Blog

I often wondered how amp-producers implements the conversions back and forth from Material (like vinyl or CD) to DRC (like Audyssey, Dirac and Trinnov a.o.) to speaker output.

How many conversions are there?

Material: Analogue or PCM or PDM with various bitspeeds.

Input: what conversion to digital does various amps make?

DRC: How many and from/to what format do Audyssey, Dirac and others use?

Preamps: with volume a.o. what digital formats?

Poweramps: IF a digital amp, then a final conversion to PDM to feed the amp, otherwise a DAC to feed the amp.

How many conversions will that be?? And how much dist will that add?

Why are DRC-vendors so secretive about what format they use for their filtering?

HiFi would benefit from as few conversions as possible. How about a standard for internal use to be used by all? Like PCM 44.1kHz 16 bits for cheaper models and perhaps 192kHz 24 bits for topend. Same software just selected by the amp-producer to differentiate their productlines.

Especially important when several different DRC shows up in the same amp, like Denon, Marantz, Pioneer a.o. which can have both Audyssey and Dirac on the same amp.

What do YOU think?

As choosing the benchmark candidates will be only from whats available in the Swedish market, I have chosen to use the listing in Swedish. If enough many readers request it in English too, by adding a comment below, I might incude that in the near future.

As I see it right now, there are three distinct price classes here, each interesting for the individual person, depending on their budget. The low budget user with an amp up to 16.000:- (SEK) around 1.500USD, The medium budget user with an amp up to about 22.000:- (SEK) around 2.000USD and the high budget user with an amp up to about 35.000:- (SEK around 3.000USD.

Prices are set by the lowest prices google serches would find at the 1:st week of December 2023 and of local offers in Sweden only. Of course widening the search to outside Sweden might produce lower prices. But the prices are to identify the three budget classes, rather than finding the absolute lowest prices. In our case we would rely on local support for the best chances of a smooth and quick start of the testbeds.

The whole idea of investing in good DRC, is to be able to invest less in expensive loudspeakers and physical room treatment to get the same or better end result with a lower budget.

The future test bed would ideally be populated with one amp from each budget category, comparing them with different loudspeaker setups with and without DRC activated.

Also interesting is to compare and evaluate high end DRC – like Dirac – with medium DRC – like Audyssey XT32 – with low DRC – like Audyssey XT and others. Of course with different loudspeakers and music/film materials.

Where we will begin, is depending of what the swedish importers and agents might supply the testbed with, by lending equipment, supported by the international producer o the product hopefully.

A year has passed, I was busy to finish several comittments and business projects, You can read more about what I do in my businessblog at: https://rationellametoder.se/

Now I am ready to put energy into perhaps my greatest interest again. DRC!

I still feel that DRC is the single most valuable component, after the speakers, to make a Hifi-system “sound like a million bucks!”.

Perhaps I will include my knowledge about decision analysis from my business, into a comprehensive tool to decide for each of You out there, what is the best choice for You to improve in a given situation?

My plan is now to get an agreement with suppliers of DRC, to lend me DRC-products to test against each other, to help YOU my dear followers, to choose the best products for You. I will start with finding a supplier that can offer the blog a DRC-multichannel product, that can be the long term reference product that other products will be tested against.

I am contacting serveral manufacturers and their local agents here in Sweden, to that end. It will take some time, but the objective is to get this going sometime in the new year.

The testsituation will to begin with have access to multiple speaker combinations. With everything from two channel Hifi to multichannel cinema setups.

Including, Altec Valencias with Tangerine drivers and JBL 077 added to the tops. Klipsch Palladiums. Velodyne DD18 sub. Kef KHT 2005.2 with Sub, Supreme 28´s a.o. Revox A77 HS with mastertape copies from OPUS3, Nakamichi Dragon, Mitchell Prisma turntable, Kenwood LM07 monoblock amps when other than built in amps are needed.

My first tape recorder bought 1972, the fantastic Revox A77 HS 19/38cm/s two track is to be restored.

It had its magnetic heads replaced for “Revodur-heads” and some components replaced for low-noise by one of two Revox-wizards of Stockholm at that time “Max Weber”.

The machine worked well for a while but was then replaced by a more practical machine, actually a casette deck! The magical Nakamichi Dragon! A dream machine pushing the tiny but practical casette tape into almost the domain of Revox. By dynamic calibration of azimuth, double capstan, three heads, metal tape capabilities and Dolby C.

The Revox was put on hold, for many years. Just took it out of retirement now, only to find that it was not working properly, the treble was way to low and recording did not work well. Could well be electrolytes aging over the 50 years of age of my machine?

So a service visit is planned to the other Revox-wizard of Stockholm “Gerhart Schubert”!

We will see what comes out of that… I´ll be back… like hopefully my old Revox A77!

Waiting for it, will be some master tapes of Opus3 of my friend since way back then Jan-Erik Persson.

Old refined technology will meet modern DRC-electronics and my Klipsch Palladium speakers!