Wavelength Proton: can it directly drive power amps?

[cvthunder]

Hi all,

 

I find this site very interesting as I've been starting to play around with my computer as a source. Found the Wavelength Proton on the web and was thinking if it can directly drive a power amplifier (specifically a spare Plinius P10 I have) with acceptable results. I have read the review of Chris on this product but I'm not quite sure if it had acceptable results when it was directly connected to his mac (the amp).

 

Regards,

 

-J

 

 

 

 

[Andrew S.]

only if you are brave!

 

[firefly0071]

I think you mean a pre-amp and then to a power amp.

 

[Audio_ELF]

The OP legitimately means "connected direct to a power-amp" the Proton has a built in analogue pre-amp so can be connected directly to a power-amp.

 

There have been warning that with this setup it **may** be possible to do things on the PC which results in full level white noise (type signal) to be passed to the power-amp which could cause damage to the speakers if not quickly stopped - a pre-amp (or power-amp) with mute or "normal" volume control can give an easy method to stop the signal in emergencies.

 

Eloise

 

[cvthunder]

Nope...my question is connecting it directly to a power amp. Connecting it to a pre-amp is obviously possible.

 

[Audio_ELF]

Quote from Chris' review... "I tried very hard to use the Proton, bypassing a preamp, connected directly to my McIntosh MC275 power amp and Avalon Acoustics loudspeakers, but the volume control scared me a bit. I really like the comfort of a physical mute button incase anything goes awry during a listening session. If for some reason I lost clock and noise was blaring through my speakers (this has happened in the past with other components) I wouldn't want to rely on any software from any operating system to save my tweeters. I did use the Proton through a preamp during the review by setting the computer's system volume around 90% and using the preamps volume control. This is certainly a viable configuration that should work for most listeners."

 

Full review here -- http://www.computeraudiophile.com/content/Wavelength-Audio-Proton-Asynchronous-USB-DAC-Review

 

I get the impression that in a more "setup and left" system, rather than the more experimental / fluid system that Chris has, there would be less potential for problems.

 

Eloise

 

[cfmsp]

 

Andrew,

 

I was a bit reluctant to drive my new J2s direct from ULN-2, but I'm quite comfortable with it now.

 

Frankly, I think the concern is a bit over-rated, while remaining legitimate. In the case of the Proton, Gordon is hooked in to the Volume control of the computer. I've not tried 'hot-rod' with my Proton, but will soon.

 

Personally, it will be quicker for me to click on (volume / play control on) the player, than to jump across the room and turn down the control at the preamp. I've not tried this with the Proton attached, but when running iTunes from a Macbook, just closing the lid will shut things down. Obviously things are a bit more complicated than that for 'headless' operation, which is frankly a bit of an annoyance.

 

As I recall from Chris' review, he was a bit timid on this issue as well.

 

Maybe it's less of an issue for me, as I have a rather low gain (20db) amp.

 

Personally, I think we'll see more and more of this, as people get more comfortable with the idea.

 

clay

 

 

 

 

[Wavelength]

Gang,

 

I do this all the time. When I have other products in and out there is always a Proton on the rack connected to my Lightning VT52 amps and directly to the speakers.

 

I use Rowmote to control the volume and have no problem muting, up or down. The Proton always ramps the volume from one setting to another.

 

This was one of the main reasons for having the volume control work on both the Line and the Headphones. I even have someone who uses two amps one in another room and uses the headphone output to drive that one and a local amp with the RCA connectors. Since the Line and Headphones take separate paths inside it works great.

 

Thanks

Gordon

 

[Guest Claude]

I dont know about the Proton, but I would trust Gordon. I do it with a QB9 directly driving active monitors and the QB9 has no adjustable Volume. I use Amarra Volume Control and a headless mini with rowmote and an Ipod Touch.

 

Claude

 

[cvthunder]

Thanks for all the information above. Hope you guys won't mind I have a few more questions:

 

* If I'd prefer to connect the DAC via a pre-amp, is there a way to disable the computer volume control facility and get a fixed line output? If not, would there be an optimal set-up with respect to the computer volume control and preamp ? (I believe Chris mentioned he had the computer volume control at 90%)

 

* What are the chances that the potentially speaker damaging noise will happen? What are the possible causes? Will I be able to stop it immediately if I take out the USB cable from the computer (it's gonna be within very close proximity from where I will be sitting)?

 

* I've tried to look for more information on the Proton with regards it will handle the input signal after the TAS1020B but can't find any. I understand from Wavelength's site that the other DACs have different DAC chips. In the case of the Proton, which chip is doing the digital-to-analog conversion? Is this an upsampling DAC?

 

-J

 

 

[Wavelength]

J,

 

* If I'd prefer to connect the DAC via a pre-amp, is there a way to disable the computer volume control facility and get a fixed line output? If not, would there be an optimal set-up with respect to the computer volume control and preamp ? (I believe Chris mentioned he had the computer volume control at 90%)

 

Actually the way it works is this... there is an 80 step volume control with basically -74dB as 0 up too 0 at Step 74 and the from 75-80 is all +1dB per step. The reason for this is mainly the 75-80 is meant for use with Headphones were the output will sag a bit due to driving low impedances.

 

So for line use only you want to make sure it is 74 or below which on the percentage side gives you about 90%.

 

* What are the chances that the potentially speaker damaging noise will happen? What are the possible causes? Will I be able to stop it immediately if I take out the USB cable from the computer (it's gonna be within very close proximity from where I will be sitting)?

 

Why would there be any noise? The only annoying thing is if you happen to put alarms and such through the dac which becomes annoying but nothing is going to be any louder or harmful than what you are doing with the rest of your system.

 

* I've tried to look for more information on the Proton with regards it will handle the input signal after the TAS1020B but can't find any. I understand from Wavelength's site that the other DACs have different DAC chips. In the case of the Proton, which chip is doing the digital-to-analog conversion? Is this an upsampling DAC?

 

DAC chips don't really do upsampling that is usually required by another silicon part. The DAC chip in the Proton is from the Wolfson family and is capable of 24/96 operation with a headphone and line output. Both outputs on the Proton are taken from the headphone output as this has volume capabilities. It is also the only port that is phase true and actually sounds and runs better than the line port. The heaphone output at the dac is split into the line output using Mundorf Capacitors and the Headphone output goes through the famous Black Gate BGN capacitors.

 

If you have specific questions it is easier just to send me an email and I would be happy to answer them. If you post here I may miss what you are asking.

 

Thanks

Gordon

 

 

[Audio_ELF]

It was asked and (partially answered)...

* What are the chances that the potentially speaker damaging noise will happen? What are the possible causes? Will I be able to stop it immediately if I take out the USB cable from the computer (it's gonna be within very close proximity from where I will be sitting)?

 

Why would there be any noise? The only annoying thing is if you happen to put alarms and such through the dac which becomes annoying but nothing is going to be any louder or harmful than what you are doing with the rest of your system.

 

I think the noise that is being referred to is reports that with Media Monkey (I think it was) loosing it's mind (my words) and outputting white noise ... this was discussed by Chris in his "Audiophile Reference Music Server" thread about 14 months ago so may not now be an issue. The relevant paragraph (towards the end of the Windows XP section) is below...

 

As with everything in life, nothing comes without a price or possible pitfall. This music server does have the capability to produce white noise that will blow every tweeter connected to the amp. In a limited set of circumstances the music server will lose clock and spit out this white noise. Some events know to cause this problem are adjusting the buffer settings in MediaMonkey while playing back music. Another possible problem can arise when changing the name of the currently playing track. This often causes a stutter in the playback, but can lead to loss of clock -> white noise -> blown tweeters. To me this is a scenario that is self inflicted and can be avoided 99.999% of the time. When listening to music don't make changes. I have yet to hear of any problems when changes are made at the appropriate time. This is certainly no guarantee but I'd be 100% comfortable using this reference music server keeping in mind the information provided here.

 

Eloise

 

[cvthunder]

Can I assume then that the Proton does not perform any upsampling?

 

 

[cfmsp]

As far as I know, the Proton does not use any gratuitous upsampling (commonly known as Asynchronous Sample Rate Conversion, or ASRC for short), which is mostly only used to 'reduce' (and I use that term loosely) jitter by DAC manufacturers who cannot lower their jitter specs in ways that do not have a negative effect on the sound.

 

I have one, sounds great.

 

clay

 

 

 

 

 

 

[Wavelength]

CV,

 

No there is no up or resampling done on any of the products. You can do this on the computer if you wish. But in most cases it sounds best native.

 

Thanks

Gordon

 

[cvthunder]

Hi Gordon,

 

Thanks for all the information about the Proton. Really appreciate you sharing all this information. While I was doing some more readings and giving it some thought, I found out from the the Stereophile website that you are coming up with the WaveLink. I decided to hold off my plans to purchase a Proton. The Wavelink might be the ideal solution for me as my Cyrus DAC-X already have a good synergy with my existing system. So instead of buying the Proton *blind* (I'm overseas with no access to a demo) to get hold of your async USB implementation, I'd probably wait for the Wavelink. In the meantime, I'd be getting an Apple TV to get started on using a computer as a source and enjoy the music.

 

-J