CurtPalme.com Home Theater Forum

Musicman · Joined: 23 Jun 2019 Posts: 7

Can 07MSP TUBE SWAP FOR A 07MP or will the power block on a 1252Q work on a 1251Q?

**Curt Palme** · Posted: Fri Jul 05, 2019 12:18 am Post subject:

Maybe. Physically the tubes are the same, but the focus voltage is different. you may need to modify the 5Kv focus circuit, but sometimes the focus control will have enough range to bring it into focus. Usually right at the end of the range of the pot. You won't know until you try.

Musicman · Joined: 23 Jun 2019 Posts: 7

Any thoughts on whether the power block will interchange.

**Curt Palme** · Posted: Fri Jul 05, 2019 1:55 am Post subject:

What do you mean by power block? Not sure if the focus voltage shift is in the HV transformer unit, or if the focus/screen control is different. But yes, they will interchange, assuming you're swapping all 3 tubes at the same time. If you're only changing one, then you have to mix and match, and play with the focus settings.

Musicman · Joined: 23 Jun 2019 Posts: 7

Thanks for your response. By power block (as identified in the manual) I meant the large block of Electronics located directly under the three lenses which slides in and out to give you access. That is irrelevant now though since I did as you suggested and changed the tube out. It performed exactly as you said it would. I had to turn the blue focus pot to the limit of its range to get it to be in focus. The focus is not like the original tube but it works. Thanks for your help. It was a learning experience.

**Curt Palme** · Posted: Fri Jul 05, 2019 2:47 am Post subject:

Oh and no, the power supply block will not interchange between the two.