Tweet
The sound of my NatPs have been a bit thin, so I decided to take my tube headphone amp and use it as the pre to my Onkyo. The difference was immediate, full sound, with deeper/punchier bass, albeit with a slight loss in clarity. What gives? Is it really the 2nd order distortion that makes the tube sound full with great bass? Can it be a impedance mismatch between my cd play/ipod with the Onkyo's pre causing a bass roll off and by using the tube this issue is eliminated?
-
-
monotonically decreasing harmonic distortion makes the sound fuller and richer, without the harshness typically associated with distortion. the impedance thing only applies to amplifiers not preamps. if you really like that full, lush sound, instead of tube preamp, use a SET tube amplifier, and you get midrange clarity in loads, while the background becomes warm and diffuse. they don't work well with ported enclosures though. -
If the input cap on the receiver is on the small side and the output impedance of the source is on the high side you could get a bass roll off. Similarly, if your receiver presents a low input impedance the source may have a hard time driving it.
Most sources have low output impedances these days, but yours could have a resistor to protect against shorts. Normally impedance issues don't arise with solid state equipment. Your tube amp may have a very high input impedance which makes it easier to drive.
Do you have another preamp you could try or a solid state buffer (easy to make with an opamp and a few resistors). The Nat-Ps I built for a friend sounded much better with my laptop directly driving a hafler DH-500 than with his Yamaha reciever. Similar to your description, a little thin. He's happy, so no need for me to mess with it.Comment
-
I tried a another pre based off a simple opamp, I did notice a bit more bass, not as much as with the tube, but more then with straight cdplayer to receiver's internal pre. thoughts? its an onkyo TX-DS989 receiverComment
-
I think it isn't the NatP's that are thin, but they reveal the thinness that your receiver's pre section imparts. The tube preamp in comparison doesn't sound as thin in this setup. I think others have covered some of the reasons.
I am not a diehard one camp or the other audiophile, but I do like good tube equipment and generally am not found of receiver's sound. That being said, I am currently listening to my Modula MTM's on my Onkyo TX-NR905 while other things get finished. Its not half bad.Comment
-
I've used tube amps and preamps with my designs, and I had one with the Nat-P's for a while.
I believe what you are hearing are massive (when compared to SS designs) amounts of second order distortion, which sounds "warm", "rich", "liquid" and full. You can test this by using RMAA (audio analysis software) with your tube preamp.
Euphonic? Yeah, I suppose so. Accurate? Not really.
Javier HuertaComment
-
Not all tube equipment has "massive" amounts of second order distortion. In fact most well designed stuff doesn't. It is just that inexpensive commercial tube gear is usually not well designed.Comment
-
Well either way all tube gear adds some sort of HD usually 2nd order. Some more then others I agree. And some can be pretty neutral.Comment
-
Its usually the amp that adds a lot of second. Tube preamps should be pretty neutral in the scheme of things as long as the load your amp presents is nice.
I am not going to argue for tube or ss or chip, that is pointless and personal. I just wanted to add that tube equipment (particularly tube preamps in this context) doesn't necessarily imply gobs of euphonic colorations and 2hd distortion.Comment
-
I dunno. I became curious when I tested my own equipment and checked out Stereophile's measurements on megabuck tube preamps. John Atkinson, in one of the reviews, stated thathigh amounts of 2nd order distortion were a given for a tube preamp design.Originally posted by JoshK
Every measurement I saw on Stereophile for tube preamps did have very high levels of 2nd order HD.Javier HuertaComment
-
Yeah I could care less what it adds or doesn't add. If you like the tube sound that's awesome. Audiophile stuff is all very personal. It's all about what you like.Comment
-
Two points. First, adding a CCS as load on an otherwise linear tube, like the 6sn7 significantly reduces HD2. Second, typical (no ccs) tube gain stages do have relatively high HD2 when compared with SS stages. However, they typically have very low tall order HD, which not many SS stages can claim.
If we use work done by guys like Geddes as truth, then the even high amounts of HD2 are less audible then much smaller amounts of higher order HD. That is generally the arguement for designing with tubes, or at least one of them.
Just for the record, I believe it is possible to design with SS to acheive the same harmonic profile, which is a lot of what pass labs stuff is about. I am also not staunchly in one camp or the other, as I have liked gear of varying technologies. And lastly, I do like tube gear and I do build tube gear. FWIW, YMMV and all that.Comment
Comment