Power amplifier or waste of money?

[KariJr]

Thanks for all the opinions and advice. I don't have much money but I still decided to order a three-channel power amplifier this morning. If I don't experience and hear any benefits, I'll probably sell the amplifier on at a small loss. I'm a Yamaha guy so I think getting involved with Dirac equipment would be too technical for me. The delivery time for the amplifier is probably long so I can ask you for instructions in advance. So do I also need 3 RCA-RCA or RCA-XLR cables and a trigger cable? Of course, you can find out by reading the instructions, but what settings do I need to change on the Yamaha for the power amplifier?

 

[Sal1950]

So do I also need 3 RCA-RCA or RCA-XLR cables and a trigger cable?

I only see L&R channels XLR pre-outs on your Yamaha so just stick to RCA-RCA for all.
They will be cheaper anyway and sound no different.
Don't expect to be bowled over with a sound improvement and it wouldn't happen till the volume goes up anyway. But considering your speakers, I still believe it may be a worthwhile improvement for a 9 channel rig. Let us know what you find.
Good luck.
PS, If you haven't already, be sure to read the Audioholics review on you A6A and set the output switches according to Gene's directions.

Yamaha RX-A6A 9.2CH 8K AV Receiver Bench Test Results!

We bench tested the Yamaha RX-A6A 9.2CH 8K 150watt/ch Atmos/DTS:X Receiver to gauge power output and uncover performance issues we discovered. We discuss the proper settings for best power delivery.

www.audioholics.com

 

[Ruediger]

Thanks for all the opinions and advice. I don't have much money but I still decided to order a three-channel power amplifier this morning. If I don't experience and hear any benefits, I'll probably sell the amplifier on at a small loss. I'm a Yamaha guy so I think getting involved with Dirac equipment would be too technical for me. The delivery time for the amplifier is probably long so I can ask you for instructions in advance. So do I also need 3 RCA-RCA or RCA-XLR cables and a trigger cable? Of course, you can find out by reading the instructions, but what settings do I need to change on the Yamaha for the power amplifier?

I haven't had one of the AxA line AVRs, but look in the menu for speaker setup. Does it have a pre-amp mode when all is handled by external amps - then use that. Otherwise it's just a matter of having the external amp connected at the pre-outs.

Yamaha YPAO is not bad at all. You should re-run it once you have changed the setup and maybe adjusted the gain of the external amp to your need, if it has that option.

As a trigger cable stick with 3.5mm mono. There are sometimes problems with stereo cables.

For a first setup you can use basic rca-rca cables you already have. If you decide to keep the external amp, you can still opt for xlr / rca-xlr or other rca cables, depending on what the external amp offers. The Yamaha has xlr out for front left and right, which is a nice feature.

ps. Hypex NC500 3-channel is a very nice amp choice for LCR channels.

 

[welwynnick]

Thanks for all the opinions and advice. I don't have much money but I still decided to order a three-channel power amplifier this morning.

Congratulations, I think that's a great decision. I'm with Sal1950 and you on this one. I look forward to hearing how you get on.
Please consider getting one of the ncx500 amps that share an SMPS3000 power supply. They're great value for money and will provide a bottomless pit of current for your 4 ohm speakers.

 

[KariJr]

I haven't received the amplifier yet but I have a question for the experts. On the rear panel of the amplifier there is a lever for gain setting (dB) 12.8/20.5/27.5/29. Which of these should I use or can I figure it out by experimenting? My settings are shown in my initial message.

 

[Ruediger]

You can play with that if you like. But if you use other channels off the AVR, the gain there is around 29db. So setting that on the poweramp matches the overall structure.

Should the poweramp do all active channels, you could set a gain that gets loud enough and then some. While leveraging the pre-gain from the units before it.

In theory it makes no sense to use a lot of amplification on a low gain signal incoming. In practice this mustn't be a real issue.

Your AVR has a certain range of added pregain to match the channels when measuring. It's probably 10 or 12db max. ( see manual).

 

[staticV3]

I haven't received the amplifier yet but I have a question for the experts. On the rear panel of the amplifier there is a lever for gain setting (dB) 12.8/20.5/27.5/29. Which of these should I use or can I figure it out by experimenting? My settings are shown in my initial message.

Start with the lowest gain setting.

If you reach 100% volume on your Yamaha and it's not loud enough, turn down the Yamaha, bump the Power Amp's gain up by one, then try again.

Do that until you've found the lowest gain that gives you satisfying loudness.

 

[KariJr]

You can play with that if you like. But if you use other channels off the AVR, the gain there is around 29db. So setting that on the poweramp matches the overall structure.

Should the poweramp do all active channels, you could set a gain that gets loud enough and then some. While leveraging the pre-gain from the units before it.

In theory it makes no sense to use a lot of amplification on a low gain signal incoming. In practice this mustn't be a real issue.

Your AVR has a certain range of added pregain to match the channels when measuring. It's probably 10 or 12db max. ( see manual).

The power amplifier is intended to be used for the three front channels and the Yamaha for surround and ceiling speakers. Are you saying that in this case I would use the 29 db setting?

 

[peng]

I really don't know if I need a power amplifier but it's on my mind and I can't rest until I get one. I live in Europe and I'm interested in Apollon Audio's product and I would like you experts to comment on whether I should order the right one.
So I'm interested in the cheaper round-edged case model.
Hypex NCOREx NCx500
Channel Configuration: Core 3(channel) with OPA 1656
Output Connection: Apollon Pure OFC Binding posts
Input Voltage: EU 180-264V
Would this be a good match for my Yamaha A6A amplifier?
I have Arendal 1528 bookshelves + a smaller 1528 center and 1528 slim surround speakers and 1961 height speakers as atmos.
I live in an apartment building and I can't listen at high volumes so is this all a waste of money?

I think you picked a good one for your 4-ohm speakers. From what I read, the NCx500 Apollon amp has 4 gain settings and RCA unbalanced outputs that would match well with the A6A, if you set it to the highest gain of 29 dB. It will not be a waste of money, though if you listen at really low level from under 10 feet, any audible benefits will be subtle at best, but if you can't rest without getting a power amp then get it and then focus on enjoying the music.

 

[peng]

The power amplifier is intended to be used for the three front channels and the Yamaha for surround and ceiling speakers. Are you saying that in this case I would use the 29 db setting?

Practically speaking it would make no audible difference to you, but in theory there is a sweet spot for a specific use condition that is dependent on your seating distance and desired SPL, once you know that range, you can pick the best gain setting that could be 27.5 or even 20.5 but no point trying 12.8, not for your speakers. To figure out the sweet spot/range, you would have to do some estimation based on calculations, so I would suggest you just set it to 29 dB. The benefits of setting it to the theoretical gain setting is most likely inaudible, but would look better on paper/graphs..

Edit: Based on Audioholics.com's measurements (see graphs below), 29 dB would benefit the center channel for sure, but when the center channel is not used, you may even try 20.5 though again, the better results will not be audible unless you really have the so called golden ears.

 

[Ruediger]

The power amplifier is intended to be used for the three front channels and the Yamaha for surround and ceiling speakers. Are you saying that in this case I would use the 29 db setting?

There is no fixed rule. It's just that you will see much less channel level adjustments from measurement when the gain internal/external is at the same level.

If you go to 20.5db the AVR will add 8.5db pregain to LCR - in theory, in reality numbers will differ.

Staying within what the AVR can do with pregain and having the external amp at a lower gain is theoretically better. What you don't want is measurement to max. out it's abilities. Like when I see on my Denon that it wants to adjust channel(s) +-12db I know it's the maximum and it probably wanted to go beyond that, but can't. That's a bad situation I would be presenting then for the AVR.

When you listen to music and only LR are active, you again want the gain structure to be optimal. So poweramp just with enough gain and a properly leveled signal into it. Music is the only thing where it could make a difference in reality. I very much doubt that in multichannel/home theater there is any difference to be heard.

But you went for that high quality poweramp - no reason not to max. out properly what it can do for you. So take the advice from post #27 and watch what the AVR wants to do when running YPAO.