Finally enough multi-channel POWER

[SilverWolf]

Well been having rpoblems with the last AVR as well as my current unit. Distortion, clipping and damaged tweeters. Long have I been complaining to SWMBO of my woes. I've been dreaming of multi-channel amps for a long time and at last a break through.

At long last I have some power with a little extra headroom and I'm a happy man for I can now listen at decent levels without distortion or the AVR going into protect. Now I didn't end up getting a dedicated multi-channel AMP but instead got a couple of commerical/studio type AMPs with more coming soon. I guess 450w per channel maybe slightly overkill but it certainly seems to be enough to annoy several neighbours lol.

[b.d]

pray tell what be they? I'm sorta on the lookout for 200+ cheap watts.

[SilverWolf]

Biema 330II is the model, most places sell them for $500ish or more but you can get them for under $300 in a buy now on eBay.

They are rated 2 x 450 @ 4ohm (2 x 300w 8ohm) they same people sell lower powered models but theres only about $20 difference between models hence why I went with the 330II

This is the store/people I got mine from

http://stores.ebay.com.au/THE-AUDIO-AUSTRALIA-SHOP_PRO-Audio-DJ-Amps-RackGear_W0QQcolZ4QQdirZ1QQfsubZ2033629QQftidZ2QQtZkm

Fan cooled but thermally cued, so the fans don't seem to come on during HT use but when playing demanding music at high levels the fans do come into use. The fans are fairly loud (about they only drawback so far) but then when the music is that loud you don't hear them. I only noticed as I was playing some very loud and then the phone rang so I hit mute and noticed the fans then. But this is no different than any Pro/Commerical AMP except most have the fans run all the time so it's a plus on these units that they don't. The other plus is unlike most Pro AMPs these have unbalanced RCA (they also have the normal commerical type) inputs so no special cables need to be made up for use with consumer level gear.

Edited September 27, 2008 by Mitcon

[b.d]

Thanks for that.

Bevan

[Grumpy]

Hey good one Wayne, I think I can hear them down here in the Port.

How many did you get and what speakers are you using them on; Fronts and rears, a centre and rear centre?

[SilverWolf]

Howdy Grumpy,

I got 2 AMPs for now, have to wait a little while till the budget allows the 3rd. I'll stop at three as I only use 5.1 system (may add a center rear at some point but not sure if I'm that bothered yet) so no need for any more. As to the speakers they are still the same unknown brand ones out of China but they sound alot better now. I'm using them to drive the mains and center and will use the 3rd amp when I get it to drive the rears.

I've got a long wait till I replace my current speakers (Xmas 09) but I have plans on what I'm getting already and it'll be worth the wait

Edited September 27, 2008 by Mitcon

[Jliang70]

Biema 330II is the model, most places sell them for $500ish or more but you can get them for under $300 in a buy now on eBay.

They are rated 2 x 450 @ 4ohm (2 x 300w 8ohm) they same people sell lower powered models but theres only about $20 difference between models hence why I went with the 330II

This is the store/people I got mine from

http://stores.ebay.com.au/THE-AUDIO-AUSTRALIA-SHOP_PRO-Audio-DJ-Amps-RackGear_W0QQcolZ4QQdirZ1QQfsubZ2033629QQftidZ2QQtZkm

Fan cooled but thermally cued, so the fans don't seem to come on during HT use but when playing demanding music at high levels the fans do come into use. The fans are fairly loud (about they only drawback so far) but then when the music is that loud you don't hear them. I only noticed as I was playing some very loud and then the phone rang so I hit mute and noticed the fans then. But this is no different than any Pro/Commerical AMP except most have the fans run all the time so it's a plus on these units that they don't. The other plus is unlike most Pro AMPs these have unbalanced RCA (they also have the normal commerical type) inputs so no special cables need to be made up for use with consumer level gear.

US companies are the leading players in manufacturing huge dometic power amplifiers and in fact the whole industry of making massive began with the making of huge pro power amps. A lot of makers of domestic HT multichannel power amp began their multichannel amp manufacturing making large pro power amp like the Biema. One such a company I know is Cinepro/Verastar and AB International amp. I owned a Verastarr power amp and before that cinepro 2k5, this company began its operation making pro gears and saw the market trend towards home theatre in early 90s and began making a selection of different models of domestic power amps. To this day Verastar still own AB international which is part of the

company's operation in making pro audio gears.

[SilverWolf]

Here's a pic for you Grumpy of what my mains look like and the 2 new AMPs, while the speakers aren't anything special I quite like the look of the AMPs though they are hidden from view normally I guess.

[Grizzly]

Nice arrangement! Is that a mesh door in front of the amps? For heat dissipation I assume.

[Grumpy]

Very tidy set-up Wayne. The gear looks good in that cabinet

You will have to tell us more of the improvements the power amps have made when you have listened to them a bit more.

I suppose you know that the tight corner position of your speakers would not be the best spot for them; But I suppose like the rest of us we have to make the most of the space we have for our gear.

Thanks for sharing a bit of your place with us.

[SilverWolf]

Nice arrangement! Is that a mesh door in front of the amps? For heat dissipation I assume.

It sure is, I have a solid door also for it also so I can have whichever works best for me.

Very tidy set-up Wayne. The gear looks good in that cabinet

You will have to tell us more of the improvements the power amps have made when you have listened to them a bit more.

I suppose you know that the tight corner position of your speakers would not be the best spot for them; But I suppose like the rest of us we have to make the most of the space we have for our gear.

Thanks for sharing a bit of your place with us.

Yup, I know about speaker placement mate been having that arguement for years with my better half. Theres always a compromise and I just have too much gear and the room is only 3m wide. SWMBO says the compromise is I can have the gear if she says where it sits. The seating is far from ideal, I wish my coffee table had ears because it enjoys the sweet spot. The system is calibrated best as I can for the speaker placement and room acoustics and things like standing waves, untill I win lotto this is just the way it will be for me. The wife has been warned of what will happen when we move or build a house in regards to the purpose built HT room .

As to how the AMPs sound, well they have improved things in a rather big way as my speakers were suffering compression alot with the lower frequencies. Music sounds much more dynamic and may perk my interest in it again but I'm more into my movies. But it's early days and will wait till I've had a chance to play alot more through them before passing real judgement. Hard to get too concerned with it as most everything else over the next year will be changed though as complete new speaker system and most likely I'll be changing the source/transport as well.

Edited September 28, 2008 by Mitcon

[kye]

must be a combination of loud levels and inefficient speakers, because I have efficient speakers and my ears give up before my 9W 300B SET amp does!

[hifi man]

I've actually tried one of these Biema units. Whilst giving great power and headroom to drive any speakers, the fans would kick in every now and again and they were quite loud as I didn't have them in a cabinet like how Mitcon has them. Good bang for buck though, some people even mod these to put in silent fans or take them out altogether.

[Gee Emm]

Here's a pic for you Grumpy of what my mains look like and the 2 new AMPs, while the speakers aren't anything special I quite like the look of the AMPs though they are hidden from view normally I guess.

G'day Mitcon

What are you using for your surround pre?

[SilverWolf]

I've actually tried one of these Biema units. Whilst giving great power and headroom to drive any speakers, the fans would kick in every now and again and they were quite loud as I didn't have them in a cabinet like how Mitcon has them. Good bang for buck though, some people even mod these to put in silent fans or take them out altogether.

Yep, they seem to be of a higher quality than I would have expected for the price point. Though I had thought seeing as they had the unbalanced RCA inputs that the input level would be -10dBv. But for the average person there might be enough gain without it. I myself are going to get some sort of a line driver/shifter though and get the levels matched. I have noticed alot of people talking about or doing the mods for the fan noise. I've not noticed them coming on when playing movies but they do come on when playing music (dynamic stuff at high levels). It doesn't bother me much then as the sound level is high enough I caan't hear them (also may be a help having them in the cabinet).

G'day Mitcon

What are you using for your surround pre?

I'm just using a Pioneer AX2AS AVR.

[Grumpy]

Wayne, was that you that won a SA award yesterday?

Back on topic; Do you have a SPL meter to see how loud you actually listen to your music and movies with?

[SilverWolf]

Wayne, was that you that won a SA award yesterday?

Back on topic; Do you have a SPL meter to see how loud you actually listen to your music and movies with?

Award ? Not that I know of (yet)

Actually I do, I thought I had given them all away but I found I had one still just the other week. I've not tested at what volume I normally listen at but not that you bring it up I might just do that tomorrow. All I know is I want it louder and it's most likely already too loud hehehehe. I suspect though it's prolly in the 105-115dB range for movies but I'd have no idea for music but normally lower than the peaks in my movies.

Will test it and let you know, I sure hope it's not louder than that lol, could be why I never hear my wife asking me to do house chores.

[Grumpy]

The award was for a animal rescue sanctury and I'm sure they called it mitcon or was it mitcom.:mad:

Can't hear the missus calling hey? I might have to start listening a little louder too then. I find that apart from drum solos;) I consider what i call loud in the mid 90dbls to the 100dbls. Funny how in my place the volume control reacts to beer intake though.

[SilverWolf]

Ahh, that might have been Minton farm, Bev's place. It wasn't me anyways.

I've not got anything with a decent drum solo, would love a good listen. I went out yesterday in-fact and bought the first bit of music in a very long time. Couple of Music DVDs, Best of David Bowie-Peter Gabriel's Secret tour, Prince's Rave 2000 and a Michael Jackson one.

Edited October 6, 2008 by Mitcon

[A9X]

Biema 330II is the model, most places sell them for $500ish or more but you can get them for under $300 in a buy now on eBay.

They are rated 2 x 450 @ 4ohm (2 x 300w 8ohm) they same people sell lower powered models but theres only about $20 difference between models hence why I went with the 330II

This is the store/people I got mine from

http://stores.ebay.com.au/THE-AUDIO-AUSTRALIA-SHOP_PRO-Audio-DJ-Amps-RackGear_W0QQcolZ4QQdirZ1QQfsubZ2033629QQftidZ2QQtZkm

Fan cooled but thermally cued, so the fans don't seem to come on during HT use but when playing demanding music at high levels the fans do come into use. The fans are fairly loud (about they only drawback so far) but then when the music is that loud you don't hear them. I only noticed as I was playing some very loud and then the phone rang so I hit mute and noticed the fans then. But this is no different than any Pro/Commerical AMP except most have the fans run all the time so it's a plus on these units that they don't. The other plus is unlike most Pro AMPs these have unbalanced RCA (they also have the normal commerical type) inputs so no special cables need to be made up for use with consumer level gear.

Very interesting. I've wondered about the quality of these amps for a long time, after seeing the listings on ebay regularly and may get some later for the rears.

Farnell sells a quiet fan for $20 or so that would probably fit. After I finish testing my big rack of Pro amps I'm going to change out a few of the fans but probably only in the LF and sub amps. The Yamahas seem to stay off at normal levels.

[SilverWolf]

Well though it was time for some news now I've had a chance to give them a good listen. It's turned out to be bad news, though the sound had improved in ways that would be expected from more power there is an horrid tiny electric scratchy noise coming from the tweeters. We only noticed this during some quieter critical listening and have sine found that it's there even when no sound is being played. So while I guess some folks fine Pro PA type AMPs to work well I don't think these Biema units suit. I doubt it's a fault as both units do it, and now when I increase the pre-outs levels with a MX882 it just makes this noise even louder. I may be jumping the gun here as it may be something else in the mix but I doubt it as when I hook up a DVD player directly the sound is still there only quieter, would have never known except we now know what to listen for and am looking for it.

For all I know it could be ubalanced input related but I doubt it, not sure where to go fom here but I think it's back to just using the AVR for the power .

[SilverWolf]

Well, I'm at a loss. Have dumped the line driver and just running the AVR pre-outs directly to the AMPs again and all seems fine. I'm pretty sure that the AVR is feeding enough signal for the AMPs and the input on the actual AMP is unbalanced. Now to just wait for my new speakers and see how it all sounds.

[A9X]

Well, I'm at a loss. Have dumped the line driver and just running the AVR pre-outs directly to the AMPs again and all seems fine. I'm pretty sure that the AVR is feeding enough signal for the AMPs and the input on the actual AMP is unbalanced. Now to just wait for my new speakers and see how it all sounds.

I suspected some grounding issue or something else as I have no trouble doing this with a variety of pro amps.

I have no manual for the Beima, but from the pics I would expect it to be balanced in - all pro gear is.

Just clicked on a sleazebay listing for one of these and they have RCAs too. Interesting. Not sure how the signals are handled internally but I suspect one phase only is connected to the balanced in and the TRS to both.

Edited November 11, 2008 by A9X

[SilverWolf]

I suspected some grounding issue or something else as I have no trouble doing this with a variety of pro amps.

I have no manual for the Beima, but from the pics I would expect it to be balanced in - all pro gear is.

Just clicked on a sleazebay listing for one of these and they have RCAs too. Interesting. Not sure how the signals are handled internally but I suspect one phase only is connected to the balanced in and the TRS to both.

If you have a look at Altronics at this AMP on this page it has a link to download the manual and also the circut diagram. This AMP looks a little strange in the fact is has RCA inputs, it was suggested to me that they are also -10dBu but I'm pretty certain they are not. Input sensitivity is rated at .77v to 1v of sine wave so that in my mind is like half way between -10dBu and the Pro +4dBv. Either way I think they get enough signal from the AVR to reach full rated and they seem to be fine with the RCA input.

I've never heard a earth/ground noise like the one I heard and at first was sure it asn't that. But the more I think about it the more it may have been exactly that. The cables I was using to interface was RCA to XLR (cold and - briged) to the MX882 then I tried unbalancded XLR to TS again bridged.

I was going to get a 3rd one of these to complete a 6channel set-up but now teh design of my mains is to handle even more so I may have to find something with at least 400-450wpc @ 8oHm. So I may then have to go back to using a bridged lead, though I wonder if putting an ground from chassis to chassis might help if I get a buzz again.

[SilverWolf]

I suspected some grounding issue or something else as I have no trouble doing this with a variety of pro amps.

I have no manual for the Beima, but from the pics I would expect it to be balanced in - all pro gear is.

Just clicked on a sleazebay listing for one of these and they have RCAs too. Interesting. Not sure how the signals are handled internally but I suspect one phase only is connected to the balanced in and the TRS to both.

Just another question, as you say you use a few Pro/PA type AMPs do you use them with a consumer level source ? If so do you use a line driver of some sort or do you find that you get enough signal to feed the AMPs without trouble.