Sonic Impact 5066 Parts List & Modifications

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frugal-phile™
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Re: Input Schematic

panomaniac said:
Here is the input schenatic for the Sonic. A bit different from the Tripath app notes.

This should help in bypassing any or all of it.

Good work... L1/C1 form a 2nd order low pass filter, C3 a 1st order high pass. Interesting that they use an L instead of another RC section -- guess that gives them better control over the Q. Gets one thinking about the buffered SI...

dave
 
I have a new multimeter on the way that can measure capacitence to within +/- 2.5%. It should be here within a week. At that point, I can probably finish mapping out the SMD caps on the board and publish a complete parts list.

I almost went for the DMM with Inductance testing too, but I couldn't justify spending 2.5x as much.

This new one (http://www.circuitspecialists.com/prod.itml/icOid/4631) should be better than the cheap ratshack one I have now. I skipped the one with True RMS function for one that could measure parts more accurately. Anyone have an opinion on this? I figure I'm going to be measuring parts values and such more often than taking true RMS measurements.
 
motherone said:
I have a new multimeter on the way that can measure capacitence to within +/- 2.5%. It should be here within a week. At that point, I can probably finish mapping out the SMD caps on the board and publish a complete parts list.

I almost went for the DMM with Inductance testing too, but I couldn't justify spending 2.5x as much.

This new one (http://www.circuitspecialists.com/prod.itml/icOid/4631) should be better than the cheap ratshack one I have now. I skipped the one with True RMS function for one that could measure parts more accurately. Anyone have an opinion on this? I figure I'm going to be measuring parts values and such more often than taking true RMS measurements.

EPO, a local parts supplier has a elcheapo brand for 59.95. It measures capacitance, inductance, and has a temperature probe. It seems as accurate as my more expensive meters, and the cap reading are about the same as my expensive standalone capacitance meter.
These are perfect, but I damaged the temp probe recently cramming it in my parts box. I am considering buying another just to get the temp function back.

George
 
Soooooo, let me see if i have this correct. C3/C4 are first order high pass filters, correct? And they are responsible for the low frequency roll off, correct? So replacing them with a larger value should fix this "problem"?

If C3/C4 is really .33mfd and its before the 20k resistor wouldn't that give a roll off way lower than the 200hz mentioned before? Assuming I'm totally wrong, and theres a pretty big chance I am. What value would be good for the lowest possible rolloff before DC becomes a problem?

Thank you for accepting my humble ignorance.
 
theAnonymous1 said:
Soooooo, let me see if i have this correct. C3/C4 are first order high pass filters, correct? And they are responsible for the low frequency roll off, correct? So replacing them with a larger value should fix this "problem"?

If C3/C4 is really .33mfd and its before the 20k resistor wouldn't that give a roll off way lower than the 200hz mentioned before? Assuming I'm totally wrong, and theres a pretty big chance I am. What value would be good for the lowest possible rolloff before DC becomes a problem?

Thank you for accepting my humble ignorance.

The way I see it, there is a 10K parallel to the 20K, so the result is 6.67K. This gives a -3dB point of 72 Hz. This is close to the measurements shown.
The frequency response of the Tripath evaluation board is shown as -0.5 dB at 20 Hz. This is mainly due to the evaluation board having a 2.2 ufd cap, compared to the 0.33 ufd.
My speakers are only flat to a lttle below 40 Hz. I hear a real softening on the lowend, but the upper bass seems okay. This is the area where the SI is only a couple dB down.

George
 
The way I see it, there is a 10K parallel to the 20K, so the result is 6.67K. This gives a -3dB point of 72 Hz.

I wasn't even thinking about how the 10k resistor would effect the total resistance because its before C3/C4. That makes a lot more sense though, thank you for enlightening me.

I think I'll replace them with some 3mfd caps. Another dumb question, will it effect the XO point if I put the cap before everything else on the input and remove C3/C4? I only ask because I measure my input impedance at 14k, 10k+ a 4k resistor I added in series.
 
panomaniac said:
FYI:
C3/C4 are 0.33uF C1/C2 are 100pF.
Thanks to Gary P over on Audio Circle for those values. He came up with a schematic at the same time I did.

The rest are yet to be mapped.


Great work Pano. More helpful info. I think this poor little sonic impact is going to be nude to the modders of the world soon. It sounds like you guys may finish mapping this thing before my multimeter even arrives :D

I'm still waiting on the good ol' postal service to bring me my goodies from Digikey. I'll probably start working on the boards tomorrow, but I don't know how far I'll get if the remainder of my parts don't arrive.

Does anyone out there have an inductance meter to measure the DCR and inductance of the coils? I'm wondering if they're the same as whats on the datasheet or not. It'd also probably be handy to know what the values of the SMD inductors (L1/2) on the board are as well.
 
Just a quick note that my parts finally arrived today. The panasonic 680uF FM caps listed above do NOT fit directly on the board. The drop in replacement for the 330uF cap should be part number P12378-ND, not P12377-ND.

This might not matter to some of the modders out there, as new coils may be larger in diameter, and relocating the cap would be neccessary anyways.

The resistors I did wind up ordering, Digikey Part# RHM20.0KHCT-ND is correct. They're 20.0K Panasonic 1/10watt 0603 SMD resistors.

Anyhow, for my next modded SI, it looks like I'll be locating the caps on top of the chip or immediately next to it. I'm debating whether to try it with 2x 1000uF or 2x 680uF -- I'm not sure how much more capacitence these boards need.

I also picked up the Ultrafast rectifiers (MUR460) diodes for the Digi01 regulator boards, so I should have my 13V PSU up and running soon as well.

I'll let you all know how the resistor/cap replacement goes once I'm finished.
 
motherone said:
Just a quick note that my parts finally arrived today. The panasonic 680uF FM caps listed above do NOT fit directly on the board. The drop in replacement for the 330uF cap should be part number P12378-ND, not P12377-ND.

This might not matter to some of the modders out there, as new coils may be larger in diameter, and relocating the cap would be neccessary anyways.

The resistors I did wind up ordering, Digikey Part# RHM20.0KHCT-ND is correct. They're 20.0K Panasonic 1/10watt 0603 SMD resistors.

Anyhow, for my next modded SI, it looks like I'll be locating the caps on top of the chip or immediately next to it. I'm debating whether to try it with 2x 1000uF or 2x 680uF -- I'm not sure how much more capacitence these boards need.

I also picked up the Ultrafast rectifiers (MUR460) diodes for the Digi01 regulator boards, so I should have my 13V PSU up and running soon as well.

I'll let you all know how the resistor/cap replacement goes once I'm finished.

I have only swapped the cap on one of mine so far. The cap used is a Nichicon 16v, 680 ufd UHE cap. They are lower impedance and cheaper than the FC caps. Have not checked the FM series.
Newark is the supplier. The Nichicon is the same diameter as the stock cap, only taller.

George
 
Richard U said:
Panelhead,

Who makes that mutimeter you mentioned and where did you purchase it?

Richard

Off thread, but I think it is CE, the model number is VC9808. I got it at EPO in Houston.
It does AC and dc volts, ac and dc current, frequency, inductance, capacitance, temp, and resistance.Also measures bipolar hfe.
They are 59.95.

George
 
Panelhead said:


I have only swapped the cap on one of mine so far. The cap used is a Nichicon 16v, 680 ufd UHE cap. They are lower impedance and cheaper than the FC caps. Have not checked the FM series.
Newark is the supplier. The Nichicon is the same diameter as the stock cap, only taller.

George


I have a huge number of the HE caps for my gainclones and som CD transoport/DAC mods I'm planning.. I think the UHE are meant to compete with the FM series, while the HE are to compete with the FC series. I think you can also order the UHE at Mouser?

I also have a slew of cerafines and such as well, but only in the 220-470uF range. They're so huge that I'm not sure if it's worthwhile to try and use them (the 470uF/16V is rougly the size of a 470uF/50v standard electrolytic).
 
Hi all,

Thought I would jump in on this thread. These amps are just too much fun to play with.

Posted by motherone
Just a quick note that my parts finally arrived today. The panasonic 680uF FM caps listed above do NOT fit directly on the board. The drop in replacement for the 330uF cap should be part number P12378-ND, not P12377-ND.

I was planing on using the 10mm cap in this location. It looked like there is enough lead length on the inductors to raise them up slightly and then bend the leads sideways a bit to make enough room for the larger cap. Does this plan have a chance?

I have most of the chassis mods made on my er... a... dead SI amplifier. Not much to do untill the freshly ordered amps get here next month.

Check out the chassis mods, the plans for the onboard power supply mods (and why it's dead...:cannotbe: ). Just finished adding a SI 5066 project page to my webpage.

Gary

Gary P's DIY page
 
Gary P said:
Hi all,

Thought I would jump in on this thread. These amps are just too much fun to play with.



I agree. I've been having a blast with the little suckers. Even if they're not the ultimate in audio, they sure have been fun to toy around with. So cheap and so easy to mod.

Gary P said:

I was planing on using the 10mm cap in this location. It looked like there is enough lead length on the inductors to raise them up slightly and then bend the leads sideways a bit to make enough room for the larger cap. Does this plan have a chance?


I tested this on my stripped SI board, and you can fit a 10mm cap easily if you remove the inductors and remove the rubber shrink wrap on them. Otherwise, you'll probably need to angle them quite a bit to squeeze it in there.

Gary P said:

I have most of the chassis mods made on my er... a... dead SI amplifier. Not much to do untill the freshly ordered amps get here next month.

Check out the chassis mods, the plans for the onboard power supply mods (and why it's dead...:cannotbe: ). Just finished adding a SI 5066 project page to my webpage.


I took a look at your page, and if you're going to power this thing with batteries, I really think that going overboard with the caps may wind up being detrimental rather than helpful. I think I'm stretching it right now with 2x 1000uF caps soldered on over the chip.

There's quite a bit of info in the gainclone threads about the problems you run into with larger caps (mainly due to their inductance).

I think the easiest mod would be to put a 1200uF or 1500uF 10mm cap in there with the removed rubber boots on the inductors. That should give you plent of capacitence without having to resort to the funky soldering that I'm doing. A 10mm 1000uF panasonic FM is about the same height as the 8mm 680uF panasonic FM. The other caps shouldn't be too much taller.

Whether or not this will fit in your case is another story =)

Even with my outboard PSU (a 2.4A 15VAC wall wart + a LM338 regulator w/12,000 uF pre-regulator capacitence and 470 uF post-regulator capacitence), I'll only be going with the 2x 1000uF panasonic FM's on the SI.
 
Hello everyone, I just had a quick (off-topic) question about SI mods:
I am just getting into audio and have not had any experience with modifying, do you guys the SI would be doable as a first project? Also, do you have any suggestions about reading material that could bring me up to speed? I trying to hopefully replace my Sophia electric baby amp with a modded SI.

Thanks
Chris
 
the dude abides said:
Hello everyone, I just had a quick (off-topic) question about SI mods:
I am just getting into audio and have not had any experience with modifying, do you guys the SI would be doable as a first project? Also, do you have any suggestions about reading material that could bring me up to speed? I trying to hopefully replace my Sophia electric baby amp with a modded SI.

Thanks
Chris

I think most of the mods are pretty easy (recasing, swapping the electrolytic capacitor). The advanced mods require you to desolder and solder surface mount devices, which requires a fine-tipped soldering iron, patience, and a steady hand.

I've managed to toast 1 SI in my modding endeavors by lifting some traces when soldering on new SMDs. I have to figure out what to do with this now somewhat broken amp, and whether or not it can be salvaged.

I definitely think they're worth playing with, and the price of entry is so low you almost can't go wrong, even if you do nuke 1 or 2. At least you'll gain some invaluable learning experience.
 
Motherone: thanks for the encouragement!

About reading up on electronics though, I have VERY little knowledge and would like to learn a lot more, I guess I could just go to the library and search (Considering I work in the HQ of one of the largest library systems in the country) but if you guys had some suggestions about some "good reads" that would be great.

Thanks again
C
 
the dude abides said:
Motherone: thanks for the encouragement!

About reading up on electronics though, I have VERY little knowledge and would like to learn a lot more, I guess I could just go to the library and search (Considering I work in the HQ of one of the largest library systems in the country) but if you guys had some suggestions about some "good reads" that would be great.

Thanks again
C

No problem. I'm pretty much a beginner myself compared to most of these guys. But I read a lot and try to keep up on the easy stuff :D

I cut my teeth on the books by Forrest Mims at radioshack. I think the first one was Getting Started in Electronics .. Which is probably 20+ yeras old now.
 
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