Soundhound, need help again!

Hi Soundhound...you answered some of my questions on installing a tube preamp with the 950. My next question is, I have bought a tube amp to play with ( single ended triode 8 watts)can I hook this into the mains of the tube pre for 2 channel listening and leave the 770 connected into the 950 for movie watching? Then when I choose the 950 on the pre the 770 would kick in. If this makes no sense is there a device that would allow me to do amp switching depending on which component I'm using (TT or CD)

You can only have one power amp connected to your speakers at a time. Probably the best solution would be to use a speaker selector switch. I think that Radio Shack might even carry one.

Alternately, you might just use the single ended triode amp for your mains all the time - for movies and for music rather than the Outlaw 770. I would bet a week's wages that it would sound better than the Outlaw amp (sorry Peter!).

The only limitation would be power output, but SET amps clip so softly that you might not even notice it. Try it and see - you may be surprised!

Wow. Big Spender. Like me, Soundhound freelances so, if he chose the right week, this would amount to a $0 bet.

Very clever, Hound.

Shhhhh....never mind that man behind the curtain!....

Thanks again Soundhound. Do you feel this type of amp can deliver the power that is needed for movies? I have a small area that I use for my music/movie enjoyment and I don't need reference levels to enjoy them. This is why I thought the tube amp might be ok, if not it goes back on sale.

I feel it is certainly worth a try. You will probably be surprised how much loudness 8 watts can make, and like I said before, these amps clip very gently so you probably won't hear it if it does clip. When they clip, they do not generate the same levels of high frequency distortion that a solid state amplifier makes when it clips, so there is not the same potential for damage to your tweeter. If you do hear clipping, then go back to the 770 amp, but if you don't, the SET amp will sound much better for movies and music.


[This message has been edited by soundhound (edited January 07, 2004).]

Thanks Soundhound. What are your thoughts on zero auto transformers from Paul Speltz? From what I have read they seem to make a big difference. I can pick a used pair up for $300, should I do it?

Won’t this cause timbre mismatch between center (plus surrounds) and main?

Using a tube amp for the mains will not make a timbre difference, it will only make a listenability difference - the mains will sound better. A good tube amp should have a flat frequency response, which is the main determinant of timbre differences. The center really can use a huge dollop of tube amplification because this channel carries the dialogue which more often than not sounds harsh to begin with. There will not be any huge timbre mismatch though if it is solid state.

Thanks Soundhound. What are your thoughts on zero auto transformers from Paul Speltz? From what I have read they seem to make a big difference. I can pick a used pair up for $300, should I do it?[/QUOTE]

I am not familiar with these transformers, however I would stay away from autotransformers (if they are indeed autotransformers) - SET amps sound fine already. The traditional transformer used in a SET amplifier is actually not something that needs "fixing" as long as it is of high quality. Any SET amp of good quality will sound great in stock form, or with some subtle mods. I have replaced the coupling capacitor between the plate of the driver tube and the grid of the output tube with a NOS oil capacitor which made a difference for the better. I also constructed a regulated DC power supply for the filament of the 300B output tube for noise reduction reasons since my horns are 106db/watt efficient and need a squeaky clean noise floor.

If you get the urge to tweak, I would stick with maybe a higher quality traditional output transformer, maybe oil coupling capacitors, and if your amp uses a 300B output tube, Svetlana makes a very fine one.

These amps sound just stunning as-is.