Simple PP Power TX?

[chrisb]

I just received a board and parts kit for a Simple PP, and it's time to start collecting mechanical parts / TX, planning layout, etc.

Out of curiosity, has anyone experimented with separate plate & filament TX on any of George's designs? This is something that I've done in the past out of necessity with several scrap box projects, and except for the slight increase in real estate required, they worked out well enough.

Looking at Edcor and Hammond pricing, it might not necessarily cost more to go to separate iron for the low & high voltages.

With any luck, this will be one of at least 3 amp projects that I'll get happening during those long cold winter nights on the wet coast.

[chrisb]

well, since no particularly strong advice one way or the other, I went ahead and ordered the 272HX along with sundry other parts for this and several projects from PCXN - upon their arrival, it'll be time to start mock-up of parts layout

I may even take some pictures.

[DigitalJunkie]

Should work fine,perhaps even better than a single transformer because any HF switching noise (SS rect.,etc.) won't creep into the filament windings (and vice-versa) via capacitance between the windings. Also,if you feel so inclined,you can add a standby setup,and heat the filaments before powering up the B+.

[tubelab.com]

I went ahead and ordered the 272HX

The 272HX is an "all in one" transformer. It is the one that I am using to run my Simple P-P. It works good. You will get about 350 volts of B+. Use a good quality EL84. I use JJ's in my amp. I have some old Sylvania 6BQ5's that work good too. Some of the stuff sold as EL84's on Ebay will glow red.

[vinylkid58]

Originally Posted by chrisb

With any luck, this will be one of at least 3 amp projects that I'll get happening during those long cold winter nights on the wet coast.

Tube amps were made for this climate. Nothing like gathering around the hifi with a hot beverage.

jeff

[tubelab.com]

With any luck, this will be one of at least 3 amp projects that I'll get happening during those long cold winter nights on the wet coast.

I am at the other extreme climate wise. The winter is the only time of year that I can set my table saw up outside to make speaker cabinets. Last Saturday (Oct. 30) the temp hit 90F in the afternoon.

[chrisb]

Originally Posted by tubelab.com

The 272HX is an "all in one" transformer. It is the one that I am using to run my Simple P-P. It works good. You will get about 350 volts of B+. Use a good quality EL84. I use JJ's in my amp. I have some old Sylvania 6BQ5's that work good too. Some of the stuff sold as EL84's on Ebay will glow red.

OK - now I'm at the point where I'm connecting the wiring to the board and have a dumb question - the 272HX has center taps on both filament windings - as these are not used, do I simply dead-head them?

[tubelab.com]

the 272HX has center taps on both filament windings - as these are not used, do I simply dead-head them?

Yes, tape them up, cut them off, or hide them in any manner you choose such that they are not connected to anything. The 5 volt center tap will have full B+ voltage on it.

[chrisb]

Originally Posted by tubelab.com

Yes, tape them up, cut them off, or hide them in any manner you choose such that they are not connected to anything. The 5 volt center tap will have full B+ voltage on it.

thanks George - easily done - see my other question re pentode mode screen supply - forgive me if this has been answered before, but my search skills are worse than Dave's speaker construction