well if the toroid is buzzing i would look at noisy mains line first maybe you have something else thats putting out dc on the line till it warms up i dunno
the last place i lived all my torroids buzzed continuously i put kill switches on the back of all those peices so i could sleep, where i live now they are silent
the last place i lived all my torroids buzzed continuously i put kill switches on the back of all those peices so i could sleep, where i live now they are silent
I thought I would revive this thread and talk about some of the things I've done to help out this DAC.
I started w/ mqualia's mods. Good place to begin and definitely helps the sound quality. Next, I changed the opamp to a LME49720. It was an improvement, though not huge. Decoupling this opamp and then biasing it made a bigger improvement.
The results with the new opamp weren't all that unexpected. What has surprised me is the benefits of Stillpoints ERS cloth around the amp. First and foremost is the transformer. Putting the cloth around much of the outside of the transformer made a surprising difference. I guess it puts out a lot of EMI/RFI. Also, I put the cloth on top of each of the 4 10,000 uF electrolytics and then added it between the top 2 caps and the bottom 2 caps (so going from left to right) with good effect. Didn't seem to do much with I put it in an up-down fashion. And finally, putting some on top of the main chip helped as well. Interestingly, I found that the cloth can only cover the middle part of the chip. If it's too high or too low, it causes a hum.
So, there you have it. And remember, if you're playing with the Stillpoints ERS, make sure you take care so that it doesn't catch fire on you.
I started w/ mqualia's mods. Good place to begin and definitely helps the sound quality. Next, I changed the opamp to a LME49720. It was an improvement, though not huge. Decoupling this opamp and then biasing it made a bigger improvement.
The results with the new opamp weren't all that unexpected. What has surprised me is the benefits of Stillpoints ERS cloth around the amp. First and foremost is the transformer. Putting the cloth around much of the outside of the transformer made a surprising difference. I guess it puts out a lot of EMI/RFI. Also, I put the cloth on top of each of the 4 10,000 uF electrolytics and then added it between the top 2 caps and the bottom 2 caps (so going from left to right) with good effect. Didn't seem to do much with I put it in an up-down fashion. And finally, putting some on top of the main chip helped as well. Interestingly, I found that the cloth can only cover the middle part of the chip. If it's too high or too low, it causes a hum.
So, there you have it. And remember, if you're playing with the Stillpoints ERS, make sure you take care so that it doesn't catch fire on you.
Has anyone tried changing the output filter of this amp?
I don't know why if took me so long to realize how screwed up the output filter is. It could be one of the reasons this amp never got very good reviews and was considered unreliable.
The output filter consists of two 11uH (29 turn T-106) in series with a 0.22uF from output to ground. That seems like the first mistake, because the inductance should only be 11uH, not 22uH. The output Zobel also seems to be way off; it uses a 68R resistor in series with 6 x 0.05uF capacitors (0.03uF total), for a Fc of 7.8kHz.
I'm going to try bypassing one of the inductors and also change the output Zobel to 20R + 0.1uF. I'm guessing this will be a much needed improvement.
I don't know why if took me so long to realize how screwed up the output filter is. It could be one of the reasons this amp never got very good reviews and was considered unreliable.
The output filter consists of two 11uH (29 turn T-106) in series with a 0.22uF from output to ground. That seems like the first mistake, because the inductance should only be 11uH, not 22uH. The output Zobel also seems to be way off; it uses a 68R resistor in series with 6 x 0.05uF capacitors (0.03uF total), for a Fc of 7.8kHz.
I'm going to try bypassing one of the inductors and also change the output Zobel to 20R + 0.1uF. I'm guessing this will be a much needed improvement.
I was mistaken with the layout of the filter/Zobel components. The filter is actually 22uH + 0.3uF and the Zobel 68R + 0.22uF, not that it matters.
I changed the filter to 11uH + 0.22uF and Zobel to 20R + 0.1uF and made a few other changes. The highs are nice and crisp now like they should be.
I also replaced the blown panel meter bulbs with orange LEDs so I don't have to worry about them blowing again.
Before...
After...
I changed the filter to 11uH + 0.22uF and Zobel to 20R + 0.1uF and made a few other changes. The highs are nice and crisp now like they should be.
I also replaced the blown panel meter bulbs with orange LEDs so I don't have to worry about them blowing again.
Before...
An externally hosted image should be here but it was not working when we last tested it.
After...
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.
Well, to answer my own question,
It is a fuse for one of the low voltage power supplies.
Why it blew (and 2 other times) is a mystery that I will no doubt never solve.
But with the forth one, it is running.
Next time, I will put a MUCH bigger one in, and watch something smoke to solve the mystery, and order a new emotiva.
Can someone tell me what the green led is in front of the tripath? It is out now, but was illuminated when the fuse blew.
It is a fuse for one of the low voltage power supplies.
Why it blew (and 2 other times) is a mystery that I will no doubt never solve.
But with the forth one, it is running.
Next time, I will put a MUCH bigger one in, and watch something smoke to solve the mystery, and order a new emotiva.
Can someone tell me what the green led is in front of the tripath? It is out now, but was illuminated when the fuse blew.
Sorry to tell you this, but the Tripath module commited suicide along with the output FETs. I had one of mine do this, and then killed two replacement modules experimenting with repairs/mods.
I don't know what the failure mode is, but when this happens the output FETs end up fried as well. It seems a bad module can kill the FETs and vise versa; a vicious cyle.
If you want to repair it, you need to replace the blown FETs and the module.
I purchased some spare modules from Rodin Audio a year or so ago; they were $42.32 each + postage. If you want to see if they are still available you can try calling (800) 950-1449 x314. Tell them you have a "Carver Pro ZR-1600" that needs a new TA0104A module.
As for FETs, I would replace them with IRFP4227.
If repairing it isn't worth it for you I might want to purchase it.
EDIT: Oops, I guess I read your last post wrong. So it's working now?
When the light is green it means the amp is in protection mode (or it's dead). The only time I had that fuse blow is when mine self destructed, so that's why I assumed the same for yours.
I don't know what the failure mode is, but when this happens the output FETs end up fried as well. It seems a bad module can kill the FETs and vise versa; a vicious cyle.
If you want to repair it, you need to replace the blown FETs and the module.
I purchased some spare modules from Rodin Audio a year or so ago; they were $42.32 each + postage. If you want to see if they are still available you can try calling (800) 950-1449 x314. Tell them you have a "Carver Pro ZR-1600" that needs a new TA0104A module.
As for FETs, I would replace them with IRFP4227.
If repairing it isn't worth it for you I might want to purchase it.
EDIT: Oops, I guess I read your last post wrong. So it's working now?
When the light is green it means the amp is in protection mode (or it's dead). The only time I had that fuse blow is when mine self destructed, so that's why I assumed the same for yours.
Yes, it is working (so far).
I really don't trust it though. I bought a 4 pack of fuses, and blew the first three experimenting. I thought I was on to something when a fuse would stay good when I did not use a cheater plug, and then blew when I did. (Stupid I know, but when I plugged it in without the cheater plug - needed to get rid of a slight ground loop - it worked.)
But now it is running fine (with the cheater plug) so that theory was laid to rest.
I think I am going to blow the six hundred on the emotiva. What would this thing be worth to you? Are you in the States?
I really don't trust it though. I bought a 4 pack of fuses, and blew the first three experimenting. I thought I was on to something when a fuse would stay good when I did not use a cheater plug, and then blew when I did. (Stupid I know, but when I plugged it in without the cheater plug - needed to get rid of a slight ground loop - it worked.)
But now it is running fine (with the cheater plug) so that theory was laid to rest.
I think I am going to blow the six hundred on the emotiva. What would this thing be worth to you? Are you in the States?
Dangnabit.
Stick a fork in it.
Green LED, and no sound. I'm not going to deal with it.
shoot me an offer if Anonamityville is in the States.
If I were real ambitious, it would make a good starting off point to build an amp. The rails are about +/- 74 volts. Dunno how powerful the toroid is though...
Stick a fork in it.
Green LED, and no sound. I'm not going to deal with it.
shoot me an offer if Anonamityville is in the States.
If I were real ambitious, it would make a good starting off point to build an amp. The rails are about +/- 74 volts. Dunno how powerful the toroid is though...
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.