Service: Behringer DEQ2496 modification.
Supplier: Audiosmile - UK
Approx cost: *169 GBP + VAT (17.5%) (this includes return shipping costs to anywhere in the UK)
Reviewer: Nick Whetstone - TNT UK
Reviewed: February, 2007
There is no doubting that the Behringer DEQ2496 is a very useful tool to both the professional musician and the hi-fi enthusiast, but it is generally agreed that it is not quite audiophile quality. I own one but only ever use it through its digital input and output, keeping well clear of its own input and output circuits. Most people using a DEQ for serious hi-fi will be using its digital output into an external DAC. Others have carried out various modifications to the input and output circuits, but that is only feasible if you have the know how and skills. Now, any owner of a DEQ2496 can have the output section of their equipment modified by Simon Ashton of Audiosmile. Simon claims the modifications vastly improve the sound quality of the DEQ, in fact good enough for it to stand as a high quality DAC, albeit one that can perform a lot of other tricks as well through the digital sound processing.
This is from the Audiosmile web site:
"The AudioSmile modifications remove the entire standard output stage from the signal path. The audio signal is taken directly from the output of the high quality DAC chip and passes through only one resistor (with a capacitor in parallel) and a single transformer. The components used are of the highest quality - the transformers are made in England specifically for audio use, and the resistors are 0.1% tolerance wire-wound."
"The resistor and parallel capacitor form a simple 1st order low-pass filter which reduces ultra-sonic noise from the DAC. The transformer serves a duel purpose by summing the differential output of the DAC, significantly further reducing noise, as well as removing DC from the audio signal."
In short what Audiosmile are doing is to remove a complex circuit built from cheap components and replace it with an ultra simple one using top quality components, in this case the output transformers. As they explain, that is the way top-quality hi-fi used to be made before the accountants took control, and transformers gave way to opamps for reasons of cost, both purchase price and transport, the transformers often weighing as much as the rest of the equipment.
So how does all this work affect the sound quality of the DEQ2496? I should mention the modifications in no way change the appearance of the DEQ although it is quite a bit heavier. I initially connected up the review sample in my second system. Fed by my modified CD723 through its digital input, the output was taken to my valve pre-amp and then to a Charlize amplifier powering my IPL A2 speakers. Comparing it to my stock DEQ2496, there is a clear improvement. The sound is more transparent, has slightly more detail and better controlled bass. It produces a 'large' sound. By that I mean that elements of the music appear large, somehow more 'out of the speaker'. If I had a criticism of the sound, it was that on some tracks it sounded a little too much, too 'in your face'. This may have been a combination of the DEQ and my home-brew valve pre-amp because using a passive pre amp, this did not occur. I therefore carried out the rest of the auditioning with the passive attenuator instead of the valve pre-amp.
Next up I compared the sound of the DEQ against the two NOS DACs that I had available, the Monica2, and Scott Nixon DacKit, both of which were powered by a linear 12 volt power supply. While there were slight differences between the DACs, it was impossible to say that one was better or worse than the others, although long-term listening may reveal a preference for one or the other. I concluded that the modified DEQ was very capable DAC, with the bonus of the DSP capabilities.
That could have been the conclusion of this review, but as I was also reviewing the at-tunes SB+ (a rebuilt and highly modified version of the Squeezebox that is an excellent transport), I decided to try the modified DEQ with that (in my main system). In this more revealing system, the DEQ was clearly preferable to either of the NOS DACs. In fact, the sound of the SB+ playing through the DEQ was very close to the sound of the SB+ on its own, no mean achievement!
However, I should also point out that this was with the DEQ playing into the Burson Buffer. Without the buffer, the DEQ sounded slightly thinner and the sound stage was not quite as large as with the SB+ on its own.
In conclusion, I have to report that the modifications made to the DEQ do 'what it says on the can', i.e. improve its sound quality, and turn it into a very capable DAC! If you already own a DEQ, you may care to consider having it modified before spending out on another DAC. If you are using your DEQ in your hi-fi, and relying on the analogue output, then you should consider this upgrade before replacing other items in your system.
Audiosmile also have tentative plans to take the DEQ2496 to an even higher level, with modifications to the power supply, re-clocking, and analogue input modifications. Much will depend on customer demand so if you have any specific needs, contact them for a chat.
* This review was intended to come out prior to Christmas until some careless handling by the carriers put things back by a month. Audiosmile intended to offer a Christmas discount and in the circumstances will now offer a discount for two months following the publication of this review. Contact them for more details.
© Copyright 2007 Nick Whetstone - www.tnt-audio.com