What headphone amp to buy-Sennheiser HD 600?

Great Bill. Post your results once you get them. I'm sure it may be helpful to others with the Stax amp you have. I'll be curious to hear how they stack up to. Did the seller have any input on the subject? Have fun rolling!

Marco

Just to add a bit to the input above: I have a Portal Panache, and a Berning Micro-Zotl. I don't use your cans, but a pair of Sony MD3000's. The difference between the two amps is not subtle, and though the Panache has a decent headphone section for an integrated amplifier, it just doesn't approach the smoothness and refinement of the Berning. Listening to the two A/B I do not want to listen to the Panache very long, and it doesn't take golden ears to hear the difference (love it as an integrated amp though). I cannot speak to the synergy with your cans specifically, but if they are the same cans Peter brought over (one of the Senn cans I'm sure) I didn't much like them in comparison to the Sonys, for whatever that is worth. The Senn's I heard sounded much less lively and dynamic than the Sonys on the Berning. Peter can say which model they were. So, as Peter indicates, it may be a matter of Synergy...or? Peter has both Senns and Sony so he could speak more to that.

Marco

I do like Headfi.org as a resource too. My only reservation about it, and this is a gross generalization (I hope), but in reading many posts there it seems to be a much younger crowd, and or a crowd that has different musical tastes than my own. I'm sure there are exceptions, but I don't read them much. It seems to be a much smaller crowd than Audiogon, which is understandable given the narrowed scope of the subject. The types of music used as resources for Headphone reviews there are often nothing I'd listen to much myself. Just to be sure, I just went over there and right away found this recent thread on what folks there used as source material to test out their new cans. There are currently 47 responses, so it is a pretty wide sampling, yet the general trend is toward music I rarely listen to (rap, electronica, pop, the occasional typical audiophile recordings...Krall, DSOM, blah, blah...but mostly much more dynamic, poppy, rock electronic stuff). Is this a fare reflection of headphone use in general at this level, or just those who choose to spend time writing about it on online forums do you think? BTW, I mean no offense at all to those who have different musical tastes, they simply are not mine. Speakers/Headphones that sound great with Electronica, Pop and Rap are not necessarily going to sound superior with Accoustic, Folk, Vocals, for example. Bottom line is, like with what I read here, I take what I read with a large grain of salt and do try to read as much as I can elsewhere as well. I still would not hesitate to recommend Headfi.org as a good resource. But it is a different crowd in general than those I see posting here. I'm sure there's crossover, but I get a strong impression that it the two camps are quite different nonetheless.

Marco

Tube rolling sounds like a pretty intense undertaking.

Hey if you can tip cows over at night, then tube rolling ought'a be a breeze! No meadow muffins to look out for either!

Because you are talking about a headphone amp that will likely use only a few, smaller tubes, you may be making it seem more complex and expensive than it actually is. Headphone amps are mostly auto-biasing so you don't have to worry about constantly adjusting the bias. With a tube amp it is basically a plug-and-play scenario with swapping the tubes. As Swampwalker indicated, some of the NOS tube prices are as out-of-hand as real estate in Manhattan. But you really don't need to go there to get satisfaction and great results from trying different brands of tubes. Once you choose and amp and are familiar with the tubes it uses, just do some reasearch here and on other Internet forums as to what others with the same amp have preferred. There are a few really excellent sources of new and NOS tubes to consult as well (The Tube Store, Vintage Tube Services, VTV, Upscale Audio, to name a few). You don't have to spend a fortune on NOS tubes - there are current production tubes that arguably have the potential to perform just as well if not better. Anyway, just don't rule it out...on a headphone amp it's no big deal.

Marco

My profound ignorance regarding tubes is becoming increasingly apparent to me.

No call for embarrasment at all. That's pretty much where most of us started. If you've read the responses so far, then at least you know SOMETHING. Besides, with much of the plug-and-play, auto-biasing circuits designed into most headphone amps, preamps, and many power amps, you really don't need to get much beyond Big Bird and Ernie to enjoy what the potential of tubes are in audio gear. Just use the two ears you've got and make your own decisions. Who knows, you may prefer SS...stranger things have happened. Seriously, there's plenty of folks who go that direction. For me tubes, at their best, have an ease and a natural, lifelike presence that SS can only strive for but never quite reaches the same mark. Yet I've heard SS amps I've really enjoyed for what they have to offer that tubes cannot. Or perhaps a hybrid solution that utilizes both tube and SS technology. Go out there and listen. Pick your poison and enjoy the music. Another option is that many of the head amps are available on a short trial period (7-30 days usually) from either manufacturers or dealers. You may be able to get a few and compare in the comfort of your own home. The only drawback there is that the sound may change, either subtley or profoundly, as the circuits burn in with use. Tubes also change after an initial burn-in. So you may be missing out on some aspect of performance without a burn-in period. If you are in a vast metropolis, just find a local dealer who might have some examples and bring your cans and your music. A local audio club may be another option. Or plead here on this forum for other members in your area who may allow you to come listen to their gear. I'd bet you'd find one or two who might be willing, since you are an established member.

Have fun!

Marco

Duane sounds like a good friend to have. I had a B&K EX140 which is the dual-mono version of yours. It is most definitely a kinder gentler version of SS with a softness that many folks like to call "tube-like" while still delivering the SS goods (you mention that tighter bass line). There are SS amps that can do all that even better. I'm really enjoying my simple Portal Panache, which puts out the same amount of power. Though I wouldn't call it soft or warm, it is very engaging and enjoyable. So I haven't given up on SS stuff altogether. I've never heard the Stax, but I know they have a reputation of being a very unique headphone. Let us know what you think.

Marco

Ah, sorry I missed that you might be rolling 300B's. WhooHaaa, then you are talking some bucks. Still many amps using those tubes are auto-biased as well. Actually I've recently been doing a bit of rolling in my 300B amps and have really been initially very impressed with the new Svetlana tubes that are only around $240 pair from CONUS in Canada. They offer more detail, clarity and impact in the midrange on my rig, at the expense of some of the overall balance, and do-everything-right of the WE 300B's that I've grown accostomed too. I wasn't at all fond of the TJ meshplates...just overall too soft. I could happily live with the Svets. WE's still rule to my ears, but not such a clear winner in comparison with the new Svets. Yes, rolling tubes in a 300B amp can be an expensive endeavor.

Marco

Holy guacamole! "only" 240 clams, for a pair of TUBES?? Just how long can these tubes be expected to LAST (I'm reeeaaally hoping you say at LEAST a year or more)?

Well, yes, they should last at least a year. I don't know about the Svets, but the WE's are rated for around 10,000 hours. But if you think the $240 price tag is pricy, you don't wann'a go there! The Svet's are aiming to be, at least structurally, a copy of the very popular WE's. In terms of sonics they sound different indeed on my amps. The Svets have a crystalline mid-range, striking in that effect...almost etched. The WE's give up a bit of that kind of sharply focused clarity for a better overall balance throughout the range (IMO and in my amps) reaching a bit more into the lower registers and delivering better detail there as well as in the highs. But that Svet midrange is pretty amazing...I was very impressed with them.

I forget how you got into 300B amps...was it you or someone else suggesting a Cary? This started out as a headphone amp thread....now if you are still looking at headphone amps that utilize tubes you don't have to worry as much about dropping that kind of coin on tubes, as most use smaller, less expensive tubes. If you are listening to your headphone amp to supplement your main system then I'm quite sure your tubes there will likely last you several years before having to change them. My MicroZotl takes 2 12AT7's and two 6SN7's. Total cost to retube is about $80 for some nice NOS stuff. You could spend more, and you could spend less depending on what you're satisfied with. Kind of like buying wine in a way. The tubes definitely have different flavors which can be more or less accentuated by the actuall circuit/component they are going into. There are tube amps that just use two tubes as well...even cheaper to retube, and not necessarily better or worse than amps using more tubes, bigger tubes or different tubes. Certainly they'll all sound different...but it is really up to you to decide which you prefer.

Marco

I don't even know what kind of tubes it uses.

I believe it uses 6CG7 (also 6fq7) - fairly common and not expensive. My preamp uses (only) two of those tubes and I like it very much.

No experience with the Stax stuff to comment on.

Marco

Probably a typo on Swampwalker's part, but the tube is a 6CG7/6FQ7. It is not a 6FG7, which does exist, but I don't think is a drop in replacement for the former.

Inexpensive: read roughly $10-20/tube for good stuff. I've liked the GE's and JAN. There is one oddball tube I rolled that I cannot put my finger on right now that also was quite good. As I said, their a pretty common and not at all exotic tube. The differences in my amp, and those in your amp will not likely be the same. You should just get a few pairs and listen for yourself. I haven't found there to be as much of a difference in the NOS tubes of this type, than those in the very covetted, overused, much inflated, sometimes counterfitted 6922/ECC88 family. If your amp used those you'd be in for a roller coaster ride.

Marco

Mdhoover - Here's a nice sellection of NOS tubes for your amp. (Insert usual disclaimer here...no relation to the seller, blah, blah, blah)

Marco

I can only speak for my preamp, which is a Cary SLP-50A - I like the RCA cleartops....BUT you should ask the seller since he had a Stax setup and would know better which ones worked best in that application. They will not necessarily be the same as those that worked in my pre.

Marco

Bill - Though it may sound complicated, it really is very simple. Once you've done it once or twice it'll be a snap. I don't know the Stax procedure either, but most manufactures give you easy access to the points you'll need to read and change the bias. BTW, many modern tube amps now use some kind of auto-biasing circuit eliminating the need to bias. Here's the basic procedure (trying to simplify for newbee, though it really is pretty simple): Get yourself an inexpensive digital multimeter from Radio Shack that reads in milivolts. Turn the amp on with the headphones (speakers in the case of a regular amp) connected, the volume turned all the way down, and no source connected to the amp. Let the amp warm up for 3 minutes or so. Each tube will have two contact points to take a reading. Set the multimeter to read mV and use the +/- probes to contact the two points for a single tube. This will give you a reading on the multimeter which may or may not be close to what you are aiming for. You will need to know exactly what the manufacturer reccomends for that amp for optimum performance (as Swampwalker said, a manual will be very helpful through all of this). Let's say it is .37 and your meter reads .49 - this would mean your bias for that tube is too hot and you need to lower it. To change the bias of the tube there should be either a knob, or more likely a screwdriver slot, in which case you'll need a small screwdriver. The knob/slot is connected to the pot(entiometer) Swampwalker was talking about and is there to adjust the bias. With the meter still touching the two points readin the bias of the tube, turn the screw quite gradually counterclockwise to lower the current (bias). You will see the numbers go down. Get the number to come as close as you can to .37 (or whatever number the manufacturer recommends as the bias point). Usually there is a tolerance of a few milivolts, and it will fluctuate/drift a bit, so just come as close as you can and don't worry about it. Go to the other tube (you only have two) and repeat the procedure with the proprietary pot and reading points for that tube. Once you've done the second, you may want to go back and check the first and re-adjust, and do the second once more too. After that, you're done. You should probably check/adjust the bias once a month or so. Again, once you've done the procedure once or twice it's a snap. It definitely is not time consuming for two tubes. First time will likely take all of twenty minutes perhaps since you'll be learning by doing. After you get it down you'll be able to do it in five minutes.

Marco

I use a Fluke. No need to go that direction. Take Swampwalker's good advice. That'll do the job just fine. Since you are new to this, have the salesman show you just how to set it to read mV. It should be clearly marked...but just in case...

Marco

You're welcome Bill...enjoy!

Marco

PS Fluke manufactures various electriconic test tools. Overkill for your purposes - no need to spend that kind of money. I think their least expensive multimeter is currently around $150. Save your money and buy some new music.