Preamp Tubes for KR AUDIO 18 BSI

I need some help on this amp here, i've done searches with the tube # on the internet and nothing really shows up...

what can i use to replace those 4 input tubes?
it will be such a great help...

going to modify it and going max, heard the result is nirvana...

Even now, im' at 90% of satisfaction, and so far i never gives me a problem.
The owner's manual should be able to tell you the type of tubes used. The tubes themselves are also probably labeled as well. Once the stock configuration is known, just let us at least know the type of tubes you already have, what type of music you play, and perhaps what you perceive is lacking in the sound that you are getting. Suggestions can then be made based on cost, and sound characteristics of variously branded NOS as well as currently (and plentiful) available types.
Mr Mcfarland, thanks for your reply =)

I never knew it has that much to know, i thoght it is just a tube.

The tubes are Ei- Yugoslavia ECC-82 an the other set are 5687WB.

The treble gone abit, never happen before, so i guess it is time to be replace them? They were long here...

So type of tubes should i be looking into replace them?

currently, it have all the juice from treble to bass, but the soundstage is not as clear and 3D as solid states amps, thats the field i want to improve on...

or that part is not done by tubes?

Please teach the silly me hehe, thanks =)
Hello Deramg. The two outside tubes are the 5687's. The 5687 is a dual triode developed for use in computers. The original nos tung-sol black plate 5687 is "far and away" the best sounding tube of that type. You may also substitute the 5687 with a 6900 or 7044 [ direct plug in replacements]The two inside tubes are 12au7/ecc82 dual triodes.The Ei ecc82 isn't a bad sounding tube but can be vastly improved upon with many brands of nos 12au7/ecc82 types but it is imperative that they are quiet and non microphonic. The early 60's vintage amperex bugle boys are terrific in that spot.
hehe, PERFECT =)

Thanks alot people, i guess i'll got hunt those tubes...
arhhh... does the 5687 has more variant?
There is only a pair of old 5687 out there and no 6900 or 7044.

Dual Triode - does it mean all dual triode can be use?
I saw a Tung Sol Gold Pin 12Ax7/Ecc803S is dual triode too...
Hello Deramg. No sir, you cannot use any dual triode tube. The 6900 or the 7044 will sub for a 5687 but do NOT use a 12ax7/ecc83 or ecc803 as they will not work.
Deramg. What type of 5687's are you using now. The 12au7 should have the bigger influence in the KR.
I think now it is using the Jans Philips.

I don't know when these tubes are purchased and start using... and i don't know how to check the health of those tubes, so i better replace them all at once... life long trouble free hehe.

Correct me if im wrong guys, starting a few days ago, some part of extreme side of the treble sound are gone/lost. My favourite songs became obvious faded. Does it gotta do with the output tubes (300B) or the preamp tubes more?

Sorry for my igorance... but people who don't ask are more silly =)