Quest for the Best Amplifier

[Mike Hanson]

Now, these are the numbers about 2 ohm and 1 ohm loads.

Whether this is in fact relevant to big PMCs is another argument entirely - I get it! We can discuss it technically. But then there's listening - I try never to question subjective impressions so if someone says it's not relevant in their particular set up, then it's not relevant.

- The Orchard figures into 2 ohms are here: https://orchardaudio.com/starkrimson_ultra_500w_specs_and_test_results/. Should double from 500W to 1000W into 2 ohm, but instead halves again to 500W - this is why I said into 2 ohms "it doesn't blow up" but that's all.

- Bryston 14B-SST a little better but really similar story, last sentence from JA "The clip point into 4 ohms was just over a kilowatt (27dBW), but the amplifier was running out of grunt into 2 ohms, with 720W available at clipping (22.6dBW)." https://www.stereophile.com/content/bryston-14b-sst-power-amplifier-measurements

- To be fair the Hegel H600 mentioned, looks to be a legit muscle amp! And it's an integrated, I'm impressed. Doubling all the way to 2.3kW into 1 ohm.

Hegel H600 Network-Attached Amp Lab Report

Lab Report Hegel's dry wit is illustrated by the very precise '2x303W into 8ohm' specification for its H600, a figure met in practice at 2x315W and 2x600W into 8/4ohm, respectively. These numbers are largely unchanged from the outgoing H590 flagship [HFN Oct '18] as is its near-identical dynamic...

www.hifinews.com

@MattSPL can chime in directly here perhaps with his impressions, which I think are more recent than mine (mine are based on older PMC/amps).

These numbers are interesting, but I doubt the PMC impedance is dipping that low, and if it does, it would be for a very small frequency range, so not a major concern. Having heard the amp, I'm concerned even less.

I was surprised that the Hegel didn't sound better than it did. I was a good amp, bettering the SE400, but well short of the Orchard.

 

[Mike Hanson]

I have the Starkrimson Ultra modules and initially ran them off a Hypex supply and was quite impressed when compared with Naim 135's , Hypex NC500's and my Hackernaps.

One of the reasons I bought them was that I knew there would be potential to improve them with work on the power supplies. The boards have on board voltage convertors for +/- 12 v for the analogue input stages and a single rail for the driver stages. I replaced the Hypex SMPS with an RCore transformer per channel with 45000uF of capacitance per rail which brought about an improvement. Then I replaced the on board SMPS convertors (which are fed from the main power supply rails) each with completely separate supplies with ALWSR's. This brought about the very greatest improvement and may well be an amplifier end point for me. The Starkrimson amps aren't cheap but very well put together and can be improved with additional DIY if you are happy to invalidate the warranty (three PCB tracks have to be cut).

John

Very interesting! I'm about to start on a second dual mono build for myself, using a big 1000VA toroid with 4 secondaries, and 60,000µF per rail. I didn't realize the input stages could take a separate supply, so I'll ask Leo at Orchard about that.

 

[john.luckins]

I wouldn't expect Leo would recommend such hacks of his masterpiece, and a certain amount of reverse engineering is required, but the line regulation and noise of the DC to DC converters he used though good for such devices, is poor compared with completely separate supplies including transformers. Ground/0 volt return currents of the main supply can also modulate the smaller supplies. PM me if you want details of what I have done.

John

 

[OzBrit Audio]

I have the Starkrimson Ultra modules and initially ran them off a Hypex supply and was quite impressed when compared with Naim 135's , Hypex NC500's and my Hackernaps.

One of the reasons I bought them was that I knew there would be potential to improve them with work on the power supplies. The boards have on board voltage convertors for +/- 12 v for the analogue input stages and a single rail for the driver stages. I replaced the Hypex SMPS with an RCore transformer per channel with 45000uF of capacitance per rail which brought about an improvement. Then I replaced the on board SMPS convertors (which are fed from the main power supply rails) each with completely separate supplies with ALWSR's. This brought about the very greatest improvement and may well be an amplifier end point for me. The Starkrimson amps aren't cheap but very well put together and can be improved with additional DIY if you are happy to invalidate the warranty (three PCB tracks have to be cut).

John

Very interesting John

I've just ordered my transformers today for my mono block build. I've just emailed Tiger Toroid to add a 12-0-12 secondary

So tell me what improvements did it make to the overall sound?

And do you find the Orchard that little bit lacking in tonality that that Mike described in his review. Do you have a valve pre driving the Orchard?

And how much improvement did the linear supply make over (presumably) the Hypex SMPS?

 

[OzBrit Audio]

Now, these are the numbers about 2 ohm and 1 ohm loads.

Whether this is in fact relevant to big PMCs is another argument entirely - I get it! We can discuss it technically. But then there's listening - I try never to question subjective impressions so if someone says it's not relevant in their particular set up, then it's not relevant.

- The Orchard figures into 2 ohms are here: https://orchardaudio.com/starkrimson_ultra_500w_specs_and_test_results/. Should double from 500W to 1000W into 2 ohm, but instead halves again to 500W - this is why I said into 2 ohms "it doesn't blow up" but that's all.

- Bryston 14B-SST a little better but really similar story, last sentence from JA "The clip point into 4 ohms was just over a kilowatt (27dBW), but the amplifier was running out of grunt into 2 ohms, with 720W available at clipping (22.6dBW)." https://www.stereophile.com/content/bryston-14b-sst-power-amplifier-measurements

- To be fair the Hegel H600 mentioned, looks to be a legit muscle amp! And it's an integrated, I'm impressed. Doubling all the way to 2.3kW into 1 ohm.

Hegel H600 Network-Attached Amp Lab Report

Lab Report Hegel's dry wit is illustrated by the very precise '2x303W into 8ohm' specification for its H600, a figure met in practice at 2x315W and 2x600W into 8/4ohm, respectively. These numbers are largely unchanged from the outgoing H590 flagship [HFN Oct '18] as is its near-identical dynamic...

www.hifinews.com

@MattSPL can chime in directly here perhaps with his impressions, which I think are more recent than mine (mine are based on older PMC/amps).

I think the 250W into 2R is a limitation of the SMPS power supply not the an actual amplifier module. Orchard quote a maximum current at 20A which maybe be peak but that equivalent to 800W into 2R

 

[john.luckins]

I find the Orchard to be more neutral, precise and transparent after the PSU improvements with lower background noise and the maintenance of the separation and tonality of instruments, particularly piano and vocals, when things get busy and loud. The differences in acoustics and depth between recordings and even between tracks on the same albums are much more evident. It is also sounds much better and no less satisfying to listen too at lower volumes, in fact my wife never asks me to turn it down or up these days as she used to as the clarity is very consistent and engaging whatever the volume. On Tuesday I will start a thread in the DIY room on my modifications to the Starkrimson to answer some of the incoming questions.

John

 

[OzBrit Audio]

Really good discussion Mike

We don't get enough talk on this forum on peoples listening impressions especially when it comes to amplifiers. I think it all helps when people are trying to make there decisions on what to do next.

Yes listening impressions are subjective. One mans meat etc etc but how else do we start when making our decisions?

 

[Mike Hanson]

Really good discussion Mike

We don't get enough talk on this forum on peoples listening impressions especially when it comes to amplifiers. I think it all helps when people are trying to make there decisions on what to do next.

Yes listening impressions are subjective. One mans meat etc etc but how else do we start when making our decisions?

I think it takes a good while for one to develop a sense of what they're hearing. It starts with a simple, "I think I (dis)like that," and hopefully develops into the ability to consciously discern the many elements mentioned in my opening post.

Any reasonable person will continually critique their objectivity, and look for confirmation from measurements and other listeners. Unfortunately, measurements don't tell the whole story, and everyone perceives things differently, so we're always left second guessing to some extent. Regardless, I do think it's a skill that can be learned and improved, but never perfected

If we are convinced of our satisfaction, then that's the most important thing, because we have a chance at contentedness. Then we have to remind ourselves that our solution may not solve others' problems, but our experience might. So, we share our stories here and hopefully learn from one another.

 

[Cesare]

I'm interested in where the 200w requirement comes from. PMC themselves suggest 10w as a minimum.

I think people have an idea that large speakers are like large cars (or trucks) and that you need a large engine to move the mass, and therefore you need a large power amp to drive large speakers. It's actually the exact opposite, large speakers are efficient and have low power requirements, it's the small speakers you have to be wary of

Anyhow, back to PMCs. They used to sell lots of Bryston amps to partner their offerings in studios, and so that's pretty much the starting place. Lots of studios use 3bs and 4bs, but also I seem to recall seeing lots of chord 1032s as well, so that's probably another option to consider.

For studio use, the idea is to have a totally neutral, reliable, workhorse amp on these main monitors, and the above are good examples of this. I think the approach is sound. Don't expect sparkle and something magical from the power amp - buy for linearity and control of the speakers.

For the sparkle/distortion you want, choose the front end + pre to provide this. Mix and match is fine, so a valve pre adding distortion and warmth matched to a pair of brystons/class D wonders feeding studio monitors allows you to get the sound of the pre into the room without it being played with. This also makes it much easier to think about matching, as basically only one component is adding the character you want, and the rest of the components are neutral.

 

[darrenyeats]

I would say people misunderstand big *amps*. They think they are going to sound slower and bigger. The opposite is true, when a speaker is hard to drive, a big amp sounds nimbler and the sound seems *quieter*. Some people perceive it as duller and even call it lifeless but quieter is what actual dynamic range sounds like (to the contrary a "big bold" sound is compression). A similar thing happens when speakers are activated. People often say the sound only comes to life at higher volume. That's because the microdynamics and plankton is all there, it's suddenly just at a much lower level than the peaks! The very definition of true dynamic range.

I see this even here where the listeners reported the Hegel was nimbler (compared to the fastest of the other amps) and somehow smaller. This is IMO a typical initial reaction to hearing a properly gripped loudspeaker. It's worth perservering at such a moment though, I see this as a moment to look for improvements elsewhere (perhaps even another amp BUT one that grips similarly, and/or sundry other changes) - the potential for a better end result lies this way IMO.

So this thread has reinforced my existing views. We can each choose to read the same information in our own way! Anyway I shall try not to rain on this parade longer.

 

[music fiend]

I do agree that not properly driven speakers tend to sound as if "on edge" and when properly driven it's almost as if music slowed down and became more natural/ organic.

 

[darrenyeats]

I do agree that not properly driven speakers tend to sound as if "on edge" and when properly driven it's almost as if music slowed down and became more natural/ organic.

The problem as always is multiple processes are occurring and they can in some ways compensate for each other. The end result is what counts which is why technically better X doesn't always give a better end result (unless Y and Z other changes are also made).

 

[music fiend]

The problem as always is that there multiple processes occurring and they can in some ways compensate for each other. The end result is what counts which is why technically better X doesn't always give a better end result (unless Y and Z other changes are also made).

Yes, I agree. Amp+Speakers should always be looked at as a unit. And they are never meant to play in an anechoic chamber.

 

[Beobloke]

Energized air

Just to be say, if your amplifier successfully manages ‘energized air’, I’d switch it off and stop using it immediately…

 

[Mike Hanson]

I'm interested in where the 200w requirement comes from. PMC themselves suggest 10w as a minimum.

I think people have an idea that large speakers are like large cars (or trucks) and that you need a large engine to move the mass, and therefore you need a large power amp to drive large speakers. It's actually the exact opposite, large speakers are efficient and have low power requirements, it's the small speakers you have to be wary of

Anyhow, back to PMCs. They used to sell lots of Bryston amps to partner their offerings in studios, and so that's pretty much the starting place. Lots of studios use 3bs and 4bs, but also I seem to recall seeing lots of chord 1032s as well, so that's probably another option to consider.

For studio use, the idea is to have a totally neutral, reliable, workhorse amp on these main monitors, and the above are good examples of this. I think the approach is sound. Don't expect sparkle and something magical from the power amp - buy for linearity and control of the speakers.

For the sparkle/distortion you want, choose the front end + pre to provide this. Mix and match is fine, so a valve pre adding distortion and warmth matched to a pair of brystons/class D wonders feeding studio monitors allows you to get the sound of the pre into the room without it being played with. This also makes it much easier to think about matching, as basically only one component is adding the character you want, and the rest of the components are neutral.

You noticed that 10 watt minimum spec. I think that is inconsideration of the target audience for this particular model. That large number would scare off many people with home systems, who have much lower powered amps. Also, many home systems could have tube amps, and 10 watts of tube power can be more significant.

Note that there is a studio version of the speaker that's almost identical, but it's minimum indicates 200W, IIRC.

 

[darrenyeats]

[*]Dr. Lonnie Smith “Paper Tiger” – This has loads of bass from the organ pedals, many extreme percussive elements, and the Hammond needs to have an intense tonal complexity when the Leslie starts to spin. Rhythmically it has the primary elements, plus a long loping gate that often doesn’t come through in lesser systems. If it sounds sleepy, then its a fail.

When it started I almost rolled my eyes, seemed like a "audio show" recording. Then the hammond kicked in and the piece musically took off like a rocket! Lovely.

Enjoyed the rest of the songs too. Thanks.

 

[Hooch500]

Ive been watching the development of GaN devices in domestic amps since I read about them a few years ago. I tried a Hypex based amp a few years ago, loved the idea of power without the weight and heat, but ultimately found myself listening less and less. I've probably circled around with solid state and valve designs several times since I first built a valve amp at the tender age of 14. I went through a period about a decade ago of building them again, SE, P/P etc and always enjoyed the build - some of them sounded pretty good too. My scope packed in ages ago and I really don't have the time anymore and they are quite time consuming to build. I've never actually built an SS amp, just changed out caps, trannies, boards etc.

I've had good results with a valve pre and SS power, so I'm looking at a project soon. If anyone up North has a Neurochrome or similar I'd be interested to hear from you as given the outlay would like a listen first.

 

[wainwj]

Haven't heard my PMC's with Bryston, but immediately prior to buying them I heard them with the latest Chord integrated.
The dealers room appeared to be far more appropriately sized than my own and the sound was good enough to convince me to take them. Regardless of this though they sound massively better to me powered by my own high current, high class A biased amps.
Not huge watts but plenty of wallop behind them.
Far, far more to my preference that the Chord combination.

 

[OzBrit Audio]

People on here talk about using valve preamp or a buffer in this case to 'add distortion' to get the desired sound. I don't think that is the case, I Think it's more complicated than that.

A well designed valve pre or at least a simple gain unity gain valve buffer as used in Mikes example above should have very low THD, certainly well below the audible threshold. I while back I had a Woo Audio headphone amp capable of putting out over 1W. It used a single valve and total THD @ 1W was < 0.01%. It sounded sublime btw and I wish I never sold it.

I think putting the valve buffer in the chain to achieve the desired sonic signature is not about 2nd harmonics. This maybe true for many valve power amplifiers which generally produce much higher levels of THD but at lower power level valves are much better behaved!

 

[Columbo]

Ive been watching the development of GaN devices in domestic amps since I read about them a few years ago. I tried a Hypex based amp a few years ago, loved the idea of power without the weight and heat, but ultimately found myself listening less and less. I've probably circled around with solid state and valve designs several times since I first built a valve amp at the tender age of 14. I went through a period about a decade ago of building them again, SE, P/P etc and always enjoyed the build - some of them sounded pretty good too. My scope packed in ages ago and I really don't have the time anymore and they are quite time consuming to build. I've never actually built an SS amp, just changed out caps, trannies, boards etc.

I've had good results with a valve pre and SS power, so I'm looking at a project soon. If anyone up North has a Neurochrome or similar I'd be interested to hear from you as given the outlay would like a listen first.

I had the Technics SU-R1000 for a short while, which is a Class-D GaN. I was more than impressed and may have kept it over my Hegel except that it put out a little too much heat for my sauna of a room (which surprised me for Class-D). Would like to circle back to GaN at some point.