@OnAudio. You open bom etc for first preliminary design version for 48 hours. Why time-limited? That could indicate that you want a business venture, and would like free ingeneering work from this community. On the other hand, I can understand the name Studio grade since threads with fancy naming gets more views. Just look in pass section.
So are you trying to make a commercial design or are you just asking advice about your (a bit overadvertised?) Hobby design.
Cheers to all!
So are you trying to make a commercial design or are you just asking advice about your (a bit overadvertised?) Hobby design.
Cheers to all!
If you believe someone is threatened by your unproven designs, you must be smoking some really hard stuff. 🙄
As pointed out, there is an incredible number of proven designs here, with the real-world measurement results and listening impressions.
You are free to believe that your designs are the best, but for others to take a note, you have to provide some hard evidence.
Can you clarify what is special about this amplifier schematics, it looks like standard symmetrical differential amplifiers and compensation, enhanced cascode VAS, VBE and triple emitter ouput stage… Although , having active load in symmetrical differential stage might prove difficult to achieve to have a well defined stable bias for next stage…..maybe I have overlooked something…. 🤔 In fact, it is way it is shown b/c of the multiple connecting points….
Also, I did not know that recording studio needed a so powerful amplifier (+/-60VDC, triple emiiter, double output). I thought that monitor studio speakers are not so demanding for amplifier (slew rate is not an issue)? Maybe someone can educate me….
Or maybe there is no claim but it is just another project for Diy?
Fab
Also, I did not know that recording studio needed a so powerful amplifier (+/-60VDC, triple emiiter, double output). I thought that monitor studio speakers are not so demanding for amplifier (slew rate is not an issue)? Maybe someone can educate me….
Or maybe there is no claim but it is just another project for Diy?
Fab
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I’m relatively new to power amplifier design, but not general analogue/RF design, and certainly not circuit simulation. I would be really keen to know if this amplifier has actually been built and tested, as the biassing on Q4 and Q12 looks, um, poorly designed. The closed-loop will ensure that their collector currents are the same, but nothing defines what it actually is. The simulator will put conductances on all nodes to get DC OP information but they won’t be present in reality, so some real surprises could be waiting there. Which is why I ask if the amplifier has been built.
The renders presented don’t seem to match the schematic - there are trimmers and fuses in the render but not the schematic, again things that will materially affect circuit operation. If I had a penny for every schematic I’ve seen that uses ideal voltage sources for supplies and ideal grounds, where the circuit didn’t work when built, I would be retired, living on a sun-drenched beach.
I’m not saying this amplifier doesn’t work, but I think it is fair to say that insufficient evidence has been presented so far to not have some caution. Which is why the question about if it has been built…
The renders presented don’t seem to match the schematic - there are trimmers and fuses in the render but not the schematic, again things that will materially affect circuit operation. If I had a penny for every schematic I’ve seen that uses ideal voltage sources for supplies and ideal grounds, where the circuit didn’t work when built, I would be retired, living on a sun-drenched beach.
I’m not saying this amplifier doesn’t work, but I think it is fair to say that insufficient evidence has been presented so far to not have some caution. Which is why the question about if it has been built…
Most studio speakers these days are active, having direct digital (and analog) inputs from the consoles.
Jan
Jan
Who is the greater fool? The fool or the fool who argues with him?
On page 200 of Cordell’s book he says of the complementary ips with current mirrors he states “This is not a practical and reliable circuit.” Self also makes the same observation. Self tried a simpler circuit, but there remained some stability issues. Cordell’s suggestion is to add complexity and adds another two transistors and four resistors which does allow for the setting of VAS bias current at the cost of some loss of gain and increased offset voltage. I would not proceed with this until those input stage issues are addressed as mentioned also by the previous posters.
There is a certain aesthetic appeal in the symmetry of this input stage, but in practice it doesn’t work well apparently.
I think this is what ostripper was talking about when he described the circuit as “touchy”! 🙂
There is a certain aesthetic appeal in the symmetry of this input stage, but in practice it doesn’t work well apparently.
I think this is what ostripper was talking about when he described the circuit as “touchy”! 🙂
We talked about the stability of the VAS current in OnAudio's "Not Blameless" thread.
A successful design needs tight tolerance of the gain in its two complementary halves. In practice, that requires keeping the gain relatively low.
Ed
A successful design needs tight tolerance of the gain in its two complementary halves. In practice, that requires keeping the gain relatively low.
Ed
I respect all the views and freedoms of speech within the forums by laws aired so far. Thanks for making this forum great. Birds of a feather flock together and all that goes with that. Were all here to learn, adventure and whet our audio appetites. Why would I hold out on you? In the spirit of great diyaudioship the gerbers and schematics are now available for an extra week. Check post 1. Am I that other author?
What is anything, anything is whatever you call it. That's the power of narratives and stereotypes. Given a set of equally functional items, the one that will become popular will be based on a winning narrative. That's why your personality type impacts your success in life. The observer and the effect are co-joined. Fashion is driven by a narrative, looking fashionable over time has been changed by a narrative. Even wars are narrative driven. Just like the intelligent synthetic machines we are building to create nirvana on earth, human consensus is gradient driven. A very smartly dressed person on stepping out of the house, if they are told they are shabby, once this though is implanted they will start feeling shabby and start acting shabby no matter what they are told later on in the day. They start projecting their implanted fears onto others and others start seeing them as shabby. It becomes worse if the first narrative is reinforced anywhere within the day by another observer. It becomes a steep descent. It may not necessary work this way and may work out the opposite way and will depend on the personality type. A shabby dressed person on stepping out of the house if they are told how smartly dressed they are, they will feel and act smartly no matter what they are told later on in the day. Later observers will be co-erced through telepathy to agree on the smartness although a non infected observer may tend to disagree. As we said anything is whatever you call it. Just like synthetics, biologicals are also highly programable.
Deep 😉
I think the art should stay solely in the music and non in the reproduction system. I don't want the reproduction systen to distort the message of the art - it should be presented as the artist intended - not how a reproduction unit designer want it.
I agree on your observations but I suppose you present it as an analogy to amp design - as such, it is not a good one as I see it.
//
I think the art should stay solely in the music and non in the reproduction system. I don't want the reproduction systen to distort the message of the art - it should be presented as the artist intended - not how a reproduction unit designer want it.
I agree on your observations but I suppose you present it as an analogy to amp design - as such, it is not a good one as I see it.
//
I dont know… I’d still be doing something - even if it was just limited to putting prototypes together on a perf board and leaving it sprawled out on the kitchen table/desk.
Rules were meant to be broken. What are they going to do? Kick out the one tenant that actually pays his rent?
Rules were meant to be broken. What are they going to do? Kick out the one tenant that actually pays his rent?