I have been playing around with resistors again in the R1 and Rf positions. I initially started with some MK132 resistors and noticed an improvement in overall sound. I decided to get some nude Vishay s102 (TX2353) and some Shinkoh Tantalum resistors to compare. They are remarkably different sounding sounding resistors. The Vishays are smooth, very laid back, and distant. The Shinkohs are very forward, detailed, and thick. They really add presence and body to the sound. I found that using all four of the same seemed to be too much of one thing, so I settled on 2 of each.
I'm very surprised at the difference these resistors make after reading about how little change there is compared to cap changes. It seems these resistors are completely overlooked in mods, especially other amps with smd components. Maybe I'm just the odd one out....
Up next are some MPP toroid I wound up earlier this week. My fingers are still sore, so I haven't been motivated to even touch them again yet.
I'm very surprised at the difference these resistors make after reading about how little change there is compared to cap changes. It seems these resistors are completely overlooked in mods, especially other amps with smd components. Maybe I'm just the odd one out....
Up next are some MPP toroid I wound up earlier this week. My fingers are still sore, so I haven't been motivated to even touch them again yet.
Hi dweekie,
Your fingers should not be sore from winding the MPP cores.
My cores that have a permeability of 60 needed only 15 turns for the 15uh my amp11 requires.
Those cores need 16awg wire to keep the temperature low so it is a bit harder to turn.
Could you let us know what functions the resistors R1 and Rf have.
I don't have a TA10 so I have to locate them on the data sheet of the chip.
Greets,
Klaus
Your fingers should not be sore from winding the MPP cores.
My cores that have a permeability of 60 needed only 15 turns for the 15uh my amp11 requires.
Those cores need 16awg wire to keep the temperature low so it is a bit harder to turn.
Could you let us know what functions the resistors R1 and Rf have.
I don't have a TA10 so I have to locate them on the data sheet of the chip.
Greets,
Klaus
They are the gain/feedback resistors (R2, R4, R5, R6) - http://www.tripath.com/downloads/EB-TA2024.pdf
My Vishay resistors don't have much time on them (not the 100 hours everyone says it needs for break-in). The Shinkohs have more than enough. That may or may not have any effect on my initial assessment. It's a good sounding combination for me now.
I used some 18gauge wire on the 60u MPP cores, 16 turns for 11uH. I don't have a sensitive inductance meter, so I'm going to have to trust myself and the calculator I used. I played it overnight and it isn't warm at all.
My Vishay resistors don't have much time on them (not the 100 hours everyone says it needs for break-in). The Shinkohs have more than enough. That may or may not have any effect on my initial assessment. It's a good sounding combination for me now.
I used some 18gauge wire on the 60u MPP cores, 16 turns for 11uH. I don't have a sensitive inductance meter, so I'm going to have to trust myself and the calculator I used. I played it overnight and it isn't warm at all.
Thanks Dave
I couldnt figure out how to reset the jumpers from the pdf. manual. Your little diagram made it a ten minute job. It sounds better on my setup as well. So far I have mardis sig. mods, astron smps- this made a big difference, and a Bottlehead preamp.
What is next?
Thanks
Davec113 said:
I couldnt figure out how to reset the jumpers from the pdf. manual. Your little diagram made it a ten minute job. It sounds better on my setup as well. So far I have mardis sig. mods, astron smps- this made a big difference, and a Bottlehead preamp.
What is next?
Thanks
I left my amp running during a rainstorm and when I woke up, all I heard was a tapping sound from the speakers. The power had gone out during the night. Now I get nothing to come out, and the dc at the outputs measure 3.5V. I guess this is the sign of a completely dead chip?
If it's tapping, it's not dead - just trying to get out of the coffin! 
The tap-tap, or click-click means there is a short somewhere, the amp is protecting itself. Did it rain on the amp??
Check around for a short circuit, there may be life in the old girl yet.
The tap-tap, or click-click means there is a short somewhere, the amp is protecting itself. Did it rain on the amp??
Check around for a short circuit, there may be life in the old girl yet.
Yeah, she should be OK.
I've repaired several 'ticking' amps and its usually a blown cap on the outputs.
Hope the DC hasn't damaged your speakers though🙁
I've repaired several 'ticking' amps and its usually a blown cap on the outputs.
Hope the DC hasn't damaged your speakers though🙁
Thanks a lot guys, its very reassuring. I've been very lucky with mistakes lately on this amp, and hopefully it'll be able to come back to life. Since the timing of the problem correllated perfectly with the power outage, I was a bit worried about a possible power surge which could have killed the chip. Blue led works, it clicks when hooked up to the amp, and the voltage at the outputs is 3.5v. The output voltage is completely unaffected by the dc offset adjustments. Hopefully these indicate a problem beyond the chip so that replacing the parts is possible. If I can't find the issue, would one of you be able to provide a repair service?
Hey Panomaniac,
Audiomagus is shipping a Trends with your level one / value mods out to me this week. How long will it take to settle in before the sound is optimum?
John
Audiomagus is shipping a Trends with your level one / value mods out to me this week. How long will it take to settle in before the sound is optimum?
John
It should sound really good right out of the box, then go sour for a couple of days.
After about 50 hours or more of play, it will clear up and sound better than new. I suspect this is caused by the electrolytic power caps forming (breaking in).
At least this is the experience of most users. Please let us know what you think - now that I have unduly influenced you. 😉
After about 50 hours or more of play, it will clear up and sound better than new. I suspect this is caused by the electrolytic power caps forming (breaking in).
At least this is the experience of most users. Please let us know what you think - now that I have unduly influenced you. 😉
panomaniac said:
Thanks Pano,
Break in won't be a problem after all as it will be 3 - 4 weeks before my new speakers arrive.
I've owned the cheap Sonic Impact, a Super T, Charlize and Clari-T, and so the Trends is / was pretty much inevitable. With your magic touch, I'm hoping it will be the best of the lot.
John
dweekie said:
Okay, I tried to run the soldering iron over the chip legs and made sure there was no short. The input to the chip is okay and the chip to the speaker outputs is okay. Where it gets funny is that there is -6v at the ouputs. There seems to be something going on between the ground plane and the speaker output. This may be why I'm reading -6v at each output. Is there a method to determine if the chip is at fault, or if it's something else? I would assume a power surge would more likely kill the chip than other components, but I'm a little unsure how to proceed at this point. Any suggestions?
Take it out of the case completely. Some of the tracks near the edges of the boards are NOT ground planes.
If the red protective coating on the board is scratched it will be shorting something to ground.
If the red protective coating on the board is scratched it will be shorting something to ground.
Just thinking about it the last ticker I had was the diodes......
Do a diode check with the power off.
Do a diode check with the power off.
Thanks for the replies. The diodes were fine, but the problem seems to lie elsewhere. I was wrong about the groundplane interaction. I measured the ouput at the pins directly this time. Power input is 12V. Measuring from the power input pins, 6V comes out of both + terminal pins, and 0V at the - terminal pins. The + pins are right next to the power pins, but I would expect to see 12V and not 6V should they be shorted. Turning the dc adustment screw does absolutely nothing. I'm not sure how the dc adjustment works, but could the problem lie within there, is the chip at fault, or is it something else?
Hi there,
I have a Trends TA-10.1 and are pretty pleased with it considering the price. But I have terrible unbalance between the two channels and it's getting worse. I have to remove the original volume pot and buy a new one.
Now to the question, I've read most of this tread and what's been said on other forums but I'm not sure. What is the best volume pot for this little amp...? I just want it to be easily soldered, fit well and have a better quality then the original.
Thanks in advance.
/Christian
I have a Trends TA-10.1 and are pretty pleased with it considering the price. But I have terrible unbalance between the two channels and it's getting worse. I have to remove the original volume pot and buy a new one.
Now to the question, I've read most of this tread and what's been said on other forums but I'm not sure. What is the best volume pot for this little amp...? I just want it to be easily soldered, fit well and have a better quality then the original.
Thanks in advance.
/Christian
That's my experience too, and from others as well. No inputcap or power supply swapping is going to change it. I guess it's got everything to do with the internal feedback circuit, or maybe even an internal ac coupled stage with little on die capacitors. I have tried about everything but there is no way you will ever get the Trends or any other TA2024 amp kick your *** in the bass and lower midrange department like other amps can. This makes them rather unusuable as fullrange amps to me. The higher mids and highs are nice though.
You're right about the input cap and power supply work, (assuming the power supply can deliver the required current without driopping volts)
The increase in bass with higher output impedance amplifiers is a well known phenomenon with most of the Fostex FE series drivers. That's why people love using them with tube amps.
try putting 2 ohms in series with your drivers or use pathetic cable for speaker wire like an old telephone cord.
you only lose about 1dB overall but the bass increases compared to the HF because of the impedance curve of the driver.
The increase in bass with higher output impedance amplifiers is a well known phenomenon with most of the Fostex FE series drivers. That's why people love using them with tube amps.
try putting 2 ohms in series with your drivers or use pathetic cable for speaker wire like an old telephone cord.
you only lose about 1dB overall but the bass increases compared to the HF because of the impedance curve of the driver.
rajacat said:
Well.....out of curiosity I reinstalled the Obbligato PIOs' and the collapsed soundstage was no longer evident. I think the problem was that I had accidentally connected both speakers (Omega Hemp Dipoles) in mono mod in my biamped configuration'
'The Obbs. have a nice expansive soundstage and a very mellow midrange. However, the bass is not too impressive and overall they seem to be a little too polite. The bass is somewhat loose and I'm left with a desire for more transparency and resolution. I'm curious about the film Obbligatos but Davet said that they sound the same as the PIOs' in his system ( I believe he has Omega speakers too).
Sonicaps don't get much respect here despite being favorites on some other forums and with other amps. Has anybody listened to well broken in (200 hours +) Sonicaps with the Trends? They are relatively cheap so maybe I'll be the designated lab rat. On the other hand, I could play it safe and just install the Auricaps.
'
'I just received some Panasonic CE 3300uf power caps. Hmmm... would these tighten up the bass? I'll soon find out.🙂
Give them a chance to burn in, you might start to like them more... They do sound a little unfocused and sludgy when first hooked up. I now also use them in my monica 2 usb dac 🙂
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