Archive: DPA T1 and Bigger Bit

Digital Delight

By Michael Jones

July 2004 (first appeared August 1993)

DPA T1 CD transport, $2800. DPA Bigger Bit D/A converter, $2650

A decade ago, separate CD transports and converters were the choice of many audiophiles. DPA had an interesting take of producing a CD transport – by entombing a complete CD player inside DPA’s own chassis. This review first appeared in the print version of AudioEnz in August 1993.

 

First formed in 1980, Deltec Precision Audio (now reformed as DPA) have become one of the more interesting of UK hi-fi manufacturers. While DPA began in amplification, over the past three years the firm has gained fans, sales and fame for their digital-to-analog converters. Here we look at the Bigger Bit D/A converter ($2650) and its new accompanying transport, the T1 ($2800).

Why two boxes?

Two box CD players can have many advantages – at least in theory. Seperating the various component parts of CD playback, both physically, electrically and in terms of power supply interaction.

A two-box CD player is not inherently superior in sound to a good single box player, at least in the more “real world” areas of the marketplace that this magazine addresses. For example, I have heard a number of transport/converter combinations that are sonically inferior to a good one box player.

It’s a similar situation to that of amplifiers. Merely separating the preamp and power amp sections of an amplifier does not (necessarily) sound better than a well designed, well engineered integrated amplifier.

DPA claim a few tweaks for their transport and converters. Their main areas of concern are RF (radio frequency) noise suppression and jitter. For the former they use thick aluminium for shielding and RF decoupling between the digital and analog parts of the Bigger Bit. For problems caused by jitter, DPA developed a synch-lock facility called Deltran.

Construction

The T1 transport would have to be the largest and ugliest CD transport or player I’ve laid eyes on. Large in size (460 x 500 x 120mm) the T1 is short on aesthetic appeal.

Continuing the rounded theme established with previous DPA models, the T1 has a 3mm thick aluminium chassis and cover. The front panel is 10mm thick aluminium, again with rounded corners.

The front panel has a cut out on the upper right, for access to the player controls. Only the basics (open, play, pause, stop, previous, next, fast reverse, fast forward) are on the T1.

The rear contains the (by now) standard CD player connection of audio and digital (both coaxial and optical) outputs. Plus the Deltran connections.

Lifting the lid on the T1 was very interesting. For entombed inside the T1’s large chassis is a complete Marantz CD52 mk2 compact disc player!

Many CD players are based on Philips source items, so I had better explain just what I mean by complete. I’m not referring to just the disk drive, nor am I referring to just a Philips-sourced printed circuit board. Inside the T1 was a whole Marantz CD player, complete with the rear panel with its outputs, and a sticker on the back of the Marantz identifying it as such!

The reason for the large size of the T1 was clear – it had to enclose an existing CD player. Even the distinctive rounded front panel of the Marantz appeared to have been left on, with the DPA’s 10mm front panel attached to it with double sided sticky tape.

There had been a couple of changes from the basic CD52 mk2. The Marantz headphone board was gone, and the D/A converter (a Philips 7350) had been removed from the underside of the main PCB. A spare space in the right rear of the Marantz now housed the Deltran board.

DPA say that changes have also been made to the power supply. However I could not see any differences in this area between the Marantz and the T1.

An $1800 increase in price over the Marantz CD52 mk2 ($1000 in New Zealand) seems a little over the top for DPA’s changes.

In contrast, the construction of the Bigger Bit is all original and very tidy. A smaller unit (197 x 278 x 74mm) the Bigger Bit has a solitary LED on its 10mm thick aluminium front panel. The rear of the Bigger Bit contains the usual audio outputs and digital (coaxial and optical) inputs. Next to the optical input is another optical connection, labelled Deltran Output. This output enables the T1 transport’s digital output to be controlled from the Bigger Bit.

Inside, the bigger bit is immaculately constructed. Surface mount components are used, giving a different and tidier look than many electronic components. The bigger Bit uses the Philips DAC7 (or 1547) chip for digital-to-analog conversion, fed from a Philips 7350 chip. DPA claim that careful attention has been paid to earthing, power supply regulation and RF decoupling between the digital and analog sections.

Operation

Setting up the T1 and Bigger Bit takes a little more time than is normal for a CD player or two-box player. Besides the connection between the transport and converter, the Deltran connection (a standard optical cable) has to be made. The transport, converter and Deltran switch all have to be turned on in the right order to get it all working.

Using the PDA combination from the remote control is the same as any Philips-based CD player (the remote is the same as comes with the CD52 mk2). I like remote controls – I wish my preamp came with one – and operated the T1 from the remote for much of the time.

However, I also use a CD player from the front panel and here I found things that I did not like. Unless the T1 transport was placed very high, it was difficult to see the controls in the cut out. Using these controls wasn’t helped by the lack of tactile feedback. Often I had thought I had pushed the right button, only to find that nothing had happened.

The 10mm aluminium panel that Marantz has stuck to the front of the Marantz can make it difficult to load and remove CDs. A “lip” over the CD caused by this panel caught many of my CDs.

With the Bigger Bit tuned on, TV reception of Channel One was degraded. While the picture degradation was not huge, it is curious that this should happen at all. After all, it has never happened with any other CD player I’ve reviewed. Even worse, if a CD was player while Channel One was one, the picture was degraded to the extent that it was unwatchable. Curiouser and curiouser.

Sound

I may have my doubts about some aspects of the T1’s construction, but I have no doubts about the sound of the DPA combination. It’s magnificent!

Just about every CD player I’ve heard has a residual grain or hashiness about the sound. Sometimes its almost subliminal, but comparison to something better shows that it is there.

The DPA combination, when using Deltran, is the most hash-free CD player I’ve heard. Electronic artefacts to the sound vanish, leaving music without hash, electronic glare or grain.

There are “audiophile” CD players that attempt to reduce grain by smoothing over the sound, making the music “inoffensive”. This also takes all of the excitement and life from the music, swapping one form of distortion for another. The DPA combination does not do this. Music from the DPA is alive, dynamic, exciting and all the other adjectives from my well-thumbed thesaurus.

That the DPA combination can achieve this sense of life without becoming hard, harsh or irritating is quite an achievement.

The sense of clarity and being able to hear into the music was stunning. An example: Dvorak’s Serenade for Strings tosses the theme between a number of string groupings. With the DPA combination, the various string combinations were clearer than I’ve heard them in the past, without sounding unnaturally separated.

That’s one of the interesting aspects of the DPA. It does not sound “analytical” (good, as this is a distortion of reality) yet the combo displays a wealth of information, arranged in a way that concurs with reality.

Soundstaging information is very well portrayed. The independence of images from the speaker boxes while using the DPA combination was stunning. A realistic sense of depth (where images were clearly differentiated, yet integrated into whole) made listening to well recorded classical discs most rewarding.

The only area of criticism was the lack of authority to the bass. Compared to CD players with hefty power supplies, the sense of weight to the sound, when appropriate, was diminished.

The above comments relate to the use of the Deltran connection between the T1 and the Bigger Bit. Removing the Deltran connection noticeably degraded the sound, becoming homogenised, less interesting and involving. The results were still very good, but I’d be surprised to find anyone preferring the DPA combo without Deltran.

I also compared the T1 with two CD players used as a transport. Unsurprisingly, the Marantz CD52 mk2 sounded identical to the T1 (without Deltran). My Sony CDP-777ES used as a transport was less successful than either the T1 (no Deltran) or Marantz as a transport into the Bigger Bit.

Conclusion

Despite the somewhat dubious parentage of the T1 transport, it in combination with DPA’s Deltran sync-lock and Bigger Bit converter delivers the goods sonically. The combination offers a superbly transparent, emotionally involving sound that I would be happy to live with.