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    Toob tips for newbies, and I'm one, too

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    deepee99

    Posts : 1260
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Toob tips for newbies, and I'm one, too

    Post by deepee99 on Sat May 30, 2015 5:58 pm

    1. Forget everything you learned in your ham radio days. A 6550 tube is not a 6146A.
    2. All the bad habits you acquired running sold-state, no matter how good, do not apply to tube amps and preamps. Tube amps are much more sensitive to loads than are s/s gear. And tube amps tend to be far more input voltage sensitive. Shop for speakers and rectifiers accordingly.
    3. Tube amps distort. So do s/s amps, though the show-room guys with their $1000/foot connecting wires don't seem to notice.
    Did I mention DISTORTION?
    It's a matter of personal flavour. That's where tubes trump s/s -- you've got a bulk of choices.
    If you start with a Bob Latino amp, you've got a bullet-proof platform.

    arledgsc

    Posts : 330
    Join date : 2012-11-30
    Location : SF Bay CA

    Re: Toob tips for newbies, and I'm one, too

    Post by arledgsc on Sun May 31, 2015 12:56 pm

    Tube amps are different animals but very satisfying sound quality that gets me back in the groove for listening to music and that is what it's all about. You have to throw out the spec sheets when comparing tube amps to s/s. A well-built ST-120 with the right tubes operates way above its price class. Very recently purchased a new DAC with a lot more detail/ clarity and the ST-120 makes it shine and sparkle without harshness. The s/s amp sounds closed in and clinical in comparison.

    But tube amps are finicky and require occasional attention though - just like any loved one!

    Bob Latino
    Admin

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    Location : Massachusetts

    Re: Toob tips for newbies, and I'm one, too

    Post by Bob Latino on Sun May 31, 2015 1:42 pm

    Tube amps ..

    The Good
    (1) they tend to reproduce a 3 dimensional sound stage better than SS amps as long as your speakers are well placed in the room. People tend to push their speakers up against a wall because "the missus" likes them that way (out of the way.) Try pulling your speakers out from the wall 2 to 4 feet (if you have the room to do so). You will probably be rewarded with better soundstaging and less boomy bass.

    (2) I never found a SS amp that could reproduce acoustic instruments like a sax or a trumpet the way a good tube amp can. The same for the human voice provided the mixing engineer hasn't digitally messed with track to alter the vocalist's voice. Listen to a Diana Krall recording sometime. With a good tube amp - she can appear to be "in the room"

    (3) Tube amps do tend to sound somewhat louder than their solid state counterparts of equal power rating. A lot of this has to do with the way that tubes "distort" at very high signal levels. They tend to distort gradually and somewhat gracefully when pushed hard. I have had a number of customers mention to me that their VTA ST-120 sounded as strong as the 100/120 WPC SS amp that it replaced.

    The Bad
    (1) Tubes have a finite life. Tubes will wear out after a while. You will lose a tube now and then. Sometimes they just give up the ghost. Tubes require more amp maintenance.

    (2) Tubes give off a lot of heat. In the summer in a small room, you may be uncomfortable with your tube amp on after a few hours.

    (3) If you want/need a lot of watts, you will pay a lot more "per watt" for a tube amp than a SS amp.

    Bob

    sKiZo

    Posts : 1285
    Join date : 2013-04-01
    Location : Michigan USA

    Re: Toob tips for newbies, and I'm one, too

    Post by sKiZo on Sun May 31, 2015 2:21 pm

    This is what my ST120 replaced ...



    200wpc with 400wpc instantaneous peaks. Granted, a bit long in the tooth. Original plan was to have some fun with the tube amp while I rebuilt the MC2205, but frankly, there hasn't been all that much incentive. The ST120 runs rings around it for tone and depth (once again, probably age and miles has a lot to do with that), and easily creates the same SPLs I'm happy with. Bonus, I still get power protect lights on the speakers, but no more crunchy sounds when clipping.

    Go ahead, try and listen to Porcupine Tree without clipping ... can't be done!

    deepee99

    Posts : 1260
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Toob tips for newbies, and I'm one, too

    Post by deepee99 on Sun May 31, 2015 2:38 pm

    Bob L.,
    I certainly concur with your pros and cons. (Well, you're the pro, how could I not?)
    Yes, Diana can certainly Krall into your lap with the proper tube configuration. Art Pepper, Leonard Cohen, most any DG classic recording, ditto.
    I think an issue not dealt with sufficiently on this board is speaker efficiency. Solid state amps and low-efficiency acoustic suspension speakers crept onto the scene at about the same time. You needed lots of juice to run the sealed boxes, which tubes do not provide and thus made solid-state high-watt amps attractive.
    There lately seems to be a renaissance in high-efficiency speakers. Speaker efficiency ought to be a consideration when selecting a tube vs. s/s amp.
    Horns are of course the best in terms of dB/watt. but to my ears they suck. Seas and Scanspeak make some very good high-efficiency drivers in the traditional cone mode. Tyler Acoustics makes a very good 90 dB/watt speaker in their Decade series, and I have heard of even 103 dB/watt stuff.
    Speaker efficiency tips the equation back to toobs, IMHO.
    Plus, all distortion being unequal, there's a plethora of options with toobs unavailable to the sand amp drivers. In other words, you can flavour your sound with tubes to your liking. Not possible with solid state.

    Kentley

    Posts : 295
    Join date : 2015-03-06
    Age : 64
    Location : Worcester, MA

    Re: Toob tips for newbies, and I'm one, too

    Post by Kentley on Sun May 31, 2015 3:29 pm

    It's good to get back to the basics once in a while and see the Big Picture of "Why Tubes?" All of this info is crucial to us tubies. I'm especially drawn to the admonitions of deepee about careful matching of components, and also to Bob's comments about speaker placement. Going the "extra mile" with these critical factors can make the difference between "good bang for the buck" and SPECTACULAR SOUND.
    Yes -- all equipment "distorts" to one degree or another, if you remember the true meaning of distortion is "alteration". I suppose our goal, then, is to find the type and level of distortion we can live with. For example, I have pretty severe tinnitus from my rock 'n' roll days, so I must always be conscious of what my high frequencies are up to. The next guy might be more concerned with deep bass. At any rate, it's good to return to square one, folks. And don't forget to occasionally listen to music, rather than merely listening to your gear. Happy Tubing!

    sKiZo

    Posts : 1285
    Join date : 2013-04-01
    Location : Michigan USA

    Re: Toob tips for newbies, and I'm one, too

    Post by sKiZo on Sun May 31, 2015 4:37 pm

    You want to talk speaker placement ... try Carver Holography. An inch either way, or a degree of toe or inclination, can totally collapse the stage.

    Pure madness, making the effort required to actually make that work ... but pure bliss when it does.

    PS ... my Big Mac XR16 speakers are rated 89db and the ST120 drives them fine. Big bonus for holography is they're "isoplanar" with all the drivers centered vertically and acoustically equidistant in the boxes - that works best with this setup.

    Kentley

    Posts : 295
    Join date : 2015-03-06
    Age : 64
    Location : Worcester, MA

    Re: Toob tips for newbies, and I'm one, too

    Post by Kentley on Sun May 31, 2015 4:39 pm


    "PS ... my Big Mac XR16 speakers are rated 89db and the ST120 drives them fine."

    It's the Special {spatial} Sauce, Mr. sKiZo.

    Bob Latino
    Admin

    Posts : 2374
    Join date : 2008-11-26
    Location : Massachusetts

    Re: Toob tips for newbies, and I'm one, too

    Post by Bob Latino on Sun May 31, 2015 5:06 pm

    deepee99 wrote:Bob L.,

    There lately seems to be a renaissance in high-efficiency speakers. Speaker efficiency ought to be a consideration when selecting a tube vs. s/s amp.
    Horns are of course the best in terms of dB/watt. but to my ears they suck. Seas and Scanspeak make some very good high-efficiency drivers in the traditional cone mode. Tyler Acoustics makes a very good 90 dB/watt speaker in their Decade series, and I have heard of even 103 dB/watt stuff.
    Speaker efficiency tips the equation back to toobs, IMHO.

    Hi David,

    Quite true .. The only issue that VERY efficient speakers have is that they magnify any residual amp/preamp noise/hum. People buy a 100+ dB efficient speaker and then they are going to drive the speakers with very low SET power amps. SET amps, by their very nature, nearly always have higher noise levels than push-pull amps. A high percentage of a push-pull amp's noise cancels out inside the output transformer before it ever reaches the speakers. I had Email and phone conversations with a manufacturer of fairly efficient speakers who told me that he liked the sound of his VTA ST-70 amp with his speakers because the VTA ST-70 had more headroom than any SET amp and also had noticeably lower noise levels than any SET amp he had tried with his speakers.

    Bob

    deepee99

    Posts : 1260
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Toob tips for newbies, and I'm one, too

    Post by deepee99 on Sun May 31, 2015 6:01 pm

    Bob Latino wrote:
    deepee99 wrote:Bob L.,

    There lately seems to be a renaissance in high-efficiency speakers. Speaker efficiency ought to be a consideration when selecting a tube vs. s/s amp.
    Horns are of course the best in terms of dB/watt. but to my ears they suck. Seas and Scanspeak make some very good high-efficiency drivers in the traditional cone mode. Tyler Acoustics makes a very good 90 dB/watt speaker in their Decade series, and I have heard of even 103 dB/watt stuff.
    Speaker efficiency tips the equation back to toobs, IMHO.

    Hi David,

    Quite true .. The only issue that VERY efficient speakers have is that they magnify any residual amp/preamp noise/hum. People buy a 100+ dB efficient speaker and then they are going to drive the speakers with very low SET power amps. SET amps, by their very nature, nearly always have higher noise levels than push-pull amps. A high percentage of a push-pull amp's noise cancels out inside the output transformer before it ever reaches the speakers. I had Email and phone conversations with a manufacturer of fairly efficient speakers who told me that he liked the sound of his VTA ST-70 amp with his speakers because the VTA ST-70 had more headroom than any SET amp and also had noticeably lower noise levels than any SET amp he had tried with his speakers.
    Bob
    So, brother Bob. is an SET amp in the offing?

    Bob Latino
    Admin

    Posts : 2374
    Join date : 2008-11-26
    Location : Massachusetts

    Re: Toob tips for newbies, and I'm one, too

    Post by Bob Latino on Sun May 31, 2015 6:17 pm

    No SET tube amp in the offing .. Not enough power and insufficient headroom to driver normal efficiency speakers. Your speaker choices become much more limited if you go the SET route ..

    Bob


    deepee99

    Posts : 1260
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Toob tips for newbies, and I'm one, too

    Post by deepee99 on Sun May 31, 2015 6:39 pm

    Bob Latino wrote:No SET tube amp in the offing .. Not enough power and insufficient headroom to driver normal efficiency speakers. Your speaker choices become much more limited if you go the SET route ..

    Bob

    Yep you're right there. We're talking 130 dB/watt here. Not within the normal realm.
    Just re-installed 6550s in my M-125s, all silver on the getters. Can't imagine better sound.

    bluemeanies

    Posts : 120
    Join date : 2015-02-09
    Age : 66
    Location : Folsom Pa.

    Re: Toob tips for newbies, and I'm one, too

    Post by bluemeanies on Sat Jun 06, 2015 10:17 pm

    How do the 6550's compare with the KT88's?

    deepee99

    Posts : 1260
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Toob tips for newbies, and I'm one, too

    Post by deepee99 on Sun Jun 07, 2015 9:51 am

    bluemeanies wrote:How do the 6550's compare with the KT88's?

    You could start a tong war here with a question like that.
    I don't think there's any consensus on the power tube front. I personally prefer the original New Jersey-built TS 6550s, but cannot compare them with the British-made KT-88s from that era.
    I do have a set of the modern, Russian-built Genalex KT-88s that are very sweet, plus a couple of years' experience with the modern New Sensor/Tung-Sol KT-120s, which IMHO give the best bang for the buck. They're bullet-proof and deliver superb sound, and don't break the bank when replacement time (conservatively 3,000 hours) comes.
    Much as I like 'em, I won't be buying any more of the original Tung-Sol 6550s as the price has gotten way out of hand. Jim McShane at http://www.mcshanedesign.net/tubes.htm , my go-to guy for the newly-built Russian tubes, recommends the Genalex "Gold Lion" KT-88s and will get no argument from this quarter, and they cost about the same as KT-120s -- about $200 for a quad with shipping all in.
    New old-stock British KT-88s or American 6550s are going for $600 or higher per quad, probably unmatched, and you're taking your chances on the seller... not worth it.
    The only new output tubes I disliked were the Winged-C Svetlanas and the General Electric 6550s. They were too tinny-sounding.  Some folks swear by them, however.
    Give some thought to experimenting with your driver tubes; they can have considerable influence on the sound flavouring, more so than the power tubes. Plenty of old-stock and current production copies out there, and if you don't like what you get you won't be throwing $400 out the window.


    Last edited by deepee99 on Sun Jun 07, 2015 9:52 am; edited 1 time in total (Reason for editing : Clarification)

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