Announcement

Collapse
No announcement yet.

Tweaking tubes

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Tweaking tubes

    Having completed two tweed deluxe builds recently I have a number of questions related to tweaking the sound – specifically through tube substitutions and a question about speakers.

    I completed a Tubedepot Tweed a month ago and a Mission build about 10 days ago. As of now I much prefer the sound of the Mission – though I like the TD build. The TD seems like a dirtier sound – I can get the dirty sound from the Mission but I feel I have more control of it and it has a wider range.

    The TD has a Weber AlNiCo 50 watt Blue Dog – still breaking that dog in. The Mission has a 20 watt Weber 12A125A Vintage Series AlNiCo. The 20 watt speaker seems to have less of a dirty/buzzy quality (buzzy is not a great word as the speaker doesn’t buzz but the sound is colored differently – hard to describe). I have swapped cables and played each amp through the other speaker but I’m not sure yet how much the speaker contributes. My ear is not yet discerning enough beyond saying in general I prefer the 12A12A 20 watt speaker, but swapping the speakers doesn’t account for the difference between the two – as far as I can tell. With the TD build I did upgrade the caps to Orange drops and F&Ts. (My mission build is Mallory and F&Ts)

    First question about speakers - should the 20 watt sound clearer than the 50? Is it just that the Blue Dog needs more breaking in time?

    Now to the tubes. The TD kit came with a JJ 5ARA rectifier, two JJ AV6GT output tubes, and two JJ 12AX7s in the preamp stage. She was running a little high voltage at the first filter cap and a forum member suggested I swap in a 5YGT for the rectifier tube and it brought the voltage down just right.
    Because the standard Tweed comes with an 12AY7 in the V1 preamp stage I swapped out the 12AX7 in this position and it did make it less gainy. I used a US made GE NOS 12AY7 that I had (it was originally a pricey tube). I would like to try further experiments – wondered about the impact of having two 12AY7s in the preamp stage, also wondered about a 12U7 which supposedly has even less gain?

    Also I wondered how much the output tubes contribute to sound quality and whether forum members have some insights or ideas about this?

    I am totally hooked and having fun and it would be great to hear from those of you who have been doing this a long time.
Working...
X