Sonic Impact 5066 Parts List & Modifications

[weng]

YES. I do it all the time. Works well.

thanks pano.

 

[cpemma]

OK, stealth mod & re-cap done and the amp still works...

Next stage is to rehouse in a Hammonds extruded Al case, adding some stiffener uF across the new power socket, a new pot & connectors.

What's the favourite methods for screening and earthing (signal grounds, pot grounds, power ground, case)? Use the existing pot ground wire point on Conn#1 as signal ground, power negative & case to battery negative?

I gather the speaker wires should be tightly twisted, and I'm moving the on/off switch to the back panel to avoid signal wires. There is a bit of LF hum now if you get your head near the speakers, I'm hoping tidying the wiring rather than stuffing everything back in the plastic case will get rid.

 

[dynoforce]

Stealth Mod and Stiffener Power Cap Help

I was replacing C10 with 330uF Pana FC cap and messed something up. Now my power switch will not work.

Instead I now connect directly to the C10 position from the 12V input, i.e. +ve of 12V -> +ve of C10, ground of 12V -> ground of C10.

I would like to add a few 1000uF Pana FC caps in parallel as stiffeners but I am confused of how the connection would be.

I am thinking I will need to connect this way,
+ve of 12V -> +ve of cap -> +ve of C10
-ve of 12V -> -ve of cap
Am I right?

I have also performed the stealth mod. While bridging C4, I came off. So I just added a blob of solder in the position. For C3, it did not come off.

How can I know tell if my bridge worked on C3?

Can someone tell me how I can check this with a Multimeter?

I am using 1uF Nichicon FG caps for my input and the amp sounds fantastic. Now I know what bass rolloff means.

I have been getting great advice from this forum. You guys are great.

Thanks in advance.

 

[Lostcause]

I was replacing C10 with 330uF Pana FC cap and messed something up. Now my power switch will not work.

That's the problem with going straight to C10, you bypass the switch.

 

[dynoforce]

That's the problem with going straight to C10, you bypass the switch.

Lee, the power switch did not work right after I replaced C10. I thought I lost the board. So, I tried going straight to C10 and it worked.

I will try to add a power switch in another position.

I am wondering if I can add a stiffener cap by connecting the +ve 12v -> +ve of stiffener cap -> +ve of C10, -ve 12v -> -ve of stiffener cap -> -ve of C10.

This connection is similar to your diagram (http://www.diyaudio.com/forums/attachment.php?s=&postid=878013&stamp=1143328719) in Post #207,http://www.diyaudio.com/forums/showthread.php?postid=878013#post878013, of this thread, except the connection of the -ve to C10 directly.

I really appreciate your reply.

Ooi

 

[Kooka]

Lee, the power switch did not work right after I replaced C10. I thought I lost the board. So, I tried going straight to C10 and it worked.

I will try to add a power switch in another position.

I am wondering if I can add a stiffener cap by connecting the +ve 12v -> +ve of stiffener cap -> +ve of C10, -ve 12v -> -ve of stiffener cap -> -ve of C10.

This connection is similar to your diagram (http://www.diyaudio.com/forums/attachment.php?s=&postid=878013&stamp=1143328719) in Post #207,http://www.diyaudio.com/forums/showthread.php?postid=878013#post878013, of this thread, except the connection of the -ve to C10 directly.

I really appreciate your reply.

Ooi

That is my problem too: if I use the diagram Lostcause posted my led stays on and does not ares about the switch. This is why I aonly replaced c10 witha 1000uF cap, and not added the offboard 10.000uF cap. I do not know if your suggestion would solve the problem...

 

[cpemma]

Lee, the power switch did not work right after I replaced C10. I thought I lost the board. So, I tried going straight to C10 and it worked.

Did you by any chance also remove the original 2.1mm power socket? According to post#1 (and standard config for a centre-pin-positive socket) this switches ('make' with no plug inserted) on the negative line, so removing the socket would leave an open circuit between the battery negative wire and the board ground.

The pot switch is on the positive line.

Though I think you may be taking the sketch too literally, any local isolation switch needed can be fitted on the red wire between psu & cap.

 

[Lostcause]

Did you by any chance also remove the original 2.1mm power socket? According to post#1 (and standard config for a centre-pin-positive socket) this switches ('make' with no plug inserted) on the negative line, so removing the socket would leave an open circuit between the battery negative wire and the board ground.

The pot switch is on the positive line.

Though I think you may be taking the sketch too literally, any local isolation switch needed can be fitted on the red wire between psu & cap.

Yup! Like the man says, use the PSU as the on-off switch.
I don't bother with the LED (remove it) it takes unessessary regulated current so I go direct to the onboard power cap(s). Whether it be a replacement C10 or wired directly to the pins.
By the way, third time unlucky for me, my usual wiring direct to the pins has toasted my chip so beware....or at least be careful!

Happy modding

Lee

 

[jringels]

Amp Cuts out at high volume

I hope this is a simple question. I recased my 5066 in an aluminum case with RCA outputs. I duplicated the L+ and L- and sent it to two jacks, I duplicated the R+ and R- and sent it to two jacks. So I have 2 Left Jack and two Right Jacks, each with a + and a -. The mounting screw of the jack and the negative feed are connected to themselves and are not insulated from the case. When I crank the amp, as it nears max volume, the sound cuts in and out. Is my problem that the L- and R- are tied together through the case?
Thanks to all for an excellent thread, I would not have attempted this mod without it!

 

[cpemma]

Re: Amp Cuts out at high volume

Is my problem that the L- and R- are tied together through the case?

Yes, each amp channel is bridged mode, so there is no common ground on the outputs.

 

[phn]

This is probably a stupid question. I have searched here, but found nothing that was of help to me. I'm going to use a 15V laptop SMPS and need to get it down to 12V. This has been mentioned in this tread. But I need details.

I know how to use voltage regulators (fixed or variable) with toroid transformers. But how do I use a voltage regulator with a SMPS that has + and - and not + and ground? Do I simply connect the regulator + in/out and ground to minus or do I need some form of rectifier? Do I need the filter caps?

 

[jringels]

Thanks for the reply. That worked, for about 2 minutes. It was 11pm and the family was sleeping so I stuffed 4 speakers into the sleeves of my coat and cranked the amp. I no longer heard the cutting, but one of the speaker wires came loose and must have shorted. Now I only have the Right Channel! I thought this baby had "intelligent short circuit protection".

Did I burn up the Left Channel or am I missing something? Thank you.

 

[dynoforce]

Did you by any chance also remove the original 2.1mm power socket?

cpemma, I am still using the on board power socket. My original intention was to replace C10 with a better cap. After doing so, I tried to power it on but to no avail.

So, I took a chance and went directly to C10 and it worked. The LED lights up too.

Though I think you may be taking the sketch too literally, any local isolation switch needed can be fitted on the red wire between psu & cap.

Thanks for this suggestion. I am currently using the PSU's switch to power the amp but I plan to fit a soft start switch to the amp soon.

Yup! Like the man says, use the PSU as the on-off switch.
I don't bother with the LED (remove it) it takes unessessary regulated current so I go direct to the onboard power cap(s). Whether it be a replacement C10 or wired directly to the pins.
By the way, third time unlucky for me, my usual wiring direct to the pins has toasted my chip so beware....or at least be careful!

Happy modding

Lee

Lee, you guys are in a different league, I first used a soldering iron like 2 weeks ago. I am a real PHD, Put It Here Dummy. If it is not for this forum, I would have never taken the plunge to mod the amp.

So, the connection of the big cap, I take it that I can connect the following way
+ve 12v -> +ve of stiffener cap -> +ve of C10
-ve 12v -> -ve of stiffener cap -> -ve of C10?


Thanks for the help.

Ooi

 

[cpemma]

That worked, for about 2 minutes. It was 11pm and the family was sleeping so I stuffed 4 speakers into the sleeves of my coat and cranked the amp. I no longer heard the cutting, but one of the speaker wires came loose and must have shorted. Now I only have the Right Channel! I thought this baby had "intelligent short circuit protection".

Did I burn up the Left Channel or am I missing something? Thank you.

This article on how bridged mode works may give the clue,

Amplifiers that use a single supply, such as car audio amplifiers (or the 5066) may use bridging without output coupling capacitors. In this case, the output of each amplifier in the bridge will not be zero volts at no signal but will be at half the supply voltage for maximum undistorted voltage swing. This is acceptable since if both amplifiers have the same offset the net effect of bridging is to cancel out the offset.

OK with everything connected, but if a loose speaker lead is grounded it could spell curtains.

 

[phn]

I know how to use voltage regulators (fixed or variable) with toroid transformers. But how do I use a voltage regulator with a SMPS that has + and - and not + and ground? Do I simply connect the regulator + in/out and ground to minus or do I need some form of rectifier? Do I need the filter caps?

Does my question make sense? I really don't want to start a new thread with this, much less one that makes no sense. I have downloaded spec sheets to dozens of voltage regulators, 78L, LM, LT, LF, LE, LD, MAX, etc., none which makes me the least bit wiser.

 

[Lostcause]

So, the connection of the big cap, I take it that I can connect the following way
+ve 12v -> +ve of stiffener cap -> +ve of C10
-ve 12v -> -ve of stiffener cap -> -ve of C10?


Thanks for the help.

Ooi

Yup, that will do just fine...

I've never connected the -ve to the cap before (everywhere else though!). I tend to leave the shortest return path from the chip, so I solder it to the solder slug, although you could do that if you wanted to.

Lee

 

[cpemma]

I'm going to use a 15V laptop SMPS and need to get it down to 12V. This has been mentioned in this thread. But I need details.

I know how to use voltage regulators (fixed or variable) with toroid transformers. But how do I use a voltage regulator with a SMPS that has + and - and not + and ground? Do I simply connect the regulator + in/out and ground to minus or do I need some form of rectifier? Do I need the filter caps?

For a source like a wallwart or SMPS with a floating negative, just treat it as the 0V line and tie it to the amp ground via the regulator ground. It's already DC, no further rectification needed. Use the film capacitors as per datasheet right next to the regulator pins, any big stiffeners nearer the amp.

 

[phn]

cpemma, thanks.

Floating 0, ground, etc. are mostly Greek to me. And because of that I'm very careful about everything I do. Not that that's a bad thing when you deal with 230 V. Say I who just just melted the multimeter probes and had sparks flying in the then pitch black room.

 

[cpemma]

Floating 0, ground, etc. are mostly Greek to me.

Ground's actually Germanic, grund, and I think the Arabs came up with 0.

 

[weng]

hi,

i am going to mod my SI amp soon. but after reading panomaniac's website, i am kinda confused on which mod to do. what can you guys recommend as an all-rounder, the "classic" or "stealth" mod? also, i want to know the value of the output cap so i can change it once and for all.

maybe this has already been answered before but forgive me for asking again as this is a very long thread to dig up for info.

TIA