Give me an Amp Crash Course

[Steve81]

Any ideas?

One possibility is the Cambridge CXA80. It's got a decent range of digital inputs including USB, adequate power, a sub output, and it doesn't look half bad IMHO. Cambridge units tend to be put together pretty well IME as well. Cost is the only real downside at $1,000 MSRP. Of course he might be able to wheel and deal his way down a bit.

 

[killdozzer]

Guys, you're great. I didn't even know you're discussing this. There were no alerts under my nick name.

I do have some time now to think this thoroughly.

I WAS thinking about picking up a second hand Crown, but only because I need to return the borrowed amp after a couple of days.

So a 200$ Crown/Luxman combo was still a joke for most part. I would get rid of it after I get the money to settle down with something that hits the spot.

Now, about that spot… I am trying to find a ‘Camelot’ piece of equipment. For me it is a good and strong, well built intgr. amp with addition of DAC with USB input and bass management, and it would be nice to have a phono (I’ll explain). Preferably with a CD player as well and it has to look good to me. For this I could come up with 1000$, perhaps 1200$ after some time.

I do know this is much to ask, really, I do know this is difficult, so I start distilling; first goes the CD player. I have one (Philips, although the tray is not opening, but I have another one (Technics) down on the south, on the island I grew up on, I have to see whether that works), so I don’t need a CD player.

Next goes the USB if I can use HDMI to do the same (@Steve81 said it can and I have no reason not to trust him).

Then we can trim a little bit of power; I see these babies playing with 2x35Wpch into 8Ohm like a joke and I cannot go too loud in a loft. So let’s say 2x80/2x90 could do the job.

And I could even go for industrial ugly, like NAD, but at least it is funny looking.

The problem is, as I said about A-S701, when it goes across these borders and you still have to pay a lot. I’d ask myself “what the hell was I doing, going trough hundreds of combinations to end up with something that doesn’t do what I want, cost a lot and I’d gladly hide it in the closet?”

This means I’m still on the crossroads. If I don’t find my ‘Camelot’ amp, there’s only so much I’ll give in. After that I’ll start looking for cheap, cheap and cheap.

What I can’t live with is giving a lot and still object for whatever reason.

As for your questions and the phono stage; my father is not using his somewhat big records collection. Further down the road, after the sub and stands and some sort of CD player a turntable will top it all of.

killdozzer

 

[killdozzer]

Question: are all the sources going to be digital, i.e. an input for your PC, one for a CDP? If that's the case, with the Crown in the picture, a DAC/digital preamp like my XDA-2 would get the job done. One possibility is this; it has balanced outputs to drive the Crown, and you can simultaneously run a subwoofer off the RCA jacks and use the sub's built in low pass filter/phase knob to effect a decent blend or preout>sub input for bass mgmt>sub's filtered output>amp input.

If possible I'd like to have the possibility not to duplicate the signal for bookshelves and the sub. As far as I see it, if you run the sub off the RCA jacks, bookshelves would still get the full signal. I like your last suggestion; pre-out to sub and back to mains in.

This is where my questions start again; these terms are not standardized. I found: tape out, rec out, loop out, pre out... some of these are different, but loop out and loop in is suppose to get the signal into the processor and back. It looks the same to me. I think if it can go into the processor, it can go into the sub trough the crossover and back. It is some sort of signal processing after all.

Maybe I'm wrong. Is the signal leaving the preamp and going into the processor any different than the one I would lead into the sub? Like stronger, weaker, amplified, distorted, raw...? I don't know.

killdozzer

 

[Swerd]

@killdozzer – Don't you realize we love to spend someone else's money.

As Steve suggested, Cambridge Audio CXA80 or CXA60. Both have digital and USB inputs, and subwoofer output (did not mention if sub out is filtered or unfiltered).

CXA80 80 wpc, about $1100

CXA60 60 wpc , about $800

As always, see if they are available and at what price.

https://www.cambridgeaudio.com/products/cx/cxa80

https://www.cambridgeaudio.com/sites/default/files/product/giudes/cxa_product_brochure_english_1.pdf

Unlike the Yamahas, the Cambridge Audio does not have a phono stage. That ability can always be added externally with a small inexpensive device such as an Audio Technica PEQ3.

 

[Steve81]

This is where my questions start again; these terms are not standardized. I found: tape out, rec out, loop out, pre out... some of these are different, but loop out and loop in is suppose to get the signal into the processor and back.

Preout is pretty standard term, but you can always check the manual if something sounds like it could be one. Tape/rec outputs are different in that they're a fixed line level output, i.e. no volume control. They're also not typically affected by tone controls.

 

[killdozzer]

Preout is pretty standard term, but you can always check the manual if something sounds like it could be one. Tape/rec outputs are different in that they're a fixed line level output, i.e. no volume control. They're also not typically affected by tone controls.

This may also be the case with the 'loop out - loop in' thing. If it's designed to go into the processor I can imagine one would want a clean straight signal so that he can adjust it in the processor.

This is what I'm talking about:

Nova 150

This I ask only to understand better. If I came across this in any amp I'm considering, I'd like to know whether I can use it for my purpose.

And this Rotel is the one that came very, very close, being a intgr. amp, DAC, CD player with 100Wpc/8ohm, but the connectivity is crap and I mean that. It looks like they thought since it has a lot no connections are necessary. I think it has on single analogue input and two digital ones. And furthermore, the USB is not as Universal as one might conclude from the acronym; it takes only apple products.

 

[killdozzer]

I also found these:

- bi-amp out
- my link out/in
- split out-in

@Swerd you did make a comparison once, between the Peachtree Audio and a Yamaha and Yamaha was a clear winner. But it seems that Peachtree Audio stumbled upon this new generation of hifi enthusiasts' philosophy, who like to listen to their PC, CD and Vinyl and have a decent sound. There's a new model coming out that is stronger has most of the features (both B and A type USB-DAC that takes PC, phono, it has 150Wpc AB Class and it has some neat specs - rated 250W into 4ohm, discrete headphone amp, huge damping factor if you can believe their specs, very low distortions and so on. Announced price is 1500$ (same as KEF's so I'll get it for 900$ ei, @Steve81 ?)

P.S.: yesterday i turned the volume way up with no music playing (just for a test) and there was a lot of humming noise. Then I unplugged the TV (the same one I took out of the storage room because I though I'll need it for the receiver ) and the humming was gone. There was almost nothing audible coming from speakers even at 100% power from the amp.

Should I keep looking/worrying or should this be a closed case?

 

[Steve81]

Per Peachtree's website, it looks to accomplish the same thing as the preout/main-in combo.

Loop feature to add an external tube buffer, EQ or other processor into the signal path

 

[Alex2507]

Any ideas?

Yeah, the Crown until similar power becomes easily affordable.

For now that Luxman has pre-outs so bass management is covered.

Is that set up still viable short term or am I just getting excited for nothing?

 

[Swerd]

… But it seems that Peachtree Audio stumbled upon this new generation of hifi enthusiasts' philosophy, who like to listen to their PC, CD and Vinyl and have a decent sound. There's a new model coming out that is stronger has most of the features (both B and A type USB-DAC that takes PC, phono, it has 150Wpc AB Class and it has some neat specs - rated 250W into 4ohm, discrete headphone amp, huge damping factor if you can believe their specs, very low distortions and so on. Announced price is 1500$.

The new Peachtree seems good on paper. It may have all the connections you need. And you like it's appearance. I have a few other thoughts.

The USB PC connection standards seem to change often enough that what is now the newest and latest may soon become "yesterday's news". Make certain that any amp you buy has additional analog and digital connections that you will not use for now. Consider it room for expansion. Let's imagine that in the future, a different and better type of PC connection appears. If your amp has unused connection points, you can always buy an inexpensive converter box (dongle) of some kind that allows you to use it. Similarly, don't consider the existence of a built-in phono stage as important. It's nice if you need it, but there are many small and inexpensive external phono stage preamps available. They all would require an unused pair of analog audio input jacks. Consider them no different than a PC dongle.

The price is $1500 (USA). Because it is a new product, you may have to wait a year or more (?) before lower prices are available, if ever.

The Peachtree power amp section is class D, not AB. Peachtree says "New generation ICEPower amplification - 150 watts per channel", ICEPower means class D. The smaller size and lighter weight chassis are also clues. Does that make an audible difference between a class AB amp? I don't have any first-hand experience with class D amps, so I will guess probably not. The only reason I point this out is that a class D amp should be less expensive to make than a class AB amp, such as in the old school & ugly looking Yamaha.

I found no mention of a subwoofer output jack. The photo of the rear panel does not allow me to clearly read it. It does mention a "Loop" feature that allows adding an external processor (tube buffer, EQ, etc.) into the signal path. I assume this might be used for a subwoofer, but I am not certain about that.

I am unimpressed by Peachtree's talk about head phone amps. I find that irrelevant. I would much rather listen to good speakers, such as your LS50s , than any headphone.

P.S.: yesterday i turned the volume way up with no music playing (just for a test) and there was a lot of humming noise. Then I unplugged the TV (the same one I took out of the storage room because I though I'll need it for the receiver ) and the humming was gone. There was almost nothing audible coming from speakers even at 100% power from the amp.

Should I keep looking/worrying or should this be a closed case?

Closed case.

1. Unplug the TV or move it somewhere else.
2. Turning the volume up with no music is a rather silly test.

 

[ski2xblack]

You may be able to eliminate the ground loop caused by the TV with one of those ground loop isolator adapter thingies on the coax. If that's in fact what's going on, they're a cheap and effective fix.

 

[killdozzer]

1. Unplug the TV or move it somewhere else.
2. Turning the volume up with no music is a rather silly test.

By mere coincidence I changed two variables at the same time and was wrong about the source of buzzing noise. At the moment I'm listening music via a 3.5mm jack which is plugged into my laptop and going into 'aux' RCA connectors on the amp. When my laptop is off and everything is connected this way and I turn up the volume on the amp there's a lot of noise. (I don't have to turn it all the way up to hear it and it is pretty loud)

When I turn on the laptop and everything else is connected the same way, it is completely quiet.

I just wanted to ask is this a concern?

I know it's a silly test, but I wouldn't hear it otherwise. I wanted to see whether the amplifier or cables pick up any static. Usually I bring the volume up after I start playing a song so I wouldn't notice the buzzing that way.

killdozzer

 

[Alex2507]

At the moment I'm listening music via a 3.5mm jack which is plugged into my laptop and going into 'aux' RCA connectors on the amp.

You're getting analog audio out of the laptop? I'm no computer expert but I understood that to have a high noise floor compared to external sound cards which keep that signal in the digital domain until it's out of the computer.

If you have to bring your ear within a foot of the speaker to hear hiss and static with the volume at a normal level but no music playing, it's normal. If you can still hear it at 4 feet away or even worse, at the listening position, then you have a problem. You won't be the first to chase a phantom hiss by unplugging the water cooler.

 

[killdozzer]

You won't be the first to chase a phantom hiss by unplugging the water cooler.

I really only wanted to see is there a reason to worry (a reason for someone not looking for one )?

It is very loud until you turn on the laptop. Everything is connected as I described and when I turn on the amp first and turn on the volume you can hear it even from another room. But!! it disappears when I turn on the laptop.

I start hearing it with the volume knob in the position as in the pic:
(and after 10 it is aprox. a fat bumble bee having a crush on your head - loud)

killdozzer

 

[Alex2507]

I didn't read your post carefully enough at first but I get it now. I have no clue what happens to the laptop's on board analog audio out when the power goes off but I wouldn't be more than a day or two without an external sound card especially if some unexplained noise was being shot out my new speakers. You know?

 

[killdozzer]

I wouldn't be more than a day or two without an external sound card especially if some unexplained noise was being shot out my new speakers. You know?

There is this strange aura of wisdom around your practicality!!


Sound advice for sure.
killdozzer

 

[Alex2507]

Oh ... and it could be your laptop charger dirtying up your on board sound card.

 

[Swerd]

When you hear the noise, the laptop is off but connected to the NAD. And if you turn on the laptop, the noise disappears. Puzzling.

1. Is the laptop relying on the battery, or is it connected to a power outlet?
   
2. If it's connected to a power outlet, does the noise disappear if you unplug the laptop?
3. Is that power outlet the same as the power outlet the NAD is connected to? If so, try using a different power outlet for the computer or the NAD.

 

[killdozzer]

When you hear the noise, the laptop is off but connected to the NAD. And if you turn on the laptop, the noise disappears.

Correct!

I'm sorry, I've been away on a business trip (if you can call it that) I haven’t seen your post, I will do the tasks in the afternoon. So far I can answer the first one; laptop is plugged in the power outlet and it is the same as the one that NAD uses.


(I’m still “jaw-dropingly” amazed how these speakers sound. I think my brain is actually the one having the break in period)

killdozzer

 

[Alex2507]

A thousand bucks in speakers usually does the trick for me too. Wait until you find a sub. That's 75% of the music right there.