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Question about byamplification

Hi guys

A question for those with experience and knowledge.

 

I'm thinking about experimenting on byamping with my valve amp, the Line MagneticLM-508, and a class D power amp I have, both driven by my Audio-GD HE-1 preamp.

 

As my speakers, the Q Acoustics Concept 500, have two pairs of binding posts, I was thinking about connecting the LM-508 to the highs binding post and the class D to the lows ones of the speakers.

 

I don't have an active external crossover, so I was suggested on splitting the RCA output of my preamp to both amplifiers. I know that I will probably have trouble matching the gains of the amps as they are likely different, but I have tubes with different gains and also the LM508 has a knob with different negative feedback settings (different gains) so I can try to match them, at low volume levels of course.

 

The one millon dollars question is if I'm risking on blowing a tweeter with the LM-508? The speakers manufacturer said I should be careful since the LM-508 will only be running the tweeters and it could "see" a high impedance load at frequencies below the crossover point (2.5 Khz).

 

On the other hand, people with experience on byamping told me that it should not a risk, I should only start with low volume levels and go up carefully.

 

Has anyone experienced something similar? Am I risking the tweeters or the amps?

 

Any thoughts or suggestions are appreciated.

plga
carlsbad's avatar
carlsbad
1,551 posts
 

you don't need external crossovers to biamp so long as the most powerful amp has gain control. Many will tell you that you do.  Those of you who think your internal crossovers should do the job are correct.   

As I interpret the OP question, and i don't know  the answer, since his speakers are 2 way, and the tube amp will just be powering the tweeter, so  the tube amp will sometimes have very little load on it.   can it be damaged from that (like a tube amp can damage transformers if running without a load on them). 

Jerry

 

yogiboy's avatar
yogiboy
5,701 posts
 

You can use this Schiit SYS to match the output levels on your amps!

https://www.schiit.com/products/sys

spenav
429 posts
 

@plga 
Yes you can. That’s perfectly safe. Most refer to this as bi-wiring. By the way, it’s bi-amping not by-amping. But people who have actually done both would tell that bi-amping is the next level. In fact, it’s not even close, the difference is noticeable and worth the trouble. Good luck. 

elliottbnewcombjr
5,469 posts
 

your speaker’s crossover is prepared for biamp. you only need a volume control for the strongest amp, cut it to match the other amp.

https://www.schiit.com/products/sys?Finish=259&gclid=Cj0KCQjwsdiTBhD5ARIsAIpW8CJgw97ajn9NPQ8oL2vaq3FHhNlgD9FJcD3lema4BvaaxX8DWgCsJHMaAlt5EALw_wcB

I would buy an in-expensive SPL meter to help with the adjustment.

hole for tripod mount at seated ear height, ...

better yet, find a remote volume control.

........................

later (or now), sell your class D, get a pair of mono-blocks with volume control on them.

...............................

another way is to control the volume after the amp, on the way to the speakers

 

made for adjusting levels of amps of car woofers

 

donvito
400 posts
 

@yogiboy +1 That SYS is all you need! @ elliottbnewcombjr is making a Mountain out of a Molehill!

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