Audio Asylum Thread Printer

Get a view of an entire thread on one page

FAQ / News / Events

SET Asylum

Jeff, Thanks

173.57.91.172

Yada

In Reply to: RE: Some more questions posted by drlowmu on April 12, 2010 at 21:33:36

Jeff, thanks for helping me get a bit of a grip on this.

Question, if a tube could run anywhere from 1k hours to 10k hours, I can easily see the benefit of 10x more tube life. Is there any way to begin to quantify or characterize how much sonic quality is lost (if any) when a tube is run for maximum tube life? What sonic attributes if any are lost when maximizing for tube life? Also, if somehow "hot rodding" makes a tube sound better, what are the sonic attributes of "better"?

Still more questions: I thought Electraprint made transformers, or do they make tubes also? What benefit would a transformer manufacturer or an amp manufacturer have in running a tube hot (thereby minimizing tube life and maybe some customer satisfication) unless they thought it would sound better? Which brings me back to what is the nature of the better sound? And is there a point at which running an amp hotter simply won't make the sound any better? And could it make it sound worse if it's really too "hot"?

Thanks for helping with the learning lessons. I appreciate it.

Follow Ups:

RE: Jeff, Thanks - tube wrangler 23:25:43 04/12/10 (0)
Relax a moment and just think. Let's say your Boss wants you to take out the garbage everyday at the same time.

Let's say you're a good guy and know what you're doing. Now, think: which way is going to get the best, most harmonious job of having you take out the garbage each day-- a Boss who WHIPS YOU each time before you take it out, OR-- a Boss that simply lets you take it out in the best way?

I think the answer is obvious.

Vacuum tubes do not perform well while being whipped, either.

You ask : "How much sonic quality is lost when a tube is operated for maximum tube life?"

That question is irrelevant because there is no such thing. When a tube is operated at its maximum life rating, it IS SONICALLY SUPERIOR to ALL OTHER operating points, period. VERY, blatantly, and audibly superior.

It is up to the amp designer to let that sonic superiority GET OUT of the amp's circuitry and actually drive a speaker with it.

Some problems arise in doing this, and are dictated by CUSTOMERS and designers who know nothing about amp design except what they study, prove, and read. Simple Common Sense is often left out.

(1) Is WATT RATING. It is ASSUMED that more watts= more power into a speaker. But, it might mean that it's nothing but more watts burned-up and not converted into actual music. In any case, the less power the amp produces, the better the speaker, speaker cables, and amp wiring and layout have to be in order to properly drive the speaker. You can see how this works-- if you want to use cheap, thin copper wiring in an amplifier, then MOST of the power will be burned up in the amp, or delayed musically in such a way that it will produce more heat than music even when it DOES get into the speaker. The bottom line of this is simple: if your amp is cheaply built, simply apply more watts and hope some of it gets through. The customer dictates this approach when he refuses to pay for good amp engineering which costs money, but really works.

(2) Is "tube charts". Customers love to read these things, the assumption being that one should design for a "flat load-line". Well, that's nice. Looks pretty on paper. Even fools a few people. Just one problem: tubes SOUND BEST at the RIGHT OPERATING TEMPERATURE, period. End of discussion. Regardless of "tube charts and curves". Regardless of anything else at all.... . Period.

For the NOS 45, the right temp. on normal types is reached at 245 volts across the tube, and at 28 ma. plate current. That WILL NOT give you a full two watts, and, if the amp is built efficiently (yes, expensively), then it will drive some tough loads easily, and reproduce the full musical bandwidth.. That doesn't mean you can short it out with a 89 db/watt speaker and expect music. For that, you use 1500 watt Solid-State unit, and forget tubes.

So, as you can see, tubes get Hot-Rodded by many who use them. They do this for several reasons: (1) It's the cheap way to force some output thru the cheaply built amp. (2) It looks good on paper-- they are scared "it won't be linear" if they stray from those tube charts straight-line sections-- but this is baloney. Also, music IS NOT linear, and neither is hearing. (3) It used to sell tubes in the tube-era, and few today realize that those old figures are meaningless today. (4) Customers want more watts/per dollar. That is just STUPID. Today, we have many examples of excellent, uncolored musical speakers that run at under 1/4 watt. Together with the latest studio A/D-D/A converters, it's been the greatest advance in audio in the last 5 years.

---Dennis---
RE: Jeff, Thanks - drlowmu 22:08:12 04/12/10 (3)
Yada,
Well, more good questions.
If an amp sounds better when the tube is run hotter, at or above the Manufacturer's spec, it is usually because that amp is poorly executed internally, as far as transfer function, and design of its power supply.
I find best results are obtained with over-designed power supplies, that have a natural stability, under all types of music playback. In addition to the supply's design being as near perfect as possible, the amplifier's internal transfer function becomes a matter to properly address, proper wiring of components, as to wire types, and lengths, and lay outs, so as to NOT LOSE complex musical information inside the ampfilier!!
Particularly in SE amps, where the power supply is INCLUDED in the audio circuit. !!
Most audio equipment is NOT made this way, it is made to a price point, or by individuals who deem such an approach as unnecessary. So, with poorly conceived and wired amps, the hotter the tube is run, sometimes - the better it may sound, at first. But alas, it is only temporary, as the tube quickly degrades due to the hot rodding.
Consider the "Golden Ratio" in design, things like you car, truck, lawnmower, and your Type 45 tube run BEST and longest when designed at or near that number.
And yes, when thoughtfully designed, the Type 45 at 7 watts dissiaption will sonically outperform the same tube running at its full rated 10 watt dissipation, in a good amp. Its easy to hear.
Your family car runs a lot better at 65 MPH than at 100 MPH, and I say it will probably run a LOT longer at 65 MPH. Others will no doubt disagree with me on this topic, and that is fine.
Jeff Medwin

Edits: 04/12/10
- RE: Jeff, Thanks - tube wrangler 23:57:00 04/12/10 (0)
  Perfect post, Jeff. Thank you.
  For those interested in detail/discussion/rants/ravings on this subject: Refer to my old posts on TUBEDIY-- from about 2006 onward. Things got really hot in those days, as usual, I was not always believed, but people who played my amps certainly believed! I laid it all out for you-- to be read years later. Jeff is kind enough to continue mentioning those ideas, and he is also trying to make available power supply parts that will contribute to proper vacuum tube operation in the best ways through better power supply parts. Btavo!
  A vacuum tube is nothing special. It's just another piece of Physics. You play with it until it (ITSELF!) is operating happily, comfortably, and really humming along. That automatically guarantees at least 20,000 hours of operation from it, and that insures zero sonic degradation over at least 10,000 hours, something that is TOTALLY NECESSARY in order to fully enjoy music.
  After all, once you spend days/weeks/months getting an audio system to really perform, wouldn't you like it to STAY that way? It will, if all of the active and mechanical devices are operated in a non-stressed mode.
  Of course, that is just simple Common Sense.
  ---Dennis---
  
  Edits: 04/12/10
- 7 watts dissapation - Yada 22:24:43 04/12/10 (1)
  Jeff, Thanks again. I noticed in a couple of your posts the reference to 7 watts dissapation; is that something you have found to be an ideal spec? How is that measured? Thx!
  
  PS, what are your favorite 45 and 300B amps? and tubes?
  
  - Ever hear a Jeff Korneff 45 amp?
  - RE: 7 watts dissapation - drlowmu 22:45:37 04/12/10 (0)
    Yada,
    
    These are just MY personal opinions:
    
    I was taught to NEVER use a stock 300B by my ultra-smart, superb listening, audio mentor. (B-1925, D-1988). The 2A3 and the Type 45 are generally superior sounding. Stock W.E. 300Bs are for people who don't "get it" with high efficiency speakers.
    
    The EML line, available today, is probably the best sounding audio tubes ever made.
    
    They will outperform all NOS 45s and 2A3s, due to their superior design, linear filament structures, etc.
    
    Actually Yada, in 2010, for some low efficiency bookshelf speakers I own, I am building a DC SE VAIC AV-32B amp. That VAIC tube is the circa 2001 predecessor of EML's very nice 300B-XLS, which is probably the only other non 45 or 2A3 tube I would use. Oh, the NOS 2A3 does well at 10 or 10.5 watts dissipation. Just my tastes and prejudices !! The 2A3 is my favorite all-around tube.
    
    Jeff

Post a Followup:

FAQ

Post a Message!

Forgot Password?

Moniker (Username):
Password (Optional):
	Remember my Moniker & Password (What's this?) Eat Me
E-Mail (Optional):
Subject:

Message:	(Posts are subject to Content Rules)

Optional Link URL:
Optional Link Title:
Optional Image URL:
Upload Image:
E-mail Replies:	Automagically notify you when someone responds.

To view your new posting or follow-up, click on the RELOAD or REFRESH button on your browser.

This post is made possible by the generous support of people like you and our sponsors: