Re: Re: total beginner, I am...
Barry, this is exactly the advise, I was looking for. I really appreciate the graph, I can actually understand.
I will take your advise ver batum, thank you so much.
gychang
Barry, this is exactly the advise, I was looking for. I really appreciate the graph, I can actually understand.
I will take your advise ver batum, thank you so much.
gychang
audio1st said:
where did u get parts?
I couldn't look at your final work, but can you tell me where and which part you got and installed?
I like to exactly duplicate your mod.
gychang
I couldn't look at your final work, but can you tell me where and which part you got and installed?
I like to exactly duplicate your mod.
gychang
PCHuggs said:
Hey, folks. I just got my sonic impact the other day.
I brought the box in when I got home from work and powered it up with a cheapo 12v 1A wall-wart I was able to scavange.
I must admit being quite dissapointed! Bass was almost non-existant. Mids were harsh and aggressive. The whole thing sounded thin and hard. Of course, as it came off my porch it was probably 20 degrees F.
6 hours of play later it had managed to mellow some. Still sounds thin, but imaging is a step up from my previous cheapo small amp. Detail in the vocal range is starting to come out as well. I've heard that the T-amp likes some time to burn in, so we'll see how things develop. I haven't given up on it yet - we'll see how it sounds at 50hrs.
I am considering the standard round of upgrades. The input caps I see in the diagram are 2.2uf auricaps. I wonder if anyone has thoughts on other caps and/or values? At parts express (www.partsexpress.com) the 2.2uf Auricap is $15.06. They also have an Audio Cap Theta - (polyprop) Film and (tin) Foil 2.0uf for $16.47. I understand that the Film and Foil type caps are supposed to be superior to the metalized film type of the Auricap? They're almost the same price... Has anyone any thoughts on capacitor choice? Would a difference be noticable in this application?
Also the values are 2.2uf vs. 2.0uf. Was 2.2uf chosen for a reason, or was it just judged to be 'large enough'? Is 2.0uf sufficient?
What about the HF shorting caps (.1uf) on the speaker terminals? I don't imagine you'd want to change the values, but would a quality upgrade make sense here? A dayton .1uf polyprop cap is a mere 70 cents...
Also, what kind of current ratings are being used on power supplies?
Thx for your thoughts - A
I brought the box in when I got home from work and powered it up with a cheapo 12v 1A wall-wart I was able to scavange.
I must admit being quite dissapointed! Bass was almost non-existant. Mids were harsh and aggressive. The whole thing sounded thin and hard. Of course, as it came off my porch it was probably 20 degrees F.
6 hours of play later it had managed to mellow some. Still sounds thin, but imaging is a step up from my previous cheapo small amp. Detail in the vocal range is starting to come out as well. I've heard that the T-amp likes some time to burn in, so we'll see how things develop. I haven't given up on it yet - we'll see how it sounds at 50hrs.
I am considering the standard round of upgrades. The input caps I see in the diagram are 2.2uf auricaps. I wonder if anyone has thoughts on other caps and/or values? At parts express (www.partsexpress.com) the 2.2uf Auricap is $15.06. They also have an Audio Cap Theta - (polyprop) Film and (tin) Foil 2.0uf for $16.47. I understand that the Film and Foil type caps are supposed to be superior to the metalized film type of the Auricap? They're almost the same price... Has anyone any thoughts on capacitor choice? Would a difference be noticable in this application?
Also the values are 2.2uf vs. 2.0uf. Was 2.2uf chosen for a reason, or was it just judged to be 'large enough'? Is 2.0uf sufficient?
What about the HF shorting caps (.1uf) on the speaker terminals? I don't imagine you'd want to change the values, but would a quality upgrade make sense here? A dayton .1uf polyprop cap is a mere 70 cents...
Also, what kind of current ratings are being used on power supplies?
Thx for your thoughts - A
AdamThorne said:
Too large a value and you'll get an objectionable switch-on thump, 2uF or 2.2uF will extend the bass roll-off frequency low enough to beat most speakers.
See the FR curves, the ones rolling off from about 30Hz are using 2u2 IIRC.
On power supply, you'll get far better bass with a few more amps available. 2A minimum, though if you're buying go for 3A-5A. And make sure it's a regulated supply.
Hi Adam,
Glad to know you want to jump into the world of T-Amps. You'll have fun.
But I can see that you have not been doing your reading and your homework.
😉
The stock Sonic Impact is not a great sounding amp, it needs a lot of help to really sing. That el cheapo wall-wart power supply is not helping, either.
The most important mods are the input caps - anything between 1.5 and 3uF will do. The stock input caps are 0.33uF, which puts the -3dB point at about 24Hz, just as my charts show. I've used lot of input caps, the AudioCap Thetas are nice, very clean, very neutral. My favs are the Obbligato paper in oil of copper tube caps. But they're B-I-G.
But subjectively, the amp is even more bass shy than that. Because the power supply can't keep up. The Sonic doesn't have much power to begin with, you don't want the power supply holding you back. SO... You need a good quality supply of at least 2 amps, and you need to get some bigger power caps in there near the chip.
That will get you started.
Read some of the treads here and take a look at my site. All the info yo need is here or there. Happy Modding!!
Glad to know you want to jump into the world of T-Amps. You'll have fun.
But I can see that you have not been doing your reading and your homework.
😉The stock Sonic Impact is not a great sounding amp, it needs a lot of help to really sing. That el cheapo wall-wart power supply is not helping, either.
The most important mods are the input caps - anything between 1.5 and 3uF will do. The stock input caps are 0.33uF, which puts the -3dB point at about 24Hz, just as my charts show. I've used lot of input caps, the AudioCap Thetas are nice, very clean, very neutral. My favs are the Obbligato paper in oil of copper tube caps. But they're B-I-G.
But subjectively, the amp is even more bass shy than that. Because the power supply can't keep up. The Sonic doesn't have much power to begin with, you don't want the power supply holding you back. SO... You need a good quality supply of at least 2 amps, and you need to get some bigger power caps in there near the chip.
That will get you started.
Read some of the treads here and take a look at my site. All the info yo need is here or there. Happy Modding!!
The other really important thing to get some more bass going is to replace the power reservoir cap (C10, the one between all the inductors) with a higher value, low ESR type. You can go up to 680uf with the same diameter as the one on there. Adding even more low-ESR capacitance right off the board can also help. There have been plenty of discussions on these forums on all that
Inductors can also be replaced, although In my case the change was not too dramatic with those. Others report different results.
--Buckapound
Inductors can also be replaced, although In my case the change was not too dramatic with those. Others report different results.
--Buckapound
Well I've got my upgrade parts for the SI. But I'm suffering from a bit of confusion - the board pictured in audio1st's diagram seems to be of a different revision than mine. As (hopefully) you can see, c3 and c4 are both on the top side of my board.
On the top I've found R1 (1.5 Kohm) and R2 (20 Kohm) and R02 (10 Kohm). I saw a post way back down the thread about the R2 / R02 label scheme being confusing, so I'm assuming that R02 (as mentioned on the actual diagram) is the correct resistor. But I can't seem to spot R01. This is as of last night. Maybe fatigue was setting in. But as I look at these pics I took of the board, I still can't see R01.
Any of you jokers mod this particular board revision and remember where R01 is? Also, is R01 10 kohm as R02? Maybe I can find it with my DVM...
On the top I've found R1 (1.5 Kohm) and R2 (20 Kohm) and R02 (10 Kohm). I saw a post way back down the thread about the R2 / R02 label scheme being confusing, so I'm assuming that R02 (as mentioned on the actual diagram) is the correct resistor. But I can't seem to spot R01. This is as of last night. Maybe fatigue was setting in. But as I look at these pics I took of the board, I still can't see R01.
Any of you jokers mod this particular board revision and remember where R01 is? Also, is R01 10 kohm as R02? Maybe I can find it with my DVM...
Attachments
There seems to be a new version of the Sonic Impact shipping now. I think picklegreen was the first to point it out.
I have one on the way and will have a look. Seems like it's time to update all the info!
Can you hold off for a bit? Or there might be someone else here who has the ew version and can help.
I have one on the way and will have a look. Seems like it's time to update all the info!
Can you hold off for a bit? Or there might be someone else here who has the ew version and can help.
R01 should be right by L1, which looks as if it's right next to L2. Could it be under the plastic cup for the volume control plug? I usually tear that thing right out.
Interesting to see that board. Looks like they have heavied up a lot of the power traces.
--Buckapound
Interesting to see that board. Looks like they have heavied up a lot of the power traces.
--Buckapound
"R01 should be right by L1, which looks as if it's right next to L2. Could it be under the plastic cup for the volume control plug? I usually tear that thing right out."
Hmm I had been intending to leave the plastic plug there, as I have not yet picked up a replacement pot. But I suppose I could wire it up off-board until I am ready to stop using the stock pot. I'll have a look mmm... maybe tonight or possibly... Thursday.
Pano - do you happen to recall what thread picklegreen mentioned the new t-amp in?
Hmm I had been intending to leave the plastic plug there, as I have not yet picked up a replacement pot. But I suppose I could wire it up off-board until I am ready to stop using the stock pot. I'll have a look mmm... maybe tonight or possibly... Thursday.
Pano - do you happen to recall what thread picklegreen mentioned the new t-amp in?
You can take the wire cutters and start chopping away at that plastic thing--at least on the one end where the treasure (R01) may be hidden. Won't ruin its functionality, at least for temporary use.
--Buckapound
--Buckapound
And I don't even have one of the new ones yet. 
Been out of stock. But should have one soon, I'll post info as soon as I can.
Anyone else with a new version, please post what you find.
Been out of stock. But should have one soon, I'll post info as soon as I can.Anyone else with a new version, please post what you find.
Here is a pic identifying (I think) R02, C3 and C4. I haven't been able to spot R01 yet. Note that R01 is not the same as R1. Hope you can make out the pic... 🙄
It has been suggested that R01 is under the big white plug. I have discovered that carving away the plastic of the plug while not carving away anything else is somewhat difficult (with the tools I have, anyway). Careful examination shows that the plug seems to sit pretty flush against the board, however, so I don't think anything is underneath it. But I guess you never know.
I am considering doing a "just the caps" mod rather than the initially planned "stealth" mod (as per panomaniac's site), since R01 is hiding from me. I'll have to go back and re-read the merits of the various mod styles to come to a final decision on that.
Adam
It has been suggested that R01 is under the big white plug. I have discovered that carving away the plastic of the plug while not carving away anything else is somewhat difficult (with the tools I have, anyway). Careful examination shows that the plug seems to sit pretty flush against the board, however, so I don't think anything is underneath it. But I guess you never know.
I am considering doing a "just the caps" mod rather than the initially planned "stealth" mod (as per panomaniac's site), since R01 is hiding from me. I'll have to go back and re-read the merits of the various mod styles to come to a final decision on that.
Adam
Attachments
Are you sure that C4 on your picture is an input capacitor?
I tried to change that to one 2,2uF cap I've bought (I only tried with C4 alone, not both C4 and C3), and all I got was lots of noise in the speakers when i turned it on.
I'm 99% sure that it was the C4 on your picture i tried with. Or does both capacitors need to be the same value to make it work without a lot of noise?
I tried to change that to one 2,2uF cap I've bought (I only tried with C4 alone, not both C4 and C3), and all I got was lots of noise in the speakers when i turned it on.
I'm 99% sure that it was the C4 on your picture i tried with. Or does both capacitors need to be the same value to make it work without a lot of noise?
It looks to me as if C3 and C4 are still the same, R01 has become R3, R02 is still R02 and R1 is now R80. So for the Stealth mod, the only thing different seems to be R3 instead of R01..This is just my opinion from the photos as I don't have a new board..
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