What tubes to get / do I NEED to change the bias?

[heartben]

Howdy partners!

I am still getting all my ducks in a row to rock again and part of that falls on getting my amp sounding the best it can. I know the tubes in my amp haven't been changed for a LONG time so I guess it's time I look into it.

So basically I have this 70's Fender Bassman Ten (silver face, 4x10 speakers) - I need help with the following:
*Not sure which tubes to get, I think 6L6GC? Also unsure of the preamp tubes.
*Don't know almost anything about setting a bias - and not 100% sure how important it is.

So here is a picture of what my amp looks like (these aren't mine, but the same amp):



This picture is probably a lot more useful.

Anyways, help with this stuff would be awesome. I am pretty sure my tubes were microphonic when I got the thing like.. 7 or 8 years ago..I can't even remember.

Thanks as always, hopefully I can get this think back in shape. Oh side note- any idea what type of products I can use to clean the grill? I was thinking of like.. scrubbing bubbles or something with bleach in it - that might ruin it though eh?

[bronzetalon]

https://www.eurotubes.com/cart/index.ph ... ory_id=103

you can also check out dougstubes

eurotubes has a bias probe you can buy and you can do it yourself but thats up to you really

[Uncle Grandfather]

Check out Brent Jessee Recording & Supply. He stocks LOTS and LOTS of NOS tubes. His website is VERY informative about what to expect from the different brands and tube types. He also stocks also of off branded tubes at a discount....so you can get that exact $200 tube for $120 or whatever because it's not branded with the makers name. I've spent $1,000's with him and never had a bad experience. Great reputation.

http://www.audiotubes.com/

[heartben]

I looked at those tube kits from eurotubes but they seem to come with an extra preamp tube for some reason?

[Uncle Grandfather]

I looked at those tube kits from eurotubes but they seem to come with an extra preamp tube for some reason?

2-6L6/ 2-12AX7/ 1-12AT7
those are the tubes you need. Brent Jesse Recording and Supply , audiotubes.com gives all this information and more.

[chillerthanmost]

I've picked up so many tubes from Brent @ audiotubes. Great dude to deal with and good prices for NOS and ANOS tubes. I always suggest that route with older amps that put out high voltage ratings. I've ran through so many modern tubes with some of my amps, for me it's just worth it to spend a little more on older made tubes. Granted, I'm not familiar with the amp in question here enough to know the voltage the power tubes will be seeing. If it's nothing crazy, then picking up any matched power pair, and those three preamps will work. Whether it's though Brent, or Dougstubes, TubeDepot, TubesAndMore, etc, etc.

I always recommend setting the bias whenever you re-tube an amp. I don't do it as often as I should which is probably why I've gone through so many tubes. Sometimes, even the same brand of tube you're using to replace old ones with, have a higher/lower mA setting. If your original ones are low and require your amp bias pot to be pushed up, and you replace them with a set that read high and don't change the bias, they will or might run too hot and die much faster. If your amp has a bias pot anywhere, even inside, you can simply buy two bias probes or a set bias tool online, do some quick and simple math, and set the bias yourself. If you're not comfortable doing so then any shop that works with amps in house will do it. Or ask around if any friends you have work on amps or are familiar with the process.

[amnesiac305]

While it is easier/safer to use a bias tool, you don't need one. All you need is a multimeter and know where to measure. Though it might sound TGP to recommend NOS/ANOS tubes, I completely agree in using them with older high voltage amps. There definitely is something to the lower quality/lifespan of modern tubes (power tubes).

[rfurtkamp]

I'm an odd one, in that I'll be the first to admit that in the day we *never* bothered to bias anything. You went down to the hardware store or Radio Shack, got a couple tubes, swapped them in, and rocked on. I don't think I ever biased anything unless components got changed/transformers got replaced.

I haven't changed in practice as I've gotten older - I buy "will not break up" 6L6 tubes of whatever vintage, run them into the ground, and repeat.

I recently had to retube my Deluxe, and ended up with new production Tung Sols. They sound good, don't break up as advertised (I bought the maximum available hardness rating), and it sounds like a 6L6 amp should.

If you want power tube distortion, all bets are off, but I just don't like it.