Definitely check with the manufacturer first.
And I second the Kevin Deal recommendation. I needed new GZ37 rectifiers for my Art Audio PX-25 and he delivered the goods. You get exactly what's advertised(no fakes or failures) with him and he stands behind his tubes 100%, not true of every tube dealer out there. Just be sure to do your homework and know what you are looking for before calling, things are usually pretty busy at Upscale and Kevin doesn't always have time to chat freely.
And I second the Kevin Deal recommendation. I needed new GZ37 rectifiers for my Art Audio PX-25 and he delivered the goods. You get exactly what's advertised(no fakes or failures) with him and he stands behind his tubes 100%, not true of every tube dealer out there. Just be sure to do your homework and know what you are looking for before calling, things are usually pretty busy at Upscale and Kevin doesn't always have time to chat freely.