, as these all have considerable damping factor. The only amps I own that fall in the low damping category would be the McIntosh and a venerable Nakamichi PA-7, which has a damping factor of less than 60. This PA-7 shines in the midrange, however it shows little control over the 1.2tl's and turns the bass into a sloppy mess, as I find do most amps with low damping. The 3402 has far greater detail, and is far faster, IE....Pace, rhythm and timing once again. I'm thinking that your facts and mine perhaps are existing in parallel universes.

Once again, I will agree to disagree.

Best,

Paul

F1nut

Do yourself a favor and hit up Google or somesuch for info on damping factors and how it affects the end result. There is considerably more to it than you seem to think.

beemer

F1nut wrote: »

Do yourself a favor and hit up Google or somesuch for info on damping factors and how it affects the end result. There is considerably more to it than you seem to think.

Indeed, however after being involved in this crazy hobby since the "receiver wars" back in the 70's I prefer to let my ears decide what sounds good. They haven't let me down yet.

Once again, my universe regarding sound and yours appear to be parallel to each other.

Best,

Paul

heiney9

beemer wrote: »

Once again my listening impressions do not align with yours. I find amplifiers without sufficient control over woofers to be quite dull. Pace, rhythm and timing come into play as well. The QSC's nor the Crowns lack detail. According to your thoughts I should reconsider every amp I own, including additional amplifiers from Levinson, Krell and Classe, as these all have considerable damping factor. The only amps I own that fall in the low damping category would be the McIntosh and a venerable Nakamichi PA-7, which has a damping factor of less than 60. This PA-7 shines in the midrange, however it shows little control over the 1.2tl's and turns the bass into a sloppy mess, as I find do most amps with low damping. The 3402 has far greater detail, and is far faster, IE....Pace, rhythm and timing once again. I'm thinking that your facts and mine perhaps are existing in parallel universes.

Once again, I will agree to disagree.

Best,

Paul

If the Nak PA7 is a "sloppy mess" then you have issues else where. The PA7 is a superb amp, especially with SDA's. I agree 100% with F1. Specs are there as a road map but there are way too many variables to use them strictly to make a choice. I understand you like what you like, but your correlation is a little off IMO. You may like the pro amps better with your ears..........but the reasons don't have anything to do with some of the terms you are using to state why you dislike the Nak, Levinson and Mac.

H9

Systems

beemer wrote: »

In my world damping factor is critical.

Don't forget those really big DF numbers cease to exist once the speaker cables resistance gets added to the equation.

beemer

heiney9 wrote: »

If the Nak PA7 is a "sloppy mess" then you have issues else where. The PA7 is a superb amp, especially with SDA's. I agree 100% with F1. Specs are there as a road map but there are way too many variables to use them strictly to make a choice. I understand you like what you like, but your correlation is a little off IMO. You may like the pro amps better with your ears..........but the reasons don't have anything to do with some of the terms you are using to state why you dislike the Nak, Levinson and Mac.

H9

I do not dislike the Nak, the Levinson or the Mac. You misread my post. Yes, the PA7 plays "nicely" on the 1.2tl's, my point is I have heard better. Most folks wouldn't call it a sloppy mess, however that's my opinion after hearing the speakers powered with with a better amp. My standards are high. Does the PA7 sound "good"? Yes. However would you put a throttle stop on your Ferrari? Or tires that did not match up with the performance characteristics of the car? The Ferrari will still be an amazing performer with 70% throttle, however you would never know the true potential available.

GV#27 wrote: »

Don't forget those really big DF numbers cease to exist once the speaker cables resistance gets added to the equation.

Correct. Also do not forget that those really low DF #'s are also reduced by the same resistance.


I seriously doubt that anyone besides myself and my friends who have visited my home has heard a PLX 3402 driving 1.2tl's. :cool: It sure looks to me that no one here has tried it.

Best,

Paul

kawizx9r

Just like to add that the Moscode 600 driving 1.2tl's I've heard definitely pounded with authority. Comtemporary music, instrumentals everything came in loud, clear, natural and very warm sounding. Wanted to add some input on the "amps driving 1.2tl's" scene. I personally own a pair of SDA 1C's and I get all that same rich and warmth sound as well behind a Moscode 300 and am very pleased with the results although sound quality isn't up to par really...he's got much better speaker cables/IC's and a tube pre so yea.

Systems

beemer wrote: »

Correct. Also do not forget that those really low DF #'s are also reduced by the same resistance.

But the percentage of change(reduction)is far greater with high DF #'s.

For instance an amp with say a DF = 800(8 ohm load/.01 ohm output impedance) .If you add .2 ohm's of resistance for the speaker cable then the resulting DF (8 ohm's/.01 ohm's +.2 ohms) will equal 38.


Whwereas an amp with a DF= 80(8/.1 ).
adding .2 ohm's for the speaker cable gets you(8/.1+.2) DF= 26.6


While having a certain amount of DF is necessary IMO ultra high DF is not a good indicator of sound quality.

heiney9

GV#27 wrote: »

While having a certain amount of DF is necessary IMO ultra high DF is not a good indicator of sound quality.

It's not really an indicator of sound quality at all, it also doesn;t make the amp cleaner or faster, etc, etc. Way too many other variables to single out a couple of specs printed on a piece of paper.....as you well know GV, not responding to you directly but to the OP as I know you already agree with me.

H9

Schurkey

F1nut wrote: »

Now, those amps that claim really high damping factors also have to own the fact that they can only do so by applying huge amounts of negative feedback and lots of negative feedback means greater phase shift issues and the greater the phase shift issues, the greater the distortion and greater distortion results in less detail.

I need some education.

I'm aware that negative feedback is commonly used to decrease some forms of measured distortion.

I did not know that negative feedback could affect damping factor.

I though damping factor was a result of power vs. output impedance; and output impedance was more a result of the power supply than of negative feedback.

Am I wrong? How does negative feedback affect damping factor?

Systems

Schurkey wrote: »

I did not know that negative feedback could affect damping factor.

Negative feedback can decrease output impedance thus increase DF.

and output impedance was more a result of the power supply than of negative feedback.

No its the impedance of the output stage that determines output impedance not the power supply.

F1nut

How does negative feedback affect damping factor?

For a technical explanation I would suggest an online search as that is beyond my knowledge level.

ultra high DF is not a good indicator of sound quality.

Point, match, set.

snow

One of the problems I have seen with pro amps is they dont sound very musical as a whole, in fact most sound rather harsh. the distortion level at is usally higher on these because in the settings they are designed for it doesnt really matter. The S/N ratio is usally much lower also. Your QSC amp may sound good to your ears Paul and if so bully for you thats all that really matters. I noticed you mentioned pace rhythm etc with your QSC amp versus the Denon POA amps. I think what you may be hearing here with your QSC versus the Denons is a increase in current, if you can provide high current on demand for the transients it makes the music come alive faster tighter.

I feel that for me at least a high quality home audio amp is a better choice you can still get plenty of wpc, current with one but get a much cleaner more musical end result.



REGARDS SNOW

F1nut

Errrr....I hate this edit time limit!!! That should read point, set, match.

beemer

snow wrote: »

One of the problems I have seen with pro amps is they dont sound very musical as a whole, in fact most sound rather harsh. the distortion level at is usally higher on these because in the settings they are designed for it doesnt really matter. The S/N ratio is usally much lower also. Your QSC amp may sound good to your ears Paul and if so bully for you thats all that really matters. I noticed you mentioned pace rhythm etc with your QSC amp versus the Denon POA amps. I think what you may be hearing here with your QSC versus the Denons is a increase in current, if you can provide high current on demand for the transients it makes the music come alive faster tighter.

I feel that for me at least a high quality home audio amp is a better choice you can still get plenty of wpc, current with one but get a much cleaner more musical end result.

REGARDS SNOW

Agreed. Many "Pro" amps just plain do not sound good, however just as many do. My only issue here is I toss out something that sounds excellent as an option to folks here, yet speculation abounds, and not one other poster besides myself has heard the setup in question, yet many are ready to cut it down without even hearing it! Bahhh.

Paul