Ian's Horizon - mods and stuff
- Thread starter plasmod3
- Start date
So that cat is out of bag? It is an off the shelf AKM dac chip in the Horizon. Yes a very interesting choice specially for those that enjoy DSD. If it is a newer AKM dac chip, the Direct DSD feature is limited to DSD256.
Why? That's like asking why use a Bosch ECU in my Porsche 911 GT3 and ignoring the sum of the entire masterpiece...
I'm not ignoring anything, I'm sure it sounds very good just as your Porsche is amazing to drive. It doesn't make it less interesting of a choice in my opinion. I'm happy Lampizator aren't hiding what components they are using. I wish I knew what was used in my Poseidon.
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A better analogy than the ECU would be the engine as the dac is the heart of the Horizon dac.
Give the GT3R or GT3RS a drive and see what the differences are attributed to compare to your GT3 and then you will understand why the choice of dac IC or discrete dac in a Digital to Analog converter component is so important.
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I can assure you it does DSD512 just fine. In fact my PGGB resampled DSD512 file sound glorious!
It depends what AKM chip it is. If it is the newer AKM chips, the digital input filter chip does receive DSD512 but it processes it with internal filters. If DSD Direct is enabled then the digital input receiver will down sample the input DSD512 stream to DSD256 before passing the s data stream on to the DAC. This is all very well documented and a limitation of DSD Direct on current AKM chips.
steve williams
Site Founder, Site Owner, Administrator
Well, you do get sound out with DSD512, but it doesn't work as direct. If you look at AK4499EX datasheet, assuming that the Horizon is using one of the latest AKM dac chips, you can see that the DAC chip can operate only at DSD128 or DSD256 rate.
AK4499EX has essentially two things to select. Sampling rate 5.6/6.1 or 11.3/12.3 and the "sound quality mode":
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steve williams
Site Founder, Site Owner, Administrator
Thank you Mike, very kind words indeed . I really enjoyed your system when i was over - especially that Ampex - wow that was a big brother moent for melet me just say that Ian has visited me in my room, and is a very serious and knowledgable person. and has some extremely serious gear. which is his to talk about, not me. but anything he is doing I give him enormous benefit of the doubt about. if he likes it, it's probably doing some special things we would all appreciate. OTOH all the cautions are also valid.
most of us here, especially me, are not in a position to attempt these things. and mostly those who can afford top level gear, don't have the chops or guts to mess with that said gear.
fun stuff, and a privilege to observe. I'll get my popcorn.
The mods was a learning journey and i cut my teeth on an allnic l10000 replacing about 90 % of the components there. After that i got twitchy with the horizon. I will say the circuit design of the horizon is absolute genius. All i do is just replace a few discretes and drawing on my experience on wires and cables to make it better still.
I think the more i look at our audio hobby the more i realise 'cost no object' is really akin to a de beers advertisement. Regardless of the phrase , for a manufacturer it makes no sense to do cost no object given 1 margins and 2 the availability of really high end parts for mass manufacture. What they dont skimp on though and constantly challenge the paradigm is the circuit design and that i can only marvel at the work everyone has done.
The components have to be trialed. It took me a while trying different parts to get it right . One rule which is ok but not really a rule is go on price. the more expensive the part is the better it will sound - as a starting point then you mix and match from thereon . For eg with hokes - it is easy to think that a japanese mu metal can is better than an european one - so i took a leap of faith and it worked very very well indeed
Also the kansei caps will be better than korean caps or chinese caps .In the circuits ...at least in the horizon luksz has marked out the signal resistors by using better resisters on those specific ones - i took his lead and just replaced them. not only same value and better quality but most importantly up the wattage on those. Higher wattage means less heat and therefore a better sound ( less oscillation in the resistor, heat stress, performance thermal envelop etceI remember for PAC (1st version at least), the dac chip is in charge of doing everything except DSD512 and there is something special about direct DSD or 1bit DSD for DSD512 only. I could be wrong here.. And I indeed found that Pac playing DSD512 sounds somewhat different than other formats and I like it, which is why I use Hqplayer to upsample everything to DSD512..
I believe Horizon does… Well, it seems like the picture for the DAC board has been taken out, but I recall that there is a diamond shaped thing on that board (pretty stands out actually) which is like what the Pacific has for DSD512…? I don’t see why Lampi would remove it from Horizon if they don’t have a better solution…
This thread to moved to diy i see - all the way at the bottom so i am not sure who will ever see this thread and whats possible here - anyway lets carry on This is an exciting mod i did!
An external power supply. Now why would a external power supply be that interesting if anything? Thats because this power supply does both 4v and 5v. Sean Jacobs helped me with it , its regulated uses a great transformer of the same grade as the front 2 silver one in the horizon
4 and 5v means i can use all the main power rectifier tubes out there without a resistor - that makes a huge difference in the soud. I have this mounted onto a gabon ebony bord ( true ebony ie not the fake ones proliferating out there) used some very great vintage wires and hooked them onto the 5v supply on the tube board that i have showed earlier in photos.
This is a relatively simple mod but it has set me free from the use of resistors . only a b4 to octal adaptor is needed and i made one using parts and wiring off a few decent dead tubes . The effort and results of this is very well worth it , especially when you get liberated from the sound signature of another passive component.
This is an exciting mod i did!An external power supply. Now why would a external power supply be that interesting if anything? Thats because this power supply does both 4v and 5v. Sean Jacobs helped me with it , its regulated uses a great transformer of the same grade as the front 2 silver one in the horizon
4 and 5v means i can use all the main power rectifier tubes out there without a resistor - that makes a huge difference in the soud. I have this mounted onto a gabon ebony bord ( true ebony ie not the fake ones proliferating out there) used some very great vintage wires and hooked them onto the 5v supply on the tube board that i have showed earlier in photos.
This is a relatively simple mod but it has set me free from the use of resistors . only a b4 to octal adaptor is needed and i made one using parts and wiring off a few decent dead tubes . The effort and results of this is very well worth it , especially when you get liberated from the sound signature of another passive component.
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I have now known Ian a long time. imho he is in rarified air among those with DIY talents and love for this hobby. I am simply amazed every time we converse regarding tubes or components. And he is extremely confident in his experimentation and trade. But more than anything else, again imo, he is the kindest and most trustworthy person you can come across in this industry. And I truly believe it all comes from his own passion for audio and exploration. It has been a privilege to meet Ian through wbf.
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thank you very very kind of you Tom
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