2. amps-preamps
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4 amplifiers to drive 1 pair of speakers?

Hi

Sorry I am still quite a young audiophile (less than 1 yr old)
Was wondering if its possible to use 4 amplifiers (eg 300b which is quite low powered) to drive a pair of speakers? 

I.e. pre amp output --> Y splitter into 2 different 300B amplifiers for each channel. Each amplifier can take either the top 2 or bottom 2 binding posts of the speaker.

My speakers are 90db 8ohm (more like 4ohm in real life), and im afraid that 2 300b PP amplifiers ~18W class A is insufficient.

Thanks!
thegreenman
timlub
2,040 posts
 
@thegreenman.... You are correct to worry about Impedance dips.  It does somewhat matter about where (what frequency) they are, but the real problem is to try to get an impedance/phase sheet on your speakers.  Normally impedance dips are accompanied by phase angle dips.  This is where many many tube amps crap on themselves.  
I read that each speaker had 2 binding post?  So yes, assuming that you are running them as mono's, you could conceivably run your  amps that way. 
erik_squires
16,118 posts
 
Well, you should try it first. :)

But active bi-amping may be a much better way to go.  Use a solid state amp for the low end.  Put a capacitor in series with your top end amps.

THe thing about passive bi-amping is your amp still has to reproduce the full voltage swing (+ or -, corresponding to in/out on the speaker).  You do reduce the current, which stiffens up the amp, but if you can remove the bass from the amp the full power becomes available for the high range.
ebm
9,311 posts
 
Very weird idea.
atmasphere's avatar
atmasphere
11,837 posts
 
You can monostrap stereo tube amplifiers if you are careful. But generally speaking they don't sound as good- less delicate, more heavy-handed.


So a Y adapter is used at the input and the outputs are wired in parallel. However, the 16 ohm tap becomes the 8 ohm output and the 8 ohm tap becomes the 4 ohm output.

oldhvymec
5,101 posts
 
Bi-amp with valves units.. The only issue for me would be heat. It's tough enough to deal with valve amps in the summer months, much less 4 of them.. You might want to rethink that one.

Eric offered SS for BASS duty that is a lot better ides. COOL running class Ds will certainly liven up the joint.. I quit using valve amps for bass duty 20+ years ago.. They work better NOT doing bass. Pretty simple.

Regards
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