Erik Mandaville Posted August 21, 2003 Share Posted August 21, 2003 Wolfram: I am hoping you are on the forum this evening. I have not been able to respond to your email until just now -- sorry about that. I have sent an email, but thought I should post to you here,too,just in case you are logged on. I would be happy to help with your AE-1 interest, if it is not too late. Coupling capacitors would also take very little time to install. Just send the capacitors you think you might like. I have the schematic, and can test all plate and heater supplies at the same time. I have an accurate tube tester, and can also include tube status readings if you would like. Let me know how this goes. If you can provide some other specifics of your system, that would be helpful. Things such as: Interconnect length between preamp and amplifier/s (if you happen to know the per/ft. capacitance of the cable, this would be useful) Amplifier input impedance and sensitivity speakers (Klipsch, perhaps!?) Send an email when convenient... Erik Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted August 21, 2003 Author Share Posted August 21, 2003 Wofram: This picture shows my AE-1 in our other system. The speakers a much less senstive than the Klipsch or Lowthers, and the preamp is virtually silent. I can just barely detect a little background noise when my ear is literally touching the driver. Of course being half deaf in one ear helps! Honestly, if you have very sensitive speakers, you may experience some background noise which is only evident in the most quiet of music passages, or when no music is playing but the system is turned on. Other than that, it is an extremely transparent, well-built preamp. You must make sure the wiring to the power switch on the front is either shielded or at least twisted, as chances that generated noise can be picked up on the very nearby grids. I had some problems with this, and shielded cable from the volume controls to the grids helped very much. One can also use series resistance between the amps and preamp, but this effectively increases the output impedance of the preamp. That can reduce noise, but at the same time possibly cause roll-off at the high frequency extremes. Wolfram: totally disregard my question about the capacitance of your cable. This is typical techno-pickyness on my part, and is nothing to go to any trouble over. The length of the cable can be important, although this preamp is a strong preamplifier, with very good drive capability. Erik Quote Link to comment Share on other sites More sharing options...
sheltie dave Posted August 21, 2003 Share Posted August 21, 2003 Erik (and Wolfram), are you the other party talking to Jonathon regarding the Cary? I offered him what he was asking, but have not heard back as yet. He said there was another offer on the table. If it is just a matter of you being first in queue, that is not a problem - I will talk to Lloyd regarding his Octal 6 preamp kit. It will be interesting to build that bad boy, and I have a friend who has experience constructing circuit boards. Regards Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted August 21, 2003 Share Posted August 21, 2003 Erik, you always did like putting things shared in email in forums! heh... Lordy. Quote Link to comment Share on other sites More sharing options...
dubai2000 Posted August 22, 2003 Share Posted August 22, 2003 Dave, yes, that's right - I have been in touch with Jonathan regarding the preamp. It looks as though I was in line first, so I really appreciate your understanding. Thanks a lot. Erik, you've got mail. Wolfram Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted August 22, 2003 Author Share Posted August 22, 2003 Wolfram: I have some more thoughts/possibilities/suggestions on this. 'You have mail.' Erik Quote Link to comment Share on other sites More sharing options...
sheltie dave Posted August 22, 2003 Share Posted August 22, 2003 Wolfram, I sent you two e-mails re the Cary preamp. As I noted, it is always a concern on E-bay and Audiogon that you prefer dealing with honest people rather than a sharp businessman. That listing was at least a couple weeks old before he got any responses ( and all generated via Dean and Mobile from this forum.)I will not bid up the preamp, and I hesitate to involve myself in buying it for the stated price at this point. He seems hellbent to get more $, and while I offered him full asking price, he would not commit to the deal, stating he had someone else (you) he needed to talk to again. At this point, the Octal 6 looks much more interesting and a better value for the buck. I know Lloyd is honest and will provide what he states for a good price without changing his story. The Cary owner ought to be careful, lest he negotiate his way out of two good faith offers in a vain effort to get more money. How hot is it over there today? We hit 103 farenheit yesterday in St. Louis! Regards Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted August 22, 2003 Share Posted August 22, 2003 This is disturbing to say the least. He should simply go with the first response to his ad willing to pay the asking price. This impromtu auction approach is really sad to hear. Too bad. On the Octal 6, it does appear to be an interesting design, although be careful of the hum issue mentioned in the TNT comments. Sadly, Mr. George doesnt appear to even list what speakers he is using referring to "high efficiency" speakers in one line and a vague reference to 92dB speakers in another. Who knows which and what he had partnered with the octal 6 and various amps. The difference between a pair of 92dB speakers and some 100-104db horns is not small. Maybe I missed a more succinct reference. It also appears as of the Octal 6 demands a bit of care in amp association. Still, it looks to be an interesting design from an honest designer. I sure wish either had tube rectification. I would also debate whether to make the Octal 6 as a 6v amp to use 6SN7. I have so little experience with the 12v version of this tube, I cant comment. IT surely is cheaper! kh Quote Link to comment Share on other sites More sharing options...
NOSValves Posted August 22, 2003 Share Posted August 22, 2003 Kelly, Well I can tell you my Ultra 4A is absolutely dead silent on Line inputs at this time. The Phono has just a slight hint of hum at about 95% on the volume dial which needless to say is way beyond what even my ears could take DB wise . The 12V versions are electrically Identical to the 6V version simple rewire of the heater pins. I'm going to rewire mine sometime in the future for the 6V just for kits but I really don't think there will be a big difference. The Octal 6 I really have no experience with I have to have a phono section and I myself just have little faith in any product that a flick of a switch changes its mode of operation just seems like there has to be trade offs to accomplish it. What is the word on Tongsul 6SN7's there in a tall envelop ? Also Zenieth branded 6SN7GTB with the silvering running 1/2" down from the top ? Should I post up some pcitures of the tubes I'm talking about ? Craig Quote Link to comment Share on other sites More sharing options...
dubai2000 Posted August 22, 2003 Share Posted August 22, 2003 Dave, thanks a lot for your mail. I agree that the whole thing seems to start feeling a bit odd. Until now I don't quite give up on the unit, but I have my limit too. I answered his last post stating that someone offered more than the asking price. Depending on his response we'll see how things develop. Wolfram Quote Link to comment Share on other sites More sharing options...
sheltie dave Posted August 22, 2003 Share Posted August 22, 2003 Wolfram, I got a call from the gentleman twenty minutes ago. He stated that he had an offer of $600 for the Cary - I told him I would go no higher than $550 and thanked him for his call back. If he e-mails or calls you, make sure that you get solid info on this second party before you match unless you NEED the preamp. As far as I know, we are the 2 parties involved. Last time I checked he still lived in Minnesota, so there is no way an offer from me at $550 could in any way be construed as $600...and ditto yours Caveat emporer! Quote Link to comment Share on other sites More sharing options...
NOSValves Posted August 22, 2003 Share Posted August 22, 2003 Boy Kelly your real helpfull on the 6SN7 front ? Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted August 22, 2003 Share Posted August 22, 2003 Craig, post the pics and I'll take a look. I havent heard a lot about either of those particular tubes and they werent in the big 6SN7/6592 tube test I did a few years back. But they might resemble some of the tubes. A handful are pictured here, too. I wrote comments for each but didnt put them up due to the usual. Take a look here: 6SN7/5692 Pictures - Click for full Post some pics too. kh Quote Link to comment Share on other sites More sharing options...
NOSValves Posted August 22, 2003 Share Posted August 22, 2003 I'll go take some snap shots for you now. But here is some interesting reading concerning 12SX7 and 12SN7 tubes. By Eric Barbour © 1997 The 6SN7 was a major introduction in 1939, and became a standard for medium-mu twin triodes. Many types that were popular in audio were directly derived from it: 6CG7, 6FQ7, 12BH7, 6BX7. Yet the early history of this family was more concerned with war than with good sound. In 1946, RCA introduced a version with a 12-volt heater intended for use in 26-volt aircraft radio equipment. Although similar in physical construction to a 6SN7, the 12SX7(VT-207) was specially processed and characterized to run with a plate supply of 28 volts. The 12SX7 was used in a few radios and was obsolete by 1955. Very few audio experts have even heard of it. This is one of the cleanest-sounding dual triodes in existence. It is never found in any kind of box other than military JAN tan. Any 12SX7 can beat even the best 6SN7s. It was made by Ken Rad and RCA, although GE is said to be an original manufacturer. (This appears to be one of those types that was made by GE under contract to RCA.) New-in-the-box 12SX7s are often discarded as "useless," because there are foolish people who like to claim that 12-volt heaters have some kind of mysterious sonic penalty that 6-volt heaters don't have. Operation of the heater on DC will take care of this peculiar claim, as the gurus babble that hum induction into the cathode becomes "uncontrollable" above 7.5 volts. This bizarre statement is made more often than you would think, and it automatically condemns classic tubes like the 12SX7 to the landfills. The same goes for the neglected 12SN7, although the 12SX7s I have tried were superior to any SN7 type. Another reason for discarding them is visual inspection; most 12SX7s were heavily burned in before shipment, resulting in shiny "getter spots" on their tops, directly over the cathode ends. This is also seen in some old 6SN7s, 6SL7s, 6J5GTs and other tubes. It is often assumed by the ignorant that these spots indicate and old, used tube which will test weak. It is an amusing trick you can play on radio collectors, in order to coerce them into parting with their fine NOS 12SX7s at a low cost. Quote Link to comment Share on other sites More sharing options...
sheltie dave Posted August 22, 2003 Share Posted August 22, 2003 Hey Craig, just about everyone has been great when offering help within the forum. Kelly, Dean, Erik, and you do a fantastic service to us newbies that are staggering about trying to find a good component at a good price. "Newbie" is a relative term, as I would be completely at home buying, selling, swapping and stealing in the solid state millieu. Tubes are a completely different animal! The Cary would probably be a good deal at $600, but the road travelled in this situation appeared to be confusing and not totally above board. Half the sale is making sure your buyer is happy before buying the equipment - discussing how it will interact to improve your setup, how it will match what you listen to, and so on. With the Cary, I was getting a good sense of its abilities from the forum, but nothing from the seller other than give me more money and it is yours. In no way were forum members part and parcel of what transpired with the Audiogon seller. It's great that members patrol Ebay, Audiogon and other sources for equipment they feel will enhance our systems. Once in a while potential sellers might get greedy, develop sellers' remorse, or really be the south end of a horse heading north, but it is no reflection on the forum member who recommended us to "check this out." Craig, I'll be heading out to be the radiation safety officer at the Dawn Mine decommissioning outside Spokane, WA for the next two months. I'll be coming back to the Lou at the end of September for our wedding aniversary...my wife claims the main reason I'll be back is to send you the LK-72 and the 299c, and while she might be wrong, you will be seeing them NLT OCT 4th in your box. Ciao for now! Quote Link to comment Share on other sites More sharing options...
NOSValves Posted August 22, 2003 Share Posted August 22, 2003 Ryan, Actually there is a way to wire the 6SN7 with the current 12V supply. I will ask Lloyd about the particulars. Heck right now I'm running 12SN7's preamp and 6SC7's in the phono section. I believe you wire them in a way so the tubes themselves split the supply but I'm not sure. I know right now the 6SC7's are sharing a 12V supply 6V each. Craig Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted August 22, 2003 Share Posted August 22, 2003 Ole Eric Barbour is a card and was seen a LOT before and while working for Svetlana with articles all over the net. He has some interesting ideas and contributions. A search will net you quite a few articles on tubes as well as circuits. You sure dont see him anymore unfortunately; he seemed to disappear. George Wright also does some things with these tubes in his latest pre. Gear using them is rare but I have to admit, I have only heard good things about them in the underground. You just dont see them traded around as much due to the above. kh Quote Link to comment Share on other sites More sharing options...
NOSValves Posted August 22, 2003 Share Posted August 22, 2003 Dave, Whenever you get them here is fine and dandy with me. Its to bad about the Cary seller I bet that is a fine preamp. I had Rick (Audioflynn) over today and I'm pretty sure my Mark III and Ultra 4A left him stunned !! I'm sure he will chime in Sunday or so he is off to look at a nice piece of property in northern Michigan the lucky Dog. Craig Quote Link to comment Share on other sites More sharing options...
NOSValves Posted August 22, 2003 Share Posted August 22, 2003 Kelly, Here you go this is the best my little camera can do. The plates on all these tubes basically look Identical Black same holes and shape. Tung-Sol there marked 6SN7 GTB Black Plates Zenith and a Arvin look Identical and both marked 6SN7 GTA Black plates 2 Philco and a Rauland all marked 6SN7 GTB and look Identical Black plates Sylvania and Zenith both marked 6SN7 GTB and Identical Black plates Quote Link to comment Share on other sites More sharing options...
dubai2000 Posted August 23, 2003 Share Posted August 23, 2003 Well, the seller and I agreed on the price and the unit should be shipped off on Monday. This was my first Audiogon experience and seems I could have hit on a less greedy gentleman. Anyway, now I am looking forward to the preamp and hope it's worth the investment. Wolfram Quote Link to comment Share on other sites More sharing options...
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