[musicdre]

  Do they make good, or any, tube amps with the kind of power you’re looking for?

a tube amp with 150wpc+ would be a behemoth boat anchor, run hot as hell, cost a fortune to re-tube and be besides the point.  tube amps are about a burnished, glowing sound, not about massive power outputs.  they dont really compete with ss amps - each has their own pros and cons.  imho anyway.

PS i love tube amps and the new ss (gan fet, ncore, purifi etc) amps.

[catluck]

Musicdre - words of wisdom.  And, your list doesn't include the often troubling spitting, hissing, etc., of one tube just not wanting to play nice with the other tubes in the sandbox.  And, not that it's a sonic issue but the ridiculous inefficiency of tube amps is bothersome to me.  But, more importantly, as I've noted, GanFets now seem to be closing the gap to glorious, "burnished" tube sound such that it becomes ever more difficult to justify the wastefulness associated with tube gear and this coming from a dyed-in-the-wool tube guy for at least the last 30 years. Consider this quote from   Michal Jurewicz (head engineer at, and founder of, Mytek) when discussing the need for faster Mosfets,


"...but it's not yet 100% what could be accomplished. For a better squarewave you need power transistors called GaN-Fets.  It's a game changer for class D. In the next few years we will see examples of class D proving to be the best sounding amplifier technology with the use GaN-Fets..." (Stereophile, May, 2021, Vol.44, No.5)

Far as I'm concerned, we're already there.  Note the descriptors used by those on this thread who actually tried a GanFet product albeit not mono's and maybe not XLR.  Using monos and XLR to take best advantage of the kit may not provide the pleasurable distortion spectra of tubes but, well, the little 5 lb.., 300 watt, MiniGans continue to sit atop the 100 lb., 845 mono space heaters, figuratively and literally, which have remained silent since I started listening to the MiniGans.

[newzooreview]

Far as I'm concerned, we're already there.  Note the descriptors used by those on this thread who actually tried a GanFet product albeit not mono's and maybe not XLR.

I received a pair of Mini Gan 5 monoblocks from Class D Audio on Monday. They are in the system now, breaking in.

After some e-mail with Class D Audio, they offered to install WBT speaker posts (WBT-0708Cu) that I purchased and had shipped directly to them.

As they were building out the amps, they received a batch of updated boards. The production sticker on the bottom of the amp indicates they are version 5.3. Class D suggested in e-mail that the improvements were small gains in sound quality and in power for the monoblocks. I would not know what "small gain" means or whether one would notice in an A/B comparison.

The MG5-monos (picking a term to avoid confusion with generic GaN amp discussions) had the LEDs dimmed by Class D at my request. They are still too bright for evening listening. If I keep them, I will put some removable black circles (e.g., computer camera blocking vinyl stickers) over the power buttons. I can't fathom why blazing blue LEDs are put in equipment that will be used in low light settings, but it's not a problem unique to the MG5-monos.

They are solidly built with formed steel cases. Unfortunately the cases are ferromagnetic. This seem like an even more dubious choice than the LEDs. At least with the WBT binding posts there is nothing ferromagnetic directly in the signal path. I can't inspect the interior due to the "voids warranty" sticker over one of the case screws, but the copper wire should be directly soldered to the copper binding post that is well insulated from chasis.

They get just a bit warm. One is sitting on 1.5" risers above the other and neither of them is very warm. The chasis  is well ventilated, but they don't seem to generate much heat anyway, as expected.

The jumpers came set at the medium gain level. I left them there since low gain is only 2 dB less. I might move them to low gain if I keep them, since the M3 Sapphires do not need much gain from the amp.

I have them connected via Anticables Level 5.2 XLRs to the Holo Serene KTE preamp.

Hopefully this will give me an idea of the optimal sound available from Class D Audio at the moment. Once I have 200 hours on the MG5-monos I should be able to share realistic impressions. I measured the dB of my Pass Labs XA-25 with a couple of test tones and dialed in the MG5-monos to the same +/- 0.5 dB levels, so I will be able to  compare apples to apples.

[genjamon]

Looking forward to your impressions, NewZoo, even if not a “review.”

[catluck]

NewZoo - looking forward, like others, to your thoughts on sound quality.  I also just ordered another pair of upgraded monos.  As you noted, Tom indicated that the distortion specs, already claimed to be .006% were not much impacted but that available power is increased. Tom wrote,

"The difference with the new monoblocks is in the case of your amp, we use one beefed up channel from the Mini 5 amp, and the new version we're actually are using two channels paralleled. What this means is more power and a little cleaner. You will most likely notice the power, but your current amps are already at .006% THD_N so no noticeable difference there....  Everything will probably sound a little better believe it or not!  maybe it's just me, but I seem to be hearing little micro details I never heard before... could just be my imagination, but they sure sound great!"

We'll see. For certain I continue to hear details on cd's I'm intimate with on the M3's, having had them for about 19 months, that I didn't hear prior to the MiniGans (and using XLR/monos identical to the current set-up). Should be receiving the new upgrades tomorrow.  If they do sound better I'll ship my current pair back to Tom for upgrade as well.  Again, looking forward to hearing your thoughts.

[lazbisme]

OOPS! another monkey wrench tossed  into the decision making process!! Definitely looking forward to comments on the "new" GAN5 monos".

[newzooreview]

Looking forward to your impressions, NewZoo, even if not a “review.”

New Zoo Revue was a weird children's show back in the 70s. Two hippies and a life-sized frog, owl, and hippo (more hippies in costumes, I think). They had events and interactions and sang songs. When I was a kid sick with a fever on the couch at home on a school day it all made sense.

When signing up for AudioCircle a long time ago I randomly decided to use that as a forum name. But I botched the spelling. Then people thought I was some kind of audio reviewer. So it goes.

[genjamon]

And the rest, as they say, is history. As father to a four year old, I really enjoyed hearing the backstory. Sounds like a pretty fun show.

[catluck]

NewZoo - Tom wrote the following and asked that I post it so here goes,

"Please mention on the thread that it's not recommended to leave the amps on all the time as they actually run a little warmer when just idling. These amps don't require really long break in times like some other equipment. Also, just so they know, since the upgrade we have to raise the prices of these to $1535.00 for the pair and will do so Saturday as these just cost more to make. These are already the best value in audio today and by a far margin. We'll also be listing single mono amps."

Like the M3's, these amps, IMO, sit at the inflection point where better performance costs multiples of their purchase price.  And that doesn't mean that you'll necessarily find any speaker or amp that does everything better than either the M3 or the MiniGans.  But we breathlessly await New Zoo's comments.

[Sp33ls]

Real interested to hear your impressions on the GaN5, newzooreview, especially how they compare to the XA25.

I'm new to this forum, so I can't search yet. But, I'm curious if any Spatial Audio owners have paired SA speakers with some FirstWatt gear, like the SIT-3.

I'm looking at the X4's as my next speaker purchase (and one which would hopefully last me for a very long time,) and I fell in love with the sound and value of these high-end DIY builds. Especially those using the rare and legendary VFETs (designed specifically for audio.)

When I was in school, I actually worked in a nanotech lab where we "grew" GaN transistors, amongst other things like photovoltaics. Pretty neat stuff.

I may end up grabbing one of these GaN amps to use in summer months and/or when I want to use the speakers but don't want the Class A sound/heat.

I agree with Mr.Big earlier on in this thread. It is indeed nice to have the ability to swap amps based on mood. Keeps things fresh (and prevents the gear treadmill.)

Can't wait to read some more X4 reviews too.

[RonN5]

Just saw this… who is going to take the plunge?

https://www.usaudiomart.com/details/649902973-atma-sphere-class-d-monoblocks-like-new/

[Early B.]

Just saw this… who is going to take the plunge?

https://www.usaudiomart.com/details/649902973-atma-sphere-class-d-monoblocks-like-new/

This is impressive. I'd love to hear how they sound.

[RonN5]

Good price… they are getting favorable reviews on Agon.

[orchardaudio]

Orchard Audio offers a trial period as well but with a restocking fee.

Thank you for giving my amps a try.

Please note this "restocking fee" only applies when you make a purchase using PayPal. This is because Paypal does not refund credit card fees when I issue refunds.
If you make a purchase using the other payment methods there are no fees, you are only responsible for return shipping.

This is outlined in my return policy here:
https://orchardaudio.com/refund_return_policy/

[Early B.]

Well, I said I wasn't gonna do it, but I tried anyway and failed....

I attempted to compare the Mini GaN5 to my VTV Purifi amp in my main system, but the ultra-cheap binding posts on the GaN5 had holes too small to accept banana plugs (actually the male side of the tube connectors). I can tolerate them on a secondary system, but if the GaN5 was on my main system, I'd rip out those binding posts.

[newzooreview]

but if the GaN5 was on my main system, I'd rip out those binding posts.

Yeah, the only reason I decided to try Mini GaN5 monoblocks was that they offered to install WBT binding posts if I sent them a set. Their stock e-bay binding posts with output wire soldered to foil-thin metal bits made out of who-knows-what are a terrible choice.

The intense, piercing blue LEDs, even when "dimmed" are also a bad choice. It's in a frequency range near UV that makes it very distracting. The amp needs a dim and off toggle switch for those.

I think it is admirable to keep costs to a minimum. Maybe a "Plus" version could be offered for folks who don't mind paying a bit more for decent binding posts, an LED dimming/off switch, a gain selector switch instead of bare jumpers dangling out of the back, output wiring of known quality and composition, and casework that is not ferromagnetic. The XLR connector seems to be hard-wired to the board, so using at least a good quality neutrik there vs. the current e-bay part (at least by appearances) would have to wait until the next batch of boards is made. The RCA connectors are also super cheapies.

I also wonder about the statement that the amps should be turned off when not in use because they are less efficient when idling. So far the Mini GaN 5's have been running 85% of the time, so I haven't left them on idle for more than an hour or two. But they get only mildly warm. My XA-25 gets almost too hot to touch. The XA-25 draws 250 watts at idle and is biased to be just barely tolerable when putting your hands on the heat sink.

With the Mini GaN 5 getting just barely warm, what is it that is at risk if it is sitting idle? This risk is not mentioned in the manual, so asking someone to forward a comment about it to one audio forum also seems bizarre. If this is an issue, then the manual should be updated and an e-mail sent to existing customers. An explanation of the actual risk would also be helpful.

So far, there is definitely break in happening. It's at 75 hours. I understand that the capacitors are smaller in GaN amps, due to the needs of to circuit, but I'm still thinking that a basic 200 hour break-in will be a fair starting point for drawing conclusions. It won't hurt to be safe, I think.

[genjamon]

All good thoughts, Newzoorevue. I’ve been considering buying one to try in place of my Odyssey Kismet stereo amp that’s on my TV system, but the comment about needing to turn it off when not listening has given me pause. The reason the odyssey works so well for my TV purposes is that I never have to turn it off and it’s ready to go whenever spouse or child want to use the TV.  If they had to turn it on and off on their own, There would be no end to the grief and troubleshooting requests I’d get when things didn’t work right. Klaus is emphatic to leave it on 24/7 if possible, so it’s a good fit on that front. I thought with Class D, leaving on 24/7 would be even less of an issue, given the cool running and lower power consumption.  Guess not.

[Early B.]

I think it is admirable to keep costs to a minimum. Maybe a "Plus" version could be offered for folks who don't mind paying a bit more for decent binding posts, an LED dimming/off switch, a gain selector switch instead of bare jumpers dangling out of the back, output wiring of known quality and composition, and casework that is not ferromagnetic. The XLR connector seems to be hard-wired to the board, so using at least a good quality neutrik there vs. the current e-bay part (at least by appearances) would have to wait until the next batch of boards is made. The RCA connectors are also super cheapies.

Wow. That "Plus" version you described would easily double the price and it would only yield a nominal sound quality improvement. Probably not a good business model, although I'd be willing to pay $10 more bucks for better binding posts.

 

[Early B.]

All good thoughts, Newzoorevue. I’ve been considering buying one to try in place of my Odyssey Kismet stereo amp that’s on my TV system, but the comment about needing to turn it off when not listening has given me pause. ...  I thought with Class D, leaving on 24/7 would be even less of an issue, given the cool running and lower power consumption.  Guess not.

Don't let that discourage you. Sounds like BS, but I'd suggest speaking to the seller to get more details on the risks of leaving it on. 

[newzooreview]

Wow. That "Plus" version you described would easily double the price and it would only yield a nominal sound quality improvement. Probably not a good business model, although I'd be willing to pay $10 more bucks for better binding posts.

The set of 4 WBT posts cost $175.90 with shipping. However, there may be a better $10 no-name alternative for the binding posts they are currently using. I just decided to get something that matched the posts on my M3 Sapphires.

A lot of audio companies offer a "special edition" of their equipment for folks who would like it. It seems to be a successful business model, in fact. The "special edition" is often about 30-50% more expensive, targeting the most beneficial upgrades for that sort of additional cost.

I think the updates I was listing were as much about usage/operation as about sound quality. I have no idea whether the binding posts are improving the sound compared to the stock ones because I don't have both options to compare.

In any event, break-in continues and the sound quality will be what matters.