Review of the Audio-GD FUN - A modular Dac / Headphone amp / Preamp - Page 83

I think the BA Mod with the Earth HDAM has finally settled after almost 3 weeks of burn-in. The sparkle and treble have return after disappearing for about a couple of days. The modded Earth in the FUN seems a totally different beast now. No longer does it sound clinical with a touch of fizziness in the treble. It now sounded natural, quite airy and good separations and depth of soundstage. One thing that really impresses me about this mod is how it affects the dynamics swing of a piece of music. Quite a difference between soft and loud passages. Love the way it sounded in orchestral music, with strings sounding as they should and proper delineation of the woodwinds, bass, cellos. Drums have a snap of attck that is quite punchy. At the moment, I'm enjoying the BA modded Earth far better than with the ADA4527-1BRZ. The Moon has been modded as well and will be next to burn-in. First impressions are really liquid mids and solid bass with clear trebles.

Does anyone use the FUN with LCD-2? I'm thinking about buying audezes...

Did output impedance measurements on my Fun today. With a load of 47 ohm I measured output impedance to ~ 5.75 ohm. I wonder how Audio-gd has come up with the specified 1.5 ohm number.

Quote:

Originally Posted by rhythmic_impulse 

I think the BA Mod with the Earth HDAM has finally settled after almost 3 weeks of burn-in. The sparkle and treble have return after disappearing for about a couple of days. The modded Earth in the FUN seems a totally different beast now. No longer does it sound clinical with a touch of fizziness in the treble. It now sounded natural, quite airy and good separations and depth of soundstage. One thing that really impresses me about this mod is how it affects the dynamics swing of a piece of music. Quite a difference between soft and loud passages. Love the way it sounded in orchestral music, with strings sounding as they should and proper delineation of the woodwinds, bass, cellos. Drums have a snap of attck that is quite punchy. At the moment, I'm enjoying the BA modded Earth far better than with the ADA4527-1BRZ. The Moon has been modded as well and will be next to burn-in. First impressions are really liquid mids and solid bass with clear trebles.

What you describe is exactly how I would attempt to explain the differences, well done rhythmic_impulse ! The BA cap mod works equally well on the Moon OPA but I will let you discover these changes rather than preface them here. It's all a part of the FUN (pun intended).

It's funny though, loads of folks have resisted doing these mods because they cannot fathom how such a simple tweak could be so beneficial....those that try it find out as you did that there is something to it and it transforms the HDAMs from good to great. I always seem to end up with the cap modded Earth module in the gear that can use one and then forget all about swapping these things out.

I haven't (personally) bothered cap modding a SUN module yet (others have and had good results) since I really don't like OPA's with boosted lows and highs ( a "U" curve so to speak). My preference is to try and remain as faithful to the original track as possible (even if the HDAMs are not exactly true representations of neutral in the classical sense).

Peete.

Quote:

Originally Posted by brat 

Does anyone use the FUN with LCD-2? I'm thinking about buying audezes...

I plugged a set of LCD-2's into my FUN at a head-fi meet.  They ran fine and that's using the sun opamp.

Quote:

Originally Posted by Pricklely Peete 

Try the cap mod on the Earth module ( 1uf PIO of 60V rating or greater across the HDAM's + - PS pins in parallel). That little mod helps deliver what you describe as lacking in the Earth module. I use K42 series PIOs for this job and it's a perfect match. It works equally well on the other 2 module flavors but I find for the A-gd gear (using A-gd HDAMs) the cap modded Earth gives me the most natural presentation of the 3. Of course that's just preference on my part.

 

The K42's are cheap but work very well.

 

Peete.

Hi Peete,

I really want to try the cap mod that you mentioned but I am not sure what to do.

Is the K42 PIO refers to the Russian K42-Y2? You said the voltage can be greater, how about uf? must it be 1uf?

And I am not sure what is the HDAM/s + - PS ? Can you show me?

Thanks!!
 

Quote:

Originally Posted by fourwed 

 

Hi Peete,

 

I really want to try the cap mod that you mentioned but I am not sure what to do.

 

Is the K42 PIO refers to the Russian K42-Y2? You said the voltage can be greater, how about uf? must it be 1uf?

 

And I am not sure what is the HDAM/s + - PS ? Can you show me?

 

 

Thanks!!
 

 

There are numbers on the underside of the HDAM right next to the pins to help, you can't miss them.

There are a couple of solder pads right next to and in line with each power pin.  The other solder pad that each stock Evox Rifa film cap is connected to leads to the white ground wire.

I'm kind of noob when it comes to opas so I need some advices. I ordered  this Dual Opamp Adaptor little too hastily without knowing what kind of AD797BRZ I should order for it.

So I found this single AD797BRZ from ebay and I would need to buy 2 of those for the adaptor, right? Then there is this dual AD797BRZ that do not need any adapter, as it already has one. So should I get 2 single opas for the adapter, or the pre-built dual.  Is there there any differences with those two AD797BRZs in sound quality? Lastly I do not have any extra power source for my Audio-gd FUN and I read somewhere that opas get better with extra power, so can I drive dual AD797BRZ fine without the extra power source?

Quote:

Originally Posted by mikael83 

I'm kind of noob when it comes to opas so I need some advices. I ordered  this Dual Opamp Adaptor little too hastily without knowing what kind of AD797BRZ I should order for it.

 

So I found this single AD797BRZ from ebay and I would need to buy 2 of those for the adaptor, right? Then there is this dual AD797BRZ that do not need any adapter, as it already has one. So should I get 2 single opas for the adapter, or the pre-built dual.  Is there there any differences with those two AD797BRZs in sound quality? Lastly I do not have any extra power source for my Audio-gd FUN and I read somewhere that opas get better with extra power, so can I drive dual AD797BRZ fine without the extra power source?

If you need AD797B, it does not have PDIP version and so your Dual Opamp adapter is useless. Just go for the pre-soldered dual AD797BRZ. There should be no large difference between the pre-soldered and the DIY one, although some will think the quality of solder and adapter might affect the sound.

Personally, I don't think you need an extra power source for the opamp. I know with a better power source, the opamp should sound better. But if you really do this, you might then need to consider to give an extra power source to the clock and the upgrade list becomes endless........

I think it's the Russian K42-Y2 indeed.  My OPA Sun has a ceramic capacitor, metallized polypropylene film capacitor, and a 10uF tantalum capacitor for bypass.  The tantalum made the biggest change, I suppose that the film cap didn't as much because it's such a small value, lol.  But then those metallized polypropylene film caps quickly become very large (physical dimensions) and expensive if I want larger values.  For the PIO cap, I would go with some value between 2uF and 10uF, I suppose.  That's what I've seen recommended for film bypass caps.  You should also add a 0.1uF ceramic capacitor (C0G/NP0 type).  You can get those from fleabay, Digikey, Mouser, etc.

If you decide to try the tantalum capacitor, beware that it is polar and you need to connect the negative end to pin 4 and the positive to pin 8, otherwise you may damage your equipment.  The capacitor will be labeled to help you.

Thanks Mad Max. I will give it a try later.