pictures of my non-functioning mod!
here are some pictures i took of my currently botched t-amp stealth mod based on audio1sts lovely diagram! hopefully there is some silly red flag here that someone can pick out.
this looks a bit of a mess but nothing is mounted/secured yet as i wanted to make sure everything was ok before cleaning it up.
for power i'm using the same power supply that i use with my working un-modded t-amp. the board gets power as the led lights up when i turn the switch on.
thanks!
dij
here are some pictures i took of my currently botched t-amp stealth mod based on audio1sts lovely diagram! hopefully there is some silly red flag here that someone can pick out.
this looks a bit of a mess but nothing is mounted/secured yet as i wanted to make sure everything was ok before cleaning it up.
for power i'm using the same power supply that i use with my working un-modded t-amp. the board gets power as the led lights up when i turn the switch on.
thanks!
dij
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Hi Dijon,
I'm sorry I don't have much insight to offer here after looking at your pics. Do your caps have red wires on one side and black wires on the other? That's the only thing I'm confused about...
Something you can try though to make sure your bridging operations were successful is to set your multimeter to the "200 Ohms" range (or the lowest resistance range), and put one probe at the board's input where you removed the white plastic header, and the other probe at either R1 or R2, depending on which channel you're looking at. You should see a very low resistance (depending on the resistance of the inductors L1/2, which is probably low). If not, make sure you're probing the correct side of R1/2, and if that doesn't give you anything still, try checking the resistance between L1/2 and R1/2. If you still aren't getting a low resistance, then your bridging might not have worked properly...
As an aside, what camera are you using there? I wish I could get my digi-cam to take such sharp closeups.
It looks like a DSLR...
Jeremy
I'm sorry I don't have much insight to offer here after looking at your pics. Do your caps have red wires on one side and black wires on the other? That's the only thing I'm confused about...
Something you can try though to make sure your bridging operations were successful is to set your multimeter to the "200 Ohms" range (or the lowest resistance range), and put one probe at the board's input where you removed the white plastic header, and the other probe at either R1 or R2, depending on which channel you're looking at. You should see a very low resistance (depending on the resistance of the inductors L1/2, which is probably low). If not, make sure you're probing the correct side of R1/2, and if that doesn't give you anything still, try checking the resistance between L1/2 and R1/2. If you still aren't getting a low resistance, then your bridging might not have worked properly...
As an aside, what camera are you using there? I wish I could get my digi-cam to take such sharp closeups.
It looks like a DSLR...Jeremy
thanks jeremy, hmm..i was hoping for something obvious! oh well, maybe i'll try some of those tips with a multi meter.
yes my caps (auricap 2,2uf) have 1 red and one black wire. my red wire is going to my board, my black wire is connected to the pot. in the last picture on the lower right you can just make out the green disc of one side of the cap with the black wire coming out of it.
--dijon
my digital camera is a quite old and long in the tooth Nikon Cookpix 990. pictures were taken in sunlight on the macro setting (the flower icon, not the mountain ) it's bigger than i'd like but it still takes great pictures so lug it around with me. i think you can get these on ebay for quite cheap nowadays.
yes my caps (auricap 2,2uf) have 1 red and one black wire. my red wire is going to my board, my black wire is connected to the pot. in the last picture on the lower right you can just make out the green disc of one side of the cap with the black wire coming out of it.
--dijon
my digital camera is a quite old and long in the tooth Nikon Cookpix 990. pictures were taken in sunlight on the macro setting (the flower icon, not the mountain
) it's bigger than i'd like but it still takes great pictures so lug it around with me. i think you can get these on ebay for quite cheap nowadays.multimeter results
tried to edit this into my last post..but time had expired..
here are my multimeter results. i've only just gotten one of these so i'm not too sure how to use it. the OHM setting has an auto range so i just left it be. the left input->R01 is .1ohm (the side toward top of board) the left input->R01 is 2.914 kohm (bottom side). the right input_>R02 is 2.867 kohm (the side toward top of board) and .1ohm (sometimes reads 000.0 maybe too small for my probe) (on bottom side of the board). i'm assuming i'm using the probes the right way around. black is on input and red is on the pads.
my whole goal was to do this by blindly following a picture - not knowing anything about electronics. now it looks like i might actually have to learn something...damn.
tried to edit this into my last post..but time had expired..
here are my multimeter results. i've only just gotten one of these so i'm not too sure how to use it. the OHM setting has an auto range so i just left it be. the left input->R01 is .1ohm (the side toward top of board) the left input->R01 is 2.914 kohm (bottom side). the right input_>R02 is 2.867 kohm (the side toward top of board) and .1ohm (sometimes reads 000.0 maybe too small for my probe) (on bottom side of the board). i'm assuming i'm using the probes the right way around. black is on input and red is on the pads.
my whole goal was to do this by blindly following a picture - not knowing anything about electronics. now it looks like i might actually have to learn something...damn.
Hi Dijon,
Ah, well that's good that the input to R01 is very low resistance. If you check the schematic, there isn't really anything in between the input and R01 - I actually meant R1, rather than R01... I'm not sure why they labelled the board like this - it seems like they're just inviting confusion such as this... The general idea here is to make sure signal is getting from the input across your solder bridge.
I just checked the DC resistance across L1 (I have a dead board, and it's less than one ohm according to my multimeter.
Jeremy
Ah, well that's good that the input to R01 is very low resistance. If you check the schematic, there isn't really anything in between the input and R01 - I actually meant R1, rather than R01... I'm not sure why they labelled the board like this - it seems like they're just inviting confusion such as this... The general idea here is to make sure signal is getting from the input across your solder bridge.
I just checked the DC resistance across L1 (I have a dead board
, and it's less than one ohm according to my multimeter.Jeremy
Hi Dijon,
sorry not to get back sooner but I've been away for the weekend..
I must say that everything looks very nice, well done. Could you just check on something that HansR said and that is the speaker posts. Did you drill big enough holes in the case to make sure no part of the post touches it? You can check with your meter (ohms), the figures are approx 35k ohms between any two posts.
Let me know ,Barry.
sorry not to get back sooner but I've been away for the weekend..
I must say that everything looks very nice, well done. Could you just check on something that HansR said and that is the speaker posts. Did you drill big enough holes in the case to make sure no part of the post touches it? You can check with your meter (ohms), the figures are approx 35k ohms between any two posts.
Let me know ,Barry.
Hello everyone! This is my first post here! I've done audio1sts stealth input mod on my t-amp and I've got a big problem... Only on channel is working! From my computer the working channel plays both channels and with a cd-player it just plays one, the one inserted at the time. I've gone over the board a hundred times and resoldered almost everything. I don't have a picture at the time but I suppose I could borrow a better camera to fix one or two if needed.
Best regards, blubbo
Best regards, blubbo
Boy am I happy! With pure instincts I bought a new rca plug today, (stupid, eh? How's one of those gonna fail?) and suprisingly it worked after changing it! Have to give a big thanks to audio1st for that "schematic"! It's a new amp really!
By the way I feel quite stupid now, beeing new and all...
Also thanks Eggzy, that I did not know!
By the way I feel quite stupid now, beeing new and all...
Also thanks Eggzy, that I did not know!
A lots of noise on the T amp
Hi every body
I have mod my T amp according to Audio1st dia using some cheap stuff. The details as following:
1. replace powe supply cap with Nichicon 3300uf, 16 v. soldered on pcb
2. replace input cap with two cheap oil cap, namely Remix 2.0 uf, 250V (don't know where it comes from, bought on with 20 cent here in my place). I could find the caps that you use here.
3. Replace across caps at the speaker output jacks with two 0.15 uF Corald Jonhson poly propylene caps
4. Bridge c3, c4 and remove R01 and R02.
5. Change cover, jacks but use cheap internal wire and cheap pot
I use 12V DC 3.2 A adaptor.
Result: a lot of bas improvement, better image. its another amp, sure. But.......... there are alot of noise. It should be as quiet as mouse using the said dia, right?
I guess it is because of the cheap pot because if I increase the volum, the noise is bigger until close to the max level, it is suddenly.disappeared. Or is it because of the cheap wire? and I donot have good soldering skill?
thats what I guess and because I'm definitely know nothing about electronics, you might have better idea than me.
Any advice will be appreciated!!
Thanks in advance
Hi every body
I have mod my T amp according to Audio1st dia using some cheap stuff. The details as following:
1. replace powe supply cap with Nichicon 3300uf, 16 v. soldered on pcb
2. replace input cap with two cheap oil cap, namely Remix 2.0 uf, 250V (don't know where it comes from, bought on with 20 cent here in my place). I could find the caps that you use here.
3. Replace across caps at the speaker output jacks with two 0.15 uF Corald Jonhson poly propylene caps
4. Bridge c3, c4 and remove R01 and R02.
5. Change cover, jacks but use cheap internal wire and cheap pot
I use 12V DC 3.2 A adaptor.
Result: a lot of bas improvement, better image. its another amp, sure. But.......... there are alot of noise. It should be as quiet as mouse using the said dia, right?
I guess it is because of the cheap pot because if I increase the volum, the noise is bigger until close to the max level, it is suddenly.disappeared. Or is it because of the cheap wire? and I donot have good soldering skill?
thats what I guess and because I'm definitely know nothing about electronics, you might have better idea than me.
Any advice will be appreciated!!
Thanks in advance
Hi Genki,
Well this could be a lot of things but the first thing to do is twist the output wires together so the ground acts like a shield.
Do the same on your input wires.
Try shielding the input caps with tin foill (Ensure you dont short anything with it)
get back after you have done this.
Well this could be a lot of things but the first thing to do is twist the output wires together so the ground acts like a shield.
Do the same on your input wires.
Try shielding the input caps with tin foill (Ensure you dont short anything with it)
get back after you have done this.
Hi Genki,
You don't say what kind of noise you're having, bet I guess it's buzz from your description.
Mostly likely a grounding problem. Are you using sheilded wire on the inputs? Are all your connection points well shielded? It is common to hear the noise increase when you turn up the volume control, then have it go away at some point. That is almost always a ground problem. You may need to connect the amp board or input connectors to ground, or maybe even disconnect it. Grounding problems can be difficult to trace.
Let us know how it goes!
You don't say what kind of noise you're having, bet I guess it's buzz from your description.
Mostly likely a grounding problem. Are you using sheilded wire on the inputs? Are all your connection points well shielded? It is common to hear the noise increase when you turn up the volume control, then have it go away at some point. That is almost always a ground problem. You may need to connect the amp board or input connectors to ground, or maybe even disconnect it. Grounding problems can be difficult to trace.
Let us know how it goes!
Thank you Pano and lostcause
The noise is the background noise, it buzz on my speakers. I think that's the grounding problem. I have tried shielding the input, out put wires with tin foil but there's no change. Finally, I have connected the out tag of the input jacks to ground, using a piece of wire and connect it to the ...........water tab. Then all the noise disappeared
It sounds great now. My Tannoy SRM 12x sings really fantatic. If any body says Tannoy is lack of bass then he should try my T amp...
But there is a small problem, you guess, I cannot connect to the water tab for grounding all the time. Do you experts have any better way to deal with this grounding problem?
The noise is the background noise, it buzz on my speakers. I think that's the grounding problem. I have tried shielding the input, out put wires with tin foil but there's no change. Finally, I have connected the out tag of the input jacks to ground, using a piece of wire and connect it to the ...........water tab. Then all the noise disappeared
It sounds great now. My Tannoy SRM 12x sings really fantatic. If any body says Tannoy is lack of bass then he should try my T amp...
But there is a small problem, you guess, I cannot connect to the water tab for grounding all the time. Do you experts have any better way to deal with this grounding problem?
Grounding can be very difficult. And just think, you have a very simple system. Image a recording studio or a live show! Big headaches.
Sometimes the amps can work well with no connection to ground at all (think iPod or portable radio) other times you will have to have a ground wire. Is anything else in your system connected to ground? It sounds like it is not, or the water pipe trick would not make a difference.
It is very hard to tell you how to fix it without actualy being there. The very smallest things can make a big difference. Your easiest choice is running a wire from a good ground to your amp. Does your house or building have gounded power mains outlets? Can you run a wire to the water pipe?
Sometimes the amps can work well with no connection to ground at all (think iPod or portable radio) other times you will have to have a ground wire. Is anything else in your system connected to ground? It sounds like it is not, or the water pipe trick would not make a difference.
It is very hard to tell you how to fix it without actualy being there. The very smallest things can make a big difference. Your easiest choice is running a wire from a good ground to your amp. Does your house or building have gounded power mains outlets? Can you run a wire to the water pipe?
Thanks Pano
The amp sounds really different. If not connect to the water pipe, the buzz is just hard to accept. You can hear it from 4 metter far from the spearkers. With the water pipe then the sound is even better, not only the noise is away.
But I'm wondering if I did some thing wrong because before that there is no noise, right? and most of you donot have this problem with the same kind of moding. Do you think what and where I can look at on the PCB to check the ground problem?
When I change the case of the amp, i just desoldered the DC jack and connect with a peice of wire to bring it out of the PCB, but I broke the small foot of the jack which connect to the PCB (the grounding foot). When I use wire, I just connect it to the next foot on the PCB(which are inter connected with the broken one). But I'm not sure this is the problem.
Don't have a good camera to show you what I did, hope you can imagine.
The amp sounds really different. If not connect to the water pipe, the buzz is just hard to accept. You can hear it from 4 metter far from the spearkers. With the water pipe then the sound is even better, not only the noise is away.
But I'm wondering if I did some thing wrong because before that there is no noise, right? and most of you donot have this problem with the same kind of moding. Do you think what and where I can look at on the PCB to check the ground problem?
When I change the case of the amp, i just desoldered the DC jack and connect with a peice of wire to bring it out of the PCB, but I broke the small foot of the jack which connect to the PCB (the grounding foot). When I use wire, I just connect it to the next foot on the PCB(which are inter connected with the broken one). But I'm not sure this is the problem.
Don't have a good camera to show you what I did, hope you can imagine.
genki said:
I've a similar problem, maybe not quite as bad as you, but nearby sources of interference will vary with each person, so don't think you've fouled up the mod. I'm thinking its partly splitting & spreading the ribbon-cable pot leads out (to accommodate the bulkier new input caps) and jamming everything back just to make sure it still works, some are probably too close to where they shouldn't be. I've asked for "best practice" ideas in the SI 5066 Parts List & Modifications thread before spotting your post & the responses, hum is curable.
Mind you, there are warnings about what we're doing...
cpemma said:
Good link! I can certainly tell you that big caps will pick up noise, just put your finger on one while the amp is running. Buzzzzzz.
Thus you should be careful to used shielded cable wherever possible and keep the caps shielded, if only by the metal chassis. Usually works.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.