Hammond 1609 for 15 Watts guitar amp?

[Cassiel]

Rated for 10 watts but then i read this:

When using for guitar amps 50 to 75% more power can be used with no ill effects.

Is that true? No problems whatsoever? Amp is for a friend so i must be sure.

[tubelab.com]

A Hifi grade OPT must pass 20Hz to 20KHz (or it should). The lowest note on a standard guitar is in the 80Hz range. Some people use non standard tuning that can go a bit lower. You can definitely run more power through an OPT at 80Hz than you can at 20 Hz. At least twice the power should be no problem as long as it is used for a standard electric guitar. A bass guitar goes down to 40 Hz and they can be tuned lower, so 15 watts through a 10 watt OPT should still be OK.

Going the other way, I bought a bunch of "80 watt" guitar amp OPT's that I have been using in HiFi applications. They are realistically a 25 watt OPT over the entire audio range.

[Cassiel]

Thanks Tubelab, as always great info coming from you. I'll go ahead.

[GeertSlootweg]

Used said 1609 in PP EL84 power amp with very good results indeed. Go4it!

[rojoknox]

Originally Posted by GeertSlootweg

Used said 1609 in PP EL84 power amp with very good results indeed. Go4it!

According to Sylvania data on the 7189 tube (relative of EL84), when in PP UL mode it wants 11K plate-to-plate load resistance (8K for usual pentode mode). GE data on 7189-A shows lowest distortion and highest power at 5K-6K load resistance (one tube). That's why I chose a 1609 (10KCT primary) over a 1608 (8KCT) for my "AMP II". Glad to hear you had very good results, and I'm looking forward to same.