T2K Posted July 27, 2003 Share Posted July 27, 2003 Keep reading the recs and praises of the Scott 299 A'sand B's, and the occasional apology from the owner of a lowly 222-C Scott amp. So although my question may belong in the 'Technical' forum, I'll ask it here. What difference is there in the circuits of the 7189 based 299's that would make their sound so far superior to that of the 7189 based 222's? As info, I have (2) Scott 222-C's, one restored and one original (as far as I can tell), and they both sound good. I also have a Scott 233 and there is a possibility that I may eventually prefer the sound of that amp/tube (more listening required). Any and all technical comments appreciated. Keith Quote Link to comment Share on other sites More sharing options...
AndyKubicki Posted July 27, 2003 Share Posted July 27, 2003 Keith, you ask a great question here. I have a 222D (and I'm not apologetic!) and have wondered myself about the difference I would hear in something like a 299 series. But at least there you are talking about a different output tube...7199 vs 7189. Quote Link to comment Share on other sites More sharing options...
bkrop Posted July 27, 2003 Share Posted July 27, 2003 I dont think the 7199 is an output tube, in my 299-C it is used as a " split load phase inverter" . I am not an expert by any measure, so take this with a grain of salt. Quote Link to comment Share on other sites More sharing options...
Marvel Posted July 27, 2003 Share Posted July 27, 2003 Andy, I thought the 7189 was similar (or same as, close to) an EL84. The 7199 is used in many old amps (my Dynaco ST70) as the linestage/phase splitter. I didn't know anyone used it for an output tube. Is this true? Marvel Quote Link to comment Share on other sites More sharing options...
dubai2000 Posted July 27, 2003 Share Posted July 27, 2003 My 222c uses indeed EL84 (I always forget what the American equivalent is) - just like the Eico. I think it's a great (i.e. musical) tube. So far I have not heard any amp using this as an output tube which sounds bad - even new stuff (LOL).I think the Scott is really fine, but I had the Eico first and its tubes are NOS all the way. The 222c uses modern tubes and that might count for the difference. For a while I used some Telefunken tubes instead of new ones and that seemed to give more transparency to the sound, but since having got those separates listed below, both, Eico and Scott, have moved to my study where they combine nicely with the Heresy - but those are no Khorns and the room is simply too small to do them justice. Wolfram Quote Link to comment Share on other sites More sharing options...
NOSValves Posted July 27, 2003 Share Posted July 27, 2003 Its all about the phase splitter setup and the Class of Operation of the Output tubes. I'm sure a certain person will come in and try to disprove me on this but the 222C/D are biased further to the class B side of Push Pull AB1 than a 299A/B in all actuality the 299A is the biased the deapest into Class A of the 7189 based Scott amps. The Phase splitter setup on the 299A/B are both AC balance adjustable and less dependent on primo phase splitter tubes to split the AC signal to the push pull pair of tubes per channel. To the normal user this doesn't mean much because they can not adjust the AC balance properly anyway. But if you have your amp professionally rebuilt and setup than this difference shows through with less distortion. The amp can play clearer thru its usuable wattage without distortion caused by the phase splitter being out of balance. Craig Quote Link to comment Share on other sites More sharing options...
Deang Posted July 27, 2003 Share Posted July 27, 2003 Well, I would prove you wrong -- but I'm too busy reading about coffee beans. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted July 27, 2003 Share Posted July 27, 2003 coffee beans ??? Quote Link to comment Share on other sites More sharing options...
T2K Posted July 27, 2003 Author Share Posted July 27, 2003 "With a few math equations, I could prove this, but I'm not wasting my time anymore. Nobody on this forum would understand them anyway." Now I resemble that Ryan! I believe I'll go back and reread some of this again. Thanks for the comments so far. Keith Quote Link to comment Share on other sites More sharing options...
Guy Landau Posted July 27, 2003 Share Posted July 27, 2003 Wow, I guess that Ryan is indeed an expert. Quote Link to comment Share on other sites More sharing options...
kjohnsonhp Posted July 27, 2003 Share Posted July 27, 2003 ---------------- On 7/27/2003 8:22:44 PM guy landau wrote: Nobody on this forum would understand them anyway.---------------- Why the mad at the world attitude? Quote Link to comment Share on other sites More sharing options...
lynnm Posted July 27, 2003 Share Posted July 27, 2003 Many,many years ago a man approached the gates of a village. Stepping down from his cart he lead his horse to some green grass beside the pond and let him eat and drink and rest. After tending to the creature he sat beside an old fellow sitting against a tree and asked Pray tell me sire are the people in yon village friendly ? The old fellow smiled and said Yes you will find them so. Eventually the traveller reharnessed his horse and mounted his cart and departed happily toward his new home. A few days later another cart approached. The driver struck his pony several times and screamed you'll eat and drink when it is time. He then tied the pony to a stake and went to the pond and refreshed himself. He stomped over to where the old man sat and said, " I left my last town because all of the people were lazy and stupid and corrupt ! Are the people in yonder village the same or worse ?? The old man looked up sadly and said Yes you will find them so ! That old man was amazing - In 100 years he never made a poor prediction ! Quote Link to comment Share on other sites More sharing options...
T2K Posted July 27, 2003 Author Share Posted July 27, 2003 I'm not too proud to admit that I know nothing about Scott amps. I specialize in listening to them. If the occasion does arise that one of them needs someone's technical expertise, I know a couple of guys that will help me out. Thanks to both of you. Since I'm not doing anything right now, I'll ramble on about what I've been doing lately for fun. For quite some time now I have been using a Scott 222-C with Klipsch bookshelf speakers that are vented and feature a exponential cone/tweeter. I used a Klipsch SW12II for the low end fed by the Scott derived center channel RCA output. The setup is very dynamic and throws a wide soundstage with great imaging and a rock hard center image to boot. Lately I bought a pair of KT-LCR's and their sound is totally different than anything Klipsch that I have ever heard. The speakers sound 'dark', is the only word that I can think of. DeanG's reference to this scenerio lately was right on target with what I was hearing with the Tractrix horn. The Tractrix horn seemed to kill the imaging somewhat and the hi end that was previously beamed to my ears was now gone. The center image is somewhat softer. I tried Tele 12AX7's with the 222-C/exponential setup and loved the detail the Tele's provided. Problem was, the upper end was a little more than I could stand. There seemed to be more bass using the Tele's, although it wasn't as tight as before. Back in with the RCA 12AX7's. After shelling out $80 for a Scott 233 that was loaded with Telefunken's, the bright idea came to me to try out that amp with the 'dark'/sealed speakers. The 7591 tubes seem to give a brighter sound to my ears, as opposed to the 7189. The speakers sounded better. Then I thought of that great Tele detail that I had been missing. In goes the Tele 12AX7/ECF82's. Out comes that butyful detail that I had missed, without the ice pick in my ear hi's. The 233 has speaker level outputs for a center channel, and I used that to feed the inputs of the SW12II. Improved matching. Before the sub overplayed the exponential/vented speakers. Better match now, smoother transition too. I'm not sure which I like more. They both sound great. Better than I thought any pair of bookshelf speakers could sound. For me, in my room, with what little time I have to use it, this stuff makes for a great budget 2-channel system. It just don't sound budgety. Gotta go. m00n has a question. Keith Quote Link to comment Share on other sites More sharing options...
jt1stcav Posted July 27, 2003 Share Posted July 27, 2003 He is partially right...I don't understand it! How can I when I use SS McIntosh? LOL Quote Link to comment Share on other sites More sharing options...
Deang Posted July 27, 2003 Share Posted July 27, 2003 I never see Craig recommend anything unless someone asks. Besides, don't 299A's and B's outnumber the C's at a rate of about 10 to 1 on the used market? Maybe the C's are great, and no one wants to sell, fine. However, people buy what's available. Maybe you could go ahead and show us the math. Some here aren't as dumb as you think. While you're busy trying to piss all over Craig, his basement keeps filling up with amps (of all different types). BTW, you're wrong about the Class A thing. Quote Link to comment Share on other sites More sharing options...
Deang Posted July 27, 2003 Share Posted July 27, 2003 That's a very good story Lynn. No wonder no one likes Craig. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted July 27, 2003 Share Posted July 27, 2003 Another post not worth replying too ! But I guess I should help clear things up for the forum members that may not understand or be able to read between the lines. Plate, screen and bias settings have everything do to with class of operation. Companies in the Mid 60's were under fierce competition in price and Watts. Anyone can access the tube Data for the 7189 and see what the specs are here http://hereford.ampr.org/cgi-bin/tube?tube=7189. Watts are never free companies were forfeiting some sound quality for a few extra watts there all guilty of it not just Scott. I like 299 because there cheaper and easier to rebuild really kills me parts count on the 299B to replace is substantially higher than any other of the series with the 299a coming in a close second. The 222C and 299C are the absolute easiest to rebuild and require the least parts ! There is no such thing as a phase splitter without a AC balance function that does a perfect phase inversion never was and never will be these are tubes, resistors and capacitors we are talking about none of these things are perfect ever !! Simple is not always the best the only sure thing about a simple amp is its the cheapest way to build it. Craig Quote Link to comment Share on other sites More sharing options...
T2K Posted July 27, 2003 Author Share Posted July 27, 2003 Damn, I guess we have to add Scott Tech questions to the taboo list, along with speaker wire and interconnects. Quote Link to comment Share on other sites More sharing options...
AndyKubicki Posted July 28, 2003 Share Posted July 28, 2003 I should know better than to rely on my memory... 222 A & B use a 6BQ5 output tube 222 C & D use the 7189 299 A & B use the 7189 299 C & D use the 7591 (which I confused with 7199...sorry...I'll have to go whip my horse!) Quote Link to comment Share on other sites More sharing options...
Painful Reality Posted July 28, 2003 Share Posted July 28, 2003 The cathodyne will probably give you the best unloaded voltage balance but it still have one important problem. The output impedance will be much higher for the plate circuit than for the cathode circuit. So in the end your still stuck with problems. Williamson partially soved this by usig a combo cathodyne and a diff amp. The cathodyne splits phase with near perfect balance, but it drives an easier load than pp power tubes grid. There is no such things as free lunch. Quote Link to comment Share on other sites More sharing options...
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