UCD snubberizing, already done?

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#61
Parts is parts!

Chris,
Time for a salvage operation, got any old computer power supplies or mother boards? Could be a good source for some of the parts you will be looking for. Even an old monitor or TV could be a good source. Just be sure to discharge the CRT before you poke around in there.
Roger
 
#62
Tripath whistle stopper

Chris,

You are spot on about the larger 1,000Uf bootstrap cap recommended to stop the Tripath whistle, it does stop the whistle but it robbed the bass of any authority. Maybe I should try a better cap in this location, like a 330uF Panasonic FM.

Regards,
Dean
 
#63
Hi there,

Roger, I keep a box of junk handy, things I already took apart and just pick at from time to time. Inside are the electronics for a monitor, two SMPS, one Pioneer receiver..

I haven't found anything of that low a value, and my meter only reads to an ohm anyway, probably not even accuratly.

So yeah I think I'll be leaving it as is. I am placing an order soon though maybe I'll include a few extras to give me something to play with.

Dean, sounds like a good plane to experiment with. There is another though. Like Carlos was hinting at with a proper snubber it may be a different story. I have you experimented with that?

Although I think Bruno recommends something along 470uF to under 700. I didn't like what two parallel 470uF's did anyway. In my case the bass was extremely powerfull and the high's were nice but something in between was sadly lacking. With only one cap, the bass seemed less pronounced the highs were still great and nothing in between was lacking.

With that kind of an effect I think it well worth sampling 3 or 4 different caps for the job.

Cheers,
Chris
 
#64
classd4sure said:
I didn't like what two parallel 470uF's did anyway. In my case the bass was extremely powerfull and the high's were nice but something in between was sadly lacking.
Click to expand...

Inductance, my friend. 😀
Lower the resistor.
Then increase the cap, to at least 1,000uf.
It's worth a try, you are just smelling it. 😉
 
#65
classd4sure said:
Hi there,


Although I think Bruno recommends something along 470uF to under 700. I didn't like what two parallel 470uF's did anyway. In my case the bass was extremely powerfull and the high's were nice but something in between was sadly lacking. With only one cap, the bass seemed less pronounced the highs were still great and nothing in between was lacking.

With that kind of an effect I think it well worth sampling 3 or 4 different caps for the job.

Cheers,
Chris
Click to expand...

in my experience , it's not the cap value that may matter , it's the cap brand
for example , if you put an Elna cap , you get big bass and euphonic effect

alain
 
#67
Re: Tripath whistle stopper

deandob said:
Chris,

You are spot on about the larger 1,000Uf bootstrap cap recommended to stop the Tripath whistle, it does stop the whistle but it robbed the bass of any authority. Maybe I should try a better cap in this location, like a 330uF Panasonic FM.

Regards,
Dean
Click to expand...

Dean, is this C34 which was 100uf/35v? I changed this but my bass was still the same with a 1000uf/25v FC cap. The whistle was gone though.
 
#68
Bgt,

I used a standard 1,000uF cap for C34 that I had lying around. The AMP1B is a bridged subwoofer amp with an active linkwitz filter so it was pretty easy to tell that the authority in the bass had disappeared, to the point of I thought I had accidentally knocked the gain pot on the active filter but I hadn't. The whistle did disappear.

It really surprised me to hear such a difference in the bass.

Next time I'll try a better cap like a Panasonic FM with a snubber. Any values recommended?

Regards,
Dean
 
#70
deandob said:
Bgt,

I used a standard 1,000uF cap for C34 that I had lying around. The AMP1B is a bridged subwoofer amp with an active linkwitz filter so it was pretty easy to tell that the authority in the bass had disappeared, to the point of I thought I had accidentally knocked the gain pot on the active filter but I hadn't. The whistle did disappear.

It really surprised me to hear such a difference in the bass.

Next time I'll try a better cap like a Panasonic FM with a snubber. Any values recommended?

Regards,
Dean
Click to expand...

I am suprised to see that it changed because the capacitor is just in the psu part as a smoothing cap. to get higher gate drive.
Whatever I do with snubbers or caps. on the amps. pcb...I never have a change in bass level. Also no change in high tones really.
The sonics in general get better or worsens.
 
#71
I am always surprised people saying bass is less or more. If 1 amp. differs too much from the other in the bass segment there must be either a PSU problem or series cap being too small(I never use 1, prefer a dc offset integrator). Ofcourse the sound can be "thick" which causes an artificial sound which is rich with the bass part. I always use a lot of amps to get a general id of the sound of a cd title(the same ones). My best amp. untill now(compared it with high end marantz, rotel,nad) is my modded Crescendo which sound equals the UCD's in most areas but not in the power area(cannot drive difficult speakers). I know a lot of people here have a very low value on this 1 but properly modded it is a truly awsome amp(the original 1 was terrible).
 
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