Powerfull 5.1.

[Dxvideo]

I made a 2.1 system with two LM1876s last year. I had some noise problems about it but it is not matter of this thread.

Now I want to have a powerfull 5.1 with chip amplifiers. I need at least 20W for each FL, FR, RL, RR channels, 30W or more for Center and 100W for subwoofer. So can u recommend me some solutions.. I am not very beginner at DIY audio but I am not expert as u...

Thanx in advance for your helps....

 

[maddogjetz]

Hope this helps - depends on your definition of powerful

I haven't actually implemented one, and don't yet know the price, but am looking at this amplifier, but it looks to be feature strong, and has 50W per channel, with some nice management features.

It seems to support analog and digital input and both 2 and 5.1 outputs. I don't yet have full information (the website is lacking), but it looks like a good start.

I'm also not sure of how it sounds either (not having built anything with it).

I would welcome anybody else's experience with this amp too, as I'm considering using it for a box for several of my family and friends and don't want to find out the hard way.

Here it is:
http://www.pulsustech.com/pro/module.html?module=PSA-5860

Here is their block diagram:
http://www.pulsustech.com/tec/tec_sys.html

They say that some big name manufactureres are using it.

Hope that helps.

email me if u want to talk offline

 

[Dxvideo]

It looks pretty. But the price and availability from Turkey is important for me. The module has TOSLINK and SPDIF inputs, is it? In fact I dont need a digital input. Because DVD Player and also my PC have 5.1 ch. analog outputs. So I need just 6 channel PA, 6 channel (in 1 pot) volume control and a 100Hz LPF.. Am I right?

Thanx for your advice..

 

[Mika]

Hi,

Im working same kind of project. My system is DVD-player with 6-ch analog output, 6-ch preamplifier, 5-ch power amplifier, active subwoofer and 5 speakers. All except DVD-player is DIY.

Some information:
- 5-ch amplifier uses LM3875 chips
- Subwoofer uses bridged ESP projects P3A, L-R active crossover, Linkwitz transform and Vifa 10" woofer
- Preamplifier uses CS3310 digitally controlled potentiometers (of course there is alslo microcontroller, LCD, remote, .....)
- Speakers uses Peerless/Seas drivers

Preamp and center speaker are under construction. I can say that building your own equipment takes lots of time. But i think its worth of it.

You can find some information of my 5-ch amplifier from my website. Some pages are written in Finnish, because my english isnt any good . http://www.sunpoint.net/~crypton/

 

[Dxvideo]

Hmmm. Interesting! It looks like a professional design.. I guess I can do it by Atmel 89C52. But the disadvantage of the chip its stereo! And you have to use 3 ICs. JRC's NJW1107 IC is suit for 6 channel design. But I think the royality problems prevent to realising that. Do you have information about that IC?

For the gainclones and pre's.. Do you use a LPF for the subwoofer amp and as I can see on the sattelite amps you dont have HPF's.. Am I right? Should I use HPF or not for sat amps?

And for the sub box design.. As I can see you dont use a bass port. (or you use and I cannot see in pics?) Does that design gives a satisfactory bass level? And what PA did you use for it?

Thanks for your interest..

 

[Mika]

Hi,

Yes, im using 3xCS3310. JRC's NJW1107 is new to me, is it real audiophile IC? How it can be controlled?

I dont have any filters in my preamp, im using only DVD player filters (HPF for main/rear/center if i want and LPF for sub). Also sub has it own lowpass filter too. If your satellites are small, maybe it is clever to use HPF. 5-channel, second order high pass filter is easy to build and u can make it variable also. So it isnt a bad idea to use HPF.

Subbox is closed because linkwitz transform works only with closed boxes. SPL levels are high enough to me, but you can imagine that 8" driver cannot produce high SPL's. Linkwitz transform also gains lower frequencys about +10dB and that limits also SPL (Maximum coil travel exceeds). Subs amplifier is named as P3A --> http://sound.westhost.com/project3a.htm

 

[AJ Bertelson]

I had been looking for a cheap 7 channel amp for quite some time and found the outlaw audio 7 channel amp and thought about that, but I am now looking at the gainclones more and more.

I would just need to build the amp since I would use my HTPC as the pre-amp but I am interested in both Mika's PCB design and the links that were posted to the pulse tech site.

 

[Dxvideo]

It's not a new IC. I know it since 2001. But I guess its a professional IC because in its manual "This device is available only to licensees of Dolby Lab."

 

[Dxvideo]

And will you use an input selector, for between stereo and 5.1 inputs? Or you will have a stereo input?

Sincerely...

 

[Mika]

And will you use an input selector, for between stereo and 5.1 inputs? Or you will have a stereo input?

Sincerely...

Hi,

No, im not using input selector because DVD player plays 2-channel music from 5.1 main channels. Only selector in preamp is for sub, it selects where sub-channel takes signal: from LFE-channel or from Main-channels (summed). Microcontroller controls sub-channel select trough transistor+relay.

-Mika

 

[Dxvideo]

One more question;

Do I need active preamplifiers for 30W sat PAs and 150W sub PA... All PAs chip amp. (ex.: LM1876 x 3 for sat + LM3886 x 2 for sub). Does line level (775mV) not enough for full power?

Thanks..

 

[Mika]

One more question;

Do I need active preamplifiers for 30W sat PAs and 150W sub PA... All PAs chip amp. (ex.: LM1876 x 3 for sat + LM3886 x 2 for sub). Does line level (775mV) not enough for full power?

Thanks..

I think that u can set gain of LMxxxx so that u get full power at 775mV line level. So in theory, u wont need active preamp. But if u are planning to use only one passive potentiometer for all six channels, will you find that kind of potentiometer? When i was planning my system, i cannot find passive pot for all six channel adjust. If u can find, i think it is very good and simple way. Only worry would be channels balance particularly at low levels - One channel gain could be much bigger than other if potentiometer isnt very high quality.

- Mika

 

[Dxvideo]

I have another way to control volume.. Philips's TDA1074 is four channel electronic potentiometer. So we can use two TDA1074 via one 100K log potentiometer and we control 8 channels. But I afraid its not so simplex circuit and the chip is about 10$ each... It looks basic to control via potentiometers but in fact no! You can find TDA1074s manual in philips site.

See u