Snubberize bass amp 30-350Hz

XELB

Member
2004-12-07 11:26 pm
Lisboa
Attention, I have never tried or listened to an amp with Snubber.
But, what I can tell based in CarlosFM information is that you get the same punchy Bass, but the middle and high frequencies will be more detailed.


I olso don't know if the snubber value is the same because your range is smaller(30-350Hz).
 
i doubt a snubber would make much difference, but theres no harm in trying it. LOTS of capacitance for that one!


I hope thats not for a single subwoofer, it is way up into the region where sound becomes directional.

once you get only an octave below middle C thats 261.6 HZ imagine if all the instruments in that range and below were coming from just one speaker. it would sound terrible.

if there will be seperate channels, thats fine then :)
 
akunec said:
I'm building a 2 channel bridged amp covering 30-350hz with a Lambda TD12s. My power supply will be a similar design to Linkwitz's. Would it benefit to snubberize it, as I hear that snubberizing helps out the higher frequencies alot more and maybe not the bass?

Thanks

Definitely snubberize.
When you insert a snubber on an already high capacitance PSU, everything improves, including the bass, which gets tighter, more detailed.
 

Vil

Member
2003-01-08 10:15 am
Europe
interesting . I am working on similar 3 way active speaker design with 2 bridged LM3886 for bass 20-380hz , one LM3875 for mid 380hz-3.8khz and one LM3875 for tweeter over 3.8khz .just thinking what value of power cap can be optimal in every band ? sure I'll go snubbed .
 
Vil said:
interesting . I am working on similar 3 way active speaker design with 2 bridged LM3886 for bass 20-380hz , one LM3875 for mid 380hz-3.8khz and one LM3875 for tweeter over 3.8khz .just thinking what value of power cap can be optimal in every band ? sure I'll go snubbed .

I would suggest (per rail):

Woofer(s): 2x10,000uf (or 4x4,700uf, or 3x6,800uf).
Mid: 2x4,700uf
Tweeter: 4,700uf.
 
neutron7 said:
i doubt a snubber would make much difference, but theres no harm in trying it. LOTS of capacitance for that one!

The snubber as described on DIYAUDIO is really a bypass capacitor or RC combination (a snubber is an RC combo, or DRC combo which clamps the ringing in a diode or transistor circuit, or to dissipate the stored energy in an inductor -- like a relay, transformer or motor) --

so here's the point -- it really doesn't matter the end frequency for your amplifier -- if high frequency noise gets makes its way from the supply rails onto the input of your amplifier the "least bad" outcome is a little power dissipation, the worst "bad outcome" is an amplifer which becomes unstable or goes into oscillation.
 
jackinnj said:

The snubber as described on DIYAUDIO is really a bypass capacitor or RC combination (a snubber is an RC combo, or DRC combo which clamps the ringing in a diode or transistor circuit, or to dissipate the stored energy in an inductor -- like a relay, transformer or motor) --

so here's the point -- it really doesn't matter the end frequency for your amplifier -- if high frequency noise gets makes its way from the supply rails onto the input of your amplifier the "least bad" outcome is a little power dissipation, the worst "bad outcome" is an amplifer which becomes unstable or goes into oscillation.

Oh man...
This is very wrong, you are way off, you didn't get it yet.
I suggest you read something about loudspeaker crossover design.:idea:
 
Carlos,

It's a decoupling capacitor. Regardless of the network which an amplifier is driving you need to decouple the supply rails for the purpose eliminating RFI, EMI or random noise. HF energy can couple itself through the rails onto the inputs just by proximity if careful design procedures aren't followed -- this energy (in the best case) has to be dealt with by the XO Network.

The term "snubber" as used by On-Semi, International Rectifier, Maxim, Texas Instruments most typically refers to an RC network, or RCD network used to clamp the ringing occasioned by the parallel capacitance a diode/inductance network.

Perhaps it is too jesuitical to be precise about definitions, like calling an avalanche diode a zener diode...
 
jackinnj said:
The term "snubber" as used by On-Semi, International Rectifier, Maxim, Texas Instruments most typically refers to an RC network, or RCD network used to clamp the ringing occasioned by the parallel capacitance a diode/inductance network.

While you don't abstract yourself from the snubber applied to diodes, you are way off what I'm talking about for months.
A snubber can even be used after a regulator, with proper values and impressive results.
It has NOTHING to do with what you have in mind, it has nothing to do with the pdfs with calculations that you posted, it's a completely different story.
It has nothing to do with diodes or trafos.
I call a snubber to an RC element to ground, as TI calls it too.
But they didn't get to the PSU yet.:D
From the OPA549 datasheet, page 12:
 

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carlosfm said:


While you don't abstract yourself from the snubber applied to diodes, you are way off what I'm talking about for months.
A snubber can even be used after a regulator, with proper values and impressive results.
It has NOTHING to do with what you have in mind, it has nothing to do with the pdfs with calculations that you posted, it's a completely different story.
It has nothing to do with diodes or trafos.
I call a snubber to an RC element to ground, as TI calls it too.
But they didn't get to the PSU yet.:D
From the OPA549 datasheet, page 12:

Quod erat demonstratum --
 
Hi,
can you translate that foreign stuff back into english, oh maybe not.
Re post 11; that snubber looks very like half a Thiel network (more commonly called Zobel).
So when you talk about a snubber to be added to a power amp which are you all referring to?
A. an RC network across the rectifier diodes?
B. a Thiel network loading the output?
Some clarity would help!