Tube Guide?

[kevinmi]

To all the knowledgeable tube Gurus on this Forum: Is there such a thing as a guide to how different tubes sound? I want to expierement with tube rolling on my preamp and amp, but I can't afford to go out and buy a few of each brand of tube to try out. I'm mostly concerned about the 12AT7's in my amp and the 12AX7's in my preamp and phono amp. Also, what about the difference between KT88 and 6550 output tubes? Thanks in advance! -kevin

[sebrof]

For 12AX7 and 12AU7 do an internet search for Joe's Tube Lore. Lots of great info, if only from Joe's perspective.

The thing about general guides is that there are many variables in how a tube can be implemented circuit-wise, so generalizations do not always hold.

I suggest contacting a seller and asking the questions you have. I can recommend Jim McShane for this, others can recommend other sellers. I've asked Jim through email, he responded with questions about my gear, what I listen to, what kind of sound I like. His recommendations have been spot on. Jim's got a website with contact info.

Hope this helps, Mike

[artto]

To all the knowledgeable tube Gurus on this Forum: Is there such a thing as a guide to how different tubes sound? Thanks in advance! -kevin

Here's your guide:

Artto's "How Do Different Tubes Sound Guide"

Page 1 They all sound different

Page 2 They all sound different

Page 3 They all sound different

Page 4 They all sound different over time.

Page 5 They all change in sound over time.

Page 6 They all change in sound and noise over time.

Page 7 They have different sounds even from the same manufacturer depending on when they were made and where they were made.

Page 8 Oh yeh, they all sound different.

[]

[seti]

A Taste Of Tubes

Artto forgot to mention that they all sound different.

[kevinmi]

Thanks Guys for the input. Did you ever notice that all tubes sound different? -kevin

[USNRET]

Did you ever notice that all tubes sound different? -kevin

I haven't noticed, I got a large box full of matched quads and the smaller tubes (smaller: that's a technical term) but have yet to swap any out to see if I notice any difference.

[gartenman]

ECC801S Telefunken 1960's (the most neutral, clear and quiet 12AT7, also the most expensive)

12AT7 Fisher Telefunken 1960's (excellent high-end 12AT7, very good presence)

A2900 G.E.C. 1950-60s Special Quality black plate 12AT7; good rich sounding audio tube, full midrange

Brimar 6060 long life late 12AT7 blackplate type with yellow "T" decal Rich British tube tone, made at the Brimar Footscray, U.K. factory

12AT7 Philips Miniwatt Holland "D" getter 1959

ECC801S Siemens Munich Germany NOS 1981-1982 (neutral, clean, extended highs, accurate, quiet)

6201 VALVO

12AT7 Philips Miniwatt 1951-1952 (rich and warm, best tonality)

12AT7 GE 1951 (nice lively open sound)

12AT7 RCA (rich and smooth with great tone)

BEST VALUE:

CV4024=12AT7 JAPAN rebranded Mullard 1970's

12AT7 RFT East Germany NOS 1980's

12AT7WC Raytheon black plates triple mica 1975

12AT7 RCA gray plates

12AT7 Mullard 1970's

12AT7WC Sylvania and Philips JAN

12AT7WC GE JAN

[neo33]

Though I have had them for 5 years, I can never tell the difference between a German-made1960 Telefunken 12AX7/ECC83 and a German-made 1960 Telefunken 12AX7/ECC83.

Did I mention that all tubes sound different?

[clermontcop]

Liken that avatar you got there Kevin.[Y]

[hklinker]

I am rolling two sets. The Telefunken smooth plates are my favorite, very mellow and smooth. But if I want a brighter sound I use the Mullards which I really like too, especially with older vinyl that doesn't have a lot of high end left. I think digital music sounds better with the TFK's.

Herb

[gartenman]

I am rolling two sets. The Telefunken smooth plates are my favorite, very mellow and smooth. But if I want a brighter sound I use the Mullards which I really like too, especially with older vinyl that doesn't have a lot of high end left. I think digital music sounds better with the TFK's.

Herb

are the Mullards you are speaking the long black plates or the short gray plates?...I totally concur with your Telefunken description...awesome tube, I always think the best description of the Amperex Bugle Boys is a hybrid of the best qualities of the Telefunken ribbed plates and the Mullard long black plates which gives the best of both worlds, they also have a 3D hollographic sound unheard with any other tube...

[Guest davidness]

I recently purchased my first tube amp from a fellow forum member, a Bob Latino VTA120 (ST-120), that came with (4) Valve Art KT-88's and (3) Mullard CV4024 in the 12AT7 positions. I've driving a pair of Klipsch RF-7's.

I am a newbie, so these impressions are geared toward tube amp novices, but I hope others will learn something from my experiences.

I've never heard any other tube amp, but this thing sounds awesome, which surprsed me since I had been drving my RF-7s with the fairly expensive solid state Yamaha RX-Z7 AV Amp.

I am hooked on the tube expereince (God help me), so let's see how much I can squeeze out of the Latino VTA-120.

I immediately bought a quad of Gold Lion (reissue) KT-88's, but I didn't like their sound as well, so I switched back to the Valve Arts. I only just realized that new tubes do require a break-in period (I've read it takes about 100-hours), so the Gold Lions are back in. After all, all the reviews have been very positive. I've only got 20-30 hours on them now, but I think they're getting much better, and now already equal the Valve Arts. I think they're on their way to greatness. A would LOVE to try a quad of EAT KT88's.

I also learned that the input tubes are even more important to the sound than the output tubes, so I started looking at options to the Mullard CV4024, which get great reviews also (plus it's cheap and plentiful... for now). I also learned that the 'center' input tube is the most important of the 3, then the left/right pair which should be somewhat matched.

Through various means (eBay), I have now ordered a quad of NOS Valvo Goldpin 12AT7WA's, a pair of NOS RCA Black Plate 12AT7's, a pair of Telefunken ECC801S (supposedly the best 12AT7 tune there is), and a single Telefunken E81CC (very similar to the ECC801S).

I have not yet received any of these input tunes. I think that this selection should give me an idea of what rolling 12AT7 tubes can do for the amp. The only other tube that seems to stand out are the Amperex Bugle Boy's, so I'll probably pick up a set of those one day as well (unless I simply bite the bullet and buy a matching NOS set of the Telefunken ECC801S).

Also, the amp came with both a Sovek tube rectifier, which 'flashed and died' within a few hours, but I was also given a solid state Weber Copper Cap rectifier, which is now in there. I've heard the rectifier doesn't affect sound much (if at all), and I'm hesitant to put in a more expense (aka Mullard) rectifier given the unknown reason that first one blew so quickly. (I was power cycling while the amp was already warm/hot. Isn't that okay?)

I'll be certain to post my impressions of the various 12AT7-class input tubes once they get here (some from the Netherlands and from Germany).

Please respond with any of your own impressions of tube rolling the Dynaco ST-70/ST-120 (or similar) as it pertains to this thread. I, also, am interested in the KT-88 vs. 6550 tube.

[Paul Hale]

Wow, you guys are talking about some very expensive tubes. For a lower cost alternative, you should consider some new production tubes, some of which sound very good.

I've really liked the Sovtek 12AX7LPS for phono stage. It's very quiet (spiral filament) and rich sounding (unlike many other Sovteks). The reissue Tungsol 12AX7 is a great sounding tube. Big strong punchy and rich. I'm using the LPS in phono and the Tungsol in the line stage in a rebuilt Dyna PAS. A good combo, I think. Totally quiet with LaScalas. I had bad luck with a lot of '80s Philips 12AX7s. Didn't sound nice, kinda thin, and noisy.

12AT7 are cheaper. You can get old black plates reasonably. The new EH 12AT7 sound OK, pretty quiet, too. I don't use 12ATs much....

I've used Valve Art KT88 and they sounded very good. Better bass, more realistic that EH or SED in my amps. But the latest Chinese KT88s have supposedly slipped a lot in quality(?). Wired as triodes, KT88s are probably better than 6550 because they have a higher screen voltage rating. Gold Lions are supposed to be excellent, but very expensive.

Jim McShane is a good guy to deal with. Has new and old tubes. You can also experiment with his "almost NOS" used tubes.

PH

[gartenman]

KT88s are probably better than 6550 because they have a higher screen voltage rating.

.......higher screen voltage does not make a tube sound better, the 6550 tube was specifically designed for audio purposes, the KT88 was not...

[Groomlakearea51]

Look at tubedepot.com for cost effective stuff. I'll swear by NOS and specificlly Telefunken, for sure, but some of the new stuff is quite good quality.... I use NOS Procomm 12AX7's, and I rather like the JJ's for power (6L6GC). Never been dissapointed and you can call them and talk with them about what you are looking for.

[Groomlakearea51]

A good read for the novice entry level

http://www.vacuumtube.com/FAQ1.htm

Especially read how they work towards the bottom of the document.

[hklinker]

bnb tubes are a good source of Gold Lions and Mullards. They are on eBay.

[gartenman]

I'll swear by NOS and specificlly Telefunken, for sure

Telefunkens are awesome, especially in vintage gear, they seem to help tighten up the sound ...personally I love Amperex Bugle Boys signal tubes from the mid to late 50's...

i had the KT-88 Gold Lions in another amp and think they come pretty close if not beating the vintage Genalex KT88's... Most audiophiles agree that the Tung Sol 6550 Black Plates are the best, but the Gold Lions are a very budget friendly tube that will get you pretty close...although i got my last quad of Tung Sols for $50 each so there are buys to be found in used NOS tubes despite what some claim, you just need to find a reputable, knowledgeable source...i recently picked up 2 Telefunkens for a friend, they tested practically new...they were labeled Dynaco but were made by Telefunken as testified by the diamond logo on the bottom...thats how to get the nicer tubes cheap is to know which tubes are labeled for one company but were actually made by the major companies of the time, Eico and IEC made by Mullard; Adzam, Pope, Philips Miniwatt by Amperex, Dupont by Tung Sol are just a few more examples...2 Dynacos- $40 whereas the same tube with a Telefunken label is 2 for approximately $150.....same tube

[Audible Nectar]

For 12AX7 and 12AU7 do an internet search for Joe's Tube Lore. Lots of great info, if only from Joe's perspective.

I wouldn't bother with this TOO much - after all, Joe HATES 12AX7s and 12AU7s. He "glosses over" these in a "do I really have to do this" kind of fashion.....it's much like having Mikey do a review of cereals other than "Life" brand. His 6DJ8 comments are very good though.

While all tubes have thier synergies with specific gears, I prefer the Euro tubes by and large, and find the blue chart earlier to be a decent guide. What is noteworthy is how the Mullard and Amperexes differ with vintage....especially the Mullards, which have quite a variance from earliest to later vintages. I Like Tele 12AX7s in my vintage Mac gear, Amperex 12AX7s in most modern gear, and earliest Mullards are a very good phono tube.

[Audible Nectar]

IAlso, the amp came with both a Sovek tube rectifier, which 'flashed and died' within a few hours, but I was also given a solid state Weber Copper Cap rectifier, which is now in there. I've heard the rectifier doesn't affect sound much (if at all), and I'm hesitant to put in a more expense (aka Mullard) rectifier given the unknown reason that first one blew so quickly. (I was power cycling while the amp was already warm/hot. Isn't that okay?)

NO - that is NOT OK with a Sovtek or Sino 5AR4. Not really recommended with a Mullard, either, although they will usually "take it". 5AR4s should be allowed to cool down before powering back up again.

I DO use Mullards. I believe in the benefits of tube rectifiers on Klipsch, and I use pre 1966 Mullards in my VRDs. I stocked up in recent years.....you CAN do better than typical market prices if you look around......