effect of tubes in cd players

Generalizations cannot be made on this topic IMO, any more than generalizations about SS outputs. It is very dependent on the design. Most tube designs have poorly designed power supplies and distribution, not to mention poor parts selection, so they appear to have "bloom" or HF roll-off or flabby bass. There is no reason why a tube design cannot sound a LOT like a decent SS design, and can be even better due to better dynamic linearity. It is also very dependent on the AC-coupling capacitors. Many times, it is the capacitors that you hear, not the tubes.

There are a few tubes that just dont perform well in ANY design, but there are the same analogies with op-amps and even transistors....these are the exception, not the rule.

Ozzy62 - you have obviously never heard what good transistor design can do. Definitely not mediocre, also not stock. I takes a lot of mods to get transistors to sing IMO. The only tube amp that I have heard that delivers the bass tightness is the Wavac, and you know what that costs...I've heard them all.

Steve N.
Empirical Audio
Manufacturer

Bartokfan - I believe you and I would probably come to the same conclusion, but this is only one data point. The tube outputs on the Shanling sound better than the SS outputs as well, that is until I mod it. Then the SS outputs leave the tubes in the dust...very dependent on the design. Again, I feel that generalizations cannot be made.

I have heard good SS and good tube designs. Many more SS designs though. If you are looking for rolled-off and undynamic, then even poor tube designs can deliver this. This is why there are so many tube designers out there. It is easier to come-up with a tube design that sounds decent. It is just simpler design. It is also very difficult to design one that outperforms the best SS, particularly when it comes to HF extension, dynamics and bass tightness. The technical reason why this is the case is as follows:

Tubes require high-voltage, therefore the currents are quite small to the plate. Delivering these currents is therefore easier than the equivalent power delivery to bipolar transistors or mosfets. As a result, even "broken" power supply and power delivery designs for tubes can sound decent. I know because I have fixed a number of them. But, making them world-class requires the same care as design for SS. I have found that most tube designers do not have the experience required to achieve this. The Wavac is an exception, but I suspect that even the Wavac could be improved a bit. The other issue with high-voltage is coupling. There must be isolation, either by transformer or by capacitors. These ultimately add coloration. I have tried and measured all types of coupling caps and only within the last year or so have I found capacitors so transparent that they sound close to DC-coupled. Most designers select capacitors that I reject as too colored due to high dielectric absorption, losses or other factors. I have a DAC product myself that has tubed output, so I'm not against tubes. It is my best DAC.

Steve N.
Empirical Audio
Manufacturer

On the other hand it ALWAYS takes a few mods to get HF extension, bass tightness and dynamics out of tubes IMO, and some tubes just aren't capable.....

Steve N.
Empirical Audio
Manufacturer

I personally can't stand "warmth". I want it live and fast, and tubes can deliver this in spades if the circuits around them are designed right. There is no reason why tube designs cannot be fast, extended and with tight bass.

Steve N.
Empirical Audio
Manufacturer

Anything that colors the sound or rolls it off is what I'm trying to eliminate, of course without adding sibilance or harshness.

Steve N.
Empirical Audio
Manufacturer

Never heard the Wytechs. I have heard the $250K Wavacs. Now these can do bass for real, and tight.

"When you mention you modding the Shanling and the SS turns out sounding better, is this with modding the tube stage as well?"

Yes.

"Have you thought about disconnecting the headphone stage and coupling these transformers to those of the tube output stage?

No. I try to avoid both transformers and capacitors if possible, particularly transformers. This is because there are so many good choices for coupling caps available now. I try to DC-couple whenever possible, such as my mod for the Benchmark DAC-1.

Steve N.
Empirical Audio
Manufacturer

breginato@sanbrunocable.com - I've modded Modwright tube stages for customers in the past. They can be improved as well. Like audiofeil says "its the design".

Improvements are in HF extension and dynamics mostly. The customers were happy if that is any indication.

I have not modded anything recently, including your preamp. In fact, I'm going more the route that you are taking, designing my own gear and doing less mods. Perhaps someday you will mod one of mine.

Are you saying that it is not possible to improve the sound of these?

Steve N.
Empirical Audio