Digital Amplifier

tapeshc

Hi,

You must be wondering when every one here is switching from SS to tubes, why am talking about digital amps.

I had been reading about these digital amps for some time and came across Panasonic SA-XR55. I did read very good things about this and other Panasonic receiver. What I liked about this is that in stereo mode it uses other channel amps for two channel. You can Bi-Amp or BiWire. All this for $229.99 at amazon.com. This is all mentioned in the manual.

Rotel just came out with RMB-1077(7 Channel Digital Amp) and Nuforce, Bel Canto are already established in this technology.

Best thing I heard about these amps is that they don’t loose steam on heavy or difficult loads and bottom end is very well defined and full.

I am thinking of trying this Panasonic offering as it wont set me back by big $s, what do you think it is a good idea ? I don’t know how close it will get me to Nuforce or Rotel.

Any one here has any opinion or feedback on these digital amps ?

bknauss

Be careful with the term "digital amps"... a lot of amps are simply switching amps (Class D, stuff like that) with no digital aspect in the amp. There definitely are some amps with digital circuitry in it (the amps used in the Polk IP speakers, Class T), but there's been a big misconception that anything very efficient is a true digital amp.
End of anal engineer.

The thing to worry about with switching/digital amps is the roll off on the high end. Without going into technical detail, its a problem that's inherint with the technology of Class D and all of its flavors and must have a good design to get around the problem.

But, as always, listen for yourself and make your own opinions. If you want opinions on a true digital amp, ask anyone who came to Polkfest. Everyone seems pretty darned impressed with the sound of the IP speakers.

HBombToo

When all this buzzing started a while back I had to get my research on. I found the chip sets that go into these types of products to gain a clear understanding of what is actually going on from a design perspective. I hope the following attachment takes you to an 80 Watt chip set.

http://www.apogeeddx.com/DDXi-2051.pdf

Have fun and this is a great start of a cool topic. IP audio is the way of the future IMHO!

HBomb

cfrizz

Zero, I understand that the recievers are not all that they are pumped up to be, however, what about the Rotel that is making strictly amplifiers? What is the difference in technology there & does it measure up to standard amp technology?

HBombToo

Great outline and detail Zero.

I'll just add that there is a cool factor to this IMO and really enjoy watching new product development.

HBomb

cfrizz

Understood! I will wait until the people I trust on this board have a chance to check them out & weigh in with their opinions!

Thanks,
Cathy

tapeshc

Zero,

Thanks for your indepth analysis.

Here is the Link that got me started on this search.

Also what I have heard about Nuforce is all good or amazing I would say. May not be tube like but one of the best.

Jeff Rowland's latest offerings are also using this new technology, ofcourse with their added research.

Panasonic ? Yes you are right, you get what you pay. Its cheap construction wise, but sound seems to be good (heard so). Again its all hear-say, so needed some kind of approval from my good old friends here

AsSiMiLaTeD

Whatever happened to that little Teac amp I was hearing so much about? I can't hardly find any information on it online. Sean, you still liking yours? Know where I can find a few pics and maybe a manual. I'm thinking of hooking one up in the bedroom, am wondering if I'll need a preamp...

Danny Tse

Here's one of the discussions of the TEAC power amp at audiocircle.com. You can do a search at the "Multichannel Audio and the Digital Domain" section of that site for discussions on other such amps/receivers. The consensus is that the TEAC functions much better with a pre-amp (even though each channel offers its own volume control).

There's now buzz generated on the 'net about Onkyo's TX-LR552 digital receiver. It's been out for a while but has been overshadowed by the Panasonic and JVC offerings. You can pick up one of these for about $150.00 brand new.

AsSiMiLaTeD

wish I could find a picture of the back...

hoosier21

here is a link to the rear of a modified Teac, it has a few things removed but you get the idea.

http://www.boldercables.com/MerchantProduction/1168/teac.JPG

I have three of these amps

Danny Tse

hoosier21 wrote:

here is a link to the rear of a modified Teac, it has a few things removed but you get the idea.

http://www.boldercables.com/MerchantProduction/1168/teac.JPG

I have three of these amps

Looks like it's been modded for 2 channel operation, which was my original intention as well.

AsSiMiLaTeD

so it looks like with the volume controls on the back that I wouldn't need a preamp to work with the Teac...

hoosier21

Polkmaniac wrote:

so it looks like with the volume controls on the back that I wouldn't need a preamp to work with the Teac...

Each channel has a vol control.

ZERO
Sorry for the misleading post, I could only find a picture of the rear of the amp on the net, and it is a modded version. Mine are not modded. I have not really even played with any of the amps I got, sitting pretty in the box they were shipped in. I will use one with the R15 I got from Madmax here at work.

AsSiMiLaTeD

hoosier21 wrote:

Each channel has a vol control.

ZERO
Sorry for the misleading post, I could only find a picture of the rear of the amp on the net, and it is a modded version. Mine are not modded. I have not really even played with any of the amps I got, sitting pretty in the box they were shipped in. I will use one with the R15 I got from Madmax here at work.

wanna sell me one ?

madmax

I'm using one of the Teacs currently with my B&W DM4's. I've played with the Teac and the Sonic impact. Both have the same distinguishable sound. It is almost like listening to an electrostatic speaker. Actually, I noticed the same characteristic when we listened to the powered speakers at polk. I don't mind this characteristic but it is there. Can you still order the Teac? I bought two at the time because I thought they were becoming scarce. Cool little amp!
madmax

AsSiMiLaTeD

Hell no you can't buy them...I'm looking online and can't find one anywhere right now...

Danny Tse

TEAC A-L700P power amp.....$97.00

http://dakmart.com/website/ItemDetail.asp?ItemId=42161&cID=110

hoosier21

Polkmaniac wrote:

Hell no you can't buy them...I'm looking online and can't find one anywhere right now...

Collector's item, rare item.... hmm pricing just went up.

AsSiMiLaTeD

Danny Tse wrote:

TEAC A-L700P power amp.....$97.00

http://dakmart.com/website/ItemDetail.asp?ItemId=42161&cID=110

Sweet!

madmax

In my opinion the sound quality is worth much more than the asking price.
madmax

AsSiMiLaTeD

So those of you using these, are you using these with or without a preamp? This would be nice for a bedroom system because I can hide it from view if I can use it without a preamp. I've already got a Denon DVD player in there that does a good job as a CD player...just need some speakers...

AsSiMiLaTeD

I know this is subjective and really doesn't matter because I'm going to buy one regardless...but...

If you had to put a price tag on this piece in terms of sound quality (compared to other amps that are out there), what range would it fall in?

hoosier21

If you have a Denon with variable out, I would not use a preamp. But I would not plan on using the pots on the back, they are hard to get to, they are small, and there is one for each channel, would be a pain.

AsSiMiLaTeD

Any preamp in the $100 range you can suggest?

Danny Tse

I hope this works....the below link has some photos of a pair of TEACs modded to function as mono-blocks. Painted black. Have some photos of the back panel unmodded.

http://www.audiocircle.com/circles/modules.php?set_albumName=albuo42&op=modload&name=gallery&file=index&include=view_album.php

If you guys read the thread I originally linked to at audiocircle.com, this owner replaced his Sugden A28B integrated amp with the TEACs.

AsSiMiLaTeD

Email sent off, thanks Zero

AsSiMiLaTeD

I sent them an email asking about a passive preamp, here's the response I received:

Our Basic preamp is not actually a "Preamp", as it is a Passive Unit. Please see attached.

It just got a simple "In" and "Out" connections with an audiophile grade dual volume in a non-magnetic metal box. Connectors are gold plated RCA.

what is a 'dual volume'? Is this a good deal for $50?

PolkThug

Polkmaniac wrote:

I sent them an email asking about a passive preamp, here's the response I received: what is a 'dual volume'? Is this a good deal for $50?

Is it supposed to be more than just a volume knob for a low voltage input?

AsSiMiLaTeD

So if I use this, should I just leave the volume level on the back of the Teac at full and do all my volume controls using this box, or am I going to get some kind of gain distortion?

Obviously I know I'll use this box to control volume on a daily basis, I'm just wondering where I should set the volume on the back of the Teac.

AsSiMiLaTeD

Sweet. I'm getting one of these Teacs from Hooser(Russ) and am getting one of the passive units from monarchyaudio. Now all I gotta do is snag some inexpensive speakers and I'm good to go.