Xilica XP-8040 processor

[mark1101]

It sounds like the hiss is coming is coming from your amps.  The reason sounds like you are hitting them with so a low a signal to noise ratio that they are amplifying the noise, and you have no way to turn them down.

[Don Richard]

Use in-line attenuators - they come in different attenuations and the good ones are more accurately matched than the front panel knobs on most amplifiers. You want the amplifiers adjusted for the same gain so the processor settings will be valid if you are using canned settings.

[Chris A]

Those knobs on the front of the amps are sources of failure.  For instance, the Crown XTi series of amplifiers had a bad batch of front panel knobs and it apparently did a number on the sales of those units for some time.  I've still got two of those amps that I need to get the pots replaced - they're not standard pots and are difficult to find.

 

Chris

[NBPK402]

I have a small Yamaha Pro 4 channel amp I might try out for a while (I was going to use it for my Atmos setup down the road)....for the time being I have the hiss gone, but i now realize i was better off with the 4 Pro amps I had than the new amp setup (with no gain controls). I went this route because I had no more room in my rack. What I found out was the new setup is also costing me another 2 amps of electricity over the whole rack I had before. What I am thinking of doing is getting a 11 channel amp (since I don't need power except for my subs, and they have more than enough with the P7000S amp) for all the channels except the 3 horns. I then would just look for a nice 3 channel amp..

[mark1101]

It sounds like you get the game at this point.  I wish I would have asked about your setup prior to the purchase of the processor.  I'm sure more than just I would have commented on the no gain controls.

 

Don's idea of in-line attenuators would change things quite a bit, given the amps you have.  I'd look into that.

[NBPK402]

It sounds like you get the game at this point.  I wish I would have asked about your setup prior to the purchase of the processor.  I'm sure more than just I would have commented on the no gain controls.

 

Don's idea of in-line attenuators would change things quite a bit, given the amps you have.  I'd look into that.

I have some Shure variable attenuators, but  didn't like the way the sound changed.

[mark1101]

I looked those up.  are they the switchable ones from like -10db, -15db, -20db ?

 

If so, they are not what I thought Don was recommending.  What you need are in-line passive preamp (volume controls or stepped attenuators).  Emotiva makes some inexpensive ones. Here is a much better one.  Check out the Goldpoint stuff.

 

 

http://www.ebay.com/itm/GOLDPOINT-SA4M-DUAL-MONO-PASSIVE-PREAMP-PREAMPLIFIER-/191656546654?hash=item2c9f9ed15e

[Don Richard]

I was thinking of something like this:

 

http://www.parts-express.com/harrison-labs-6-db-rca-line-level-audio-attenuator-pair--266-242

 

Other attenuation levels are available.

[mark1101]

I get it Don.  For me, those would not work.  I would require the ability to very specifically change the volume on each channel exactly like simple gain controls can do.

 

The box above I suggested is around $500 / per amp.  Not cheap, I know.  But it's also nowhere near the most expensive.

 

If you have some nice amplifiers that you really like that have no gain controls, and spent a few thousand on them, and you find this active stuff is for you..........then I'd go no cheaper.  But that's just me.

 

As an example, the high end McIntosh amps have no gain controls...........which I simply can't understand since they are specifically built to interface with both home audio and pro audio equipment.  We all know how much those things cost.  You really need to interface with something nice and something that gives you the flexibility to adjust freely.

 

That takes the pressure off the processor controlling a lot of gain or attenaution, which is really not a good idea.  The last thing you want are processor channels set to -10db, etc.

[NBPK402]

What I am thinking of doing now is... Get the 11 channel Yamaha amp (no gain controls), and see if I can get someone to make me a  3 channel "Nested GainClone" amp with gain controls on it for my horns (horns need to be lowered in gain but the rest of the channels don't). I am assuming from what I have read that the "Nested GainClone Amps can sound as good or better than a high end Audiophile amp. If I go this route I think the Yamaha should have enough power to drive the 1/4 pies, and all my surrounds, and height channel speakers (all are 91db or better).

 

One disappointment I have in the Lexicon, and Sherbourn amps are efficiency. I am running 4 amps now to listen at -20db...whereas with all the Yamaha Pro amps I was at 2 amps.

 

 

What do you think? 

Edited August 15, 2015 by ellisr63

[mark1101]

I think that I screwed up by not asking you questions about your setup prior to recommending you try an active system.

 

I would never have recommended an active setup for HT use or as a combination HT system.  Just too much going on and it's questionable if the benefits could even be realized.  I still honestly don't know what you really have.

 

I do know you could add the passive preamp volume controls that are out there to your proposed 11 channel amp(just for the processor channels)  and be done with it.

 

I stick to my word that a REALLY NICE passive system with a few upgrades is very hard to beat with an active system without spending a lot of money.

 

It sounds like you understand what's going on and that's what's important.  You'll be able to squeeze what you can out of what you have, which is the whole game.

[NBPK402]

I think that I screwed up by not asking you questions about your setup prior to recommending you try an active system.

 

I would never have recommended an active setup for HT use or as a combination HT system.  Just too much going on and it's questionable if the benefits could even be realized.  I still honestly don't know what you really have.

 

I do know you could add the passive preamp volume controls that are out there to your proposed 11 channel amp(just for the processor channels)  and be done with it.

 

I stick to my word that a REALLY NICE passive system with a few upgrades is very hard to beat with an active system without spending a lot of money.

 

It sounds like you understand what's going on and that's what's important.  You'll be able to squeeze what you can out of what you have, which is the whole game.

I found someone that will make me a 3 channel balanced GainClone amp for the front 3 channels... I am seriously thinking of getting it, and then the 11 channel amp for the surrounds. It won't be cheap but if the GainClone amps are as good as I have read it might sound better than the Bryston 9B does plus have proper gain control, and not suck the electricity like the current 2 amps are.

[Chris A]

I would never have recommended an active setup for HT use or as a combination HT system. Just too much going on and it's questionable if the benefits could even be realized. I still honestly don't know what you really have.

 

Ahem...

 

I personally understand and recommend fully active systems for surround sound: just look at your local "high tech" movie theaters and other higher fidelity surround sound venues nowadays--that's what they are. The performance/price ratio is now becoming viable to replace the prior ways of doing things.  In fact, passive crossovers are typically only used in static PA systems that are subjected to the elements in open stadiums, etc., where weather-ability and upgrade of prior emplaced (A.K.A., old) PA horns and line arrays subject to being replaced (like Danley Sound Labs business base, for instance). 

 

Additionally, fully active home surround sound systems are basically becoming standard issue with the increased functionality of the AVPs--which I highly recommend because they typically are of higher quality in manufacturer's product lineups, and AVRs--which I am increasingly recommending less because it tends to lock users into a "well, I don't have enough channels to bi-amp or triamp all my channels with my AVR" thinking that you don't get with a good AVP. 

 

This subject area, to me, represents a major generational divide in "hi fi" thinking--the future, not the past.

 

JMTC.

 

Chris

Edited August 15, 2015 by Chris A

[mark1101]

Chris,

 

I get what you are saying.  No arguement.  But I don't personally think it's a good idea to try something that complicated for your first active system, having no experieince with it.  Heck, the cinema setup is about the most complicated there is besides a giant reinforcement network.  He is talking an 11 channel amp.

 

I just didn't think it was a good idea.  I still lack a lot of information about this whole situation.  So I'm playing it safe.  This stuff isn't cheap to figure out this maybe not what you want.

[NBPK402]

Chris,

 

I get what you are saying.  No arguement.  But I don't personally think it's a good idea to try something that complicated for your first active system, having no experieince with it.  Heck, the cinema setup is about the most complicated there is besides a giant reinforcement network.  He is talking an 11 channel amp.

 

I just didn't think it was a good idea.  I still lack a lot of information about this whole situation.  So I'm playing it safe.  This stuff isn't cheap to figure out this maybe not what you want.

Mark,

   The 11 channel amp would be for the 1/4 pies, and all the surrounds. I will only be going active on the front 3 channels (with the horns having gain controls). I had this setup all up and running (sounding great) until I started to swap out the equipment. I found a 3 channel balanced Gainclone amp with 3 gain controls on it, but I am looking at $2500. I am not sure if it is going to make that big of a difference to go to the GainClone at that price. The biggie is I want to cut the electric bill back down to like it was on the old setup.

 

What info do you need?

I am running a Oppo 103 as a source...that feeds a Krell Showcase 7.1 preamp via the 7.1 unbalanced outputs to the Krells 7.1 unbalanced inputs. It then goes via balanced XLRs to the MiniDSP DDRC-88A processors Phoenix connector blocks (balanced) which is output via RCA to XLR cables (unbalanced) to the Xilica XP-4080 crossover. The Xilica crossover output is then reduced by 10db (to the horns only), and goes directly to the Lexicon NT-512 (Bryston 9B) power amp. The horns are reduced by 10 db to get the balance correct (top to bottom), and to give me a 500hz crossover to the 1/4 pies (which I might try 400hz with).

Edited August 16, 2015 by ellisr63

[NBPK402]

Today I installed the Yamaha MX-A5000 amp... I have to say I am very impressed with it. I no longer have gain issues that cause hiss. I also have a much better bottom end than the Sherbourn did (a surprise as I have less power too). Hopefully the new Yamaha preamp will sound better than the old Krell does too. Another plus was my power consumption with everything running went from 4 amps (Lexicon/ Sherbourne setup) to 1.7 amps listening at even louder levels than before. 

[Chris A]

That's interesting.  Congratulations for hunting down at least a portion of the background noise issues.  I know that it can be very challenging to find the source(s) of the noise.

 

Chris

[mark1101]

_{4A x 120V = 480w (~.5KW)}

_{1.7A x 120V = 204w (~.25KW)}

 

_{At .10 KWH, and if you listened to your stereo for 24 hours straight it would cost .1 x .25 x 24 = .60 (60 cents).  So you cut your cost in half.  It used to cost you around $1.20 per 24 hours of listening.  Basically, even at 4A it only cost about 5 cents/hour.}

 

_{I saved roughly $80/mo by replacing almost all of our light bulbs with LEDs.  It cost me over $900.  What I found out though is that they give off so much more heat than regular light bulbs now the AC runs more.}

[Chris A]

I saved roughly $80/mo by replacing almost all of our light bulbs with LEDs. It cost me over $900. What I found out though is that they give off so much more heat than regular light bulbs now the AC runs more.

 

  Bummer.

 

But that doesn't add up, does it?  Less (infrared) heat, but more (convective) heat?  Oh, well, back to the subject at hand...Xilica crossovers.

Edited August 27, 2015 by Chris A

[babadono]

_{4A x 120V = 480w (~.5KW)}

_{1.7A x 120V = 204w (~.25KW)}

 

_{At .10 KWH, and if you listened to your stereo for 24 hours straight it would cost .1 x .25 x 24 = .60 (60 cents).  So you cut your cost in half.  It used to cost you around $1.20 per 24 hours of listening.  Basically, even at 4A it only cost about 5 cents/hour.}

 

_{I saved roughly $80/mo by replacing almost all of our light bulbs with LEDs.  It cost me over $900.  What I found out though is that they give off so much more heat than regular light bulbs now the AC runs more.}

Wow I don't get this at all. I replaced most of my in ceiling flood lamps(can lights) with leds also. They are almost cool to the touch. I can remove an 8 watt (65 watt replacement)one while it is on. Try  that with a 65 watt incandescent bulb.

Sorry for the hijack...... back to the subject.