again some pictures
Hi Chris.............twisted the wires😀
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 Chris.............twisted the wires😀
Hi Dean,
Now you see why I'm reluctant to take apart my sound card and start messing with it..... things can happen.
Sorry about your amps I'm sure the guys at 41hz will fix you up with a new chip or two.
BJT, did twisting bring about any improvements in your case?
You guys should give that PSU snubbing a try if you can I've found it very worthwhile on my homebrew amp. Everything sounds perfectly natural on it now, nothing is too complex for it to play well anymore.
Regards,
Chris
Now you see why I'm reluctant to take apart my sound card and start messing with it..... things can happen.
Sorry about your amps I'm sure the guys at 41hz will fix you up with a new chip or two.
BJT, did twisting bring about any improvements in your case?
You guys should give that PSU snubbing a try if you can I've found it very worthwhile on my homebrew amp. Everything sounds perfectly natural on it now, nothing is too complex for it to play well anymore.
Regards,
Chris
Input cable
BGT,
One minor thing to do is to replace the input cable that connects the grounds together and capacitively couples R/L together at HF with 2 separate coaxes. Leave the grounds separate till the connection on the module it’s self. This will substantially improve the HF crosstalk.
I would also like all the details on that electronic transformer you are using. You only need to answer on one thread or the other, your choice. This might be interesting enough to start another thread. These units are available in enough power to run a UcD module or 2.
Thanks
Roger
BGT,
One minor thing to do is to replace the input cable that connects the grounds together and capacitively couples R/L together at HF with 2 separate coaxes. Leave the grounds separate till the connection on the module it’s self. This will substantially improve the HF crosstalk.
I would also like all the details on that electronic transformer you are using. You only need to answer on one thread or the other, your choice. This might be interesting enough to start another thread. These units are available in enough power to run a UcD module or 2.
Thanks
Roger
Re: Input cable
I will do. This is a left over Hypex cable. Roger, thanx also for bringing the twisting of the wires to the foreground.
The electronic transformer is a 150VA one. I think I used 12 turns on 2 coils of 0.8mm wire.
The sound of this amp. is just incredible. If I ask people to listen they think it is a huge amp. and when I show it they say: this sound from this cigarette box, you must be kidding.
I think I have a photo of the 210VA one. Not every elect. transformer is fit for the job. Have some laying around that only oscillate when loaded with at least 50VA.
This is the 210VA one. Going to use it for 2 UCD 180's. 2x13or14 windings.
Power is quite stable a bit like the big toroids. Also shortcut/overload proof.
I coil the wires in a pair so it is difficult to count the turns.
sx881663 said:
I will do. This is a left over Hypex cable. Roger, thanx also for bringing the twisting of the wires to the foreground.
The electronic transformer is a 150VA one. I think I used 12 turns on 2 coils of 0.8mm wire.
The sound of this amp. is just incredible. If I ask people to listen they think it is a huge amp. and when I show it they say: this sound from this cigarette box, you must be kidding.
I think I have a photo of the 210VA one. Not every elect. transformer is fit for the job. Have some laying around that only oscillate when loaded with at least 50VA.
An externally hosted image should be here but it was not working when we last tested it.
This is the 210VA one. Going to use it for 2 UCD 180's. 2x13or14 windings.
Power is quite stable a bit like the big toroids. Also shortcut/overload proof.
I coil the wires in a pair so it is difficult to count the turns.
Chris, I think it did. The soundstage is wider. Have to listen more.classd4sure said:
Did snubberizing on them but after 2 hours of trying the sound was still the same. There is 1 underneath that did some good for the whistle.
Re: Electronic transformer
Bert,
The electronic transformer you are using is a very basic model. I would think even greater performance would be achieved with one of the more complex PFC types as this gives you some regulation. When you are winding these it would be useful to use multiple strands in parallel spread out covering the entire core. Keep it to a single layer though. This would improve regulation because of less DC resistance, reduce the heat generated and also reduce the radiated field, all worthwhile goals. If you do try this be sure to cover the primary wires with HV tape first to reduce the chances of a short. Sure wouldn’t want the high voltage to get into the secondarys. Your UcD plan sounds good, please post often and keep us up to date on your progress. Step by step on your changes to the transformer would be very useful.
I do tend to beat on people about twisting the wires. It only costs some time and can be a worthwhile improvement too. Glad to see you did it. Also don’t zip tie the power and output wiring together as this will couple noise across. Try to keep them at right angles to each other.
Roger
Bgt said:
I will do. This is a left over Hypex cable. Roger, thanx also for bringing the twisting of the wires to the foreground.
The electronic transformer is a 150VA one. I think I used 12 turns on 2 coils of 0.8mm wire.
The sound of this amp. is just incredible. If I ask people to listen they think it is a huge amp. and when I show it they say: this sound from this cigarette box, you must be kidding.
I think I have a photo of the 210VA one. Not every elect. transformer is fit for the job. Have some laying around that only oscillate when loaded with at least 50VA.
An externally hosted image should be here but it was not working when we last tested it.
This is the 210VA one. Going to use it for 2 UCD 180's. 2x13or14 windings.
Power is quite stable a bit like the big toroids. Also shortcut/overload proof.
I coil the wires in a pair so it is difficult to count the turns.
Bert,
The electronic transformer you are using is a very basic model. I would think even greater performance would be achieved with one of the more complex PFC types as this gives you some regulation. When you are winding these it would be useful to use multiple strands in parallel spread out covering the entire core. Keep it to a single layer though. This would improve regulation because of less DC resistance, reduce the heat generated and also reduce the radiated field, all worthwhile goals. If you do try this be sure to cover the primary wires with HV tape first to reduce the chances of a short. Sure wouldn’t want the high voltage to get into the secondarys. Your UcD plan sounds good, please post often and keep us up to date on your progress. Step by step on your changes to the transformer would be very useful.
I do tend to beat on people about twisting the wires. It only costs some time and can be a worthwhile improvement too. Glad to see you did it. Also don’t zip tie the power and output wiring together as this will couple noise across. Try to keep them at right angles to each other.
Roger
Re: Re: Electronic transformer
Will keep you updated. I am glued to this forum
😀
I like simplicity if possible. If it works, it works.sx881663 said:
Will keep you updated. I am glued to this forum
😀
Chris, blowing up things is the downside of DIY....
Bert, what snubber arrangement did you try?
Jan has already replied to my email with an offer for more chips at a reasonable price. Great service from 41Hz and great amp modules. I'll order them right away as I listen to this amp a couple of hours a day - much more than my main setup.
Regards,
Dean
Bert, what snubber arrangement did you try?
Jan has already replied to my email with an offer for more chips at a reasonable price. Great service from 41Hz and great amp modules. I'll order them right away as I listen to this amp a couple of hours a day - much more than my main setup.
Regards,
Dean
A lot of Carlos suggestions as I think he's the snubber king. I absolutely believe his view on snubberizing. But I think it differs per amp.deandob said:
Jan is a very nice guy.
BTW changed the input wiring on the AMP1B.
Update
There was a fair bit of interest in this thread when I originally posted, so I thought I'd post an update.
I blew up 2 x AMP1 modules trying to get rid of an annoying whistle in the bridged AMP1 used to drive my subwoofer for this 2.1 setup. I tried to replace the TA2022 chips on both boards but due to the tight spacing on the board it was difficult not to inflict damage and when I powered them back up only one of them worked.
However in my last order to Jan I bought an AMP3 just for fun, given all the hype about T-amps and the AMP3 is suppost to sound better than the T-amp (and have more power @ 2 x 25w). So the working AMP1 is used as the subwoofer amp in bridged mode and I assembled the AMP3 to give it a spin.
Now I thought I was pretty good at soldering having soldered for 25 years but this little puppy really was difficult to do as the AMP3 TA2021 spacings are so close together. However it worked first time and the comparison with the AMP1 is that it has better mid and top end (not as harsh) but perhaps not quite the same ability to properly represent complex passages. As I use an active filter to remove the signal below 100Hz the power difference between the AMP1 and AMP3 does not make a difference in my setup.
What is interesting is that after running the AMP3 for a couple of weeks, I decided to play around with the power supply to the AMP3. For the original AMP3 power supply I wound enamelled wire around my 300vA toriod (used for the AMP1) to give me 13VAC, schottky bridge with snubber caps, 4 x Panasonic FM 2,200uF caps passing though a LM1585 regulator (with a bypass cap on the Vadj leg which lowers its noise) and a 1,000uF FM cap. Good results but apart from a smoother top end I think the AMP1 was slightly better.
I thought this time I'd try the gainclone approach of smoothing caps close to the module and snubber. Using 3 x 1,000uF FM caps and snubber of 100nF in parallel with 2uF + 0.5 ohms mounted next to the AMP3, I'm amazed at the difference that this tweak makes. The AMP3 sounds better than I remember the AMP1 did, it has no problems with separating instruments in complex passages, dynamic range and soundstage has improved, and its clearer when playing louder. Now I'm not sure if its the extra low ESR of FM caps in parallel next to the module or the effect of the snubber, but this is a worthwhile tweak.
The subwoofer power supply (dual bridge with 10 x 2,200uF Panasonic FC per side) already had a similar snubber
Another tweak that worked for me was replacing all the AMP3 & AMP1 electros with Panasonic FM caps. I can't compare what the AMP3 sounded like without the FM caps, but the bass is more solid on the AMP1 with them.
I think I've got about as much as I'm going to get out of the amp, the next thing I'm looking at is upgrading the Tang Band 871 monitor speakers to the new Ted Jordan JXR6 (2" similar to the TB but better distortion figures).
Oh, I still have the 2Khz whistle from the bridged AMP1 module......
Regards,
Dean
There was a fair bit of interest in this thread when I originally posted, so I thought I'd post an update.
I blew up 2 x AMP1 modules trying to get rid of an annoying whistle in the bridged AMP1 used to drive my subwoofer for this 2.1 setup. I tried to replace the TA2022 chips on both boards but due to the tight spacing on the board it was difficult not to inflict damage and when I powered them back up only one of them worked.
However in my last order to Jan I bought an AMP3 just for fun, given all the hype about T-amps and the AMP3 is suppost to sound better than the T-amp (and have more power @ 2 x 25w). So the working AMP1 is used as the subwoofer amp in bridged mode and I assembled the AMP3 to give it a spin.
Now I thought I was pretty good at soldering having soldered for 25 years but this little puppy really was difficult to do as the AMP3 TA2021 spacings are so close together. However it worked first time and the comparison with the AMP1 is that it has better mid and top end (not as harsh) but perhaps not quite the same ability to properly represent complex passages. As I use an active filter to remove the signal below 100Hz the power difference between the AMP1 and AMP3 does not make a difference in my setup.
What is interesting is that after running the AMP3 for a couple of weeks, I decided to play around with the power supply to the AMP3. For the original AMP3 power supply I wound enamelled wire around my 300vA toriod (used for the AMP1) to give me 13VAC, schottky bridge with snubber caps, 4 x Panasonic FM 2,200uF caps passing though a LM1585 regulator (with a bypass cap on the Vadj leg which lowers its noise) and a 1,000uF FM cap. Good results but apart from a smoother top end I think the AMP1 was slightly better.
I thought this time I'd try the gainclone approach of smoothing caps close to the module and snubber. Using 3 x 1,000uF FM caps and snubber of 100nF in parallel with 2uF + 0.5 ohms mounted next to the AMP3, I'm amazed at the difference that this tweak makes. The AMP3 sounds better than I remember the AMP1 did, it has no problems with separating instruments in complex passages, dynamic range and soundstage has improved, and its clearer when playing louder. Now I'm not sure if its the extra low ESR of FM caps in parallel next to the module or the effect of the snubber, but this is a worthwhile tweak.
The subwoofer power supply (dual bridge with 10 x 2,200uF Panasonic FC per side) already had a similar snubber
Another tweak that worked for me was replacing all the AMP3 & AMP1 electros with Panasonic FM caps. I can't compare what the AMP3 sounded like without the FM caps, but the bass is more solid on the AMP1 with them.
I think I've got about as much as I'm going to get out of the amp, the next thing I'm looking at is upgrading the Tang Band 871 monitor speakers to the new Ted Jordan JXR6 (2" similar to the TB but better distortion figures).
Oh, I still have the 2Khz whistle from the bridged AMP1 module......
Regards,
Dean
New setup
Dean,
Glad to hear you are making progress. I did some checking and didn’t find an easy way of syncing the 2 amp 1 channels together in bridge mode. I am sure it can be done some way but I am reluctant to try anything as the amp 1 I have on hand is a customers. Maybe someone else can help.
2 things to consider upgrading, the output inductor and the output filter cap. From a recent experience I had with a UcD amp I now realize how important these output caps are to overall sound quality. Still haven’t received the new Auricaps but even the standard wire lead ones are a significant improvement at the cost of more EMI.
Roger
Dean,
Glad to hear you are making progress. I did some checking and didn’t find an easy way of syncing the 2 amp 1 channels together in bridge mode. I am sure it can be done some way but I am reluctant to try anything as the amp 1 I have on hand is a customers. Maybe someone else can help.
2 things to consider upgrading, the output inductor and the output filter cap. From a recent experience I had with a UcD amp I now realize how important these output caps are to overall sound quality. Still haven’t received the new Auricaps but even the standard wire lead ones are a significant improvement at the cost of more EMI.
Roger
Thanks Roger.
Are you saying that the whistle could be caused by different carrier frequencies for the two on board AMP1 modulators?
I think I'll try putting a low pass filter on the input of the bridged AMP1 internal op amps as everything else I have tried to remove the annoying whistle does not work. I dont get a peep out of the AMP3, completely silent.
I have my multichannel UCD amp waiting to be assembled and I want to do the CRD mod, replace the 2136 op amp with the AD8620 add a better regulated power supply for the op amp and use an auricap for the output filter (if they ever get made - Those auricaps are taking their time 😀).
Based on the positive experience of using a power supply snubber for the AMP3 tripath I'll definitely try it with the UCD supply.
Regards,
Dean
Are you saying that the whistle could be caused by different carrier frequencies for the two on board AMP1 modulators?
I think I'll try putting a low pass filter on the input of the bridged AMP1 internal op amps as everything else I have tried to remove the annoying whistle does not work. I dont get a peep out of the AMP3, completely silent.
I have my multichannel UCD amp waiting to be assembled and I want to do the CRD mod, replace the 2136 op amp with the AD8620 add a better regulated power supply for the op amp and use an auricap for the output filter (if they ever get made - Those auricaps are taking their time 😀).
Based on the positive experience of using a power supply snubber for the AMP3 tripath I'll definitely try it with the UCD supply.
Regards,
Dean
Amp1 and UcD
Dean,
I am sure it is a long story as to why the caps are taking so long, I haven't heard it yet.
It is my understanding that the 2 amp 1 channels do not sync together as they are frequency modulated to some degree by the program content and power being delivered. It might also be a beat frequency from interference with the SMPS being used. Worth trying different decoupling schemes as well as the snubber. I have found a lot of noise feeds through if you don’t use a cap between the power supply and the amp. I use 10,000uf and am getting great sound. These are not premium parts but ones like you would find in a high power SMPS. I think they are Nichicon 105 deg parts.
The UcD amps already are snubberized so won’t benefit much from more. The last ones I ordered were with the standard opamps so I could experiment and compare to earlier ones that had the 8620’s installed. I am trying the LM6172’s first as I have liked their sound in other applications. The first problem was a huge amount of DC offset and required coupling the – input through the same value 2.2uf Auricap as the + input to balance the input circuits at DC. This lead to less than 20 MV offset for both channels, that will work. Cost of adding another cap is as expensive as a premium opamp so it all evens out.
I plan on listening to them in the CES system this weekend. (CES, what a trip, but that’s another story altogether, will send you pictures when I get them)
Roger
Dean,
I am sure it is a long story as to why the caps are taking so long, I haven't heard it yet.
It is my understanding that the 2 amp 1 channels do not sync together as they are frequency modulated to some degree by the program content and power being delivered. It might also be a beat frequency from interference with the SMPS being used. Worth trying different decoupling schemes as well as the snubber. I have found a lot of noise feeds through if you don’t use a cap between the power supply and the amp. I use 10,000uf and am getting great sound. These are not premium parts but ones like you would find in a high power SMPS. I think they are Nichicon 105 deg parts.
The UcD amps already are snubberized so won’t benefit much from more. The last ones I ordered were with the standard opamps so I could experiment and compare to earlier ones that had the 8620’s installed. I am trying the LM6172’s first as I have liked their sound in other applications. The first problem was a huge amount of DC offset and required coupling the – input through the same value 2.2uf Auricap as the + input to balance the input circuits at DC. This lead to less than 20 MV offset for both channels, that will work. Cost of adding another cap is as expensive as a premium opamp so it all evens out.
I plan on listening to them in the CES system this weekend. (CES, what a trip, but that’s another story altogether, will send you pictures when I get them)
Roger
Roger,
You are right, the tripath chip does adjust the relative frequencies to avoid whistles.
The problem is with the onchip 10v buck converter, the whistle frequency changes when I bring a metal object near the VN10 coil and it lowers if I increase the capacitance of the VN10 filter cap. So I dont think its a grounding problem or an interference problem. This is the third bridged AMP1 module I have built and they all suffered from this whistle, and others have reported similar in bridged mode, but I will try playing with snubbers on the AMP1 board.
Keep us informed about your UCD tweaks (opamps, auricaps etc). Did you purchase a new system at CES?
Regards,
Dean
You are right, the tripath chip does adjust the relative frequencies to avoid whistles.
The problem is with the onchip 10v buck converter, the whistle frequency changes when I bring a metal object near the VN10 coil and it lowers if I increase the capacitance of the VN10 filter cap. So I dont think its a grounding problem or an interference problem. This is the third bridged AMP1 module I have built and they all suffered from this whistle, and others have reported similar in bridged mode, but I will try playing with snubbers on the AMP1 board.
Keep us informed about your UCD tweaks (opamps, auricaps etc). Did you purchase a new system at CES?
Regards,
Dean
Way off topic!
Dean
This is way off topic but no, we used the main Audience system and I was recruited to work in the room. We had some excellent UcD sound working for us.
Roger
Dean
This is way off topic but no, we used the main Audience system and I was recruited to work in the room. We had some excellent UcD sound working for us.
Roger
Dean, strange you have so much whistle from the 1B, after all the mods. I made to the power supply connections, see pics from earlier posts, it sounds really nice. I am busy now building an amp. with the "coldamp" and the Amp 2 of 41hz.
Will try and listen carefully again to the 1B's whistle.
Will try and listen carefully again to the 1B's whistle.
Thanks Bert. I'd welcome any ideas you have.
I tried different supply decoupling, shielding etc. I'm convinced its a beat caused by the VN10 supply as placing metal near the VN10 coil or changing the filter adjusts the frequency.
Regards,
Dean
I tried different supply decoupling, shielding etc. I'm convinced its a beat caused by the VN10 supply as placing metal near the VN10 coil or changing the filter adjusts the frequency.
Regards,
Dean
Hello, Bert.
Where did you get that small switching power supply?
BTW: Nice to hear that you are also evaluating coldamp modules. I have also bought a couple of them and they sound excellent!
(I built them into a case with a single LPS30 power supply from them and a 625VA transformer. The modules are just side by side and no whistles at all).
Where did you get that small switching power supply?
BTW: Nice to hear that you are also evaluating coldamp modules. I have also bought a couple of them and they sound excellent!
(I built them into a case with a single LPS30 power supply from them and a 625VA transformer. The modules are just side by side and no whistles at all).
Dean, bypassing the VN10 supply is for the whistle and bypassing the powerline input plug for the noise level.
I used a 1000uF/16V FC cap. for the VN10 supply. The orange MKT cap is 10uF/100V. That did the trick and I must say it still is a very quiet amp, maybe because of the electronic transformer from Conrad(Pierre). It is really difficult to hear a whistle, even with high effiency speakers.
Pierre, when I finish the "coldamp", still waiting for a housing, I will post here. I dont use the manufacturers PSU.
I used a 1000uF/16V FC cap. for the VN10 supply. The orange MKT cap is 10uF/100V. That did the trick and I must say it still is a very quiet amp, maybe because of the electronic transformer from Conrad(Pierre). It is really difficult to hear a whistle, even with high effiency speakers.
Pierre, when I finish the "coldamp", still waiting for a housing, I will post here. I dont use the manufacturers PSU.
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