kjohnsonhp Posted October 21, 2002 Share Posted October 21, 2002 Let the project begin! My radio buddy just checked out my new purchase and it looks like a stock pair of Dynaco ST 70 and PAS 3 pre-amp. All but one of the tubes checked out. Now I need to select the upgrade strategy. I've been given some good reading on popular upgrades so I'll review that again tonight, and I'm aware of the various upgrade kits. I'm currently thinking of simply replacing the flat tube with a matched pair of EL34's ($16/piece) and replacing the caps (orange drops are $8/piece and qty 4 seem to be in the critical audio path... QUESTION: What cap's should I buy? I'll compare the price of caps to the price of a new board kit, but it seems like swapping the caps will be cheaper. The resistors will be checked, too. I have a 5U4 rectifier which can be updated for $15. I've also been told to adjust the bias using our HP calibrated test equipment. At the moment I can get the unit updated for $93. I now need to read about all the options and see if this is the correct strategy or if other things need to be done. Suggestions welcome. Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted October 21, 2002 Share Posted October 21, 2002 For the coupling caps for that amp, You might want to try Auricaps. I think these would be a step up from the typical SBE 716p cap (which should not cost 8 a piece). I happen to love Jensen Copper Foils but they cost more. Quote Link to comment Share on other sites More sharing options...
kjohnsonhp Posted October 21, 2002 Author Share Posted October 21, 2002 Kelly, THX! I'm checking on the caps you recommended and reading the links again. I'll post my plan before I start the project. I know this isn't your favorite sample of vintage tube gear but I'm hoping with some upgrades it can serve as a test to see if I want to have an audio-only path seperate from my SS Home Theatre electronics (I'm currently using a used Outlaw 1050 which seems to be fine for Movies--although I think I should swap out the KLF-C7 for Heresy front & rear centers). I'm also making a CD for you--just a week behind schedule. It's all Boston Rock from the 80's ending with some tracks I love from my college roommate's band CRITICAL FEW...the only problem is the sound quality from cassette to mp3 to cd on these last few tracks--thus they are at the end. Quote Link to comment Share on other sites More sharing options...
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