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Originally Posted by Pricklely Peete /img/forum/go_quote.gif
30US is about as cheap as you'll find for a glass toslink including shipping...the only other place I can think of off hand is BlueJeans Cable but I don't know if they have a glass toslink....I'll have a look and see...
A disturbing note with my Zero running SUN in the H/Amp and the reg HDAM in the dac section...once the OPA's burned in I noticed the bass had leaned out considerably...almost like the volt regs could not deliver enough juice to the current hungry SUNs...I don't know for sure if this the case. Alex is redoing his volt reg section in the H/Amp section and I had talked with CC about a sep power supply and volt reg for all 3 HDAMs...anyway when I pulled the SUNs from the H/Amp section and put the LT1364's back in the bass came back to what it was before....weird. Further investigation is needed and Pench and I are in the middle of that right now...
Alex do you know the max current the stock regs on the H/Amp board can supply ? I think the dual channel SUNs are drawing what...close to 88 ma ? The LT's maybe 1/4 to 1/3 of that...although that may be incorrect. In any case I think the stock Zero can run 3 HDAMs but will need help in some form to deliver the current needed to sound great to those current hungry HDAMs..
I do have a volt reg board and transformer on the way...so I'll be able to test this theory for real in a couple of weeks. I also wasn't keen on the SUN's voicing...I found I much prefer the neutral presentation of the Earth/LC module. With the heavily modded Zero the voicing of the SUN once it had 75 hours to cook wasn't my cup of tea and found the LT1364's a much better match to my ears, but also the problem talked about earlier in the post.
Can people post impressions of the SUN module in the DAC section please so we can get a baseline of it's SQ's vs the known Earth/LC HDAM. For now I have to keep my Zero as is for the final leg of tests before the mod kit is released so I can't pop the SUN into the dac section for a little while yet
Thanks guys !!!!
Peete.
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Hey PP,
I've been testing the "Sun's" in the headphone amp section, driven by the "Earth" in the DAC section. But, I should explain why the "Earth" in the DAC section first. The "Earth" is very dynamic and very neutral, maintaining a flat frequency response over the entire spectrum. You couldn't ask for a better DAC amp solution, for so little money.
I have over 350 hours on my "Earth" and it is stable and sounding great.
The "Sun's" have about 200 hours on them, and they appear stable and mature. I did have to re-solder most of the leads; They were dropping off like crazy.
To test the whole setup, I took my stock #2 Zero and installed all 3 modules. "Earth" in the DAC, "Sun's" in the headphone amp. I used my Creative X-FI (Desktop PC) coaxial output to the Zero and plugged in my HD-650's to the Zero's headphone amp.
The results were not what I expected and caused me to spend another 3 hours cross checking everything to determine exactly what was going on. The "Suns" have 3 distinct humps in their frequency response, when compared to a flat frequency response. One at your typical sub-woofer crossover point, another at lower to mid voice frequencies, and another at high frequencies, near cymbal ride frequencies. Without the ability to measure these with test equipment, I have to generalize their locations and guess at their intensity, which I would say is under 6-8db. I'd have to hook it up directly to my 32 band equalizer to get any closer on this, but didn't have time.
Please everyone, understand something before passing judgment on the "Sun". It is supposed to be a "fun" sounding module that will enhance most listening situations, and it may indeed do this for some users. That would be great! For me however, it took my quest for a flatter frequency response and messed with it. The overall sound was colorized and did sound this way through my HD-650s. A quick swap out to the LT1364's made for a much better sounding output, with far less colorization.
With the "Sun's" still in the headphone amp section, I went ahead and tested what I could. The overall output was down by at least 20%. I could actually turn up the volume high enough to drive the headphone amp section into audible distortion! I hadn't expected this, but it makes sense when you consider the lower output. This could also be a symptom of your earlier observations on voltages within the headphone amp section. I hope your testing can determine what is actually happening. For right now, I'd have to say there is a "drain" on resources within the headphone amp section, when running two "Sun" modules.
I did test the "Sun" in the DAC section, outputting to my MKV headphone amplifier. The same 3 frequency humps were present, verifying my earlier findings.
So, to summarize my findings so far; The "Earth" works extremely well in the DAC section, and it has great synergy with the LT1364's in the headphone amp section. The "Sun" modules produce a "colorized" presentation that is not an improvement for me, in my stock Zero. IMHO of course, and YMMV.
Time permitting, I'm going to test the "Earth" modules in the headphone amp section, and use my first generation HDAM with "cap" mod in the DAC section. I want to determine if the frequency response stays flat and the dynamics carry forward. There will be much to look for, with this setup. This may be days away though.
