"New Old Stock" (NOS) tubes — vintage manufacture from the 1950s-70s — command 5×–20× the price of modern equivalents. The folk wisdom is "NOS is always better than modern production." Per Dave Friedman, Headfirst Amp Panel #9 (October 2025), this is partially true but oversold for most use cases.
Friedman ([Panel #9 116:31]): *"Don't do it. Don't do it… they don't necessarily sound that much better than tubes made today."*
Where NOS actually helps (worth the money):
- V1 (first preamp slot). The first stage has the most signal-to-noise leverage; a NOS tube here noticeably lowers the noise floor on high-gain amps. Friedman: *"maybe one or two NOS in V1 for a treat."*
- V2 in some cascade builds. Marginal benefit; sometimes worth it on a hot-rodded amp.
Where NOS is wasted money:
- All preamp slots simultaneously. Friedman: *"I don't think you need to put it in all slots."*
- Power tubes. Modern JJ, Mullard reissue, Tung-Sol, Shuguang, and Ruby Tubes match or exceed NOS power-tube quality at a fraction of the cost. NOS power tubes are a collector's market, not a sound-quality investment.
- Cathode-follower position. Friedman ([Panel #9 127:20]): *"I hate a JJ in the cathode follower."* — but the fix is "use a long-plate Chinese tube here," not "buy NOS."
Friedman's production rotation for the Friedman Jose amp ([Panel #9 118:21]):
- Power: JJ EL34.
- Preamp slots 3+: Shuguang Chinese.
- Preamp slots 1 (V1) and 2 (V2 in some configs): flexible — can use NOS for noise-floor reasons, or modern Chinese/JJ if budget-constrained.
Reference: Pete Thorn's EL34 comparison video documents the practical reality. Friedman: *"go reference Pete Thorne's EL34 video that we did."*
JMIL position: the lab doesn't model tube manufacturer character because the per-tube variations are smaller than the per-mod variations and would compete for parameter-bandwidth with more pedagogically valuable controls. Players reconstructing a Jose-school amp on real hardware should treat NOS spending as a noise-floor optimization (V1 only), not a universal tone upgrade.