12ax7 vs 5751

i have a bus route that goes straight past where i live and the road is uneven a little. when the bus goes over the uneveness my flat shudders! one of the tubes picks this up but its onlt very slight and you have to be pretty close to the speaker to hear it. it`s like the tube is vibrating. i tell you something that helps in this case is using sorbothane feet under the amp but my amplifier is pretty heavy (30 kilo`s) and i think i`ll need to purchase extra sorbothane feet. they`re very cheap and you can get them off ebay. i have them under my cd player and my bluray player too. amazingly they made a difference to the picture on my bluray player. don`t ask me how but the picture is sharper. i thought it was me but everyone thats been around here has noticed the difference too! they helped under my cd player too with the soundstage. it just seems more focused. not bad for a cheap upgrade! if i didn`t have them under the amplifier i`m pretty sure it`d be a nightmare to listen to. not sure if those tube dampers work. i might give them a go unless anyone reading this can advise otherwise.

Mcpherson please feel free to ask any question you wish ok. if i can`t help then i`m very sure others will like reynolds for instance. like you i`m a newbie to tubes aswell so any information is valuable. tubes are expensive enough without making costly mistakes. all the tubes in my amplifier are in there for a reason. i`ve done endless research on each tube as to what their sound characteristics are and kind of gambled buying them. i`ve been very lucky so far in my mixing and matching and each tube i`ve added has enhanced the sound out of my amplifier. my treasure tubes kt88-z`s look like being delayed further now because of this snow as probably will the ge 5751`s aswell :( i`m dying to fit them all in!!!

Grayf, first, I'm happy for you that you are having a good time tube rolling, learning, listening and so forth; but, I have a small piece of advise, be careful where you buy tubes from. For example, on Audiogon there are some excellent tube sellers with stellar reputations and had you bought those KT88s from say, Trelja, Grant Fidelity, Jim McShane or some others, you would have been enjoying them for weeks already, be careful my friend, so far it seems like you have had good luck. In the UK, Watson sells very good tubes among others. Best.

Reynolds
My system is:
Sony es5400 cdp
Thor ta-1000
H/K Citation 16a (rebuilt to the max) @150wpc
Focal 918s (Not beryllium tweeter)
Transparent IC (entry level I think Link)
Audioquest IC (maybe second step up in their line)
Monster Cable Z series speaker cables

Hopefully some tweaks here and there will warm things up a bit. I really cant complain, I got everything except the Focals within the last 6 months. So I basicly just got started.:)

Thanks guys for answering my previous questions.

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