490t tube change time??

I bought my 490t brand new in 1991. Dont know a thing about tubes, do they lose their luster. Any recomendations on different tubes to put in my 490t.

Also I dont want to tear up anything, are they difficult to change. I saw them in there when we fixed the drawer belt. Kinda treated them like they came fresh out of the Chernobyl plant, scared to even wipe the dust off of em...LOL

Amperes gold pins

Hello MHRP. I can not comment on what to put into your pre as I have no experience with that unit in my own system [until later on this weekend] but I can tell you this. Tubes are not needed to be held as if they were at Chernobyl as they are not radioactive and they will not trigger a nuclear reaction. That said, to prevent the inner components of the gear they go into, you do want to use great care with their handling.

The wearing of white soft cloth gloves while handling tubes is recommended but not altogether necessary. A simple Kleenex [not the type with the lotion in it] or paper towel can be used to handle the tubes. What you are trying to prevent is the oils from your hands coming into contact with the glass on the tubes. If oils do get on the glass, a Stoner product called Invisible Glass can remove them without the removal of most lettering. With older tubes, soaking a Q-tip with Caig De-oxit followed by another soaked Q-tip with Caig Pro Gold and wiping said Q-tips in and around the pins can help to clean and prevent any further oxidation that might hamper the performance of the tubes.

When taking the tubes out, gently try to slide straight out of the tube socket. If this does not work, try gingerly swaying the tube from side to side while lifting up. When you go to reinstall the tubes, simply line up the pins and push it back in. Sometimes you might have to gingerly sway the tubes back and forth in order to sit them in properly. Just make sure that they are properly seated on the socket and you will be golden. There is no way to install them incorrectly, as all of them are "dummy proof", so there is no fear of blowing your gear up because of putting them in the wrong way.

Amperes gold pins

He meant Amperex. You really can't go wrong with any Amperex tubes but the 6922 gold pin types are the best. There are also some good offerings from Sylvania and Philips that are more reasonably priced. I use Amperex orange globe 6DJ8's in my 390t. The higher end Amperex tubes are in my Sunfire preamp.

Tom just so you know! About tubes some are radioactive !!!!!!!!!!!!!!!!! Where do you think the xray machine came from!!!!

Well technically, yes. Mildly radioactive but nothing to be concerned about so long as they are sealed. Most of the radioactive ones from what I understand are for defense type applications, microwaves, X-ray machines, spark gap tubes, power tubes, gas tubes including glow lamps, receiving tubes, indicator tubes, pickup tubes, radiation detection tubes, and any other completely sealed tube that is designed to conduct or control electrical currents. The ones with higher levels of radioactivity must be labeled as such with the radioactive symbol.

I would worry more about the gas and mercury before anything else with most of the tubes I would be handling. Basically, just don't break them apart to eat them and all should be well.

Great info from everybody,thaanks.

And see I KNEW those things were radioactive...LOL

Should be fun to change out and get a feel of the different sound.

I will say the tube socket assy is not the best for tube rollin, it's kinda a pain in the ass, if you take the time to disassemble and reassemble. I did not put it back togethor, just left the tubes hanging. you will see when ya get in there what I am talkin about...

I've used both NOS Mullard ECC88 and JAN Philips 6922 Green labels, both of which are a big step up in terms of sound over the stock tubes in my SD/A-490t. The JANs are more detailled and smoother in the highs than the Mullards which have a slightly darker, more mellow sound and a bit fuller bass. My preference went to the Mullards as my favorites for this particular application (though I was perfectly happy with the JANs too, especiallu at 1/3rd the price), but in my tube DAC on another CD player, the JANs blew the Mullards clear out of the water. Different tubes have different sounds in different equipment and what sounds great in one thing can sound like crap in something else. I agree wholeheartedly with mbskeam that those tube sockets suck big time; good thing the tubes last for 20+ years!

Stay away from Sovteks. They will get the job done but they are nothing special.

My tube experience as a generality are this. Choose a tube to compliment your cdps weaknesses.

ElectroHarmonix - superb frequency extension, detailed, hard.
RCA - detailed, 3D, lean, extended highs.
Tungsol - warm, full bodied.
Sovtek - clean, tight bass, low noise.
Telefunkin - warm, lush.
Sylvania - smooth, airy, balanced.

Your mileage may vary depending on your gear.

Have any of you guys ever rolled in the same part number and yet have a different sound, as in, you pull out a set of Mullard ECC88's and then put in another set of ECC88's.

hey guys and gals, please send me any carverfest tubes that are rolled out of your amps for my 7 amp build. i have two sets now (thanks chauss), and i am in need of another 5 sets. thank you ever so kindly for your help and old tubes.....

Alright, I bought some Jan Phillips 6922 ECC88 green label's for $39.99. Im going to try them out and see if I can hear a difference before trying the much higher Amperex gold pins. Thanks for everybodys help. There is a wealth of knowledge on this forum.

Alright, I bought some Jan Phillips 6922 ECC88 green label's for $39.99. Im going to try them out and see if I can hear a difference before trying the much higher Amperex gold pins. Thanks for everybodys help. There is a wealth of knowledge on this forum.

Those are great tubes. They were my favorites before I got into Amperex tubes. Enjoy!