Making the transition from portable to full-size

Originally Posted by yodoso 

I've been using ibasso's portable D4 dac amp combo for almost 2 years now.  I've been very happy with it's dual wm8740 dacs, however It no longer works. I am looking to go full-size for my next purchase.  What are some desktop headphone amp & dac combinations that would sound better than my portable D4 and be close to a $500 price range?  It'd be nice to hear what tubes sound like and GULP am I wishing too much by hoping the new unit to be manufactured in the U.S.?

Originally Posted by yodoso 

The Bottlehead Crack looks great, but what DAC should be paired with it? How about the dacmagic?

Originally Posted by Uncle Erik 

The Bottlehead Crack is a fine amp and even better with the Speedball.

You might also consider their new Smack, which is transformer-coupled, so it'll drive low impedance headphones. I think it's just under $500.

Sorry, I can't recommend a DAC, either. But if you want to build an amp, why not build a DAC, too? There are several out there.

Originally Posted by Uncle Erik 

Oh, wow. It's been a long time since I've heard the Lunchbox and more than a year since I heard the Crack.

I can't offer anything specific, but I recall enjoying both.

Originally Posted by Uncle Erik 

First, I'm not sure the HD-600 can pull 500mW without blowing your ears out.

Think of it like a light bulb. You can put a 60W bulb on a 120V, 20A circuit in your house. That can develop over a couple kW of power. But the lightbulb only draws 60W off the line.

Headphones do the same. You can hook one up to a 500W amp, but if you're only drawing 200mW of power, the other 499.8W mostly turns into waste heat and a higher temperature in your room.

The Lyr claims 6W into 32 Ohms, so I think a lot of that power would be wasted on the HD-600.

Also, more power does not equal more quality. That's a common marketing myth. Generally, more power causes more distortion. If you don't need a large amount of power, why not use something with more refinement?

Also, I'm generally skeptical of hybrids. Tubes are high voltage devices. Chips are low voltage. The Lyr can run the 6922, which takes a maximum of 220V and the datasheet says it'll run class A at 100V. Chips usually run about 12V-24V. If you want to run both, you should probably have two separate power supplies, one for each. But power supplies are expensive and where manufacturers cut costs since only a few really understand them. So instead of a high voltage tube supply, they use the low power supply to light the filaments and pass the signal through the tubes while leaving 99% of the amplification to solid state. In other words, the tube isn't really necessary. It's just there because people want to think they're buying a tube amp. It lights up, sounds good (I am in no way arguing that solid state sounds bad - I like it quite well), and people are happy because they're "running" tubes.

I don't know if the Lyr is like that. I haven't heard one and know little about it.

But some hybrids are bogus. They'll list a bunch of electrically incompatible tubes as "compatible" with the amp. How can that be? If you want to run electrically different tubes in an amp, you usually have to change the resistors and capacitors inside to different values. It would be complicated and expensive to design an amp that could detect a different tube, determine what it is, and then adjust itself. It's fair to say that probably isn't happening. A few amps that accept multiple tubes have switches so you can can change internal values for a different tube. If you don't throw the switch, then it doesn't work or can be damaged.

Anyhow, what's happening is that these hybrids light the filament and pass just enough through the tubes to color the sound. The tubes are not being fed the voltage they need to run as they were designed to. The manufacturers are just tacking on a tube because tubes sell.

My take is to run either straight tubes or straight solid state. Run tubes as they were designed to with a proper high voltage supply. Either that or run a clean solid state design on low power. Solid state done right sounds great. But be careful with the hybrids. Some are just solid state amps with a tube tacked on and a much higher price.