GaN Amps - Anyone heard one?

[57gold]

Saw this one announced:

 

https://orchardaudio.com/shop/ols/products/strkrmsn-str-ltr

 

Certainly not a fancy case, but pretty powerful and not very expensive.

[John Hughes]

I've heard good things about them.  I ordered one from the Presale.  I'll be comparing it to my VTV Purifi Amp.  These are very comparable amps, so it will be interesting to see if I like the Starkrimson enough to keep it. 

 

https://vtvamplifier.com/product/vtv-amplifier-stereo-purifi-audio-1et400a-amplifier/

[RickyV]

39 minutes ago, John Hughes said:

I've heard good things about them.  I ordered one from the Presale.  I'll be comparing it to my VTV Purifi Amp.  These are very comparable amps, so it will be interesting to see if I like the Starkrimson enough to keep it. 

 

https://vtvamplifier.com/product/vtv-amplifier-stereo-purifi-audio-1et400a-amplifier/

Would certainly like to know the results of that comparison. What input buffer did you choose on the vtv amp?

[John Hughes]

My VTV has the Sparkos SS3602.  I chose this because the designer said it sounded the most like tubes :).  I really do love the VTV amp, I think its a giant killer and an amazing value for the money.  I just can't pass up the chance to hear what a good GaN design can do.  Both amps have the same Hypex power supply. 

 

The Starkrimson uses the OPA2211 on the input.  I don't know if this is swappable. 

[RickyV]

If I look at the pictures of the units it does not look like the OPA2211 are swappable.

[opus101]

OPA2211 is only available in SMD packages, making it extremely unlikely to be a swappable item.

[John Hughes]

That is too bad! I did some searching on that op amp.  Many threads said it was good, not great.  Also saw some threads that said that designs are really tuned to work well with some opamps, and that the OPA2211 can be a great part in the right design.  I rolled op amps in a few headphone amp designs.  That can definitely be useful.

 

[opus101]

I am sure its a great opamp but that doesn't mean it'll be transparent enough subjectively, that rather depends on implementation.

 

For example - given its a very low noise bipolar device it needs a very low impedance feedback network so as not to add extra noise. Driving a low impedance load with a classAB output stage (which pretty much all opamps have) results in additional noise on the supply lines. Depending on the PCB layout that noise could be coupled into the ground reference.

[John Hughes]

Beyond my understanding!  Have you seen the somewhat technical discussion here?

 

https://www.audio “science” review/forum/index.php?threads/starkrimson®-ultra-amplifier-modules-250-500w-into-8-4ohm.23518/

[opus101]

Yes the designer of the 'Starkrimson' modules hangs out there and he's quite responsive to questions about measurements. But on ASR you're unlikely to find subjective listening comments since the belief there is you can only trust your ears under scientifically controlled conditions.

[John Hughes]

I got my shipping notification for the Starkrimson amp today!  Will take a while, its coming first class mail across the country. 

[orchardaudio]

On 7/5/2021 at 6:31 PM, John Hughes said:

I got my shipping notification for the Starkrimson amp today!  Will take a while, its coming first class mail across the country. 

 

Looking forward to your thoughs.

[orchardaudio]

On 6/24/2021 at 5:45 PM, John Hughes said:

That is too bad! I did some searching on that op amp.  Many threads said it was good, not great.  Also saw some threads that said that designs are really tuned to work well with some opamps, and that the OPA2211 can be a great part in the right design.  I rolled op amps in a few headphone amp designs.  That can definitely be useful.

 

 

OPA2211 is essentially the same as OPA1612 with better DC performance. This is extremely important as the amps are DC-coupled you want as small as possible DC-offset on the output.

 

On 6/24/2021 at 1:25 AM, opus101 said:

OPA2211 is only available in SMD packages, making it extremely unlikely to be a swappable item.

 

With the right equipment and skill it is doable, these om-amps have a blind thermal pad which makes them tricky even for SMT soldering by hand. Otherwise I agree with you these are not swappable.

 

[John Hughes]

I got my Starkrimson today.  

 

I did some volume matching in my room with my VTV Purifi amp using white noise and Roon EQ levels so that everything should be matched within 1 db.  I used White noise and a SPL meter.  The level between the two amps was only about a DB anyways. Using balanced connections. 

 

Upon firing it up with music, cold, it sounds very similar to the the VTV.  If I wasn't listening closely I wouldn't hear a difference. After an hour, I do hear a difference, more powerful bass, possibly a darker background.  This will be fun. 

 

I won't be able to do real listening till next weekend.  

[RickyV]

6 minutes ago, John Hughes said:

I got my Starkrimson today.  

 

I did some volume matching in my room with my VTV Purifi amp using white noise and Roon EQ levels so that everything should be matched within 1 db.  I used White noise and a SPL meter.  The level between the two amps was only about a DB anyways. Using balanced connections. 

 

Upon firing it up with music, cold, it sounds very similar to the the VTV.  If I wasn't listening closely I wouldn't hear a difference. After an hour, I do hear a difference, more powerful bass, possibly a darker background.  This will be fun. 

 

I won't be able to do real listening till next weekend.  

Can you let the amp burn-in with continuous music playing? I think it will help.

[John Hughes]

I have an extensive burn in process :)

[57gold]

OK JH, two weeks in, how do they sound?

[John Hughes]

So, I have spent a lot of time comparing my current VTV Purifi Amp and the Orchard Audio Starkrimson. There is at least 300 hours on it by now. This was a difficult process.  I ended up listening to one for 24 hours and them switching and listening to the other.  That seemed to give each amp the time to impress. 

 

There is a lot of similarity.  I have a balanced system, and used the XLR connections.  I matched the amps levels with pink and white noise.  The Orchard was only about 1db less than the VTV.   Both are extremely quiet.  On my 100db efficient speakers, I can barely hear a hiss coming from my supertweeters with my ear up against them.  They also have a very quiet background with music, letting micro details and subtle cues come out of the music.  Midrange is very natural and clear and without harshness, they are about equal with midrange, which is one of their great strengths. The Orchard sounds very slightly cleaner, but that might have more to do with the treble.

 

In midrange they both excel, beautiful open uncolored midrange.  The Orchard does sometimes capture slightly more tone colors than the VTV on some recordings.  Things like oboes or clarinets and cellos can sound just a bit more woody and liquid.  

 

The bass is good with both.  The Orchard really pumps out bass energy with a really good foundation.   Even more than the VTV which is extremely good in that area too.  If you like prodigious bass and to have your foundations rocked, the Orchard is the way to go.  My system is clean down to about 25hz or so.  The Orchard had more grunt on the bottom.  But, the bass was just a bit rounded, not really soft, but the leading edge wasn't quite there. The VTV had more bass slam, more taughtness, more leading edge.  Stand up bass had more pluck, drums had more skin. But this wasn't a really big difference.  I preferred the Orchard on dramatic movies, and the  VTV with music. 

 

And here comes the big difference.  Treble, air and extension.  The Orchard always sounded smooth and clean but I gotta say, a bit polite, and dark.  This also contributed to a more recessed soundstage.  If a recording had a voice that was further down in the mix, it was cast a few feet behind the speakers.  On the VTV that same voice would be cast about even with the speakers.  But with music that projects music into the room, like trumpets or bells or cymbals, the VTV does this virtual reality thing puts them in the room in a very vivid and 3d way.  The Orchard does not.  When a track has bells or cymbals, things that shimmer, the Orchard was just missing that life.  Not in a way that I noticed it by itself, but in comparison to the VTV it showed. There were definitely pieces of music that sounded great on the Orchards - really nice and clean,  But when I switched to the VTV  I was noticing those elements like cymbals, bells, air that were missing with the Orchard. There was just so much more jump, air and convincing projection.  It's the area above 4K or so. I tried adding in EQ in Roon to the treble above that frequency and I was not able to retrieve that lost detail or sparkle. 

 

This is where I had a struggle. Because there was a cleanness to the sound with the Orchard that I did love.  But I wonder if that was because the upper treble was scrubbed away? I thought about how I could mod it to bring back that sparkle with silver wiring, fancy capacitors etc. But ultimately, I don't think the Orchard is for me. 

 

If you like the music to start at the edge of your speakers and go deep to the back wall, but not to project in front of your speakers, this is probably a good fit. That's not what I look for.  If you have dynamic, brash,  rock and roll speakers like some big Klipsch horns, this might be an extremely fun combination, filling out the bottom end and sweetening the treble. 

 

If you like transparency, air, brilliance to your sound, it might not be your ideal fit. 

 

I really liked it.  But I'll be sending it back. Now if I can get a hybrid?

 

[MarcelNL]

does one amp have negative feedback, or more, than the other? IMO it's almost impossible to compare components in different circuits unless the design is similar.

[orchardaudio]

3 hours ago, MarcelNL said:

does one amp have negative feedback, or more, than the other? IMO it's almost impossible to compare components in different circuits unless the design is similar.

To my understanding the Purifi amps have 75dB of loop gain. My amps have 31dB. That is a very large difference in the amount of negative feedback.

 

[RealityTunnel]

I found this looking for a review of the Orchard amp.

 

Sounds like I might prefer the Orchard. In my experience, overtly prominent treble, as described regarding the Purifi amp, is often distortion mistaken as detail. I note from measurements that the Orchard is much lower distortion in the upper frequencies so that may be what’s going on here.

 

Or maybe not, but I prefer smoother high frequencies in any case, so might give the Starkrimson a try.

[davide256]

6 hours ago, RealityTunnel said:

I found this looking for a review of the Orchard amp.

 

Sounds like I might prefer the Orchard. In my experience, overtly prominent treble, as described regarding the Purifi amp, is often distortion mistaken as detail. I note from measurements that the Orchard is much lower distortion in the upper frequencies so that may be what’s going on here.

 

Or maybe not, but I prefer smoother high frequencies in any case, so might give the Starkrimson a try.

It looks promising but there are no professional reviews of it yet, just 1 lightweight review by Dagogo of the streamer. Hopefully someone will do a more useful

review in the future that compares the Stereo Ultra to other known amplifiers.

[RealityTunnel]

3 hours ago, davide256 said:

It looks promising but there are no professional reviews of it yet, just 1 lightweight review by Dagogo of the streamer. Hopefully someone will do a more useful

review in the future that compares the Stereo Ultra to other known amplifiers.

According to the Google Drive link in this post -

 

https://www.audio “science” review/forum/index.php?threads/starkrimson-mono-the-absolute-sound-budget-product-of-the-year-2021.28912/post-1007725

 

- it’s one of The Absolute Sound’s Products of the Year. So it seems they have been given a professional review now…

 

[edit: sorry tried a couple of times to add the link as a hyperlink but it’s not working editing it on my iPhone…]

[57gold]

https://drive.google.com/file/d/1AYGmLtWPrmmCgPD6zcIbjQxzIHzChfhV/view

 

Believe this link will take one to the AS review of the monos.

[John Hughes]

I have ordered the Atma-Sphere Class D Monoblock Amps.  This is a 100 watt GaN amp with a novel design.  Ralph Karsten has spent 5 years designing from the ground up, it does not use the any pre-built modules, but his own circuit.  It has a linear power supply, yet each amp only uses 5 watts at idle. Coming from one of the most respected tube electronic designers, I have high hopes that this will be something special.