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Orchard Starkrimson Ultra

Mike Hanson

Mike Hanson

Trying to understand...
I've mentioned elsewhere that my friend has very hungry PMC MB2se. Prior to getting the speakers, he was running a series of Avondale amps (NCC200 stereo, NCC220 dual mono, NCC300 dual mono, SE200 dual mono). The SE200 wasn't able to drive his speakers, so I built an SE400 and an Orchard Starkrimson Ultra. We tried both, the the Orchard was substantially more capable.

The amp that I built for him used Orchards custom SMPS modules, plus the optional capacitor piggyback modules. The insides looked like this:

SMPS-Complete-Inside-Overhead.jpg

https://avzine.com/images/Orchard/SMPS-Complete-Inside-Overhead.jpg

The SE400 is still working nicely in my office (driving the Ergo IX), but I decided to build another Orchard amp for my main system (between the Cary SLP-2002 tube preamp and Klipsch Cornwall IV speakers). This time, I wanted to try one with a linear supply, just to see if there would be a different.

I asked Leo of Orchard how much capacitance he would suggest, and he said between 45,000 and 60,000µF per rail (2-4x any prior build). Fortunately I had a bunch of screw-terminal caps kicking around, so I collected/ordered the necessary parts:
  • Enclosure from AliExpress - My prior builds all used Modushop Pesante and Dissipante cases, but I decided to try something different.)
  • Orchard Starkrimson Ultra (pair)
  • Neurochrome ISS (intelligent Soft Start)
  • 1000VA with 4 28V secondaries from James Transformer
  • Avondale FWB2 rectifier (pair)
  • Kemet Capacitors (Screw Terminal: 8 15,000µF and 4 13,000µF) for a total of 43,000µF per rail
  • 1µF Ceramic caps (4), for bypass near the Kemets
  • Nichicon 4,700µF through hole caps (4), to be attached at the power inlets on the Starkrimson boards
  • 0.1µF PPS caps (4), for additional bypass at the inlets
  • Various connectors
    • IEC power inlet with fuseholder
    • Neutrik balanced XLR (as the Starkrimson is a balanced amp)
    • Neutrik SpeakON (my preferred output)
    • Keystone Binding posts (connected in parallel with the SpeakONs)
    • 1/8" female for 12V trigger input
I suspect the bypass caps will do very little, but I had them on hand, so why not? 🤷‍♂️
 
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To keep the connectors for the FWB2 modules up close to the secondaries and capacitors, I mount them on tallish standoffs:

1-SWB2-Post.jpg
 
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The Starkrimson Ultra modules have parallel power input connectors. I believe this is so that stereo amps can be wired with power from the supply to the first board, then to the second. In this case, though, I'm using the extra connectors for the additional 4,700µF electrolytic and 0.1µF PPS bypass caps:

4-OrchardPower.jpg
 
500w amps into speakers with 102db/w sensitivity? Hope your neighbours share your taste in music... Looks like a neat build.
 
Tw99 said:
500w amps into speakers with 102db/w sensitivity? Hope your neighbours share your taste in music... Looks like a neat build.
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I won't ever use all of those watts with the Cornwall, except as headroom. ;) Regardless, I've tried many amps with this speaker, and this one sounds the best by far.

My friend with the initial SMPS version is visiting in a couple of weeks, and he's bringing his amp. We'll do a head to head to see whether SMPS or linear supply is better. He can return home with whichever one he prefers.
 
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Fergus said:
You’re a better man than me! I just like to tease them mercilessly when I have something better.
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I already know that the SMPS version sounds utterly fantastic with my speakers, so I won't be suffering if I have to keep that one. His speakers are a far heavier load, so he needs whichever one does the better job.

Given my speakers are very efficient, there is a chance that it will make one amplifier seem better but perhaps not the same when on his speakers. We'll cross that bridge if we come to it.

I do have other speakers in the house, but none that are anywhere near as hard to drive as his. We may try that to add confidence to our findings, once we've compared the amps using the Cornwall.
 
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A bit of a class D agnostic here, curious though about the outcome of smps vs. linear psu with the Starkrimsons..
 
geoturbo said:
A bit of a class D agnostic here, curious though about the outcome of smps vs. linear psu with the Starkrimsons..
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My experiences with earlier Class D designs seem to align with others: they are very accurate and articulate, but ultimately rather cold and unengaging.

The Orchard (and probably other GaN FET amps) seem to be turning the tides, with the newer designs being more enjoyable overall. Compared to the Modulus-686, the Orchard is similarly clean and controlled. However, the Modulus-686 didn't grab my attention and make me want to dance, while the Orchard definitely did. 👍

I'll let everyone know the results of our power supply comparison.
 
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Mike Hanson said:
My experiences with earlier Class D designs seem to align with others: they are very accurate and articulate, but ultimately rather cold and unengaging.

The Orchard (and probably other GaN FET amps) seem to be turning the tides, with the newer designs being more enjoyable overall. Compared to the Modulus-686, the Orchard is similarly clean and controlled. However, the Modulus-686 didn't grab my attention and make me want to dance, while the Orchard definitely did. 👍

I'll let everyone know the results of our power supply comparison.
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Mike, it is interesting to note that Purifi have not adopted GaN FETs in their class D modules even though they clearly could if they wanted to. Despite all the talk of higher switching speeds and less dead time etc, Bruno and Lars have both said GaN FETs actually offer no inherent advantages over other FETS in a class D amp. Its worth searching out what they have written and spoken about on this subject.
 
Sorry I am trying to learn, what in the hand full of components on that board which is what a credit card size makes it 1000 dollars?
 
Well I have been following the Purifi story for a while now and on several occasions I nearly made the decision to do a Purifi build. But after reading numerous reviews I felt that whilst these amplifiers approach near technical perfection there was enough people saying these amps lack just a little when conveying the emotion of the music. People would talk about not liking the sound with the standard input buffer, swapping to custom buffer boards to get the sound they were looking for. etc etc Have a look at the reviews on the VtV web site and you'll see what I mean. That was enough to put me off.

What I like about the Starkrimson is people are saying they moved over from valve kit and 'weren't disappointed'. Now thats what I like to hear.

The point is for me I don't really give two hoots about the technology it's the sound that matters. From what I can see both measure pretty much close to perfection. But the StarKrimson is a much simpler build, doesn't need a buffer board and runs off a single power supply. Bruno and his team would say that about the competition, tech people always say their own tech is best in my experience.

That plus also hearing Mikes experiences was why I also purchased a couple of these boards too. Mike has beaten me to it with his posting, my post will follow shortly. And like Mike I've gone for a linear PSU.

Here's hoping I like what they do as so far I've been firmly in Class AB camp :)
 
garyi said:
Sorry I am trying to learn, what in the hand full of components on that board which is what a credit card size makes it 1000 dollars?
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Yes your right they are not cheap.

But in the same ball park as similar modules, Avondale NCC300 , Modulus 686, Purifi ET400 are a few that come to mind

To be fair to Orchard Audio is a single man operation, small volumes etc.

If it sounds great it's money well spent in my book. I'm about to find out
 
I wasn’t saying anything against GaN FETs or indeed Leo’s amps. I was simply reporting what 2 extremely clever people have said about the use of those FETs in class D amps. If they believed they offered inherent advantages then I’m sure they would have used them in the Purifi modules. Maybe they are wrong, but I think you’d be a brave man to bet on that.
 
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