I think that the different offsets are due to differences between components from the channel's inputs, I don´t see problems with these values.
The standby currents are a little low... adjust as this text from Greg´s site:
DX Blame ST Adjustments
Remind: The 100 ohms series resistors must be mounted in parallel with the fuses sockets.
After that, put back the fuses, connect a speaker, a sound source and enjoy it.
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Thanks guys. The standby current I quoted was actually the current across output transistors measured across R26 and R27. The rail standby current across 100ohm resistors before connecing fuses was somewhere between 70 and 100mA as shown in one of Carlos's youtube videos.
Hi,
those two methods are the correct way to measure Iq (quiescent current of the amplifier) and Ib of output (the output stage bias currents).
They are two quite different values and require different measurement techniques.
those two methods are the correct way to measure Iq (quiescent current of the amplifier) and Ib of output (the output stage bias currents).
They are two quite different values and require different measurement techniques.
At first there wasn't install anything for C1 and there was only a shy bass.About the -3dB response of the speaker that I don't know tried the amplifier with vintage speakers the B&W-DM14
First impressions
That's quite obvious....IF the program contains it.
I was surprised to find that not all contemporary music for instance, has much below around 75 Hz. Apart from that, you can't really hear below 50 Hz anyway..you feel it transmitted through furniture and your own bone structure. The notion that Bel sound intensity relationships apply to skeletons is perhaps too simplistic.
The issue with this filter is that it is there to block DC, not define frequency response. Its influence, if any, is minimised by ensuring that its roll-off is well out of band..as here...3HZ! 😎
Ah!........No wonder we are confused. That leaves just the parallel 100 nF cap and a roll-off frequency of about 300 Hz. Yes, no bass at all I'd say!!
That's quite obvious....IF the program contains it.
I was surprised to find that not all contemporary music for instance, has much below around 75 Hz. Apart from that, you can't really hear below 50 Hz anyway..you feel it transmitted through furniture and your own bone structure. The notion that Bel sound intensity relationships apply to skeletons is perhaps too simplistic.
The issue with this filter is that it is there to block DC, not define frequency response. Its influence, if any, is minimised by ensuring that its roll-off is well out of band..as here...3HZ! 😎
whoa , can't hear below 50Hz !! 😉 News to me !! So you say 50 hz can not be heard as a harmonics free sine tone. I concede that at high sound pressure levels your body has it's place in augmenting what a 50hz tone conveys but the tone itself is well within the easily heard audio range.
Below 30hz , this might be "more true", as the room is a greater factor in perception of this tone , but even here I can easily hear a 30hz pure sine signal as a distinct tone (with headphones).
OS
Hi Os
Hang onto those ears! Actually only said "not below 50 Hz".
I know the figures quoted in standards say 20-20KHz human hearing limits but according to controlled low SPL experiments in a uni. lab. way back when, the best in our group was a girl who got down to 32 Hz and something phenomenal like 22 KHz upper limit. The average lower limit sensitivity by the test method was 45Hz or so. That was standing at the end of a quiet corridor and responding to distant tones between 15 and 80 Hz at so many dB. I think. Well, I know I can't hear much from a Velodyne 18" sub at 30 Hz, but I can sure feel the thing and the rush of noise as everything vibrates in the room(s). At 50 Hz I do certainly hear the tone in my ear as fully dominant. Below that is an increasingly vague mix of uncertainty to some point where everything just randomly shakes at 25 Hz or thereabouts. It's not a large frequency range really, F0 -> F0/2.
Hang onto those ears! Actually only said "not below 50 Hz".
I know the figures quoted in standards say 20-20KHz human hearing limits but according to controlled low SPL experiments in a uni. lab. way back when, the best in our group was a girl who got down to 32 Hz and something phenomenal like 22 KHz upper limit. The average lower limit sensitivity by the test method was 45Hz or so. That was standing at the end of a quiet corridor and responding to distant tones between 15 and 80 Hz at so many dB. I think. Well, I know I can't hear much from a Velodyne 18" sub at 30 Hz, but I can sure feel the thing and the rush of noise as everything vibrates in the room(s). At 50 Hz I do certainly hear the tone in my ear as fully dominant. Below that is an increasingly vague mix of uncertainty to some point where everything just randomly shakes at 25 Hz or thereabouts. It's not a large frequency range really, F0 -> F0/2.
Yes, i know Carlos schematic, since i made some sims
to see how it works.
I may not be agree with some of his implementations,
but not to the point of vilifying him...
I for one look forward to his return, it is a duller forum without Carlos.
I wouldn't have the amp I am listening to now without him.
John
I wouldn't have the amp I am listening to now without him.
John
Hi Ian.
I don't think I am any more welcome than anyone else that comes with good intent and builds something.
I read but seldom post. My knowledge is poor compared to the mighty intellects around here. I understand more now than I did before I started reading Carlos mindst.
John
I don't think I am any more welcome than anyone else that comes with good intent and builds something.
I read but seldom post. My knowledge is poor compared to the mighty intellects around here. I understand more now than I did before I started reading Carlos mindst.
John
I am about to start testing my Dx Blame ES with the red PCBs 🙂
I heard a nice song that I could not find any where:
YouTube - Audio amp Dx TriAmp triple power
Carlos no longer has this song, neither able to remember its name or the singer's name. Help is appreciated on this one!
I heard a nice song that I could not find any where:
YouTube - Audio amp Dx TriAmp triple power
Carlos no longer has this song, neither able to remember its name or the singer's name. Help is appreciated on this one!
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Metal it looks very nice.
Did start building the other board and having an update about the first reduced the DC offset it's now zero
Did start building the other board and having an update about the first reduced the DC offset it's now zero
meanman, I built the ES version of this amplifier. I measured around 10mV of DC offset, this is OK with me. I calibrated mine to 25mA quiescent current, this is fair enough for me as well.
I ran both channels, they worked on the first run, no problems, no oscillation and no heat problems, this has been an amazing experience that an amplifier with many components runs first time connected to the mains. Honestly, did not spend much time checking what I soldered!
They are very very very silent, even when I am not connecting them to any source, they are deadly silent!
This is best DIY amplifier I heard indeed. Highly detailed rich highs, excellent mids and bass is just fair n OK with me. I did not expect this DIY amplifier to be so good, it deserves every penny I paid for it, even the two months of PCB art work I spent with Rudi on it. What makes me even happier is that I can go to the ST version in no time! But I dun think I will go there, I am happy with the ES version, and it is stable!
Making the angled heatsinks and drilling them was the best part of it, it was not easy to drill them manually as they are 4mm in thickness. I used bigger bolts, 3.81mm, so I had to drill both, the output transistors and PCBs, it was real fun!
The smaller heatsinks were the ones I left space for, and they exactly fit, very nice indeed, very nice, I like them so much. The transistors TO-92 spacers are from Farnell, the order code for them is 519960 for those interested in making their amplifiers look neat and beautifully assembled.
Still I got to wind the output coils now!
I hope you are enjoying your amplifier meanman, it's damn good, thanks to Carlos, whom we are waiting to come back, impatiently! I hate this sinbin thingy...
regards
I ran both channels, they worked on the first run, no problems, no oscillation and no heat problems, this has been an amazing experience that an amplifier with many components runs first time connected to the mains. Honestly, did not spend much time checking what I soldered!
They are very very very silent, even when I am not connecting them to any source, they are deadly silent!
This is best DIY amplifier I heard indeed. Highly detailed rich highs, excellent mids and bass is just fair n OK with me. I did not expect this DIY amplifier to be so good, it deserves every penny I paid for it, even the two months of PCB art work I spent with Rudi on it. What makes me even happier is that I can go to the ST version in no time! But I dun think I will go there, I am happy with the ES version, and it is stable!
Making the angled heatsinks and drilling them was the best part of it, it was not easy to drill them manually as they are 4mm in thickness. I used bigger bolts, 3.81mm, so I had to drill both, the output transistors and PCBs, it was real fun!
The smaller heatsinks were the ones I left space for, and they exactly fit, very nice indeed, very nice, I like them so much. The transistors TO-92 spacers are from Farnell, the order code for them is 519960 for those interested in making their amplifiers look neat and beautifully assembled.
Still I got to wind the output coils now!
I hope you are enjoying your amplifier meanman, it's damn good, thanks to Carlos, whom we are waiting to come back, impatiently! I hate this sinbin thingy...
regards
I did not even use a toroid. A couple of months ago, I put my hands on a 24x2 EI Japanese transformer rated at 240 watts and I am using it with the two Dx Blame ES channels. This is more than enough for me, as you can see, we are not going to party with it. For moderate listening levels, this serves just excellent.
I am also working on my version of a PIC based speaker protector that is based on Rode Elliott's design, I am almost done with it, simulations show amazing fast response!
I am also working on my version of a PIC based speaker protector that is based on Rode Elliott's design, I am almost done with it, simulations show amazing fast response!
No, when we placed the order, we knew in advance how many PCBs to order upon the number of those interested in our PCB. I tried to get an extra couple of PCBs, but was unlucky as Rudi was so much tied to the number of members interested in the PCB.
The PCB quality is excellent. I have already unsoldered many parts, especially the TO-92 transistors because I for got to use the spacers, also unsoldered many resistors and capacitors, this PCB was capable of overcoming harsh unsoldering process indeed, it was on purpose to see how good it is, and it turned out to be excellent. The good thing is that pads are large, soldering was fun with this PCB.
The PCB quality is excellent. I have already unsoldered many parts, especially the TO-92 transistors because I for got to use the spacers, also unsoldered many resistors and capacitors, this PCB was capable of overcoming harsh unsoldering process indeed, it was on purpose to see how good it is, and it turned out to be excellent. The good thing is that pads are large, soldering was fun with this PCB.
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