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Old 20th July 2011, 07:00 PM   #1
BigE is online now BigE  Canada
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Default Adding bass to an F5?

A buddy of mine built an F5, and is having problems with getting enough bass out of larger speakers, like watson lab model 10, tannoy dmt215, maggie 1.6. for example, Bjork's "All is full of love" has tons of deep bass that reaches out and blooms into the room with my modified Phase linear 400 and watson lab model 10. With his f5, the bass never leaves the speakers -- no bloom at all. This track is known for it's insanely rich and room filling bass.

He's hotrodded it to a higher bias, and claims 38 wpc.

He's got 37,000 uF Kendial caps in it, and a 400 VA toroid.

Are the caps bass shy, or is it just that the speaker needs more power? Can he achieve his goal of room filling bass by increasing PS capacitance?

Thank you.
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Old 20th July 2011, 09:20 PM   #2
Zen Mod is offline Zen Mod  Serbia
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let him make hot-rodded F5

you'll find that as cascoded or full blast F5

input is cascoded , outputs doubled
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Old 20th July 2011, 11:39 PM   #3
Itsmee is offline Itsmee  England
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Quote:
Originally Posted by BigE View Post
He's got 37,000 uF Kendial caps in it
Is that total or per rail?

It may need to settle in, give it 100 hours use before changing anything.
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Old 21st July 2011, 12:45 PM   #4
Botte is offline Botte  United States
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Try a .47ohm resistor in series with each speaker. This will add some bloom to the base as it lowers the damping factor.
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Old 21st July 2011, 01:07 PM   #5
flg is offline flg  United States
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No one has mentioned any testing of the amp? Try testing freq response into an 8 ohm resistor. Is it the amp or the load?
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Old 21st July 2011, 01:53 PM   #6
BigE is online now BigE  Canada
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Quote:
Originally Posted by Itsmee View Post
Is that total or per rail?

It may need to settle in, give it 100 hours use before changing anything.
Per rail. It should be settled in by now.
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Old 21st July 2011, 01:54 PM   #7
BigE is online now BigE  Canada
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Quote:
Originally Posted by Botte View Post
Try a .47ohm resistor in series with each speaker. This will add some bloom to the base as it lowers the damping factor.
Interesting, I'll pass it on.

BTW: What wattage of resistor?

Last edited by BigE; 21st July 2011 at 01:58 PM.
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Old 21st July 2011, 03:56 PM   #8
Botte is offline Botte  United States
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Quote:
Originally Posted by BigE View Post
Interesting, I'll pass it on.

BTW: What wattage of resistor?
5 Watt should do it.
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Old 21st July 2011, 05:36 PM   #9
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Quote:
Originally Posted by Zen Mod View Post
let him make hot-rodded F5

you'll find that as cascoded or full blast F5

input is cascoded , outputs doubled
I have the Cviler boards for double outputs. With them plus cascoded front end, what is max rail voltage (for good effect, not absolute max) and bias? assuming plenty of sink...

Russellc
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Old 21st July 2011, 05:46 PM   #10
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My F-5, standard single pair outputs, standard rail voltage and bias (but dual mono with 2 300VA transformers) playing into JBL 2235H in 5 cu ft tuned to 32 hz, b&C DE 250 compression driver with QSC wave guide has Bass, Bass all over the place....

Russellc
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