# BHK Amplifier Tube Query **URL:** \ **Category:** Amplifiers\ **Created:** [April 4, 2023, 12:21pm UTC](https://forum.psaudio.com/t/bhk-amplifier-tube-query/33159 "2023-04-04T12:21:22Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![zenmonkey](https://avatars.discourse-cdn.com/v4/letter/z/c4cdca/32.png) [@zenmonkey](https://forum.psaudio.com/u/zenmonkey)\ **Post date:** [April 4, 2023, 12:21pm UTC](https://forum.psaudio.com/t/bhk-amplifier-tube-query/33159/1 "2023-04-04T12:21:22Z")
Do the PS Audio BHK Signature pre-amp and BHK 250 power amp use same specification tubes? I suspect the tubes in my BHK 250 are spent and the only other tubes I have on hand are spares from my old BHK Signature pre-amp which I no longer own. Comparing the tubes from both amps, they both have the same pins, but am unsure if they share the same voltage. Are they interchangeable? ---
**Author:** ![sixpack1](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/sixpack1/32/6013_2.png) [@sixpack1](https://forum.psaudio.com/u/sixpack1)\ **Post date:** [April 4, 2023, 1:23pm UTC](https://forum.psaudio.com/t/bhk-amplifier-tube-query/33159/2 "2023-04-04T13:23:13Z")
The BHK250 uses 6 volt tubes. The preamp comes with 12 volt tubes but can be strapped to use 6 volt tubes. Unless you have done that and are using 6 volt tubes in the preamp than no they are not interchangeable. ---
**Author:** ![zenmonkey](https://avatars.discourse-cdn.com/v4/letter/z/c4cdca/32.png) [@zenmonkey](https://forum.psaudio.com/u/zenmonkey)\ **Post date:** [April 4, 2023, 4:57pm UTC](https://forum.psaudio.com/t/bhk-amplifier-tube-query/33159/3 "2023-04-04T16:57:49Z")
Thank you. ---
**Author:** ![watchdog507](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/watchdog507/32/7301_2.png) [@watchdog507](https://forum.psaudio.com/u/watchdog507)\ **Post date:** [April 4, 2023, 10:17pm UTC](https://forum.psaudio.com/t/bhk-amplifier-tube-query/33159/4 "2023-04-04T22:17:23Z")
I use 7308 tubes in my BHK Pre and my BHK 300’s. It’s merely a jumper setting in the preamp. It’s very easy to do.