[sydneyaudio]

Hi all,

Well after 6 months enjoying the DAC I thought it was time for an upgrade. My main complaint with the Lite DAC-Ah was occasional graininess in the lower treble - seems like a common problem. I have seen the passive output mod described on this forum, by all accounts it seems like a real fix. I also wasnted to see if I could improve the sound "quality" and that led me in a different direction. Opamp rolling with OP627/37 was suggested but then I stumbled on a local Australian site www.bursonaudio.com.

Anyway, I ended up purchasing a pair of their Hyperdynamic Amplification Modules (HDAMs) from ebay - the current quoted price is AU$85 for a pair. For a technical description of the HDAMs I suggest you visit their website.

Let me qualify this post by saying I am a real audio amateur! I dont know the proper audiophile ways of describing things but I will try my best to share my experience.

Firstly, fitting the HDAMs into the Lite DAC is a real bugger - they barely fit!! The whole DAC has to be pulled apart, top and bottom. I desoldered the OPA602s and directly soldered the HDAMs in their place. There was also a grounding wire for each HDAM. Iam sure people with better skills than me will find it easier.

I have a system of cheap components: Yamaha DVD C750 as transport (a multidisc universal player), Gecko coaxial cable, Lite DAC-Ah, Van den Hul interconnects, Marantz SR4400 HT amp, Senn HD600, and DB Dynamics Quantum speakers.

I used a variety of music: Beethoven symphonies (Barenboim), Metallica, Ella Fitzgerald (Cole Porter song book), Tabla beat science, Beuna Vista Social Club, etc.

As I have only 1 DAC this was not an A/B comparison. However, the second digital output on my transport feeds directly into the Marantz amp. Swapping between inputs on the amp, digital, and analogue (from the DAC), allows a reference point for listening. I often switched between the 2 before I installed the HDAMs, and know the differences in sound between the LIte DAC and amplifier DAC well. So, I again used the amplifier DAC as a sound reference point. (Does this make sense??)

After installing the HDAMS the difference in sound is huge! The OPA602s were never close to being this good. Volume is louder. The bass is extended lower and tighter, the treble is clearer and less harsh, and the midrange detail has improved. Soundstage is better mainly through much greater instrument seperation. In fact one of the biggest differences is in instrument seperation and note precision/decay. Vocals now seem like they are coming from a whole new place - that is in my room! Listening is much more enjoyable. I have not heard other opamps or the passive output mod so I cannot compare, but the differenc to the OPA602s and my amp DAC would be obvious to anyone
The difference was greater with the headphones than the speakers - probably reflecting the quality of the speakers!

I must mention that some of the graininess to the Lite DAC is still there, although improved. I feel this is a characteristic of the output stge of the DAC itself.

Iam so impressed with the sound that I would not hesitate recommending these HDAMs to anyone. They are an opamp rolling alternative for any application. The sellers were also pleasure to deal with as well, great communication, and well packed and fast delivery.

I have some pictures on iphoto but cant seem to upload them. Any suggestions?

Happy Listening

 

[revo_909]

so you're saying they're worth every cent? i too looking to modify my DAC-AH in the near future, and still deciding between passive output and op-amp upgrade. i've been eyeing on their super regulator for a while, any idea how well the'll go?

 

[sydneyaudio]

If your looking to get rid of the Lite Dac graininess the passive output mod maybe the way to go - very positive reviews on this forum.
The HDAMs DO NOT get rid of the graininess - but do improve it.

They do however, completely change the sound - its almost like owning a completely different device! Listening to vocals now seems like a curtain has been lifted. I think they are worth every cent. Its not perhaps, may be there is a difference - there is a big improvement!

As I said in my original post the only problem with these HDAMs is their extremely difficult to fit in the Lite dac. If I can manage to upload the pictures you can see the space limitation.

Cannot comment on their other products as I have never used them. I have a homemade RF power filter which I bought from a chap in the UK on ebay, and it does make a difference -the Lite DAC responds well to cleaner power. The power regulator looks good value for money, may be you should try it and let us know!

 

[Meyvn]

actually, these might be really cool to put in the Zhaolu, too, though getting Ori's discrete output mod and the discrete headamp may be better.

 

[revo_909]

would like to try them, but i'm still reluctant to modify my cd-player. looks like it will be passive output mod for my dac then.

 

[yo2tup2]

Quote:

Originally Posted by Meyvn actually, these might be really cool to put in the Zhaolu, too, though getting Ori's discrete output mod and the discrete headamp may be better.

I believe this HDAMs are also discrete outputs. I posted it a few months ago in a zhaolu thread, and I wanna say its where ori got the idea to do a discrete output mod. He posted a few links on how to make a discrete output after I posted it.

 

[00940]

http://www.bursonaudio.com/Why%20Burson%20HDAM.htm : this must be one of the most ridiculous piece of marketing I've read in a long time. To take the old TDA1541 as an exemple of today's productions and quality control is quite daring.

While indeed discrete designs can sound better than ICs and this HDAM could be better than the OPA602 (I'm honnestly unfamilliar with this opamp), I'm a bit worried about the solidity of the mounting, especially if the player has to be shipped. Something also bothers me in your review. It's the "volume is louder" part. If the volume is really louder, then a good old principle of audio listening states that "louder is better".

About the Zhaolu mods : the TNT-Audio review of the HDAM says that the HDAM are good as buffers (as used in the DAC-AH) but not as good as opamps as I/V. So careful before ordering too many of those expensive little boys.

 

[sydneyaudio]

Yes, agree with your comments about the marketing, it is quite strange.

In the Lite DAC-Ah I can see no problem with the mounting. The construction of the HDAMs is very solid and secure, shipping would not be an issue.

I did describe the volume as louder, but this was only one part of my evaluation. I can assure you that the difference is much more than volume, and I do know the difference!

These HDAMs are relatively expensive compared to the passive output mod and other opamp rolling options in the Lite DAC-Ah. I cannot say if they are better or worth the expense, but I wanted to share my experience with the community of this alternative. They can be had cheaper from ebay auctions...

The HDAMs I bought were intended to be used as a buffer in the output stage. A different version for the i/v stage is available. It would be interesting to hear a review from a Zhaulo owner