First Tube Amp: Advice? Keep spare tubes on hand?

If it's a manual bias you need to know how to bias them first and formost. Only because I have never owned a tube that didn't need biasing after replacement. No matter what tube I 'roll' including input and driver tubes I always start at min bias to let them all warm up first (about 1/2 hr). Then I bias them low and check the bias every 1/2 hr or so. Then I check again on a daily basis for the next few days. I have seen tubes take several days to settle down and stay properly biased.

That being said I will admit that 'factory' matched tubes can be very poorly matched. Something I learned from Jim McShane when I bought some GL KT88's and SED EL34's. I brought my 'factory' matched EL34's to Jim and he showed me how far away they were from a 'good' match.

Good Luck

Xti16 I couldn't agree more. Running an output tube on a machine for 10-15 mins. is a waste of time. Many output tubes require 24 hrs. for the innards to stabilize. I just got done installing new output EL-34's in a Conrad Johnson Amp. And sure enough with brand new tested tubes one of the Wing C EL-34's started to run away.... You have to be vigilante.

I second Usblues, and after you decide how much you like the amp, tell us what tubes it takes. Remember, NOS tubes are a good buy, but must be purchased per Usblues advice.

Hi everyone. Thanks for the sage advice. I've been listening to this Baldwin 6L6 tube amp for some time now with the current tube complement and I really do enjoy it. It is matching well with a pair of KEF 103/3 speakers I have. Big improvement in imaging and overall soundstage. I'm getting lots of nice details in various music I've hit the amp with. I think it only ran out of oomph when I was blasting some Blind Guardian.

I'm trying to find out information about the amp now.

Here is the current tubes in the amp.

3 12AU7 tubes 1 labeled Baldwin 2 Electro Harmonix
2 Harmon Kardon 7408 tubes
2 Baldwin 6L6GB tubes
1 Baldwin 54UGB tube

Replacements/spares I'm looking into based on my current budget.

3 Matched HP 5963 Large Plate NOS 12AU7 tubes to replace the current trio. That or just 3 new Electro Harmonix 12AU7 tubes.

2 TUNG-SOL 6V6GT Re-Issue tubes to replace the pair of HK 7408s.

2 Russian Military surplus 6Pi3C tubes to replace the 6L6GB amp tubes.

1 ELECTRO HARMONIX 5U4GB to replace the Baldwin 5U4GB tube.

Please let me know what you think. I'm hoping these tubes won't be a step down from what I currently have in the Baldwin amp. Is there a formula to follow with cost of tubes vs. cost of amp?

I will definitely not change the power tubes unless someone can re-bias the amp for me or I can find info onto how to re-bias this amp myself. I was told I could change the 12AU7 tubes without re-biasing the amp. Since I'm happy with the current sound of the tubes in the amp I won't change them out till a tube dies. (I know famous last words.)

Thanks again everyone for the help.