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Jose front-end V1 plate voltage target ≈ 140V — with practical floor

Across two separate panel episodes (#7 in August 2025, #10 in November 2025) Dave Friedman and Dan Gower converge on a specific voltage target for the Jose-style front-end first gain stage:

V1 plate ≈ 135–140V (Friedman: *"if it's a Jose thing in the front I like around 140, 135 to 140"*).

Surrounding stage voltages for context (high-gain Marshall-derived modded circuits):

| Node | Target | |---|---| | Phase inverter | 320V (up to 330V) | | Cathode follower / tone-stack input | 160–170V | | Normal second gain stage | ~200V | | Jose-style first gain stage | 135–140V |

Why 140V (and not lower): Friedman in Panel #10 explains the practical floor — *"140 I generally have settled on. You start getting much lower and you have a JJ tube it starts bleeding voltage out the input grid. So you have to be careful. You can't get it too low unless you use a blocking cap on the input grid."*

So Jose's voltage target wasn't arbitrary aesthetic — it sits at the lowest practical voltage where modern JJ-supply tubes don't leak grid current. Below ~140V, JJ-spec tubes start sourcing grid current, which both kills the bias point and risks audible artifacts. The voltage choice is co-constrained by tube manufacturing tolerance.

Implication for JMIL: the V0 + cascade gain-staging in the lab is voiced for this operating point. If a player swaps modern JJ tubes for older NOS, the headroom changes; the lab's audio model doesn't account for tube-spec drift but the underlying premise is "Jose's voltage target was about as low as a real tube can run cleanly without grid-leak hazards."

Related mods (2)

  • Extra preamp tube (V0 stage)T1
  • Cascaded V1 → V2 (cold clipper)T1

Citations