Thank you
I opened the TA and the power caps are some Sanyo 1500uF and the input caps some big yellow caps that says N8P 225J/250V (chinese for me, 250 V is clear).
Regarding the power supply I have a regulated power supply of 3A but at 13.8 V I have been using it with my modded SI Tamp.
Could I use it? and as wire I could use some 1.5m2 solid copper wire.
what I acan not understand is why soldering the cables directly to the board avoiding the switch. Can you explain?
In my satellite cable the shield is copper (or at least looks like) and fairly thick. I could solder the shield to ground.
I am currently using satellite antenna cable to make RCA connectors, they are good indeed. I got the recepie from TNTaudio in Italy.
Thank you
Cosimo
I opened the TA and the power caps are some Sanyo 1500uF and the input caps some big yellow caps that says N8P 225J/250V (chinese for me, 250 V is clear).
Regarding the power supply I have a regulated power supply of 3A but at 13.8 V I have been using it with my modded SI Tamp.
Could I use it? and as wire I could use some 1.5m2 solid copper wire.
what I acan not understand is why soldering the cables directly to the board avoiding the switch. Can you explain?
In my satellite cable the shield is copper (or at least looks like) and fairly thick. I could solder the shield to ground.
I am currently using satellite antenna cable to make RCA connectors, they are good indeed. I got the recepie from TNTaudio in Italy.
Thank you
Cosimo
for reduced resistance and inductance. keep short cables as well. It only makes a very small difference but it's a cheap and easy thing to do.
It's surprising how many people use a big fancy power cable and leave the tiny little black plug on the cheap power switch alone.
worth upgrading those power supply caps then.. 1500 uf id a bit small. make sure that whatever you use is an ultra low ESR capacitor.
that foil will be good for making screens if you can solder it.
If you re-case the T-amp into a bigger box you can simply unsolder the output filter coils and solder them back in from underneath the board. much easier than making shields.
It's surprising how many people use a big fancy power cable and leave the tiny little black plug on the cheap power switch alone.
worth upgrading those power supply caps then.. 1500 uf id a bit small. make sure that whatever you use is an ultra low ESR capacitor.
that foil will be good for making screens if you can solder it.
If you re-case the T-amp into a bigger box you can simply unsolder the output filter coils and solder them back in from underneath the board. much easier than making shields.
Hey Recca, I tried soldering in a 2021 chip but i broke a pin when I bent the pins the other way (that chip is basically a reversed 2024). I'd imagine you'd have to get a cheap 2024 board like an original t amp or a shure board off ebay and use a hot air solder station to swap chips.
Another cheaper option than a new Trends would be to just get an Amp6 or Charlize 2 and solder in replacement parts since you'll be changing parts on the Trends anyway. Plus, the 2020 chips are easier to obtain and swap out should it break.
Another cheaper option than a new Trends would be to just get an Amp6 or Charlize 2 and solder in replacement parts since you'll be changing parts on the Trends anyway. Plus, the 2020 chips are easier to obtain and swap out should it break.
So my problems started when I swapped out the Bias Cap and the resistors. I did it after a long day and didn't do a good job soldering. When I turned it on I got a lot of white noise and popping on the right channel. I could still hear music through the left channel through the white noise but nothing else.
I figured it was a bad bias cap so I received a new one and resoldered it as well as all of the resistors. I also removed the Pot and wired the inputs directly to the jumper block. Now I have absolutely no signal anywhere.
I just bought a used Mike Mardis Trends. If I can bring this one back to life I'll sell the other one. Sigh...
I figured it was a bad bias cap so I received a new one and resoldered it as well as all of the resistors. I also removed the Pot and wired the inputs directly to the jumper block. Now I have absolutely no signal anywhere.
I just bought a used Mike Mardis Trends. If I can bring this one back to life I'll sell the other one. Sigh...
When you say you have no signal anywhere, does that mean you have you tested the signal path in small steps? Keep one lead on the RCA center and go through the signal path with the other lead to see if the signal cuts off anywhere. It should follow from the rca to the jumper block pins to input caps to the resistors to the pins on the tripath chip. Do you get signal all the way to the chip?
You might have damaged the soldering leads on the pcb. they are very tiny at the place of the input/feedback resistors. You also might check if there is any soldering leftover at the smd tripath chip pins, that happens quite easily when soldering nearby the chip, be sure to clean it up, it happened to me twice with other smd chip and everything worked fine after removing all of the "garbage" between the pins.
dweekie said:
I was wondering myself... I have a preamp, so I bypassed the volume pot in the Trends; I'm not sure what impedance it (Trends volume pot) is. The gain and feedback resistors in the Trends are 20k, so I'd guess the input impedence will be more than that... I'm not sure what the Tripath chip adds
I was going to replace the Trends 20k resistors with higher quality resistors of the same value, but instead I ordered 68k Shinkoh Tantalum resistors because my tube preamp has 29 db gain (it can swing 44V RMS!!!). This can be reduced to 12 db internally, but all that switch does is add 392k resistors before the volume pot. I bought Shinkoh resistors for this position too, but I hope I can run the preamp full gain with the 68k resistors in the Trends... The preamp was designed for amps with 50-100k input impedance anyway, so I figure the 68k resistors might help out as far as matching the preamp with the amp. If anyone has a different suggestion, I'm all ears
Dave
Super T has a 50k pot. Here's the Stereophile link I referred to:
http://www.stereophile.com/solidpoweramps/1006sonic/index4.html
http://www.stereophile.com/solidpoweramps/1006sonic/index4.html
input circuit of the Trends without volume control is just a plain simple opamp circuit with 20K series and 20k feedback resistor. these are in parallel for ac so that makes an input impedance of 10k.
you can replace them with higher value offcoarse but be aware of instabilities when you are going too high in resistance
you can replace them with higher value offcoarse but be aware of instabilities when you are going too high in resistance
Obbligato cap update
I have revised my impression of the Obbligato PIO. After subjecting the caps and myself to 100+ hours of break-in, I now believe that they have very good bass response to go with the excellent midrange and holographic soundstage. I've come to the conclusion that most caps really need substantial hours before they can be evaluated accurately.
I have revised my impression of the Obbligato PIO. After subjecting the caps and myself to 100+ hours of break-in, I now believe that they have very good bass response to go with the excellent midrange and holographic soundstage.
I've come to the conclusion that most caps really need substantial hours before they can be evaluated accurately.Fixed it! 1st problem was battery was too weak to power the chip. It was strong enough for the LED to be on but not enough for the amp to work. I hooked up the stock psu and got some sound. 2nd problem turned out to the be the left channel feedback resistor.
I still got the background white noise that I can't pinpoint but I'm back in business. Thanks for all your help!
I still got the background white noise that I can't pinpoint but I'm back in business. Thanks for all your help!
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