Asteroid Questions: Lower Voltages

[PCollen]

The Asteroid amp has rather high voltages in the pre-amp/PI section. Would running lower voltages, closer to the Express (around 300V), 'hurt' it's performance. Would it turn it into "just another amp" if DC voltages were , for example, 435/434/340/320/300 ? I can pull up the pre-amp/PI voltages in my donor chassis. But about the best I can get for a B+ is 435.

[andrew]

Hi, I have a Matchless schematic that shows 410v on the PI and 410v on V2. I have wondered why so high?

[Teleguy61]

PCollen-
I am also interested in the effect of different /lower voltages on the
Asteroid circuit.
Running 500v or so on the plates of the output tubes is going to require a specialized PT.
I would also probably build it with a donor chassis that would have somewhat lower B+.
But I find the circuit intriguing, and would like to try it.
Pure KF-simple, signal straight through to speakers.
Anybody?
George

[Teleguy61]

Anyone's input appreciated.
TIA.
George

[M Fowler]

Teleguy I am not sure what your question is?

The Asteroid has a Heyboer PT specified and OT specified.

[PCollen]

Teleguy I am not sure what your question is?

The Asteroid has a Heyboer PT specified and OT specified.

re: my original, opening post on this topic.

[M Fowler]

If you have a donor amp with lower secondary voltage use that and the results should still produce a great amp.

Its just the same as when I built a TW Rocket with with 300-0-300 secondary PT 35w rating and used a 4k3 primary PT 35w rating into a pair of 6L6 power section. I get a 35-40w amp but it sounds great and plenty of stage volume.

[marcoloco961]

Plate voltages and plate resistor values determine how the gain stage works.

Here is a link to Merlin Blencoe's web site. There is alot of good info here, explained in a manner which is easier to understand. Good stuff, check it out.

http://www.freewebs.com/valvewizard/index.html

Merlin also has a book for sale that I hear is a must if you want to design your own circuits from scratch. It will explain what the effect would be of lowering your plate voltages. It is all relevant to your bias point of the individual tube and what you are trying to acheive with the particular gain stage.

Also, check out the thread in the garage talk forum titled "readind material on steriods". Tons of links with good info.

[Teleguy61]

Thanks guys-
George