But you end up with a product which would cost £ 000 at retail for an outlay of £ 00
No can of worms. Even though it's not an issue with the M-86, it can make a difference with some designs, and it's easy enough to identify the outer foil side and mark it when a new batch of parts arrives in the quantities we DIY'ers are most likely to have arrive. Costs nothing, why not do it?
Maybe not the best thread to deal with it, Tom is a little sensitive to construction complications that might imply his M-86 is not easy for a novice to build using only the instructions he provides.
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Maybe not the best thread to deal with it, Tom is a little sensitive to construction complications that might imply his M-86 is not easy for a novice to build using only the instructions he provides.[/QUOTE]
to be fair i found the instructions a breeze it was only the anal retentive in me that just had to ask
to be fair i found the instructions a breeze it was only the anal retentive in me that just had to ask
The original question was perfectly valid. The discussion that followed was a distraction to say the least. It was also utterly irrelevant to the Modulus-86. Interesting. But irrelevant.
You are absolutely right that I do not want people to get the impression that the Modulus-86 is difficult to build or requires any sort of special dowsing of components. As you point out, the Modulus-86 comes together pretty easily if you follow the instructions.
Neurochrome is my only source of income - by choice. I'm not getting rich and famous selling to the DIY market, but I believe I have potential to grow. However, for me to grow I need to focus on activities that are aligned with growth. Having to debunk myths via email before a sale is not conducive to growth. Losing sales because someone develops the impression that my products are difficult to assemble or based in nonsense is not conducive to growth either.
So, yes. I am a little sensitive to the messaging around my products. That's part of owning a business.
Tom
You are absolutely right that I do not want people to get the impression that the Modulus-86 is difficult to build or requires any sort of special dowsing of components. As you point out, the Modulus-86 comes together pretty easily if you follow the instructions.
Neurochrome is my only source of income - by choice. I'm not getting rich and famous selling to the DIY market, but I believe I have potential to grow. However, for me to grow I need to focus on activities that are aligned with growth. Having to debunk myths via email before a sale is not conducive to growth. Losing sales because someone develops the impression that my products are difficult to assemble or based in nonsense is not conducive to growth either.
So, yes. I am a little sensitive to the messaging around my products. That's part of owning a business.
Tom
in fact the only small gripe i had with instructions was with winding the inductor which was not easy for me until i used some tape to hold one end of the magnet wire to the battery otherwise it kept slipping and then the other end of the wire to a door hook then i pulled gently on the battery as i turned it to get nice tight loops also a bit of decorators tape round the inductor holds it all together and makes it easy to solder
Hi Tom,
I was reading through the specs looking for input impedance (need it to make some decisions on my DAC output stage) and found a slew rate row. I know it’s probably a very basic question for most of you in the forum but could you please explain what does that mean/ use for? I’d really appreciate
I was reading through the specs looking for input impedance (need it to make some decisions on my DAC output stage) and found a slew rate row. I know it’s probably a very basic question for most of you in the forum but could you please explain what does that mean/ use for? I’d really appreciate
The slew rate tells you how fast the amplifier output is able to respond to an abrupt change in the input voltage. The Modulus-86 is spec'ed at 14 V/us (or 14*106 V/s).
You can use this to calculate the highest frequency the amplifier can reproduce without slew-rate limiting:
fmax = SR / (2*pi*Vout_max)
So in case of the Modulus-86:
fmax = 14*106 / (2*pi*28) = 79577 Hz = 79.6 kHz, assuming 28 V maximum output swing.
You may find this informative: http://web2.uwindsor.ca/courses/engineering/ahmed/EE226/Lecture Notes/7. Slew Rate.pdf. If the math goes woosh over your head, don't panic. Just look at the graphs and read the text.
Now for your question regarding the input impedance: 48 kΩ, differential.
Tom
You can use this to calculate the highest frequency the amplifier can reproduce without slew-rate limiting:
fmax = SR / (2*pi*Vout_max)
So in case of the Modulus-86:
fmax = 14*106 / (2*pi*28) = 79577 Hz = 79.6 kHz, assuming 28 V maximum output swing.
You may find this informative: http://web2.uwindsor.ca/courses/engineering/ahmed/EE226/Lecture Notes/7. Slew Rate.pdf. If the math goes woosh over your head, don't panic. Just look at the graphs and read the text.
Now for your question regarding the input impedance: 48 kΩ, differential.
Tom
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Great! I understand now. Thank you.
Very nice indeed, the graphs also help visualize the effect.
Got it. Also in your specs you declare Input Sensitivity of 1.8 V RMS. Does Input sensitivity relate in any way to Input impedance? Also, even dumber question surely, is that 1.8V RMS a max or a min? (ie does my DAC need to provide that 1.8V exactly, less, or more V)
Thank you again for the hand-holding on this journey. I'm really learning a lot.
The input sensitivity is the voltage needed to drive the amplifier to its maximum specified output power into 8 Ω. 1.8 V in -> 40 W out. It does not depend on the input impedance.
It is the highest input voltage that will result in a clean output under the conditions listed in the spec table. If you provide more, the amp will clip.
There's no harm in using a DAC that can provide more than 1.8 V. I've used my MiniDSP 4x10HD to drive my 4xMOD86 amp for years. It provides 4.0 V. All that means is that I'll have to dial the DAC down by 6 dB if I'm playing a track that's recorded at 0 dBFS and I want to avoid clipping (and I want to blow my ears with very, very loud music).
No worries. I suspect you're not the only one with these sorts of questions.
Tom