Re: Re: Purpose of Sonic Impact Input Cap?
The only reason that makes sense to me is to limit bass output when used with AA batteries. It would give them longer life if bass demand is reduced. If you are modifying to use with SLA batteries or an external DC supply, the high crossover point is not needed.
speaker
Gmorris said:
The only reason that makes sense to me is to limit bass output when used with AA batteries. It would give them longer life if bass demand is reduced. If you are modifying to use with SLA batteries or an external DC supply, the high crossover point is not needed.
speaker
Panelhead said:
I'll post my results once I get the guts to tear up my last stock SI 🙂 Since these puppies are out of stock everywhere, I've been apprehensive about taking apart my "reference" SI.
Panelhead said:
You're right. It might be better to go with the 22 ufd caps instead.. However, I have a pair of 47ufd's sitting on my desk as I write this, so they're probably going in.
I did PM Peter Daniel to find out about the BG-N's.. He seems to prefer those over the Hi-Q .. I'm trying to find out if there's any particular difference.. I know the Bg-N's in a 4.7uF/50v value, but it is about 50% taller than the Hi-Q's.
Panelhead said:
Yup. I lifted a couple of pads on 1 amp. It would've been salvagable until the damn pad for the feedback resistor lifted! These are NOT high quality boards. It makes me wish we could get someone like BrianGT to design a board for these Tripath chips and make a quality non-SMD verson of these little guys. Maybe I'll PM him!
I'm not cool enough to have anything near 100db efficient speakers 😀 .. I'm stuck with some ~90db efficient monitors from Acoustic Research (AR-17s, Titanium Dome tweeter w/diamond power coating, 5 1/4" Aluminum/Magnesium cone midbass). They don't go too deep (maybe -3 @ 60hz), but they do everything else pretty damn well!
I'm wondering if the solution for the thump isn't to put a cap on the mute pin. Maybe when the amp powers up, it can be muted for a few seconds while the caps charge?
Mike
George Panelhead,
You mentioned bigger output chokes(15uH) and smaller output caps(0.01uF) for 15 ohm speakers - where did you get these values?
I am looking to run the SI with 15 ohm Rogers LS3/5A (not effecient 84dB).
You mentioned bigger output chokes(15uH) and smaller output caps(0.01uF) for 15 ohm speakers - where did you get these values?
I am looking to run the SI with 15 ohm Rogers LS3/5A (not effecient 84dB).
Output Filter
I stole ideas from others! The EB board tech sheet shows to use 0.47 ufd caps for 4 ohm speakers, and 0.22 ufd for 8 ohm. I extended this to using 0.1 - 0.15 ufd for 15 ohm loads.
The chokes was a combination. A designer said that the output chokes were too low a value for using with 300 ohm headphones. The other thing is the lowest value Solo inductor I could find is 15 uH.
I guess I could try digging up one of my 30 year old circuits books from school and try to calculate the -3dB point. The only thing there is where do you want to begin filtering the high frequency hash?
The 0.1 ufd caps and 15 uH values was a seat of the pants combination. It does not seem real critical. I have used 0.22 ufd and 0.15 both with 10 uH chokes with good results on my speakers.
Your speakers may be too much for the little SI. The power output is limited by the impedance. It is good for close to 10 watts into 4 ohm, 6 watts into 8, and maybe 4 into 15 ohms.
This may be plenty, most listening is at low 80's level.
A big help would be to raise up the voltage feeding the SI. Batteries will put 13 or so out. I used a 13.8 volt supply for a while. Played music, and left powered up around the clock. Finally measured the voltage and it was 18 volts unloaded and 16.7 idling the SI.
I think the SI will safely live at 15 volts or so. This is above the rated value, so if you kill your 29.95 amp it on you. This sholud be enough voltage swing to get another watt or so into 15 ohms.
MEXX MEXX has some real nice heatsinks that fit the 2024. These will help if pushing the amp hard. He listed a source, I think they are fairly cheap, and look fantastic.
George
jkeny said:
I stole ideas from others! The EB board tech sheet shows to use 0.47 ufd caps for 4 ohm speakers, and 0.22 ufd for 8 ohm. I extended this to using 0.1 - 0.15 ufd for 15 ohm loads.
The chokes was a combination. A designer said that the output chokes were too low a value for using with 300 ohm headphones. The other thing is the lowest value Solo inductor I could find is 15 uH.
I guess I could try digging up one of my 30 year old circuits books from school and try to calculate the -3dB point. The only thing there is where do you want to begin filtering the high frequency hash?
The 0.1 ufd caps and 15 uH values was a seat of the pants combination. It does not seem real critical. I have used 0.22 ufd and 0.15 both with 10 uH chokes with good results on my speakers.
Your speakers may be too much for the little SI. The power output is limited by the impedance. It is good for close to 10 watts into 4 ohm, 6 watts into 8, and maybe 4 into 15 ohms.
This may be plenty, most listening is at low 80's level.
A big help would be to raise up the voltage feeding the SI. Batteries will put 13 or so out. I used a 13.8 volt supply for a while. Played music, and left powered up around the clock. Finally measured the voltage and it was 18 volts unloaded and 16.7 idling the SI.
I think the SI will safely live at 15 volts or so. This is above the rated value, so if you kill your 29.95 amp it on you. This sholud be enough voltage swing to get another watt or so into 15 ohms.
MEXX MEXX has some real nice heatsinks that fit the 2024. These will help if pushing the amp hard. He listed a source, I think they are fairly cheap, and look fantastic.
George
Hi All, I have been sneaking around this forum for some time picking your collective brains and to my surprise, I have managed to kill only one of three SI's in my modding endeavors. The first met an untimely end after I yanked out the inductors and power cap. I managed to fry the chip during the installation process. The next two were less ambitious. I cut out part of the battery compartment to make room for some cheap binding posts and then swapped the input caps for 2.2uf 10v X5R's. Those caps are too big for the pads but I managed to attach small leads and soldered them in place. I paralleled the main power cap with a 1200uf 16v FM series Panasonic soldered to the bottom of the board. Those mods went reasonably well apart from lifting one pad on C3. A lead was attached to R1 and the remaining pad to keep the thing alive. The new input caps certainly do improve the bass performance, but not content to leave well enough alone, the talk of Black Gates has caught my attention. I glued a spare FM cap to the dead board with ABS cement ( the type found in the plumbing dept of Home Depot) to see if it would stick.That sucker isn't going anywhere! I want to try a Black Gate, but am unsure what voltage rating is acceptable.The 22 uf and 47uf 6.3v might add too much pop, so I am thinking of the 4.7 uf 50volt if that will work. Can someone please tell me what is the significance of the voltage rating? Is it the maximum storage capacity? Thanks for all of the reverse engineering. I would not have a clue what needs to be replaced if it was not spelled out for me.
My understanding (someone please correct me if I'm wrong) is that is the maximum *DC* voltage that can be applied to the capacitor. Since caps always pass AC, it should only strip any DC offset from the source and allow the remainder of the signal to pass through.
I, too, may try the 4.7uF/50v cap. Unfortunately, it's about 50% taller than the 22uF/6.3v Hi-Q. Another option might be part# 3-4340 from handmade electronics (hndme). It's a 2.2uF/50v Nichicon Muse FA capacitor. Unfortunately, it's still the same size as the 4.7uF BG.
I, too, may try the 4.7uF/50v cap. Unfortunately, it's about 50% taller than the 22uF/6.3v Hi-Q. Another option might be part# 3-4340 from handmade electronics (hndme). It's a 2.2uF/50v Nichicon Muse FA capacitor. Unfortunately, it's still the same size as the 4.7uF BG.
Motherone, Thanks for the info on voltage ratings. I noticed on www.partsconnexion.com the list of Black Gate caps shows a number in the value range from 2.2 to 4.7 uf but they are all quite large except for a 2.2 and 4.7uf 50v PK series which are 4x7 and 5x7mil. Do you know if the PK's are of the desired quality?
Unfortunately, I'm not much of an expert on BG's. Peter Daniel seems to prefer the BG-N's.. other than him, I haven't seen much on the subject to be honest.
Mike
Mike
BG Caps
The 6.3 volt NHX will be fine. The dc bias is only around 2 volts and the maximum ac should be around 2 volts.
I found the N series BG to be the best electrolytic coupling cap. Really think the NHX HiQ are superior to the 4.7 ufd 50 volt type.
I think the small size of the NHX helps the sonics, less inductance. Just pulled some out to look at, the diameter of the 22 ufd 6.3 v and 4.7 ufd 50 is the same. The 50 volt model is almost twice as tall.
Either should be great. Also, I read where others really are happy with Panasonic FC and FM caps for signal coupling. They would need to be oriented with the positive lead connected to the chip side.
I normally use the BG N series for coupling because I have them. Selection depends on voltage ratings. Here it would be the 22 ufd 6.3 volt.
Cost wise, the 6.3 volt are usually a lot cheaper too.
George
The 6.3 volt NHX will be fine. The dc bias is only around 2 volts and the maximum ac should be around 2 volts.
I found the N series BG to be the best electrolytic coupling cap. Really think the NHX HiQ are superior to the 4.7 ufd 50 volt type.
I think the small size of the NHX helps the sonics, less inductance. Just pulled some out to look at, the diameter of the 22 ufd 6.3 v and 4.7 ufd 50 is the same. The 50 volt model is almost twice as tall.
Either should be great. Also, I read where others really are happy with Panasonic FC and FM caps for signal coupling. They would need to be oriented with the positive lead connected to the chip side.
I normally use the BG N series for coupling because I have them. Selection depends on voltage ratings. Here it would be the 22 ufd 6.3 volt.
Cost wise, the 6.3 volt are usually a lot cheaper too.
George
Thanks George, I think that I may order a few of each(22 and4.7 uf) and see what works best. Maybe throw in a couple PK's as well since they are only $.75 each. A lot of the cost is in the shipping so I might as well stock up. I managed to snag 3 SI's a couple of weeks ago when Think Geek had them in stock for one day. Two have survived surgery and one is for a friend but I am eyeballing it as well. One of the boards came with a jumper wire between the positive side of the reservoir cap and C11. Any ideas what that is all about? Bad trace maybe?
Re: BG Caps
I just orded the 4.7uF BG-N from Kyoto. I agree that the HiQ are nicer due to their size. However, Peter Daniel has listened to both, and says the BG-N doesn't color as much as the HiQ. Since I poked around at the 2024 datasheet, it doesn't look like I can hack the mute easily (read: with a cap) to get a soft-start on the output. Now, I'm not 100% certain on any of this capacitor sound stuff, but I do want to minimize turn-on thump, so I went with the 4.7uF. I do have some of the 47uF NHX HiQ laying around as well, if I do decide to try it instead.
I have some other projects where space isn't an issue, so the N's will probably work fine for them (I ordered quite a few).
Looks like I'm going to bite the bullet and see if I can bat .500 and not toast my last amp.
George -- What inductors are you using at the output now? I'm contemplating some JW Miller toroidal's from Digikey.. I think the problem with the ones on the board is that when you're running the amp hard, they saturate and their inductance drops to 30-40% (3-4 uH) of what it should be running. These toroidal ones drop down to like 6 uH @ 10 amps, so that should hold up a little better under load.
I'm also going to get an AMT chassis for this guy. I guess it will be my "final impact". Heh. Going balls out with the resevoir caps soldered to the chip, etc.
Panelhead said:
I just orded the 4.7uF BG-N from Kyoto. I agree that the HiQ are nicer due to their size. However, Peter Daniel has listened to both, and says the BG-N doesn't color as much as the HiQ. Since I poked around at the 2024 datasheet, it doesn't look like I can hack the mute easily (read: with a cap) to get a soft-start on the output. Now, I'm not 100% certain on any of this capacitor sound stuff, but I do want to minimize turn-on thump, so I went with the 4.7uF. I do have some of the 47uF NHX HiQ laying around as well, if I do decide to try it instead.
I have some other projects where space isn't an issue, so the N's will probably work fine for them (I ordered quite a few).
Looks like I'm going to bite the bullet and see if I can bat .500 and not toast my last amp.
George -- What inductors are you using at the output now? I'm contemplating some JW Miller toroidal's from Digikey.. I think the problem with the ones on the board is that when you're running the amp hard, they saturate and their inductance drops to 30-40% (3-4 uH) of what it should be running. These toroidal ones drop down to like 6 uH @ 10 amps, so that should hold up a little better under load.
I'm also going to get an AMT chassis for this guy. I guess it will be my "final impact". Heh. Going balls out with the resevoir caps soldered to the chip, etc.
Re: Re: Re: BG Caps
Do you have a digikey or mouser part#?
Also, I couldn't find any markings on the stock one -- I thought they were 10uH/2000ma based on the schematic, but since I don't really have any reference for these sizes, I really wouldn't know 😀
I thought about going for the JW Miller 10uh/2000ma inductors. The toroid ones look good, too, especially since they should radiate less of a field than the standard ones, shouldn't they?
Wow. My amp is -33/+55 (my ubermodded one). I have a stock one that is sitting here at -3/+6 mv of offset. Must be a really sweet one! 🙂
Per channel? As in you're just putting 2 coils on 1 board and not using the other channel?
I'm looking forward to trying this with my new CD-rig. Presently it's hooked up to my old Nakamichi 7 disc changer. It's not a bad cd-player, but it's no audio nut gear.
I think once this is done (and maybe I have my monarchy DIP + CD602 mods completed), I'm going to have to look into new speakers. I'm contemplating some Triangles.. Not sure what would match well with the SI and wouldn't break the bank.
Mike
Panelhead said:
Do you have a digikey or mouser part#?
Also, I couldn't find any markings on the stock one -- I thought they were 10uH/2000ma based on the schematic, but since I don't really have any reference for these sizes, I really wouldn't know 😀
I thought about going for the JW Miller 10uh/2000ma inductors. The toroid ones look good, too, especially since they should radiate less of a field than the standard ones, shouldn't they?
Panelhead said:
Wow. My amp is -33/+55 (my ubermodded one). I have a stock one that is sitting here at -3/+6 mv of offset. Must be a really sweet one! 🙂
Panelhead said:
Per channel? As in you're just putting 2 coils on 1 board and not using the other channel?
Panelhead said:
I'm looking forward to trying this with my new CD-rig. Presently it's hooked up to my old Nakamichi 7 disc changer. It's not a bad cd-player, but it's no audio nut gear.
I think once this is done (and maybe I have my monarchy DIP + CD602 mods completed), I'm going to have to look into new speakers. I'm contemplating some Triangles.. Not sure what would match well with the SI and wouldn't break the bank.
Mike
Re: Re: Re: BG Caps
I'm glad you said it first. I have been noticing the limitations of my upstream equipment for the first time. My delay in purchasing a new phono cartridge and a better cd player/dac are now telling on me. And my current stuff isn't trash.
These amps are so revealing it's an adventure each time you listen.
Panelhead said:
I'm glad you said it first. I have been noticing the limitations of my upstream equipment for the first time. My delay in purchasing a new phono cartridge and a better cd player/dac are now telling on me. And my current stuff isn't trash.
These amps are so revealing it's an adventure each time you listen.
Hey George,
Good idea on the Triangle drivers. The 1st set of serious speakers I built were with Triangle full range drivers in a TQWT.
That was 20 years ago.
I loved those speakers! They had a little help on the high end with a Japanese bullet super tweeter, 1st order x-over.
They were amazingly life-like. No matter what you fed them, they sounded good. Would often have neighbors come to the door and knock, asking to listen to the musicians in my living room! 😀
The only draw back was a lack of bass. My puny EL84 amp didn't help any.... But Triangle have improved their drivers since then, and box design is much better now. They should sound wonderful with the modded Sonic.
Tripath+Triangle = a winning combo!
Good idea on the Triangle drivers. The 1st set of serious speakers I built were with Triangle full range drivers in a TQWT.
That was 20 years ago.
I loved those speakers! They had a little help on the high end with a Japanese bullet super tweeter, 1st order x-over.
They were amazingly life-like. No matter what you fed them, they sounded good. Would often have neighbors come to the door and knock, asking to listen to the musicians in my living room! 😀
The only draw back was a lack of bass. My puny EL84 amp didn't help any.... But Triangle have improved their drivers since then, and box design is much better now. They should sound wonderful with the modded Sonic.
Tripath+Triangle = a winning combo!
Re: Re: BG Caps
I have some of the same on my board. They seem to work well, but I have not had a chance to measure the difference from stock coils. At least they should radiate less RF and not saturate as quickly. Easy to solder in place, too.
motherone said:
I have some of the same on my board. They seem to work well, but I have not had a chance to measure the difference from stock coils. At least they should radiate less RF and not saturate as quickly. Easy to solder in place, too.
Re: Re: Re: BG Caps
Pano,
Do you have any images of the board with the toroid chokes on the board? I'd love to get an idea of their size when mounted on the board.
Thanks!
Mike
panomaniac said:
Pano,
Do you have any images of the board with the toroid chokes on the board? I'd love to get an idea of their size when mounted on the board.
Thanks!
Mike
Re: Re: Re: Re: BG Caps
Unfortunately I do not, as my stupid digital camera is on the blink, again. Grrr... But I'll see what I can do.
They are fairly large and stick up a bit. One can see why S.I. went with the little bobbin style coils. But they sure do look better than my hand rolled models!
motherone said:
Unfortunately I do not, as my stupid digital camera is on the blink, again. Grrr... But I'll see what I can do.
They are fairly large and stick up a bit. One can see why S.I. went with the little bobbin style coils. But they sure do look better than my hand rolled models!
Re: BG Caps
Cool. I have another order building up, so I may need to bite the bullet and get these in. Do the toroids stick up much further than, say, a replacement 1000uF panasonic cap (like 1" or so?)
I just don't want to waste my money if I can't fit 'em into one of AMT's enclosures 🙂
Mike
panomaniac said:
Cool. I have another order building up, so I may need to bite the bullet and get these in. Do the toroids stick up much further than, say, a replacement 1000uF panasonic cap (like 1" or so?)
I just don't want to waste my money if I can't fit 'em into one of AMT's enclosures 🙂
Mike
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