LSA Voyager GAN Amplifier

@viber6 The AHB2 in stereo is not as loud as the mono. It is also supposed to be quieter,  but I could not tell. The reason I got the mono for my Thiels, after a lot of research, including asking the designer, was because the stereo was missing that heft I look in some types of music. I listen to hard rock music occasionally, RUSH, Led Zep, AC/DC, Judas Priest, Moterhead, etc.. This type of music felt lacking with the single stereo. With the mono, the extra volume and additional power made that type of music better than the stereo version. The music that sounded great on the stereo also sounded great on the monos. The monos are worse in 2 Ohm range than the stereo. I used the monos for about a year.

When I got a KRELL K-300i integrated, a CODA CSiB, and a D-Sonic M3a 800s to try on the Thiel and RAAL. l I knew that the AHB2 mono were not giving me the 2 Ohm juice that these speakers needed.

The CODA #8 is the best I have heard the Thiels for all music. The KRELL was also excellent. The Voyager is today a keeper for me. I will get into that more in another post.

I solved the hiss issue and that lead me to upping my appreciation of the Voyager. I actually love the sound from the Voyager now with the changes I made. Next post will describe once I get some more work work completed.

So this HISS is a feature of the CODA 07x (a joke) just like all other preamps I have heard, except the Benchmark HPA4. I wish I did not sell it since I could use it in tandem with the CODA 07x.

I will post part of my email conversation with CODA because I do not want to retype the investigation I did.

Hi,
Thanks for your suggestions. They were very helpful. I am not sure about your “short the inputs” but you gave me an idea on some tests.

1) I disconnected the amps from the preamp and hooked each of them to the speaker
a. Benchmark AHB2 had no noise
b. LSA Voyager 350 GAN has a bit of hiss
c. CODA #8 was a bit louder hiss than the Voyager
The great thing was that the buzz or crackling sound went away.

2) I hooked up my Gustard X26 Pro DAC to the Voyager amp direct and used the volume. It was noisy with hiss as expected and also no buzz or crackling. I expected the same result with the other 2 amps but did not try them.
3) I then hooked up the CODA 07x without any inputs hooked up and there was a bit more hiss with the Voyager but no buzz or the crackling sound. I expected the same result with the other 2 amps and did not try them.
4) I then added my 4 inputs to the CODA 07x, one at a time. The Gustard and the Sony SACD player added some noise but no buzz or crackling. The Benchmark DAC3B added a some noise and a bit of crackling. I did not really hear the buzz. Maybe that happens with playback. So I will ditch the DAC3B from the 07x and use it in another system

I can live with the slight hiss I have now since I cannot hear it from my siting position anymore. It is not dead silent as other people are saying. I think they really do not know what I mean by dead silent. No worries now. Things are working as expected.

Thanks for helping me solve this.

An additional observation

I have an additional data point that you may find interesting. I also have a Topping D90SE DAC. It is very similar sonically to the Benchmark DAC3B. I use is in my other system. I brought it up to my CODA system after the last email and replaced the Benchmark DAC3B on the XLR 07x input. This DAC had the same amount of hiss and the same crackling sound. I then took out the Topping and put back the Benchmark DAC3B on the RCA input. It also has the same hiss and cracking sound. Luckily one of my DACs, the Gustard X26 Pro does not have the crackling sound.

With the DAC3B on the RCA2 input I checked the Gustard on XLR1, the Sony SACD player on XLR2, and my tuner on RCA1. They all had the crackling sound and hiss. When I removed the DAC3B from the 07x RCA2 input all the other inputs had the crackling sound go away, just a bit of hiss.

So unfortunately my needed DAC3B or Topping D90SE will not be used with the CODA 07x. I will improvise a solution with a optical splitter I have lying around.

My Topping D90se and Benchmark DAC3B have nothing wrong with them. So only the Gustard with the CODA 07x. Now is when things get interesting for the Voyager.

I am now dead set on using the CODA 07x and CODA #8 with the RAAL because it is superb and I spend a lot of late nights listening on the RAAL.

The Voyager now needs to step it up to work well with the Thiel. I was testing the Voyager with the Benchmark DAC3B because it is very neutral and does not seem to add anything to the signal. I wanted to just hear the amp. With the CODA 07x, DAC3B, and Voyager I thought the sound was good but could be better. Since the DAC3B was removed from the 07x due to the crackling and likely buzz issue I started using the colorful Gustard X26 Pro with the 07x and Voyager. Gustard is a warm DAC with detail and I believe a Class A output stage (whatever that means).

Now the sound was transformed. I was working on a deadline problem while my ROON server was feeding me a playlist of Classic rock that was appearing for some reason. I knew all the songs and they sounded great. My feet were moving, I was distracted, my work was stretching out longer (I missed the deadline). I just loved, loved this sound I was now hearing. There is one issue still. I feel the imaging on the amp is shifted slightly to the LEFT speaker. I think this is a amp break-in issue (must be 50+ hours now) and will settle to my normal imaging matching the AHB2 and CODA #8.

So happy with this amp now. Not so happy with the hiss, crackling, and buzz (could be a breakfast cereal). However, I am now only left with a bit of normal hiss and a missing DAC3B. Normal hiss for all preamps I know of except the Benchmark LA4 or HPA4.

I wish I had the Benchmark HPA4. still Though I sold the HPA4 for $250 less than I bought it after more than a year of use. I would not replace the 07x. That stays long term, likely forever, but I wound not mind having such a quiet preamp in the mix, especially to bring back the DAC3B.

yyz,
On the Mozart recording, track 1, Concerto 3, at 0:08 there is a very soft slow sniff or possibly a mouth breath in.  At 1:12 there is a louder but still soft sharper sniff.  It is sharper and quicker, whereas at 0:08 it is even softer but more prolonged.  The 1:12 sniff is repeated with the same musical passage at 4:35.  All these sniffs are done after the orchestra stops, and then the sniff is done about 1/2 second before they start again, as a cue.  It is only possible to hear these extremely soft sounds when the orchestra is completely silent.  We cannot hear these subtle sounds of 20 dB if there is background playing at 40 dB or so.  This reminds me of when I hear my car turn signals only when there is little road noise or I turn off the radio.

Let me know if you can hear these sniffs on your main Thiel speakers and RAAL headphones with the different amps.  Don't cheat by playing things too loudly at 90 dB when the full orchestra portions should be about 75 dB.  Headphones can seem only moderately loud at 100 dB whereas room speakers will sound very loud at 100 dB.

ricevs,
When I trialed the Benchmark AHB2 for 1 month, it was quite close to my reference Bryston 2.5B SST2.  At the end of the month break in, the AHB2 was slightly warmer than the Bryston.  Only a guess--the AHB2 was on par with my current Mytek Brooklyn Amp (original version).  My initial reaction to the Rouge was that it was rolled off in HF and fuller in overall sound than the Mytek.  The Rouge still has some variation with the hour of the day, and I think it is evolving for the better.  At 400 hours, I will reconnect my Mytek, re-break it in for a day, and then A/B the Rouge and Mytek.  My Bryston is still king for crispness, although for larger scale music, I need more power, so I am hopeful about your modded Rouge.  I will complete the 400 hours in about 2 weeks, so will contact you soon after that.