OK I'm gonna swap some tubes in my yba200-2

Discussion in 'Amps and Cabs [BG]' started by GreyBeard, Dec 27, 2007.

  1. I'm looking for a smoother flatter less clanky sound from my yba200 pre-amp secton. I'm gonna swap the 12AX7's for a pr of 12AT7's and a new 12AU7 Phase splitter.
    These tubes range in price from about $10 bucks to $100 bucks depending on the brand. Are JJ tubes from tube depot pretty good? Do I need to get them matched and balanced? I understand that it is important to get the PS 12AU7 balanced. RIGHT? Is their a particular brand that is the consensus BEST brand to buy?

    Thanks in advance.

    PS I've done the search and didn't really get a clear picture of what I need to buy other than the 12AT7's
  2. Jazzman


    Nov 26, 2002
    Raleigh, NC
    I live by the NOS RCA black-plate tubes. As far as sound goes, I haven't found anything better. The preamp tubes are reasonably priced as far as NOS tubes go.

    As far as new tubes, the JJ are pretty good. I would certainly stay away from the new Tung Sol - they are made in the new sensory factory, and from what I have seen, they are complete junk (unbalanced and test in the low 20's).
  3. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG

    Hey, I hope nobody minds a shameless plug for a great guy who loves tubes almost as much as his wife and has a gigantic stock of NOS tubes at very reasonable prices. This guy spent 90 minutes yesterday testing tubes for my SVT restoration and went through thirty RCA 6146B's to get two matched sets of three at only $2 extra a tube. He knows everything about every tube created, and can quickly steer you to the best tube for your application, even though he's not a musician and had no idea what an SVT was until yesterday. But he knows what each type of tube does, and makes a real effort to give you the best value for the price. You can call or order over the net if you're not fortunate enough to live near Orlando. Me, I'll never buy tubes from anyone else again, and you can forget those inferior Eastern Bloc tubes! NOS rules!
  4. Well, after reading everything I can find, I've ordered a pr of JJ12AT7's and a balanced JJ12AU7 for the splitter. Tubes won't be here until 1-3 so I'm still waiting.
  5. Do you guys over there in the US have access to the ECC** series of valves (tubes to you)?

    The difference is that the 12**7 series has a pretty flat response and a lower overall gain than the ECC** series generally (although I *know* someone will refute that by numbers), and the ECC** series (particularly the ECC83) has a mids-hump.

    I have found the ECC series particularly effective in valve amps mainly because of that mids-hump which gives an extra kick in the mix (The British sound).

    The ECC83 usually has more gain than the 12ax7 and the ECC82 is the equivalent of the 12AU7.

    Be a Devil - do something different!!

  6. The manufacturer, not the designation, is the reason for the perceived tonal differences. A 12AX7 IS an ECC83; they're just two different designations for the same tube. Mullard, who made most ECC labelled tubes, produced tubes that have a better midrange response than old US tubes. They both have the same gain factor.
  7. Thanks for the clarification.
  8. A9X

    A9X Inactive

    Dec 27, 2003
    The ECC etc codes are Euro designators whereas the US used a designation system based upon the filament voltage, ef 12xxx or 6xxx.

    There is no functional difference between equivalent Euro and US designated parts apart from manufacturer differences.
  9. Good info there - not intended to be spam.
  10. That's debatable.
  11. Greyvagabond


    Aug 17, 2007
    I installed JJ tubes in my YBA200-2, and the change was noticeble and good, but not huge, obviously. I used a JJ ECC81 (12AT7) in the V1 spot, and a JJ ECC83 (12AX7) in the V2 spot. I left the phase splitter; I've heard there is no reason to change it. I got mine with low microphonics from tubedepot for real cheap. Sounds great, smoother and less gainy, while when they are overdriven, a much richer sound, more overtones. JJs are a good deal