Karl's Korner
Tubes, Remotes And More!
Article by Karl Lozier

  Note: This column is a relatively new feature and items contained here have been updated this month or are new. Others have now been eliminated. This column may not appear every month but as often as the occasion arises or the need continues. In general I expect it to contain comments on a wide range of subjects including equipment and music, but not in great depth. Consider it a lumping together of items not long enough or of sufficient interest to warrant a full review or lengthy article by themselves. Comments, suggestions or questions as always for Enjoy The Music.com™ are welcomed. Clicking on the appropriate place will send your e-mail comments to me.

You will note that the first item updated for this month's issue violates my stated generalities; it is rather long and relatively in depth after a fair amount of research and time involved. It will continue to be updated as more information and comments are received by me. Feel free to contribute.

Small Signal/Mini Tubes For Pre-Amplifiers, CD Players, And Input Tubes For Amplifiers: Updated!

Senior Editor Dick Olsher seems to have really started something, in his recent review of the Heart CD player, which is basically a model 6000 by Marantz, and created by the addition of a tubed output stage. Basically Dick infers that at $750 the Heart was nothing to really brag about. Substituting tubes by some of the famous old manufacturers of yesteryears created a transformation, as Dick seemed to have expected. The new creation had become an excellent and very detailed player competing in the $3,000 price range! The stock player comes with Sovtek brand 6922/E88CC tubes, as would be expected. What other choices do you think a manufacturer has available? Dick's top substitution choice was the third and rarest member of this mini frame grid series of tubes, the 7308/E188CC. Dick's favorite was the Gold Aero model 7308, probably manufactured in Germany by the famous Siemens or Siemens & Halske Company. Those tubes were probably made almost forty years ago.

Consider the above paragraph a prelude plus the underlying reason for the following dissertation. At CES I talked with Dick about the Heart and other CD players and decided to take the plunge by ordering a Heart player in the gold/champagne colored chassis. I had a bit of a wait and George Stuppel, the importer, blamed the wait on the great interest created by Dick Olsher's rave review in our January issue and still available by clicking on our equipment archives section. I asked George if he had any of the tubes available that Dick had substituted for the stock Sovtek 6922s, or similar ones. He replied that he did not but agreed that putting in the better premium tubes made about three or four decades ago did make for a dramatic transformation echoed by many of his purchasers. He further stated that he would dearly love to get his hands on a large stock of those NOS (New Old Stock) tubes at any semi reasonable price. Small numbers would be of no value to him as the importer/distributor of the Heart players; making a few customers happy would tend to alienate the other customers and understandably so.

Thus began my search. Dick put me in touch with a couple of sources in the U.S. and elsewhere that had told him they had some S&H (Siemens & Halske) 7308/E188CC tubes for sale. By the time I contacted them a bit later in January, they were all gone and had no idea when they might find more. These tubes are no longer being made and even the ones made in the mid and late seventies are regarded as inferior to the ones made in the sixties and first few years into the seventies. I searched and searched and found as Dick had mentioned, that the internet sources for tubes, and particularly this type of tube, is a genuine can of worms, a buyer beware situation and a danger zone. Fortunately there are at least a few trustworthy and knowledgeable audio tube sellers still out there. How can you find them, how can you tell and how to be certain you can obtain the return of your money if you are not satisfied - only you can decide.

Go slowly, ask questions and only order one pair at a time. Ask if the dealer/seller is at least a bit of an audiophile. If he is, the odds tend to go in your favor; most of those have probably built their own amplifiers and preamps and have a tendency to still be vinyl-oriented listeners. I'm going to summarize my findings from various sources, but only naming one of them who I'm using as the basis for my summary. I do not recall any specific dispute from any of the other sources. In other words there is general agreement if not quite one hundred percent. Fortunately, my unofficial standard bearer has a very interesting and informative web site, www.vintagetubeservice.com. I met Andy Bouwman a few years back at one of the big national shindigs held in the Chicago area. He was and still seems to be passionate about vintage audio gear, not just tubes, that offer truly musical sound. I was particularly struck by the phrase on the cover of his brochure stating, "All tubes tested and then selected by ear". At any given time he may or may not have any of the tubes mentioned in stock; the situation for him and other tube dealers is constantly changing. Most of them keep a want list for people willing to wait.

There are three main choices in this 9-pin family of so-called mini tubes. Unlike other mini tubes they have what is called a frame grid design. The grid wire is tightly strung tungsten that is 0.00029 inches diameter. It is just barely visible without magnification. Imagine how tough it is to work with or manufacture! Siemens & Halske (much later simply Siemens) had developed a predecessor to the frame grid way back in 1926. The first frame grid tubes were developed in 1958 by Amperex of Brooklyn, N.Y. after being acquired by the giant Phillips Corporation of Holland. Yes, these tubes were just being introduced when transistors were starting to take over in the electronics field. These tubes were not designed and developed for audio use. They were developed for video and radar use. This is one of the fundamental reasons why audio engineers disagree about their use in applications such as use in stereo preamplifiers, etcetera. Audio rejects usually work fine in other applications and hopefully any seller will check their suitability for audio use. The 6DJ8 (ECC88) was the first and most common tube in the family. The 6922 (E88CC) is often listed as the rugged construction version of the 6DJ8. It's questionable if it is or if it is significantly so and what affect, if any, is there on its audio quality.

For specification lovers, the filament current rating for the 6DJ8 is actually higher than for the 6922. The 7308 (E188CC) is listed as available to military specifications. It was typically manufactured with a few internal parts changes and often considered to be the most rugged, but to what audio benefit? Here specification lovers will note that the 7308's cathode current and maximum anode voltage are approximately ten percent higher than for the 6922 and 6DJ8 siblings. In addition the capacitance output is about triple. Everyone else can forget the above numbers and concentrate on, how do they sound?

We have to have a level playing field. The legendary age for these tubes, in general, is the sixties plus or minus a few years. Even the best were not identical in manufacture or sound from 1960 to 1969. In general, in a given time period the 6DJ8 series will sound slightly fuller or richer than the 6922 manufactured around the same time by the same company. In turn, the 7308 series will tend to sound subtly tighter or leaner in the bass end than the 6922's from the same company. From company to company the fullness or richness peaks with the famous Mullard (England) brand, next in line the Amperex/Phillips; call Telefunken neutral and Siemens & Halske just a wee bit lighter/leaner than the others - and their production in the post Halske years (just plain Siemens) became increasingly lighter over the years. As a point of interest, it has been brought to my attention that any and all 6DJ8 tubes manufactured by Amperex/Phillips were actually made in Europe no matter the name on the tube or other printed information. This is not true of the 6922 or 7308 tubes. What about the other companies, you ask. What other European or American company was there in those legendary days?

Even the huge RCA tube division, with its consistently good but unheralded audio tubes, never even bothered to start production on any 6DJ8 tube types. Sure, you'll find plenty of these frame grid tubes and boxes marked as RCA. If you're able to determine the country of manufacture, with certainty, then you'll know who did manufacture them. Sweetness or smoothness in the treble range comes close to being identical for all, though seemingly differing because of differences in tonal balance related to bass fullness. The Siemens & Halske line tended to be the most detailed sounding. Between the 6DJ8's and the 6922's, the 6922's tend to be subtly less full or rich sounding in the bass range, particularly noticeable in the Amperex/Phillips line. A pair of the Amperex 6DJ8 bugle boys were sounding particularly rich and almost overly full used in my Heart CD player.

By contrast the Amperex/Phillips marked Amperex USA 6922 SQ (Special Quality) and the seemingly identically constructed marked Phillips E88CC PQ (Premium Quality) tubes exhibited none of that excessive fullness. These specially marked tubes were truly special at least in that they were tested then went through a special aging process and then retested. I also found a unique series in the Mullard line labeled 6DJ8 Gr Britain Master Series M10. My experience comparing a pair of Siemens Halske 6922s with a pair of their 6DJ8 carrying the RCA name on the tubes and the box performed similarly to the above-mentioned Amperex/Philips comparisons but only to a very slight lesser degree, an almost insignificantly slight degree. I've not yet gotten to throw any 7308 tubes into my comparative listening sessions. I'm still looking but no longer with any sense of urgency, though I would like to report personally on them.

The main purpose of the brief history and my and others' sonic impressions of the various legendary frame grid tubes is to let you know there are some other choices for you in addition to Dick Olsher's top choice for use in the Heart CD player, because it is basically impossible to find any NOS Gold Aero 7308 tubes for sale. Don't worry that you can't find Dick's favorite tube. Many people wish that they had been wise enough to stash away tubes a decade or two ago when true bargains were to be had. The main point is that you want to find tubes that have a sweet, smooth and detailed high end; I've pointed out a number of them from the legendary era of U.S. and European companies. A little fly in the "tube ointment" was Dick's finding the Gold Aero (Siemens?) tubes noticeably richer and fuller sounding that the Amperex equivalents he had for comparison. This is contrary to the expected. My guess is that his Amperex/Phillips brands were later production samples from the late seventies or even later when it was common for them to have a leaner or tighter bass range than the earlier models typically possessed.

Now I want to mention a variety of facts that may provide more insight into the background and some problems with these audio tubes. The giant R.C.A. receiving tube division was auctioned off in 1976, a victim of the overwhelming popularity of transistors. This effectively killed the supporting industries. All those tiny parts inside the tubes that had become perfected over the decades were about to become history. If ten years later, someone wanted to resurrect quality vacuum tubes it would be starting over on a lost art that wound up with little demand. The demand from audiophiles and music lovers is a grain of sand lost on a wide beach. Some tried to resurrect them in the eighties with identical appearance but unfortunately inferior performance, either brightly harsh or some being darkly veiled sounding. The main key here, is when was any individual tube made and where? Markings on the boxes are often meaningless. Markings on the tube tend to be more meaningful - sometimes. If a tube says "Germany" that is unfortunately, legally not the same as saying "Made in Germany". That's a probable scenario for the flood of Phillips branded JAN marked tubes still floating around. Look out for what some rather infamous tubes connoisseurs refer to as "Telejunkens". Evidently some original Telefunken machinery fell into Russian controlled East Germany hands so that the tubes appeared to be the real thing. They eventually flooded the market with them and are relatively common to this day. Seemingly most, if not all, were marked as 6922 or E88CC types and made in Germany, which they were. Audio quality is definitely inferior - beware. As a result companies such as Siemens stamped their tubes West Germany.

As for the frame grid tubes I've briefly discussed, Andy Bouwman mentioned to me that some time ago he purchased a forgotten stash of Siemens & Halske 6922 and 7308 tubes. These are often regarded as the best, even surpassing the general reputation of Telefunkens. He said that he had gotten 600 of them and only approximately 450 were good enough for his standards for audio use and sale. About one fourth were audio rejects. Wow I said, "I thought that the SH logo Siemens were the best tubes and had the best quality control." "They were", he replied, "but remember these were not designed for audio use and so there was little need for quality control for microphonics and the unbelievably thin wires in the frame grid are extremely sensitive to microphonics!" Even fairly loud music shakes hundred pound loudspeakers and fifty pound turntables or CD players. Think how it can affect the thin glass of those tubes. It causes ringing, exaggerated treble notes and general smearing. It is easy to grossly test for microphonics, but if you've never done it, I'm not about to tell anyone to open the case of tubed equipment with its dangerous high voltages to check for microphonics. Someone else will have to tell you what to do. Be careful if you decide to try these tubes in your preamp as in some equipment designs each of the tubes (usually two) in each left and right section must be carefully matched or very serious problems can result.

The above comments pretty much hold true for the other famous series of mini tubes, the 12 series i.e., 12AX7 and its many variations plus 12AT7 and 12AU7. Here must be added genuine RCA manufactured tubes and a few others. Also with these tubes, genuine Telefunkens were more common than they were with the discussed frame grid types. The same order of fullness/richness tends to prevail with these as with the frame grid types. Place the RCA's just before the more neutrally balanced and not quite as soft sounding Telefunkens. The famed neutrality of the Telefunkens is more readily apparent and perhaps important, when used at the input of many tubed amplifier designs where feedback loops exaggerate minute differences between tubes. All brands were affected by the aforementioned industry decline and lack of the highest quality parts and needed special chemicals for manufacture. Varying by company, by the early to mid seventies the highest quality mini tubes had become a part of audio history. Some resurrections were attempted.

Another update resulting from various sources and passing on to our readers is that much, but not all, of our audio equipment does fine with 5751 tubes replacing 12AX7 tubes. In fact a number of sources prefer a few of the 5751 tubes to any of the 12AX7s! However, the choices are daunting in detail, best left to the experts, but in addition to the ones I mentioned above are some of the various GE, Sylvania, Raytheon and Tung Sol offerings In the 12AU7 line most commonly mentioned top choices were various Amperex (Holland) versions including the well-known ones marked "Bugle Boy". As with most Amperex marked tubes including the 6DJ8, 6922, & 7308, the earliest (and often the best sounding) have white printing on the tubes, slightly later production was orange colored; both of these colorings wipe off easily almost by looking hard at them! Later green or red marked ones were more resistant to coming off and unfortunately along about that time the sound quality had started deteriorating in general. I'm led to believe that much of this applies to the tubes marked Phillips (Holland).

Rumors attribute a small deluge of tubes branded as GE still floating around the country with distinctly inferior audio quality. A pundit quipped that the ones with the superior 5 stars rating imprinted, were much closer to a 1 or 2 star audio rating. Again, it's buyer beware! While writing this article, I purchased 4 more tubes (same brand, gold pins and all) from a previous source and not mentioned in this article. This time 3 of the 4 are very microphonic and I get exaggerated click noises through my speakers when turning click stop controls. Did I mention anything about "Buyer Beware"? Good Listening.

Original Tube Dampers

These beautifully finished brass damping rings weigh a quarter of a pound. Yet they are available in the correct size for nearly all of the mini-tubes mentioned in the above tube article. They are available from Andy Bouwman at Vintage Tube Services. Seemingly a simple design, but they are not quite as simple as they appear at first glance. Bouwman particularly recommends their use with zero feedback equipment and SET amplifiers. There are many logical reasons why these heavy rings, looking like a man's oversized wedding band, can benefit sound quality. With "cageless" tube gear they add an attractive masculine touch to exposed tubes. I had 3 microphonic tubes, 1 was microphonic in the extreme, a hard glance at it would almost cause microphonic noises. Putting these dampers on all 3 resulted in 2 cures. Burial is the only alternative for the third one. Relatively expensive ($64) but worth their price in many situations. Andy does like to communicate by phone also - (616) 454-3467.

A Second Opinion - Result Unchanged + Update, Check Our Equipment Archives For The Walcott Amplifiers.

Enjoy and get informed by an excellently written review by Senior Editor Dick Olsher of a great amplifier. The review so intrigued me that I just had to listen to a pair in my home. My friend, Dr. Jim, let me borrow his pair for a three-day weekend. Within the first few minutes it was obvious that these were the best amplifiers I've ever had the pleasure of hearing in my home. My setup is far different that Dick's but the results were the same. Never heard of them? That's understandable, they don't have to bother to advertise and so they don't. Luckily they don't spend money on meaningless design features to impress people visually though I find them esthetically pleasing.

Audibly they are competitive with, or superior to, the most expensive amplifiers advertised in music oriented and audiophile magazines. They are tubed and still walk over most of the best solid-state amps in the bass range! Dr. Jim at times uses them for his Pipedream subwoofer towers, they're that good. Some info is available on their aptly named website. These amps are for audiophiles or music lovers and superbly control essentially any speakers including full range electrostatics while seducing you with their musical sound.

Because of a change of residence Dr. Jim had packed up his Wolcott amplifiers and they had not been used for months. I helped him set up his system in his lovely new home. There were some minor problems including a persistent hum through the subwoofers but his Pipedream loudspeakers sounded superb as usual with absolutely no warm up period for the Wolcott amplifiers. The stereo version of these superb monoblock amplifiers have not yet gotten into production because of a back log of orders for the original monoblock versions!

Seems Logical Why Most Of The Equipment We Review Appears To Be Highly Rated

Why not I ask you? After spending quite a bit of time and money to attend the annual CES in Las Vegas, I try to pick out items that are least decent sounding while seeming to be interesting or promising. Actually I try to aim higher than that either on an absolute basis or on a value basis. I spend many days reviewing even the simplest items and weeks for most of them. Actually poorly performing equipment often takes longer. A reviewer has to bend over backwards to make certain a negative comment is accurate; manufacturers get rather touchy about the subject. Compatibility issues may arise, instruction manuals may be confusing or even contradictory and the manufacturer may request return of his product for inspection or send out another sample. That means more break-in/burn-in hours. Who wants to spend extra time evaluating items that don't seem at least promising?

Taddeo Digital Antidote Two - Update!

At CES Dave Clark of Audio Musings handed me a very small innocuous looking gadget with RCA type inputs and an output pair of wired male plugs. Dave explained that Tony Taddeo of Taddeo Loudspeakers had developed a $995 active device to correct for problems inherent in CD players and DACs. He has now developed this patented small passive version of it. Its roughly the size of a pack of cigarettes, retails for a nickel less than $100 and is offered on a 30 day trial basis. With the attached (3 inch wires) male RCAs, plug it into your preamp or receiver and in turn plug your CD or DAC's output cables into it. Is there any snake oil inside this tiny unit - I don't think so. The unit is supposedly designed to correct for phase errors and distortions caused by CD's well known steep filters. My guess is that it has the best chance of improvement with systems that have speakers that are much better than the rest of the system. In other words, when the speakers are able to very clearly, without masking, reproduce the little nasty digital flaws originating with the CD player and possibly exaggerated in the amplification chain.

In my system it seemed to do a bit more for the solid-state player than the tube based one. In both cases, there were a couple of very subtle negative effects. Possible improvements, with its use, would center around reducing the sensation of harshness or edginess to the sound, equating with less brightness. It's worth a try with the trial offer and low price. I kind of hate to even mention it, but. During the short time I played around with this thing, I eventually ran Purist Audio Design's CD through the Taddeo Digital Antidote Two. Their latest CD is called "The System Enhancer Rev-B" and it seemed to make some additional improvement as claimed! I have to just say "seemed" because once something has been enhanced how can it be unenhanced to double check it? Oh well, this was the place for this item and my comments. Updating with a bit of recent use, I need to mention using a Taddeo Two while comparing a recently evaluated upsampling model CD player to a regular solid-state model. There was so much difference in the high end that I plugged the Taddeo unit into the solid-state player and then repeated the comparisons. No, I'm not going to tell you that the high-end response then equaled or sweetened up as much as the upsampling model player but it did go part way in that direction. Seems like for anybody complaining about harshness in the high-end response of their CD player should consider giving this little inexpensive gadget a trial. There is a web site and you can guess its name. Phone lovers can call Taddeo Loudspeaker Co. at (716) 473-9076; Faxers should try (716) 244-4106.

Remote Controls
Are You Content With The
One Or Ones That You Use?

Do you have things such as a satellite dish, VCR, cable, DVD player etcetera hooked up to play through some half way decent speakers while watching the TV or monitor? How long would it take you to explain/show someone how to use everything in your system - then could they actually do it or would it take them half way to forever to get it down pat? How many remote controls do you have? In less than sixty seconds I got up and counted 23 in my home and I'm sure I missed a few - that's ridiculous. If you haven't noticed, much of the latest AV equipment demands use of the remote for all functions except perhaps on/off, up/down, volume/channel. I'm leading up to a comment about universal remote controls. I keep looking - for some reason I don't take kindly to the touch screen types that have been proliferating lately.

A couple of years ago I brought home a couple of A/V Producer 8 models by the One for All Company. It works pretty well for me with just 1 or 2 quirks, maybe just because of my TV used as a monitor. The lighting of the button controls doesn't last worth a hoot though. Last year my searching efforts at CES resulted in my winding up with a Marantz model RC1200, which seemed and still seems very promising. In other words I've not found time to have yet learned to really master it. This year's CES efforts are the most promising ever. I had to wait awhile for this year's find, because they had sold out and were awaiting new stock - hopefully a sure sign of a successful product. Actually their current promotion was a recently introduced model that can be used in conjunction with home computers. I passed on that model instantly. I already get enough problems out of my computer. So the model on back order, Universal Remote Control Company's MX-500 was chosen. This particular model has earned a couple of recognition awards recently and I look forward to tackling it as soon as I get a little free time. I sometimes think that remotes are from Mars; unfortunately I must be from Venus or wherever. Fortunately the booklet looks intelligently laid out and has recently been updated. This unit appears to deserve your serious consideration.

It certainly has all the features typically needed or offered such as learning, macro modes, easily read LCD screen, memory retention while changing batteries and on and on. Retail price is less than $200. Check out the web site at www.hometheatermaster.com and see if you can download the latest users manual - that should answer questions you may have. May you be blessed with needing only one remote for everything video and audio and topped off with ease of use. Updating my report is that so far all is going smoothly with this excellent remote control though I have not finished doing everything with it that I want it to do for me. The various pieces of equipment in my home theater system had many applicable codes listed with the model MX-500. Though all would work a few basic control functions, typically one would operate many more functions than the others. So when setting up this model try out all the listed codes for your equipment as one or two may be much better than the others.

Can Computer Sound Woes Be Cured By A Monsoon?

The answer is yes, if its either the Monsoon model MM 1000 or the MM 2000 by the Sonigistix Company. It is also the answer for a small and simple system for any relatively small room; it has an input jack for a CD player. Nothing else is needed! It is not designed to over power computer game players. With any reasonably good source it is simply remarkably clean, clear and seemingly distortion-less. It is almost specifically designed to have the 2 small flat panels behind, one to the right and one to the left of the monitor and the little woofer/multiple amplifier box on the floor near the wall as in the kneehole area of a desk! I give these 2 and only these 2 models my highest recommendation. We have used the Monsoons for some years now. I have fooled people into believing they were listening to a high end stereo system costing 100 times as much when these tiny panels were next to the high end speakers and played at a pleasantly moderate level with Diana Krall singing with her trio. All this for $200 - perhaps the biggest bargain I have ever found! Unfortunately these two models are hard to find. Go to the web site www.monsoonpower.com. These are licensed by Bruce Thigpen of Eminent Technology. They offer a more attractive and slightly larger version model # LFT-11 featuring wood trim for the frame around the flat panels and so on, website www.eminent-tech.com. Hopefully Bruce Thigpen will send his system to me to play with so I could then also recommend it to you. I have heard it at CES in Las Vegas, but not in my own home.