| zygibajt |
What brand of those big cans do you usually use?
What are the individual sonic characters of diffrent PS caps?
As I recall Mr Nelson uses Mallory caps.
I cosider Siemens,Panasonic and Aerovox to be among the best,but which of them to choose? I don't know.
Would like to hear your opinions on that topic.
Any one ever compare diffrent brands of caps and their sound?
Bartek |
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| Nelson Pass |
I use what's reliable and reasonable, and keeping in mind
that most of these are made by the same plants, it's not
suprising that they tend to sound about the same, all other
things being equal.
Lots of capacitance and CLC or CRC type filtration really helps,
and depending on the circuit, some good film bypass can really
help - and almost never hurts. |
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| zygibajt |
Thanks for the answer Mr Pass.
| quote: | | some good film bypass can really help |
That is what I observed with Aleph 4 and Alep 3 clones.It really betters the sound.
But I also observed that putting small caps across rectifire diodes kills the sound.
As to the capacitance:
Do you think building up those high capacitances with smaller values (like ten 10000uF caps instead of four 25000uF) might improve things?
Bartek |
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| chrisx |
Hi,
I'm preparing to build Aleph 2 monoblocks - my first serious diy audio project, so I have many questions. I will be glad to receive some help...
I'm completing order list for Aleph 2 PSU, so I need advice.
What capacitance amount should I use. In oryginal Aleph 2 scheme there are four 22 000 uF capacitors used, but at [URL=http://www.web.vip.hr/pcb-design.vip/power-2.html ] there is 8 times 47 000 uF used. I guess, bigger capacitance sounds better, but is there good compromise? Is it good to use many 10 000 uF (I can buy them cheap) instead of bigger ones? For my example 40 times 10 000 uF seems to be a little crazy idea.
One more question (little bit off topic): Is 600VA/40V trafo suitable for Aleph 2? |
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| jarek |
| My observation is that a big value of capacitance and very small amount of ESR after a bridge can cause big distortion on sine wave on the secondary due to summary impedance of the secondary and diodes. Would be correct to use ordinary (not very low ESR) capacitors next to the bridge and only after filters (CRC or CLC) better capacitors with small ESR? |
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| markp |
| It is better and much cheaper to use multiple smaller caps than a few really large ones. A slew of 4x4700s is better than one 22000 by a long shot, lower ESR and higher ripple current. I like to put a cap right next to each output transistor if possible with a film bypass cap. |
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| Angel Puerto |
:cool: I have put 4X150.000 uF bypass with 9x2.200uF/63V URZA type of Nipon Chemicon, the results were fantastic.
Onother probes with small capacitors in concret 0.1 and 10 uf film I did not the previus results.
Angel |
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| KBK |
In my personal experience, the bypass caps can create resonant circuits that create minute disortions that are passed on to the output stage and can -and usually are- mistaken to be treble and spatial information when all it really is.....is accentuated distortion.
The larger value the bypass cap, the better. The lower the number of bypass caps, the better. None is best. The idea of what capacitors to use must be re-addressed from the ground up. Then we might get somewhere, but also.. then.. the idea of how to implement a circuit must again be re-addressed from the ground up. Clean slate.
Careful control over the impedance in the pathways involving the bypass caps is critical to avoiding distortion created by the resonant circuit that WILL be in effect somewhere in that large 'dynamically changing' impedance that all audio bandwidth circuts encompass. It always happens... every time. Most folks cannot recognize it as such, because the rest of the situation must be cleared up to see that.. and that is a gargantuan enterprise, ivolving everything from the 120AC, all the way up to the room and your ears.
It can even take years to tune a single system to sound right. By that time, it's so sensitive to change -and showing the effects of change- that heisenberg seems to be at play.......
All I know is I will NEVER put a bypass cap in any piece of gear again. The sense of overall harmonic integrety that is achieved without such caps in the pathway (after much hard work!).... well it is so great to hear... so natural.. so easy to listen to... so relaxing...that I am sure you will agree as well.
But first, you must conquer that gargantuan task...... |
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| zygibajt |
Great to hear your view,thanks.
Bartek |
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| Peter Daniel |
I share a similar POV (and observations): I will never add bypass cap again (unless in a digital circuit) as well. What initially seems like an improvement, eventually appears as smearing, coloration and artificiality.
Find a good cap and forget about bypasses. |
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| Bricolo |
| quote: | Originally posted by Peter Daniel
I share a similar POV (and observations): I will never add bypass cap again (unless in a digital circuit) as well. What initially seems like an improvement, eventually appears as smearing, coloration and artificiality.
Find a good cap and forget about bypasses. |
will we see an aleph with only a 1000uF BG one day? ;) |
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| trigon |
Only Nichicon Gold or Super for PS
In my Aleph 4 I have used 4 x 22000uf / 80V Nichicon Gold series caps per channel and have tried as well bypass caps and have never got as good result as without them. But I have used as well 1500W Plitron transformers per channel and IXYS 68A bridge and guess what, SOUND is just AMAZING and "Automagicaly" perfect and natural.
My Aleph 4s
I am as well building Aleph P 1.7 for which I am going to use 2200uf 100v Nichicon Gold as well as for preamp and PS.
No bypass caps at all.
Make no mistake Nichicon Gold is HI-END performer, trust me.
Trigon |
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| Dr. ODD |
Let us differ two Points
1) I can Imagine that bypassing in the signal Path can bring some Problems with the integration of the sond as one whole Thing.
2) I cant understand how bypasst caps in a Power Supply can create a resonant Circuit ? It is an often seen Method. ( OK it could be wrong in spite of that)
Maybe the Problem exists and there is a way to solve it by dimensioning the Parts. KBK do you kow any Formula to calculate this ? |
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| Panelhead |
[QUOTE]Originally posted by Dr. ODD
[B]Let us differ two Points
2) I cant understand how bypasst caps in a Power Supply can create a resonant Circuit ? It is an often seen Method. ( OK it could be wrong in spite of that)
Not only does value of bypass cap make a difference in power supply ringing, the type of cap is important also.
My tube amp building days showed that bypasses in the power supply close to the diodes or rectifier increased noise. Worst were the poly caps. A mylar cap usually was fairly quiet.
I like using bypass caps on power supply caps in the second or third stage of filtering. Placing a series choke between the rectifiers and bypass cap does wonders to prevent any ringing.
A cap I have been using lately is the 4 pole Jensens. These do not need bypasses. Also they put a little inductance in the ground leg to help clean the final dc up. Seems to filter a little of the diodes noise.
The jensens are not cheap, but 20.00 for a 10k, 63 volt cap is only doudle what the Panasonics are at Digi-Key.
If you are real serious about Aleph filter caps look at these on the Jensen website.
George |
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| Nelson Pass |
Sometimes bypassing makes the amp better, sometimes not.
Occasionally it will even cause circuit oscillation.
Experimentation, measurement, and good ears are the keys.
:cool: |
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| jarek |
| quote: | | My tube amp building days showed that bypasses in the power supply close to the diodes or rectifier increased noise. Worst were the poly caps. A mylar cap usually was fairly quiet. |
I think you are right. Bypasses decrease impedance for high frequencies and than we need more ripple current in unit of time. Because of the presence of impedance of the secondary and diodes it can not be done properly. Than we have disturbances and oscillations. |
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| Mark A. Gulbrandsen |
I used one 120,000 mfd Panasonic T-HA cap, no bypass, on each rail of my MINI Aleph recently and all I can say is that the rails are very, very clean. The caps are rated at 105 deg c. and are only 40 by 80mm in size to boot! The bottom end of the amp, especially after installing the Victoria Magnetics toroid was awsome for a 10 watt amp. I would highly reccomend them for Minis and Aleph 3's. Here is a link to that section of the Digi-Key listing.
http://dkc3.digikey.com/pdf/T033/0701-0715.pdf
The TH-A's are on page 7 of this section of the PDF.
MArk |
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