We sometimes receive amp owners question about tube substitute related to 6SN7. Here is a short summary:
- GT stands for ‘Glass Tube’.
- GTA is an enhanced version of original GT version – to allow higher plate dissipation than the GT version.
- GTB is variant of GTA, with a heater warmer control to further enhance reliability when this tube was used in TVs.
- Very early 6SN7 tubes can handle max 300V. Today’s new production 6SN7 tubes can handle max 450V.
- In short, new production 6SN7 can replace your old 6SN7 without frying the tubes. But you should not use a NOS 6SN7 designed to handle 300V, into a modern circuit of 450V.
- All our listed 6SN7 tubes (no matter what suffix it has) can electronically replace 6SN7GT, 6SN7GTA, and 6SN7GTB.
- Do check dimension clearance to make sure the different glass bulb shape can fit into your amp space!
Happy tube rolling!