Should I upgrade to Stellar GC DAC?


#1

I currently have a modest system and am considering starting on an upgrade path, by adding a Stellar Gain Cell DAC, if it makes sense. A Denon X4300H anchors my current system with pre-outs going to an Onkyo TX-SR876 driving the front /center speakers, Aperion Verus Grand II towers (all surrounds and subs are handled by the Denon for HT use). Vinyl is handled by a AudioTechnica AT-1240 USB TT with a Nagaoka MP-150 Cartridge. CDs are played with a Samsung BD-J7500 blu-ray player. All components get power thru a PSA Detect Power Center, with the Detect and AVRs conneted via PSA AC3, AC5, and Pangea AC 9SE MKII power cables. My thoughts are to direct the TT and BRP thru the Stellar, connected to another input of the Onkyo for two channel stereo. Assuming that would be the correct setup, I guess I wonder if my system is of sufficient quality to notice a difference in DAC performance of the Stellar vs the Denon?

Any thoughts would be helpful.

Thanks,
John


#2

I am not familiar with your Denon or Onkyo HTR’s, and I think it is highly unlikely that anyone here has compared your Denon HTR’s internal DAC to the SGCD while using your Onkyo HTR for amplification into your Aperion speakers. PS Audio offers a no-risk 30-day in-home trial period, and they pay shipping both ways if you return it. Why not try the SGCD for a month in your system? That is the best (and perhaps the only) way to know if the SGCD is a worthwhile upgrade. Good luck.


#3

+1 @bootzilla


#4

Thanks for the reply. I also have another question. Since I use the system in the home theater mode quite often, I noticed the GCD has a home theater pass through. Exactly how does that work?


#5

The home theater input bypasses the volume control so you can connect, say, your front channel outputs from your receiver to that input and control the volume for that input with your home theater receiver. It’s used where there is a separate amp used for two channel purposes.


#6

So, are you saying that I take the pre-outs from the receiver to the GCD? If so, hasn’t that signal already been processed by the receiver’s dac, and how does that affect what the GCD will be able to do to the signal?


#7

No. You asked what the home theater pass through is for. I was not recommending you use it in your situation. I’m not familiar with your Denon or Onkyo and do not know if it is even relevant in your system.


#8

I would use the bypass when you are using your receiver for home theater.

Switch it off and use the SGCD as a DAC for music or as a preamp for your analog.


#9

I guess I’m a bit confused about how things should be connected. How should the SGCD be connected to the receiver, in my case the Onkyo powering the front and center channels, thru the Multi-channel inputs?


#10

Why are you using two surround sound receivers? They have equivalent power (140 and 125) which is not enough to make a difference. All you are doing is creating an overly complex system. Neither receiver has pre-amp inputs allowing you to directly access the power amps without going through the volume control.

Trade in the receiver you like the least (PS Audio will give you up to 1/3 of retail.) and get a Stellar stack with either the 300 amp or even better a pair of 700s. You can then use the Home Theater mode as the designers intended and power your main left and right speakers with the PS audio amp(s). You then plug your 2 channel sources into the Stellar pre-amp and bypass the surround receiver entirely.

You can plug your blu-ray player directly into the Stellar Gain Cell DAC via the optical toslink feed. I am willing to bet the DACs in the PA Audio sound much better than either the Denon or the Onkyo. You can leave the HDMI output plugged into the receiver for surround sound use.

Are your subwoofers passive, driven with the receiver power amps, or active with their own built in amps?


#11

I have a 7.2.4 surround HT setup. The Denon has 7.2.1 capability, thus requiring a second amp for the extra set of surround speakers. I decided, in order to take some of the load off of the Denon, to configure such that, instead of using the Onkyo for only one set of surround speakers, I allow it to handle the front and center speakers, while the Denon handles all of the surround and subwoofer speakers. I’m using the Onkyo, instead of a dedicated stereo amp, because I already had it on the shelf not being used. I thought, no need to go buy another amp when I already have one. The pre-out f/c/r channels on the Denon are connected to the multichannel inputs on the Onkyo. Volume is controlled by the Denon. The subwoofers are self powered with their own amps, triggered by the pre-out subwoofer connections on the Denon.

I am indeed counting on the SGCD sounding better for stereo music listening. Just do not yet understand how make the configuration work, if it will at all.


#12

You could connect the Denon’s front L/R pre-amp outs (if it has them) to the HT input on the SGCD and then connect the Onkyo, using only the amp section if you can do that, to the SGCD’s outputs. If you have to run through the Onkyo’s preamp section as well I’m not sure what you would be gaining (other than the SGCD’s DAC section).


#13

Here is a possible system diagram. You would run the surround speakers from the Denon, it has 11 channels worth of amplifier, you would use 9 of them.

Run your front preamp outputs from the Denon into one of the analog inputs of the Gain Cell Preamp/DAC, and set that input to Home Theater Mode. This will provide a “pass thru” so you will only use the volume on the Denon for surround sound listening. You will want to set the front speakers to large in your setup menu so you get full range to the Gain Cell Preamp.

Run the Optical audio output from the Blu Ray to the Optical input of the Gain Cell Preamp for use with 2 channel music. You would leave the HDMI hooked into the Denon for surround sound use.

Your turntable can connected to the Gain Cell Preamp with the USB output or the line level connections using the turntable’s built in phono preamp.

You then would connect the preamp outputs of the Gain Cell Preamp to the inputs of the amplifier you would be using to power your main left and right speakers. You could your Onkyo, or get a PS Audio power amp or two. (trade in the Onkyo like I said in my first post.) This would also allow you to use the balanced outputs from the Gain Cell preamp to your power amp. Setting you up for the next decision:

You never said if your subs are passive or active.
You would need to figure out how you wanted to run your subwoofers. If you get a power amplifier with balanced inputs, you could use the single ended outputs for the subwoofers, or the opposite if your subwoofers have balanced inputs. You could also run the subwoofers via speaker lever if your subwoofers can do that, and the subs have their own amplifiers.

I will send a proposed diagram


#14

Here is the system diagram if you cannot open it thru PS Audio.


#15

hlg3, thanks so much for your detailed response. I think I may be getting a little closer to understanding the situation, even after a couple of Manhattans. Seems you have delved into my system layout and have come to some of the same conclusions I have, with some good additional ideas.
After reviewing the Onkyo info, it seems if there is an input thru the multichannel analog inputs, as I now have the l/c/r speakers connected, it bypasses any signal processing ( I am assuming the Onkyo DAC) via what they call Direct audio and just passes the audio signal it receives. So, I think the improved effect of the SGCD should be realized.
You mentioned I could run the surround speakers with the Denon, which I do now, and that now uses 8 of the available amplifiers. Did you get to 9 by including the center speaker? I now run the center with the Onkyo, but I guess I could change that back to the Denon, makes sense.
Next, I agree, " Run your front preamp outputs from the Denon into one of the analog inputs of the Gain Cell Preamp/DAC, and set that input to Home Theater Mode. This will provide a “pass thru” so you will only use the volume on the Denon for surround sound listening." I also agree with your suggestions re: the Blu Ray and TT options.
Then, connecting the SGCP to the Onkyo via the audio Multichannel inputs would allow a clean input to the Onkyo amp as I described in the beginning, I think. Then, your suggestion of trading in the Onkyo for a PS Stellar 300 amp is intriguing. However, it ups my $ output by about 1K. Need to think how I can justify that to the better half…
But, more important, and I thought of this earlier as I was wading thru this scenario, how do I accommodate the subs in both stereo and HT applications. Both subs have onboard amps (HSU STF-2 and VTF2 Mk5) and are now controlled by the Denon via the subwoofer pre-outs. Still don’t see how to access the subs in both Stereo and HT applications. That may be a sticking point. Obviously need them in both applications. Any additional thoughts there?
Anyway, hope this didn’t ramble too much ( I know it did), but I hope I can get this figured out and end up with the next step in a great sounding system. That’s the goal, ins’t it!


#16

Let me explain something a little different way, and see if it helps. All modern sound systems have essentially five major component parts:

  1. source components (turntable, cd, blu-ray or tuner)
  2. digital processor (DAC or surround chip to convert a digital signal to analog for digital sources)
  3. preamp (source switching and volume control)
  4. power amplifier
  5. speakers

A surround sound receiver is #s 2, 3 and 4 all in one box usually including an am/fm and/or a digital tuner. Depending on the connections on the rear of the receiver you may or may not be able to separate these functions. Your receivers have both digital and analog inputs and outputs. They do not have a true power amp input which would allow you to use your receiver as a power amplifier.

Usually, when you use the preamp out for a particular channel, the receiver turns off the internal connection to the related power amp channel so it does not waste valuable power on that amp channel when you are not using it. This allows you to use your receiver as a preamp, bypassing the internal power amps, which are usually the weakest part of the receiver because they are the largest drain on the single internal power supply in the receiver. Most receivers rate there power amps with two channels driven, not all 5, 7 or 9. Your Denon is probably only 70 to 80 watts per channel with 5 or more channels being driven. Denon is not brave enough to publish those numbers. That being said, even the S300 will be a significant upgrade from the internal power amps.

The Stellar Gain Cell DAC is two components in one box, a two channel DAC and a preamp. The Home theater mode is somewhat like the multi channel input on your receiver in that it allows a pass thru mode allowing you to use a single volume control to control all the channels in your surround system, and not having to “match” two volume controls. This is a two channel version of your multi channel input. You are still using the volume control to an extent, but with the way the Stellar is engineered and works, you are minimizing any negative outcomes.

Most multi channel inputs still use the volume control of the receiver to control output. You could test this by playing a movie and ramping the Onkyo volume up and down to see if it is a true pass through, your left, right and center channels will NOT go up and down separately from the surrounds. Try turning the Onkyo volume all the way down, and see if you still get sound through the three front speakers.

Multi channel inputs were developed so you could use the surround output directly out of a blu-ray player that might be more advanced than the surround processor in your receiver. Manufacturers know you will have to change out a disc player more often than your receiver because they are not built to last as long. This is so your receiver does not become obsolete as new surround modes are developed.

Your assumption is correct, you are not using any digital to analog processing in your Onkyo when you use the multi channel input. HDMI, Optical, USB and coaxial digital ins and outs are digital signals and must go through a DAC or Surround Sound chip (Multi channel DAC) before being sent to the preamp and power amp section of your receiver.

By trading in your Onkyo you can still get value from it. You can research PS Audio’s policy on this website and call them during business hours to talk about your specific situation, you might be able to get both at once. The SGCD/ 300 combo might only be a few hundred dollars more than the SGCD alone. You would not be wasting any money, because once you discover what a “real” power amplifier can do for you, you will want a pair of 700’s to drive your front main speakers, you then use your preamp outputs, and move the 300 to other channels such as your rears or bi-amp your center channel (one M700 per channel Left, Center and Right would be the best eventual goal and a S300 per pair of surrounds.)

Now let me address your subwoofer situation, now that I know what you have. Since you have two different subwoofers, you should not use them in a left and right stereo pair configuration with your main speakers. You can use one of them (the better one) for the low frequencies on your left an right main speakers a couple of different ways. For both connection methods you set the surround sound set up on your Denon to full range main speakers, which will send a full spectrum signal to the front outputs.

You can then either use paralleled speaker level inputs from your power amp (Onkyo), or the single ended line level outputs on the SGCD, (essentially what you are doing now) or the balanced outputs would be used once you get a S300 or pair of M700s. You would use both the left and right channel inputs of your subwoofer in either case, not the mono you are probably using now. Paul has a good video on the website explaining his opinion on subwoofer integration.

Any of these configurations will allow you to use a subwoofer in two channel or surround listening situations.
You would use your second subwoofer as the rear channel subwoofer by changing your rear channels to full range, and paralleling speaker level connections.


#17

Thanks for your overall system explanation. As I’ve been going over the set up over and over again I was slowly coming to that understanding. Since I have always used an AVR, I’ve never had to consider how a DAC, preamp, and amplifier interacted and exactly what each did and didn’t do in the system. Now I think I’m getting it.
I think I am leaning toward getting the Stellar DAC/S300 amp combo. I will check to see what a trade-in on the Onkyo is worth.
Now, as to the subs. The Denon has two sub pre-outs allowing it to base manage each individually during the Audessey setup. Looks like I will probably lose that control with the new setup. I’m sure I can probably manage that outside of the Audessey setup. Both subs have a low and high level inputs, but not balanced. So, are you saying I could use the single ended outputs from the DAC to drive the subs? (I would use the balanced outputs for the front speaker amplification) Would I need to get both right and left channel info to both subs, or could one be driven by the right channel, and the other by the left? Also, don’t understand your comment “You would use your second subwoofer as the rear channel subwoofer by changing your rear channels to full range, and paralleling speaker level connections.” By rear channel, do you mean the rear surround channels? Guess I still need to better understand that. Anyway, I’ll see if I can find Paul’s subwoofer integration explanation.


#18

You will have to forgo the independent Audessey setup option fro the subs, so far as I can figure out. the Audessey will still be acting on the overall surround system performance, just no independent subwoofer correction. You would have to set the subwoofer level to match the speaker efficiency, the room correction will take it from there.

This is if you want to use your subwoofer when you are listening to two channel through the PA Audio gear. (which I do recommend). The Denon would be bypassed at that point. Most dual (left and right) subwoofer setups pre-suppose the subwoofers are identical. The room correction is adjusting for room interaction, not overall capabilities. One of your subs is larger than the other, you risk pushing the smaller one too hard in your setup.

You might still be able to use your sub output for the second subwoofer, you would just have to try it. If it does not work, you could do as I described and it will work.


#19

Yes, I definitely want to have both subs operational in both two channel and HT situations. Just read/saw Pual’s comments on subwoofer integration and, per his recommendations, I think I will drive them with the single ended outputs of the S300. So then do I connect right channel to one, and left to the other, or somehow combine the r/l channels to go to both?


#20

That will be a question for the tech folks, class D amps like the S300 and M700 are a little different.

I would strongly suggest you not try to run the subs one on the right, and one on the left. If they were identical, it would work. With two different makes and models it would be impossible to do correctly.
Besides, most folks like more bass impact with the movies than they do with music.

I use two slightly different settings with my sub. Your Denon may allow you to have different settings, but that goes away with the PS Audio.