Multichannel preamplifier

[timc]

Hi.

Does anyone know about a cheap 4+ channel preamplifier?


-Tim

[johnaec]

What kind of sources do you plan on using? There are tons of inexpensive sound mixers out there that usually start at 4 channels, most of which include line level inputs, which will generally work OK.

John

[timc]

Hi.

I need a preamplifier for my 2 way speaker with active x-over. So input is linelevel.

Isnt the cheap mixers usually troubled with high lvl's of noise?

Any special recomandations? I have to admit i didnt think of mixers as a posibility at all. Nice :)



Edit: I have checked a few mixers now, and i can't find any with 4 mono outputs. I need 4 channels inn and 4 channels out.


-Tim

[johnaec]

I'm kinda' confused. :o: Is each channel separate, like ch1 in -> ch1 out, ch2 in -> ch2 out, etc.? If so you should be able to take the "out" from the insert jacks, if the mixer has them.

If you could clarify exactly how you desire the circuit flow, we'd have a better idea of what's appropriate.

John

[timc]

Hi John.

What i want is a 4channel preamplifier. Just like you get 7.1 inn and 7.1 preout on a surroundreciever.

The signal goes like this:

Source digital into Behringer DCX2496 ---> 2x2ways out and into a 4channel preamp ---> into 4 separate mono poweramplifiers.

I don't need, but individual volume adjustment on the channels would be a bonus.

For reference you can check the Parasound Halo P7 preamplifier. Thats what I'm looking for in a cheaper version.


-Tim

[johnaec]

Source digital into Behringer DCX2496 ---> 2x2ways out and into a 4channel preamp ---> into 4 separate mono poweramplifiers.Why not go just direct from the DCX2496 into the power amps?

John

[boputnam]

Does anyone know about a cheap 4+ channel preamplifier?:no:


There are tons of inexpensive sound mixers out there that usually start at 4 channels, most of which include line level inputs, which will generally work OK.:yes:


Isnt the cheap mixers usually troubled with high lvl's of noise?A number of Forumites use mixers in this fashion. Earl K, for one, comes to mind.


I have checked a few mixers now, and i can't find any with 4 mono outputs. I need 4 channels in and 4 channels out. And there, you are mistaken - even the cheapo mixers have Mono outs, you are just looking in the wrong place. The Aux sends are all mono. You need to find a small mixer with four Aux sends.

Shown: Rear of Mackie 1642-VLZ (http://www.mackie.com/home/showimage.html?u=/products/1642vlz3/images/1642VLZ3-Rear.jpg) for reference.

.

[timc]

Will the 4 outputs on the Mackie follow the master volume on the Mixer? I thought they were just individually lvl adjusted and did not react to the master volume.



-Tim

[boputnam]

That depends on the model.

You need to have a mixer where they can be switched to Post-Fader for that. Typically, two on a small mixer are Post-Fader (intended for FX), and two are switchable to Pre-/Post-Fader. More flexibility with more cost. Some of these are can be changed either through internal jumpers or with a "cut/solder" on the PCB's. Check the Block Diagrams.

Be aware, these Aux sends are also typically Pre-EQ, if that matters.

But like John, I wonder....
Why not go just direct from the DCX2496 into the power amps? Maybe we don't fully understand your intended signal path and use.

[timc]

Because there is no volume control on the DCX,


I will try to clarify. I run a digital input to the DCX. The DCX works as an active x-over providing me with 2 outputs for left and 2 outputs for right channel. Woofer and Treble. This results in 4 individual mono channels in need of a volume control. All EQ is done in the DCX.

This is how it is supposed to be when done :) ATM im just using it as an EQ.

-Tim

[boputnam]

This results in 4 individual mono channels in need of a volume control. All EQ is done in the DCX.Ah, got it!

So, once you set the individual Aux output levels, for your balance preference, you want to be able to change the entire system level, with one knob.

I need to think about that.

[timc]

Now we are talkin! :applaud:


Yup thats the idea. Its no problem to have 2 knobs for the maste volume. (like on a mixer)


http://www.audioresearch.com/MP1.html

This is the product i hope to be able to afford in the future for this specific task.


-Tim

[timc]

As i stated earlier using the DCX after the preamp gives it a low input analog signal. The result is bad S/N ratio.

Since im using the digital input on the DCX its not an option. I want to vary the gain AFTER the DCX. In PA application it not an issue since the volume is normally set to very loud.

The ARC will be used after the DCX.


-Tim

[grumpy]

You could also look for a used EMM labs Switchman... sometimes they pop up at
weird prices.

[matsj]

Tim take a look at this: http://www.rane.com/rpm26z.html and this:http://www.audioheritage.org/vbulletin/showthread.php?t=15919&highlight=rane

mats

[scorpio]

Not quite a pre, but they have a 6-channel volume control for the Behringer here: http://www.selectronic.fr/dcx2496_us.asp

Go about 4/5th down the page for info. Ordering via this web site is a little of a pain but very reliable in the end. (no affiliation whatosever)

Cheers,

[Don C]

You could use any recent AV processor. These usually have six RCA inputs and a mode that sends these straight to outputs after the volume control. This is needed for multi channel SACD, DVD-A. One less expensive model that I'm aware of is the Sherwood AVP9080R. Usually $300-$500 used.

[timc]

Yes i have thought of AV recievers with Pre inn/out. But there is not a great used market for them in Norway. They mostly go to friends kids etc. Exeption is the more expensive ones wich is not an option since it's just supposed to be a temporary solution.

If anyone have a cheap AV reciever (230v) the want to get rid of, let me know :)



-Tim

[just4kinks]

Have you considered the Denon DN-A7100? I'm very happy with mine. 7.1 channel, XLR outs, rackmount. What's your definition of "cheap"?

http://www.d-mpro.com/users/FolderData/%7B53D645B1-FD83-4902-98E2-C586816E9A63%7D/DNA7100%20front_thumb.jpg

http://www.d-mpro.com/users/FolderData/%7B53D645B1-FD83-4902-98E2-C586816E9A63%7D/DNA7100%20back_thumb.jpg
http://www.d-mpro.com/users/folder.asp?FolderID=4214&Tab=Overview

[timc]

That would indeed be the perfect product, but retail price is to high.


By cheap i mean like $200-$300


-Tim

[pos]

scorpio's solution is in your price range.
The only drawback is that is uses unbalanced inputs/outputs.

The other solution is to build a passive relay attenuator, like this one:
http://jos.vaneijndhoven.net/switchr/design.html

here is the theorie:
http://jos.vaneijndhoven.net/switchr/index.html

you need twice as much channels for fully balanced connections

[timc]

POS. That looks perfect. Ill save up for a 4channel version of that one. Balanced is not needed at this point.


Thanks for all the help folks.


-Tim

[pos]

there are some other kits available :
http://electronics.dantimax.dk/Kits/Selectors_-_attenuators/index.html
http://electronics.dantimax.dk/Kits/Selectors_-_attenuators/11021337032.html

prices look good

EDIT: and it is a danish website, not too far away from you !
similar kits in the US: http://www.twistedpearaudio.com/joshuatree/jt.aspx

[Don C]

That Denon looks nice, and it seems to be about $700 cheaper than it's competition. I'm wondering what the catch is, while I'm thinking of getting one.

[jblnut]

Any idea how this Denon compares to the various HK Citations ? I've been wondering about those for some time now. I'd like to get away from an AV receiver and be able to use separate amps. Just not sure it's worth the trouble....

jblnut