DX32 with Prime I/Os

[Hugh]

Do any of our readers or contributors have hands on experience with these latest and greatest I/O options from A&H. The DX32 with Prime I/Os were announced two years ago but for unknown reasons very little input from anyone is available pursuant to the A&H projected sonic improvements in real world every day use.
Hugh

[RS]

Contact Drew (FoH for Billie Eilish), he is using them on a regular basis. (That is, when there is concerts 😢)

[Brian]

The lack of reviews isn’t because they are bad. I think everyone that uses them has high regards for them. They are just very expensive and probably not within the reach of many.

[KeithJ A&H]

@Hugh –

Val had a session with well respected orchestral engineer Ian Barfoot late last year where the PRIME cards were discussed (available to watch here – https://www.youtube.com/watch?v=3IMfPzpZ4v4 )
The whole thing is really interesting, but PRIME chat starts at around 17mins.

You mention when the cards were announced (originally April 2018! – https://www.youtube.com/watch?v=nMMYZmCYrzk ):
But after years of R&D work and our announcing them, we then decided they still weren’t quite good enough so didn’t actually release them until a few revisions and almost 2 years later when we were certain they were the ultimate preamp/output modules we could produce (even to the point where we have to tweak every preamp by hand with a trim pot to allow us to adjust for tiny component tolerance ranges)…
So they were finally released at the beginning of 2020… just before everything stopped for a while…

Like @Brian says, they’re also more expensive than other modules as the design team was effectively told to concentrate on the audio quality and only on the audio quality.

Cheers,
Keith.

[volounteer]

@KeithJ A&H

Really?
There is no way to design that quality, so the tweaking is not needed?

Learn me please.
I thought that was possible since the 1960s if money was a key factor.
Now with custom ICs and DIGITAL I find it harder to believe.

If you say it is in the AD/DA circuits then I would agree that custom parts might not do what you want,
but surely you all can do your own designs to get around the tweaking and still have better quality.

On a side note, who wants quality these days?
That was the only goal when I started in the 60s.
Now everybody seems to want to add distortion and other problems to get that old time sound.

[Hugh]

Thank you again Keith for once again answering my question, The absence of information is linear with world performance conditions and the understandable tweaking that occurred. While the price point may be a bit less than three times that of a DX168 we should also remember, if the prime cards are actually as good as advertised, they are a fabulous quality/value option when compared to the going prices paid for boutique two channel pres that do not come close to the announced Prime performance parameters.
Cutting edge technology is never cheap and only when the advances are integral to a given protocol can they be justified. I have decided to pull the trigger on a DX32 with two input cards and one output card. I will report back to the forum whether or not the performance improvements justified the additional investment.
Hugh.

[KeithJ A&H]

@Hugh – No problem! Look forward to hearing your thoughts.

@volounteer – Distortion does not necessarily mean a bad sound and the distortion characteristics of FET’s, tubes/valves and transformers are often wanted because they can ‘thicken’ a signal through the addition of extra harmonics. These harmonics can also imply frequencies which you can’t hear, so with bass for example, you might want to add distortion to enable lower root notes to be ‘heard’ on systems that can’t reproduce them (e.g. mobile phones).
(We looked at how the Tube Stage Preamp achieves this in a facebook live stream here – https://www.facebook.com/112696882086203/videos/193637605577449 – sig gen’s and scoping starts at around 15mins)

Once a signal is distorted or frequencies have been lost it’s pretty much impossible to get back to the original signal, so our approach with the XCVI core as well as our preamp design is to provide a full but very clean/transparent base signal, which you can then choose to add to or mess with as you like. Giving you the full range of options.
The PRIME design takes this to the nth degree and we aimed for the modules to act like a ‘piece of wire’. That is, the preamps are the opposite of vibey/retro/fat – they are designed to capture exactly what you put into them (with respect to frequencies/transients etc…), amplify without altering the signal or adding noise and then converting to digital at high resolution to send back to the console.
The outputs were a necessary addition, because we quickly realised there was almost no point in getting such high quality in if you couldn’t then get that same quality level of signal back out.

Where the tweaking comes in is because each preamp is balanced, so to get the best response possible, both paths need to be perfectly aligned i.e. the whole thing must be completely symmetrical.
I should note too that each preamp is analogue, just digitally controlled and with digital conversion on board.
Even with the highest precision, lowest tolerance components there will be minute differences and it’s not possible (or at least not 100% reproducible) to just design this out.
Weirdly for such a new product then, we had to go back to the pretty old-school method of trim pots to squeeze out the last performance benefits we could.

Excuse the slight rant, but that’ll learn ya for askin! 😉
Cheers,
Keith.

[volounteer]

@KeithJ A&H

I am unconvinced that you can not design it out, if as you said cost was not a limiting factor.
Trim pots were old school. But these days we have better ways to do things and avoid the problems those pots bring.
And avoid the costly effort to tweak them just so.

While some people like distortion , I prefer to avoid it completely.
To me all distortion is bad sound. YMMV

You say it is impossible to design things out.
I say for you it is impossible because you have not seen how to do it yet.

[KeithJ A&H]

@volounteer – As you dislike distortion and are aiming for the purest sound, the PRIME modules are perfect for you!

[volounteer]

@KeithJ A&H

I would agree with that !!

The last 60 years was a struggle to get rid of distortion and noise problems, not add any in.
Now new people have burned out their ears with their using ear buds 24×7 blasting at 100dB+
and the old people have nostalgia for their old 78s if not their wax cylinders and how they sounded,
so they want everything to be degraded that way.

BUT
I disagree on the tweaking not being able to be designed out.
So I deduce you find it easier & cheaper to tweak than to take the effort to design so that it is not needed. Or else your engineers are stuck in a box and can’t figure out how to do it.
And I note that if you only use old methods while ignoring all the advances in technology then you would have more problems doing that to avoid all tweaking.

[Andre S]

Hi volounter,

soundengineers want to get rid of UNWANTED distortion. Not all signal distortion is bad. But maybe distortion is a bad word for a desireable effect: the addition of harmonics. Those help a signal to sit better in a mix and be heard better by adding a nice compression effect and overtones. Those make it easier for the human ear to “detect a signal”.
And as always: the dose makes the poison (I hope the german phrase translates well into english).

Cheers,
André

[Dave Meadowcroft]

@volunteer
Balanced audio has 2 sides to the signal swinging around 0v. To get absolutely pristine reproduction of the input then both sides need perfectly matched components both in values and that behave identically throughout their working temperature ranges.

To get these ‘off the shelf’ is pretty much impossible as even the highest quality components are specified to certain tolerances therefore trimming is required to correct these minor differences. Grab a good quality multimeter, a handful of high tolerance resistors of the same value and measure them – you won’t find 2 that are identical.

In most cases this is not really necessary so long as both sides are reasonably close, but the whole point of the Prime IO is to be the absolute best they can be so A&H have gone to these extremes to deliver.

So, it’s not a question of designing out but correcting for differences due to component manufacturing tolerances.

[RS]

And every high quality audio gear I have opened up, uses some sort of trim to adjust for production tolerances. So a trim is more likely a sign of quality to me…

[Hugh]

I finally managed to get the DX32 Prime card system MSRP info and the differential for 16 in 8 out is 9 times greater that the current street pricing of a DX168. @ $287 for each input channel — More than likely I will order only one input card and one out put card with the DX32. I have two additional questions: 1) Will there be a problem matching up the tweaking of additional Prime cards if needed in the future. 2) Given the unusual “custom” nature of these cards how stable is the current price point.
Hugh

[KeithJ A&H]

Hi @Hugh ,

1) The trim pot is only used for final adjustment, so it’s ‘set and forget’ with the setting part carried out during build with a scope. I only mention it as a quirk to explain the extent we went to for quality, you do not need to be concerned about it and we certainly wouldn’t suggest adjusting it in the field!

2) As with all products, pricing can change, though I would only ever expect it to be because of the market or something like taxes/tariffs rather than anything relating to the nature of the cards.

Thanks,
Keith.

[Author]

Posts