12ax7 vs 5751

hiya mikirob, funny you should say that but before i bought any of the hifi i did a massive amount of research on amplifiers, cd players, speakers, interconnects and speaker wires. the biggest gamble for me was the amplifier. as much as i read on the yaqin mc100b i still couldn`t be 100% sure it was going to be a goodun being so cheap, but there were so many good write ups i decided to take a gamble. if it turned out to be rubbish at least i could re-sell it for roughly the same price as it was secondhand. in a way i think it was good that the tubes were worn and needed replacing. at first i thought i`d made a major mistake because on first power up the pops and crackles coming out of the speakers made me think it was faulty. i decided to get a pair of the psvane 12ax7`s which transformed the sound and it was then i really started researching all the tubes. i then read about grant fidelity and chose to buy his matched psvane 12ax7`s and yes there was a small difference in sound. i then started researching good places to buy tubes from. all the tubes have been from reputed good sellers with the exception of one set and thats the ge 5751`s that i`m currently waiting on. the kt88-z`s are from a good seller in hong kong and because of the length of time it`s taken i sent them a kind of angry email. they got back to me within a couple of hours and they spent that couple of hours investigating exactly where they are. they also sent proof that they were sent on the day they said they were sent. it`s the customs here in my country is where the hold up has been but thankfully they`ve now been released so i`ll get them this week. it`s just bad luck that we now have snow to contend with! i also had a good chat with karl at karltones in my country. what a great guy he is. he spent almost an hour chatting on the phone giving me all kinds of advice and recommendations. i asked him for advice on the telefunkens and ge 5751`s and recommended both even though he stocked neither but i did buy the jan philips 5751`s off him for a nice cheap price. i make sure i always check out the places i`ve bought the tubes off. i remember reading aricles about being weary where you buy tubes off and at the prices they go for i didn`t want to make any mistakes or at leasr cut down on the mistakes. so far it`s all been good. i wont be buying anymore tubes now once i`ve got the kt88-z`s and the ge 5751`s. i think all the tubes i have are more than good enough quality and as for the yaqin amplifier......i`m stunned! i can`t believe how that amplifier has reacted to all the tube changes i`ve made. i also want to pay tribute to all the rest of the equipment i own too. i think the biggest surprise are the speakers. very cheap and they let me hear all the changes i`ve made not only with the tubes but the wires too. i hope and pray the kt88-z`s will be the last piece of this very special jigsaw. i hope anyone else with this yaqin amplifier reads this and the tube selections i`ve made. even as the sound stands now i can imagine i`ll have to spend an exceedingly much larger amount of money to beat this sound. this amplifier is very special indeed. it actually makes me wonder weather or not to bother changing any capacitors in the amp such is the level and quality of sound but we`ll see. i intend to start a new thread on this very subject once i get the tubes i`m waiting on and once they`re run in. i wholeheartedly agree with you on being careful where you buy the tubes from and i really hope others take note of this too

McPherson,

It looks like you have a nice system, but unfortunately components with which I have no experience. My best suggestion, I think, is to find a dealer that will let you take some cables home with you to audition in your system. That's how I got my system dialed-in.

Preamp: if you are using Telefunken, you could maybe try RCA. They are a bit warmer than Telefunken. If you need still yet more warmth, then move to Mullard. Andy Bowman at Vintage Tube Audio sells what he calls Andy's Picks. These are used tubes that he has tested and if you want to do some tube rolling, this is about as economical and safe a way to go about it that I know. I get all of my tubes from Andy and recommend him highly.

Speaker cables and interconnects: Cardas Cross speaker cables are warm and are worth an audition. But again, find a dealer that will let you audition them in your home.

Sorry I couldn't be of more help, but now that you have posted the list of your components, hopefully others with more experience than me will be able to help.

Best regards,

JBS

Reynolds
Thanks for the input brother. I just bought the Thor and it came with the stock Golden Dragon tubes. I am very much looking forward to experimenting with tube rolling. From what I have read, the Modwighted Sony warms up a click or two also.

Mcpherson
I own Focal JM Lab 936 non Berylium tweeter speakers and it took a combination of things to get the tone I wanted. You have to ignore all the negative crap you will read about trying to adjust the tone of your system. In my mind it is my system and I want it to sound the way I like, not the way some one else delares is correct.
The tubes you want to warm up that tweeter is most likely going to be a good old stock 12AX7 Mullards from the 50s or 60s that you put into the pre amp. The Blackburn long plate in particular. I think Brent Jesse at Audiotubes.com may have them. These are warm tubes, but be aware that almost any British tube is going to lean towards the warm side. If you can roll input tubes into the HK again look to Mullard for the best results.
The other things you want to do- although this will cost quite a bit of money- is to get Cardas "Golden" whatever interconnects, I have the Golden Refs. These copper interconnects really make the Focals sound great. I also suggest good copper speaker cables. Again ideally Cardas or Jena Lab but both do cost a lot even used . I would never the less look for them to show up. I lucked into some used Jena Labs and the sound is fabulous.
I happen to have an AE-3 Pre Amp by AES a Cary brand which uses 6SN7s which are delightful tubes for smooth and rich tone, it made a world of difference in my system. Good Luck!

Mechans
Thanks for the information. I am assuming you had a similar impression of the Focal sound as you started tinkering around with tubes and cables?