2. amps-preamps
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Help w/ preamp

Hey guys!

A while back I posted about my search for an amp...I got a ton of great suggestions and had decided on demo'ing Parasound and Anthem. I found a local Parasound dealer here in Pasadena, and I was FLOORED. I have been using a Marantz SR 7011, connected to a full Martin Logan setup: Ethos fronts, motif x center, motion 40 rears. I felt like I had never really heard my speakers once they cranked up the Parasound. I told them my budget and they introduced me to the KRELL CHORUS 5200....man, oh man. They had a floor model for sale, as they were making room for a new 7 channel. The sound was similar, but I felt like the bass had more punch, and they made me an amazing deal - something I have yet to find online (lucky me I suppose).  So, after that long story...here's a few questions:

1. I am currently using RCA instead of XLR, as the Marantz AVR doesn't have both. I am sure I am losing some audio quality here correct?
2. I am thinking about adding the Martin Logan AFX (atmos) speakers soon - but since the Krell is 5 channels, I would have to run them through the Marantz - is that a "bad" idea?
3. The store I bought the Krell from recommended I swap to the Marantz 8802 as a pre, and use a 2 channel amp to power the atmos - something like a Parasound A23, which I see fairly cheap on here. Or, I could just sell my 5200, and buy a 7200 (there's a good one on here).

I guess, my main concerns - will the sound seem "different" or "uneven" getting amplified from different sources? Whether it be Krell + Marantz, or Krell + Parasound. And, would I be losing quality running anything through the AVR (I know they are just atmos speakers, but still) as opposed to using a dedicated power amp?

Any and all advice is appreciated. Thanks@

128x128ethos4lyfe
auxinput
2,920 posts
 

A note on HDMI cables.  I had been using a low cost cable that was supposed to be "Premium Certified" for 4K / 18Gbs bandwidth.  It was the lower cost Belden FE HDMI cables from Blue Jean Cable.  What I found was that it was smearing the sound (audio data) from different sources.  I wasn't even using 4K bandwidth.  This smearing occurred even on just 108i with normal old compressed Dolby Digital 5.1.  As an experiment, I went back to my old Neotech NEHH-4200 HDMI cables and the sound significantly improved. 

http://audiosensibility.com/blog/products-2/digital-cables-occ-copper-and-occ-silver/#!/Neotech-NEHH-4200-HDMI-1-4-Cable/p/17895256/category=4059160

I had originally switched to the Beldon because the Neotech cables weren't even HDMI 2.0 / 4K certified, but I found that there were transmission problems with the Beldon (probably charge/discharge speed and jitter).  All my HDMI cables are 6 feet, so I don't have the "short cable reflection" problems.  Supposedly, the Wire World cables are even better for bandwidth because of their DNA Helix architecture (The Wire World Starlight 7 HDMI is said to have bandwidth of 28 gbs).  My Neotech cables are just excellent, so I don't have any immediate reason to move (and they are only just HDMI 1.4 certified!).

auxinput
2,920 posts
 

Bored today...so I did more research (and looking up stuff I already read).

In trying to compare AVM60 to the 8802a, here are some comments:

http://www.avsforum.com/forum/90-receivers-amps-processors/2004562-official-anthem-avm-60-thread-107.html#post51099217

One of the things that stood out was the AVM60 could be bright/thin and cause listening fatigue. In my R&D experience with analog circuits, this tells me they are using inadequate power supply capacitance and/or cheap quality capacitors than can resonate and be bright.

Other comments have stated Marantz 8802a is superior for 2-channel music. However, if you want/need room correction, it appears AVM60 Anthem Room Correction is superior over the Audessey in the Marantz. Other comments state Marantz is on the warm side when compared to AVM 60.

One thing I know is Marantz puts a significant amount into power supply. Looking here:

http://www.avsforum.com/forum/attachment.php?attachmentid=521905&d=1422970676

The 8802a main power supply has 4 x 10,000uf capacitance, which is huge for a processor like this. Looking at the DAC board:

http://www.avsforum.com/forum/attachment.php?attachmentid=530641&d=1423259930

We can see that they support the DAC circuits with a very good number of capacitors. This ensures that the DAC chips as well as the DAC I/V op amps have very good local capacitance to pull on for fast transients and a large reservoir in the main power supply for bass/midbass power.

The op amps used in the 8802 I/V section (above the DAC chips) are NJM8080G:

http://www.avsforum.com/forum/90-receivers-amps-processors/1535197-marantz-av8802-13-2-xlr-pre-pro-official-thread-54.html#post32165305

These have a very slow slew rate (5V/us) when compared to the typical op amp in analog circuits. This could be used on purpose to give the Marantz its slightly warm sonic signature. In my R&D, 20V/us is about the perfect slew rate for audio. It’s fast enough for high frequency response, but not so fast that it loses bass/mid-bass power. This is probably the only negative thing I see about the Marantz design. This slew rate could also be the reason some people say Marantz is warm compared to AVM 60. But it could also be that Marantz has so much in power supply that you are hearing a full bass/midbass sound instead of a lean / bright sound.

Another point between AV7702 and AV8802a is the main power supply. The 7702 is half the size with only 2 x 10,000 uf capacitors. Also:

http://www.avsforum.com/forum/90-receivers-amps-processors/1535197-marantz-av8802-13-2-xlr-pre-pro-official-thread-46.html#post31643465

It appears that 7702 only provide +/-10.5V to analog circuits instead of +/-12V of the 8802. This is a very small difference, but a difference none the less.

ethos4lyfe's avatar
ethos4lyfe OP
74 posts
 
@auxinput, wow thanks for all the info! You are much more versed than I could ever pretend to be! 

I have axfuallt turned away from the avm60 because it doesn't have the USB or hdmi ports on front - which I actually use quite often. 

In my research, a few people gave mentioned the McIntosh MX-122. Looks amazing, but obviously a much higher price point. That would be something much further down the road, as I have already invested a ton of money in a relatively short time.

 I love the sound from marantz, and I had actually actually swapped to denon a few months because of the previous 4k issue I mentioned. Well, that lasted 2 weeks. Missed the marantz warmth I was used to. So I swapped back and never looked back.

I'm wondering if upgrading to the 8802 from 7011 would provide a noticeable difference in sound? I know it's always a good idea to have better components whenever possible, but I'm curious if I would clearly be able to tell the sound apart? Thanks again! 
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