Istari Posted March 17, 2003 Share Posted March 17, 2003 I have the PWK setup of two Klipschorns and a Belle (all in Walnut Oil). I would like to power these with tubes and would like to do the "Three Channel Stereo" that Paul perfected. I've never seen a preamp with a center channel out (I'm not talking about surround sound here but just three channel), were any ever made? If I go with tube preamplification I could construct one of PWK's blending circuits and put it into the chassis, does this circuit still maintain the channel seperation of the L&R channels? If anyone has done this, how does it sound? I know this is a can of worms, but since there are several designs of tube amps, which is "The Best" for the Heritage series? My K-horns have the AK-3 crossover but the Belle has an AB crossover, is this a good match or should I change the Belle crossover, and to what? I know I'm pumping for a lot of info but I'm sure you guys can deliver! Thanks, Jim Quote Link to comment Share on other sites More sharing options...
lynnm Posted March 17, 2003 Share Posted March 17, 2003 Contact Al Klappenberger. He has the setup you are considering and is an expert on crossover networks besides. He currently has a thread running in Odds and Mods entitled Heresy on Steroids. Quote Link to comment Share on other sites More sharing options...
Neandertal Posted March 18, 2003 Share Posted March 18, 2003 Hello Hobbit, I built the PK style blending circuit and was extremely pleased. My current amp is (and has been for 25 years) a two channel Kenwood. I decided to try using a center channel speaker using the mixer and a Bogan mono amp and acheived better than hoped for results. The new center filled out the sound stage and since I have the center under the TV it also anchored the sound to the screen when I used the system as my own personal home theater system. I was truely surprised at the fact that the stereo sound was not diminished at all! Left and right only sounds definatley stayed to the sides as they were supposed to. This was and is most evident when watching DVD's and the sound follows across the screen as shown. I used off-the-shelf Radio Shack components to build the blender to see if it would work. I ran the left and right mains off the "A" speakers and routed the blended channel off the "B" speakers, then through the mono amp. I used the cheapest electronics (Radio Shack lightweight stuff) just to see first how it would work, with plans to upgrade if I saw good potential. Heck with it... it sounds just fine as is and I never upgraded (leaves me more time to enjoy the results). Do I recomment it...YES! With the quality of speakers you have you may well want to use high buck electronics but I am sure you would be please with the addition with most any grade of investment. My 25 year old, Heresy based system may not be the best in terms of hardware, but it certainly fullfills my needs. Bert Quote Link to comment Share on other sites More sharing options...
KGK1958 Posted March 18, 2003 Share Posted March 18, 2003 McIntosh C26, C27 and C28 preamps all had Center channel outputs. I recommend Audio Classics in Vestal NY. Kevin Quote Link to comment Share on other sites More sharing options...
artto Posted March 22, 2003 Share Posted March 22, 2003 Jim, some of the earlier vintage tube amps & receivers had a center channel output. I think McIntosh made some. The schematics Klipsch published were basically the same as the McIntosh circuts. You dont need to try & install this in the preamps chassis. In a vintage piece of equipment it will probably degrade its value. Ive been using a setup like this for 20+ years. There is no loss of separation. Someone on the forum mentioned adding a 10ohm (?) resistor to ground on the right & left channel to decrease crosstalk. I havent tried this. On the other hand, Im not experiencing any crosstalk problems. In fact, to me, even the standard circut seems to effectively increase separation. For instance, when a signal is present in only one channel, the opposite channel is effectively reduced in output. If the output level of the center speaker is properly adjusted (usually 3Db to 6Db less than that of either right or left main speaker) sound field depth is also increased, not decreased as some people seem to think. And as an added benefit, the general listening area where acceptable & stable imaging can be experienced is increased. I think youll want to use one of the circuts with at least the adjustable center channel level, not just a center channel bridge. I used extremely high precision military grade pots (like 6 turns from full off to full on) & 1% resistors. No such thing as the best tube amp for the Heritage series. Only YOU can define & quantify that. Its your ears. At the very least, extremely low noise & hum should be at the top of your list. All 3 of my speakers use the AA type network, albeit, modified by removing the zener diode protection on the tweeters, no fuses on the speakers as a whole, & disconnecting the inductor on the woofer. I havent made any comparisons to other networks. Al Klappenbergs (forum member) ALK networks seem to be fairly popular & well built. Im considering switching over to those. http://www.alkeng.com/klipsch.html Quote Link to comment Share on other sites More sharing options...
artto Posted March 22, 2003 Share Posted March 22, 2003 Klipsch "2PH3" phantom center channel circut from Klipsch Dope From Hope dealer newsletter Klipsch2ph31.pdf Quote Link to comment Share on other sites More sharing options...
Terry N. Cruse Posted March 23, 2003 Share Posted March 23, 2003 YUM! LUX & the 7T I.B.Slammin Quote Link to comment Share on other sites More sharing options...
Istari Posted March 23, 2003 Author Share Posted March 23, 2003 Thanks for the info Art & Neandertal, I have the schematics for the 2ph3 and the articles that PWK wrote and have tinkered a bit. I was able to pick up a few of the PWK DOPE FROM HOPE articles at the Custom Audio Store in Little Rock(PWK dropped in there a lot). Thanks to you Art, I now have a more complete set of articles. I Will be moving into a new home and will want to do it up right. My initial setup had the two Kornerhorns as mains and an Academy as a center. I'd like to move to tube amplification instead of the Adcom units I now have and yes, I want a low noise, low hum pre and power amp. I can do circuit work and solder so that shouldn't be much of a problem. I appreciate your input about your years with this setup. Thanks, Jim Quote Link to comment Share on other sites More sharing options...
WMcD Posted March 23, 2003 Share Posted March 23, 2003 I've set up a center channel and can't say enough good things about it. PWK may have exercised too much restraint in his descriptions of its merits. It is particularly remarkable for pop music where the vocalist gets squarely placed in the middle. I've often thought that no one, without hearing it, would believe it is just a derived channel. If anyone out there has the hankering to experiment with the mixer and a center channel, I very much recommend it. There is no reason to wait until you get "perfect" equipment. Even now you might tune to an FM stereo station on your two channel system, and then put a table radio set to the same station in the middle. Alternatively you could feed your VHS stereo output to the two channel and use the TV as a center channel. This is not the best in that the center channel is great compromise in fidelity. Still, you'll get enough of the effect to get you thinking. Gil Quote Link to comment Share on other sites More sharing options...
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