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amp question for RF7 Setup ( sherbourn vs adcom vs b&k)


bignasty27

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I posed this question to the Griffinator but I thought I would throw it out there to see what everyone else thought as well.

I am running the full 7.1 , Klipsch RF7 package with a B&k 200.7 amp and an the Onkyo SC885 Preamp. The sound is decent but I am not satisfied. I have to turn the volume way up in order to hear all the details. I was wondering if the Sherbourn 7 channels amp would be a significant upgrade to the B&K (200 watts per) or would I have to increase the wattage with an Adcom 7807 (300 watts per) in order to get that full detailed sound at lower levels as well. Was told by the salesman that I need to increase my Microfarads? Is this true? Could not find the Microfarads rating on the B&K. The reviews of the Sherbourn amps have been great but since I am in Canada, they seem tough to find. Would love to get your true opinion on my issue here and I am hoping you can help. Look forward to your response.

Thanks,

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You cannot and will not hear the difference in output between a 200W per channel amp and a 300W per channel amp. You would have to increase the power ten fold to get twice the perceived loudness out of your system. You would be hard pressed to improve the sound over your current B&K 200W x 7 amplifier which is more than sufficient. The salesman must be referring to the capacitors (stiffening capacitors are rated in microfarads) that supply the instantaneous power to the amplifier section which really is not going to make any tremendous or audible difference to you. Stick with the B&K. I am not familiar with the Onkyo preamp but I am sure it is a very capable unit as well.

The problems with hearing the details and having to continually turn the volume up and down is in the DVD soundtrack's mix and not a symptom of the amplifier at all. My suggestion would be to first get your system properly setup using the AVIA disc and a sound pressure level (SPL) meter and get all the channel levels dialed in correctly to your listening position if you have not done so already.

I have a NAD T-163 A/V Pre/Pro with the Sherbourn 7/2100A amplifier and the Klipsch Heritage big boys as outlined in my signature below and I experience the same symptoms you speak of. Different DVD's perform differently and are poorly mixed even with a hot rodded La Scala center channel I still have trouble discerning dialogue sometimes. I can toggle the center level on the NAD's remote to compensate usually I turn it up to hear the dialogue only to get pinned to the wall later when some sound effect or explosion kicks in.

Some DVD's sound great at -45 to -40 others I have to turn up to -30 to -25 to pick up the details. I hope that you are using the RC-7 center channel and monopole rears in your system and perhaps dipole/bipole side surrounds.

Does this sound about what you are experiencing?

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Wow! That is exactly what I am experiencing. I am constantly in the -30 or -25 range when watching or listening in order to get the details out but didn't think that was normal.

The preamp has a built in Audessy calibration which I have used but it turned down all my speakers to the minimum DB settings. I have not used the Avia disk but will try and get my hands on one.

I am still unclear about the microfarads. The sales guy indicated that the quality of the amp is in the microfarads rating. The Adcom and the Sherbourn have similar microfarad ratings and like I indicated, I cannot find the B&K rating anywhere. The sales guy also called my B&K a school PA amp and wanted me to "move up" to the Adcom 7807.

I have the full Klipsch RF7 package including the RC7 center and the RS7 rears, R5800 in walls and the RSW15 Sub. I have all the parts but feel that my amp is lacking and wanted to know if I could improve with the Sherbourn.

The Sherbourn would be a lateral move then??

Thanks for the help

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Im running a B&K 200.7. Yes, I have often heard that Adcom is not a very good match for Klipsch and therefore went with B&K. Adcom has a monster 7 channel 300 watt per channel amp that I was interested in for the reasons mentioned in my above post but now I am leaning towards keeping my B&K unless someone can convince me otherwise.

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I would not think your problems would be coming from the B&K amplifier. I would try (borrow/substitute) a different preamp if you have one, and see if your problem still exists. I'm also not familiar with your pre, however I would investigate the settings in that pre. I believe B&K is a pretty good match with RF-7's.

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I've heard a 200 watt B&K with RF-7's...........It had a very nice sound but was "lifeless" in comparison to my RF-7's that are in a bi-amp configuration with 500wpc Crown amps.

The B&K amp reminded me of the Denon POA-2800 amps I had with my 7's..........I think the B&K sounded better than the Denon's but neither had the nuts to make the RF-7's come alive. My two cents......from personal experience. [:D]

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The amount of microfarads in an amplifier are meaningless when it comes to it's overall sound quality. While a stout power supply is essential to headroom it means nothing unless you are running the system at reference levels or above on a consistent basis. I can assure you that B&K is one hell of an amp and your ears will give out long before it even starts running out of gas. Figures like THD and S/N ratio are the important ones and the B&K has them in spades. The Adcom will be bright with the RF's which are already bright out of the box. The Sherbourn also a killer amp as you stated would be a lateral move for you.

The Audyssey system is a compromise. Manually tuning each channel using the AVIA disk and a Radio Shack SPL meter will yield the best results and will yield audible improvements. If you want to spend money that will yield results equal to a better preamp or power amp I would wholeheartedly recommend the DeanG upgrades to the stock Klipsch crossover networks on your front three RF speakers. Do a search of the forum and you will see nothing but praise on the improvements noted by doing this. If you have priced quality caps and coils you will see that DeanG's work is actually very fair pricewise.

He custom built my network for my center channel La Scala and I rewired the whole speaker with OFC 12ga wire and gold plated spade lugs, put in the K-401K horn and I run the dual phase plug solder terminal K-55V midrange in it and changed to the K-77M for a bit more extension in the upper registers. I can hear the most minute details but still have to turn it up on some soundtracks even with 104db efficiency across the front three.

Keep the amp, tune the system, add the networks if you want to take it to another level of performance.

P.S. You don't need 500W amps with 102db efficiency speakers it's just not necessary you will never fully utilize it. You need an amp that can perform optimally in the 50W to 200W range with the lowest THD and highest S/N ratio.

I can drive my system to 130db in the living room without a hint of distortion and with incredible accuracy mimicking a live concert with only 200W x 7. Nothing like running ELO with dual Velodyne 15's at concert levels, the Cornwall's and Klipschorn's hit you in the chest like a live kickdrum!

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P.S. You don't need 500W amps with 102db efficiency speakers it's just not necessary you will never fully utilize it. You need an amp that can perform optimally in the 50W to 200W range with the lowest THD and highest S/N ratio.

I'm not doubting you......or being cocky but can you tell me why the 500wpc Crown amps simply seem to wake up the RF-7's compared to the 200wpc Denon, Marantz and B&K amps I've heard with them?

I have to say......that the 500wpc Crown's in a normal configuration don't do much for me......but in a bi-amp configuration it absolutely floats my boat!! 500 watts to the highs and 500 to the lows with the balancing network in tact. (passive bi-amping?) Separation, clarity and detail at concert levels.....four RF-7's.

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When it comes to amps numbers only tell a part of the story.I had a 200 wpc Adcom,a very well made amp with lots of power.I also had a Parasound 140 wpc amp,it sounded better and more powerful than the Adcom.The BK amps are also good amps but no better than the rest in their price range,and equalled by some cheaper(retail).

The Outlaw amps are oustanding and Emotiva are tops in bang for the buck,imo.

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For what it's worth- I'm new to running separates for my speakers and had been running my RF-7's off of a Denon AVR (100 watts/channel). I decided to try Emotiva amps because they are affordable and a lot of people hold them in high regard. Their new XPA-2 amp is 250 watts/ channel @ 8 ohms and works really well with the RF-7's, that "comes alive" description is very accurate in this case (when compared to the Denon). I also have the XPA-3 200 watts/ channel and ran the RF-7's off that for a comparison test and came away feeling that the XPA-2 had more "mojo" than the XPA-3. The XPA-3 is probably very similar to the other 200 watt amps discussed in this thread.

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For what it's worth- I'm new to running separates for my speakers and had been running my RF-7's off of a Denon AVR (100 watts/channel). I decided to try Emotiva amps because they are affordable and a lot of people hold them in high regard. Their new XPA-2 amp is 250 watts/ channel @ 8 ohms and works really well with the RF-7's, that "comes alive" description is very accurate in this case (when compared to the Denon). I also have the XPA-3 200 watts/ channel and ran the RF-7's off that for a comparison test and came away feeling that the XPA-2 had more "mojo" than the XPA-3. The XPA-3 is probably very similar to the other 200 watt amps discussed in this thread.

Not to Hijack but My Next purchase will be the Emotiva XPA-2 and the XPA-5 for my Theater Setup ... Plan to operate these with my H/K 7300

Do you recommend the use of a Voltage Stabilizer when adding on these amps?

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There was a thread about this at the Emotiva Lounge regarding voltage/ power conditioners and the Emotiva guys were saying no conditioning was necessary. They thought that some units could restrict the power draw required by the amps and recommended just making sure your circuits were adequate. You're gonna love that -2/-5 combo, I went with the -2/-3 because 5.1 was all I wanted in my HT room.

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There was a thread about this at the Emotiva Lounge regarding voltage/ power conditioners and the Emotiva guys were saying no conditioning was necessary. They thought that some units could restrict the power draw required by the amps and recommended just making sure your circuits were adequate. You're gonna love that -2/-5 combo, I went with the -2/-3 because 5.1 was all I wanted in my HT room.

Thanks for the quick response ... good to know!

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I have used 2 other preamps with similar results. the onkyo pre 885 is new on the market and has received great reviews so far.

OK . The next suspect I would accuse then, is your rooms' acoustics. Have you "tuned" your room to deal with reflections, etc.? Also, do you use any type of surge suppressor, power conditioner? In most cases these can be a good thing and lower the noise floor, in others (I've heard) they can restrict current draw from the amp if your amp is connected to them. Another option (as suggested previously) is to have your crossovers upgraded by Dean. This alone will result in much greater detail retreival.

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Thanks for all the responses. Interesting read and different amp options are great.

Have thought about the DeanG crossover.I sent him an email a few weeks back but have still not heard from him. Does anyone have his current email address? Do you know the price range to get this done??

Room acoustics? Well, the setup is in my basement. Cinderblock walls covered by new drywall with drywall ceilings and a laminate floor. I have a Monster Power conditioner.

Is the Adcom 7807 a lateral move as well?

Have never heard of Emotiva but will look into it but I may just stick with the B&K.

Any other amps or suggestions??

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ELO = Electric Light Orchesrta I was listening to the Out of the Blue CD at deafening levels. My old DBX DX5 has dynamic range expansion abilities which really adds some sparkle and improved detail on older recordings.

I would not recommend the Adcom they are traditionally bright with Klipsch and the extra 100W per channel won't make an audible difference. If you want to spend some money on a worthwhile improvement that will make an audible improvement go with the DeanG upgrades. He posts often in the two channel world try a "pinging DeanG" post in that area to get his attention. Not sure he responds to PM's try email.

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