GWSmith Posted March 25, 2009 Share Posted March 25, 2009 Well, where can I start............ First off, I am long winded as many of you may remember. My 1968 Klipschorn rebuild/restoration with full detailed photos ring some bells??? [] Anyway. I have had the very fine luck of a rare find. FIVE factory wired Dynaco Mark III amps and a PAS-2 preamp with VERY little use. One day, I knew I would finally get to start these old amps up and see if they even worked. First off, the preamp's pots and selector switch were LOCKED SOLID ! I had to saturate the shafts of these controls with a special lube over the course of a day, but finally all freed up nicely, I didn't want to rush that, since I am sure the knobs would have easily been damaged if too much force was used in twisting them. My music room is once again setup, and the K'Horns are once again made ready for listening to. All solid state chain with an Adcom 545 for power. Ok, I talk with two very good audio/music nuts from Rhode Island who's opinions I trust. We plan a 'music appreciation day' here at my home to make a project of hooking up this old gear to the K'Horns. They are excited, and one of them rounds up a Variac from a friend and instructions on how to 're-start' these amps. Ok, but first, I take the amps from my garage where I have stored them for a while, and bring them to my shop to blow 40+ years of attic dust out of them. I will send ALL PHOTOS of what they looked like when I first found them a year ago. Back to last Saturday.... I have them on my bench, remove the covers, there is nothing but GRAY FLUFF all over them, you can't even see the resistors on the pc card its so thick with this fluffy stuff ! I carefully vacuum them, then run the compressed air and they are now free from the dirt. I discover the DATE on the chasis !! An inked stamp on EACH AMP states 'Nov. 8, 1965 ! The tubes are ALL FACTORY ORIGINAL! The KT-88's have a RED CRAN number hand written on their tops, (and have the beautiful GOLD LION logo - script). A #5 on each tube in one amp and a pair of #3's on the other. The only thing that shows to be a problem is the white power cords. They were crispy and one was partially chewed by a rodent. I taped up the bare sections. The other tubes HAVE the Dynaco logo on each... I washed the covers and took them back home in prep for the guys to arrive and the fun to begin ! Sunday, my friends arrive on time, arms full of CDs and DVDs to test with AND the all important Variac ! We plug in all the AC lines to a 5 duplex power strip (I have 5 of these things, bought at Home Depot). That went into the Variac. The first amp was turned on, then held our breaths while my buddy Bob began to rotate the dial. We watched as the voltage came up. Tubes were lighting up, our test speaker (hand held 6X9" driver) when held up to the ear had the faintest hum...... GREAT.......at 120 vac, all was good so far [] Next amp.........Same thing! Hardly a hum could be heard and now we were ready to hook up the preamp - WITH original bulb in the pilot jewel!!! To our surprise, EVERY component was on, NO crackling, pops or hissing, even SMOKE FREE !! We were elated! Preamp controls were clear and quiet, even the darn SELECTOR SWITCH made only the slightest noise when moved across the detents - normal... Now was the time to connect the K'horns and interconnects to the CD player and start listening. TIME? 12:45 pm. We sampled lots of stuff, live concert, recorded classical and some very potent stuff from TELARC. If you have the 'Great Fantastic Adventure CD', you know what I am talking about. We set the volume on the preamp to 1 o'clock and selected tracks 19-21 ! Oh yeah, the DANGER ZONE ! The wall of dynamic sound was ASTOUNDING !! We just sat there with our mouths dropped in disbelieve over what we had just heard and that it was all coming from amps that have never been restored / altered / updated in any way. How could ALL ORIGINAL TUBE EQUIPMENT over 40 years old still work so perfectly ! You know, if there was ANY powersupply hum or hiss, the K'Horns would SURELY bring all those artifacts out big time, but very little can be heard.. I am very sure the Dynaco gear was hardly used, it was an experiement that was NOT successful in its setting and ended up discarded and sat dorment since the 60ies. Now, you KNOW that the PC card usually has a burn mark around the bottom of the tube socket? Not these, they are absolutely in brand new condition, except for the patina on the nickle plated chasis. HERE then is the discovery. Remember the Adcom 545? We decided to play a certain live female vocal passage from a concert recording, re-connecting the Adcom to the PAS-2 just for the heck of it.... WELL, imagine MY/our surprise when we started that same track. The effect differences were SO apparent and out right UN-listenable, that I just had to point to my beloved Adcom and say "I have had enough of THAT!" and simply hit the stop button on the player. We all laughed and quickly reconnected the Mark III's and continued to sample the mobile library the guys brought. We FINALLY turned the gear off 7 hours later! NO FAILURES. Now, I know what you all have been talking about, for we have learned first hand the beauty of all TUBE amps and preamps made to work with each other, and the K'Horns. My added thought was this... With the exception of the digital source and NOT a turntable or reel to reel at hand to try, we were actually listening to a sound that, if you had the money, could possibly have been heard back in 1965-68 since this is the time ALL these components exsisted ! The bass and stereo image from this sounds SO GOOD even by today's standards. As for the amps.... They will get cleaned up, I already started polishing the chasis and its coming out like a mirror. The AC cords and plugs will be new. I bought some nice interconnects and speaker cables (Monster THX stuff) and will continue working at this project until it is done. For now, I will leave them alone and as they are, and keep the other two in the garage as a backup pair, as I would bet, they also run as nicely. A FIFTH amp from the same 'family' is still waiting to be picked up, but I am not rushing to get it, as it will be in its dirty location - SAFE for sometime to come. You know me to take fine detailed photos of my work, and I am putting together a photograpic 'timeline' for you all. Again, many thanks to Bob Cretes for his suggestions and products put into use for my old K'Horns, and to all of you back some time ago who said to me.........GET TUBE gear hooked up to those K'Horns!". So far, its proved to be a wonderful listening experince that I or my audiophile friends could never have imagined, OR, that I would be involved with such older equipment such as this.! Stand by for the photos, and I welcome your responses as always. With warm regards, Gary 3 Quote Link to comment Share on other sites More sharing options...
GWSmith Posted March 26, 2009 Author Share Posted March 26, 2009 Here are the amps on the bench before cleaning begins. 2 Quote Link to comment Share on other sites More sharing options...
GWSmith Posted March 26, 2009 Author Share Posted March 26, 2009 The following photos are of the 40+ years of dust build up, while the amps sat silent in their attic storage place. 2 Quote Link to comment Share on other sites More sharing options...
GWSmith Posted March 26, 2009 Author Share Posted March 26, 2009 This is what was under that dust... 3 Quote Link to comment Share on other sites More sharing options...
GWSmith Posted March 26, 2009 Author Share Posted March 26, 2009 Another view of dust... 3 Quote Link to comment Share on other sites More sharing options...
GWSmith Posted March 26, 2009 Author Share Posted March 26, 2009 Heres the original RED wax cayon markings found on the tops of the Genalex 'Gold Lion' KT-88's .. 3 Quote Link to comment Share on other sites More sharing options...
GWSmith Posted March 26, 2009 Author Share Posted March 26, 2009 More photos will be coming from our first listening moments with these gems [] I will also be taking photos as the cleaning/polishing process continues. Thanks for viewing! ....Gary (sorry, the photos are not all that clear.....) 1 Quote Link to comment Share on other sites More sharing options...
DizRotus Posted March 26, 2009 Share Posted March 26, 2009 Gary, I understand your excitement. Thanks for sharing the experience and the photos. 1 Quote Link to comment Share on other sites More sharing options...
rplace Posted March 26, 2009 Share Posted March 26, 2009 5 amps....HT is 5.1. Sounds like you need 3 la scalas or 3 belles to round out the team. Great find, enjoy! 1 Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted March 26, 2009 Share Posted March 26, 2009 Groovy find, correct startup proceedure, thanks for sharing the experience with us. I particularly like the poetic bit about the sound being exactly as it would have been heard in 1965! Need to bring out some Motown or Beatles for a listen. M Quote Link to comment Share on other sites More sharing options...
Cal Blacksmith Posted March 26, 2009 Share Posted March 26, 2009 Can I say it again??? HORNS LOVE TUBES! Congrats on the "new" amps, I know I will never go back to SS if I have a choice in the matter, the sound is just so much better from tubes, the sound stage is so much bigger, deeper, taller and wider. Don't be supprised if those amps need to be rebuilt soon, those caps do go bad and even though you brought them up slowly, I would expect the caps to fail in the near future but now you know that they are worth rebuilding! Oh, BTW, don't leave old gear like that on and go away, you need to be there to shut things off if they go bad. CONGRATS on the NEW sound and welcome to another tube convert! EDIT, after thinking about it for a few minutes, I would send those amps off ASAP to get a once over done on them. Those tubes are to valuable to leave to chance that somthing won't go bad in a hurry, taking the tubes with them. ENJOY! Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 26, 2009 Share Posted March 26, 2009 Awesome story!! A few words of advise.....If you plan to keep using these amps in original condition some precaution is in order..... They may work fine with this initial slow start up via variac....but I'm confident in saying they most likely will not work long unless you use a variac every time you fire up the system (at least for the Mark III's).. The reason is the Mark III's have a very high voltage spike at turn on up near 550V which is very hard of the main power supply filter can and the main coupling caps... those filter cans didn't live a happy life when new!! After sitting for 45 years they really are not going to withstand that brutal treatment. I'd also highly recommend you replace the two main coupling caps and if so equipped the selenium rectifier with an SS diode. A 5 amp variac can be purchased for around $100 and you will not need to take an extreme amount of time to fire them up... start at 70VAC for a few minutes then 100V for a few then 115V.... do not run them at higher then 115V and they may last a very long time... doing this will stop all high voltage spikes and give these old petrified components a fighting chance of lasting for a while. Sitting idle for 45 years is nearly as bad as being in use for these components...a variac is no magic trick don't fool yourself.. Quote Link to comment Share on other sites More sharing options...
Klipschfoot Posted March 26, 2009 Share Posted March 26, 2009 A few words of advise...A 5 amp variac can be purchased for around $100 and you will not need to take an extreme amount of time to fire them up... start at 70VAC for a few minutes then 100V for a few then 115V.... do not run them at higher then 115V and they may last a very long time... doing this will stop all high voltage spikes and give these old petrified components a fighting chance of lasting for a while. Sitting idle for 45 years is nearly as bad as being in use for these components...a variac is no magic trick don't fool yourself.. Is there a way that tube amps can be put into "sleep" mode? Would there be an advantage in this to avoid sudden bursts of power somewhat like power on delays in newer equipment? As I write this, I did a quick google and found this: http://www.n9adg.com/articles/amplifiers/power-on-delay-for-tube-amplifier.html Just wondering. Quote Link to comment Share on other sites More sharing options...
GWSmith Posted March 26, 2009 Author Share Posted March 26, 2009 THANK YOU so much EVERYONE for your nice responses, with ideas andcautions [] I do have a heavy duty Variac at the shop, I will haveto make sure it works, and then I will make it pretty and put it intooperation with these vintage if not fragile tube gear and do the run up slowly each time. I will also check out that link for the delay start up. PLEASE check back often for the latest photos. I plan over this weekend to be doing the continued work I promised to finish. Tell me more about wiring up a NEW SS diode! These DO have the selenium rectifiers! I think Bob Cretes steered me in the direction of a fellow on the forums that had all these photos and directions on updating the MK III's Could someone let me know about this information, or who it was so I could ask some questions? Again, thanks, and STAY TUNED [] All best, Gary 1 Quote Link to comment Share on other sites More sharing options...
mark1101 Posted March 27, 2009 Share Posted March 27, 2009 Congrats on the great vintage stuff. You have some nice classic equipment there. I would like to join the group of those issuing cautions about these old pieces. Honestly, I can't believe some of the comments. To use a variac and such. My comment would be to NOT USE the equipment at all. It is simply dangerous. You could burn your house down. These things are definitely not in a safe state to use and need to be rebuilt to be made safe. I surely would not connect them to my speakers either. That is suicide and I don't care how great it sounds, they will soon fail. It's coming. I would protect my investments and everything around by sending them to a competent Dynaco Tech (like Craig), and pay the money to have them properly restored before something unfortunate happens. I'm just trying to inject some reality. I know you are really happy and having some fun right now. I could tell you a story about a unit that lit up on my kitchen table when it had been playing just fine. Trust me you are not playing safe at all right now. Just trying to help. Quote Link to comment Share on other sites More sharing options...
GWSmith Posted March 27, 2009 Author Share Posted March 27, 2009 Hello Mark1101... About a year or so, I was mentioning this find (I had not acquired it yet), and there was someone that make a comment much like yours. I would like it very much if you could send me to Craig so that I could get the ball rolling on service for these amps... Do you feel that the PAS-2 is at risk as well ??? DO right back soon. Many thanks for your concerns. ........Gary 1 Quote Link to comment Share on other sites More sharing options...
Marvel Posted March 27, 2009 Share Posted March 27, 2009 Gary, Craig already did post. He was being polite. NOSValves IS Craig. He can be reached through the forum, or you can contact him at his website: http://www.nosvalves.com Bruce Quote Link to comment Share on other sites More sharing options...
mark1101 Posted March 27, 2009 Share Posted March 27, 2009 Tigerman, Good move. You will have some nice long lasting and fine sounding amps that you can feel confident about and know that they will not likely just melt down. After 40 years these old amps need new parts to be safe. The unit I spoke of that burned on me was an old HH Scott LK-72 that I eventually sent to Craig and had rebuilt. That was almost 4 years ago and I still use the unit all the time today. I have not had any issues with it and it still sounds great. Quote Link to comment Share on other sites More sharing options...
GWSmith Posted March 28, 2009 Author Share Posted March 28, 2009 Thanks so much BRUCE for the heads up. Funny, I had no idea that it was Craig that actually wrote about the Variac !! I am replacing the AC cords with brand new ones for starters. And I would like to replace the components he suggests BEFORE firing them up again.. Meanwhile, I would like to continue polishing the chasis up, and at least make them look good while waiting for the parts[]. Again, DO keep watch here for the photos coming soon! Hey there Mark! Great on your Scott LK-72, I'm sure it is a very nice piece and most likely very HEAVY with all those transformers! Take care, Gary 1 Quote Link to comment Share on other sites More sharing options...
mark1101 Posted March 28, 2009 Share Posted March 28, 2009 It sounds like you know what you are doing. Good deal. Quote Link to comment Share on other sites More sharing options...
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