Roger, this is the thread Eric (bdp24) is referring to:
https://forum.audiogon.com/discussions/st-70-best-sounding-version
Regards,
-- Al
https://forum.audiogon.com/discussions/st-70-best-sounding-version
Regards,
-- Al
Does anyone care to ask an amplifier designer a technical question? My door is open.
I closed the cable and fuse thread because the trolls were making a mess of things. I hope they dont find me here.
I design Tube and Solid State power amps and preamps for Music Reference. I have a degree in Electrical Engineering, have trained my ears keenly to hear frequency response differences, distortion and pretty good at guessing SPL. Ive spent 40 years doing that as a tech, store owner, and designer.
.
Perhaps someone would like to ask a question about how one designs a successfull amplifier? What determines damping factor and what damping factor does besides damping the woofer. There is an entirely different, I feel better way to look at damping and call it Regulation , which is 1/damping.
I like to tell true stories of my experience with others in this industry.
I have started a school which you can visit at http://berkeleyhifischool.com/ There you can see some of my presentations.
On YouTube go to the Music Reference channel to see how to design and build your own tube linestage. The series has over 200,000 views. You have to hit the video tab to see all.
I am not here to advertise for MR. Soon I will be making and posting more videos on YouTube. I don’t make any money off the videos, I just want to share knowledge and I hope others will share knowledge. Asking a good question is actually a display of your knowledge because you know enough to formulate a decent question.
Starting in January I plan to make these videos and post them on the HiFi school site and hosted on a new YouTube channel belonging to the school.
I design Tube and Solid State power amps and preamps for Music Reference. I have a degree in Electrical Engineering, have trained my ears keenly to hear frequency response differences, distortion and pretty good at guessing SPL. Ive spent 40 years doing that as a tech, store owner, and designer.
.
Perhaps someone would like to ask a question about how one designs a successfull amplifier? What determines damping factor and what damping factor does besides damping the woofer. There is an entirely different, I feel better way to look at damping and call it Regulation , which is 1/damping.
I like to tell true stories of my experience with others in this industry.
I have started a school which you can visit at http://berkeleyhifischool.com/ There you can see some of my presentations.
On YouTube go to the Music Reference channel to see how to design and build your own tube linestage. The series has over 200,000 views. You have to hit the video tab to see all.
I am not here to advertise for MR. Soon I will be making and posting more videos on YouTube. I don’t make any money off the videos, I just want to share knowledge and I hope others will share knowledge. Asking a good question is actually a display of your knowledge because you know enough to formulate a decent question.
Starting in January I plan to make these videos and post them on the HiFi school site and hosted on a new YouTube channel belonging to the school.
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- 845 posts total
can you find the thread. I had no luck. Here you go: https://forum.audiogon.com/discussions/st-70-best-sounding-version/post?highlight=dynaco%2Bst70&... Someone asked about the differences between an RM-10 MkI and MkII so perhaps you can educate them. Also, the OP already uses an RM-10 in their main system and is looking at an ST70 for a secondary system. |
How can some do with so little power and others "think" they need all those watts? Truth is nobody measures and the majority guessing are way off.Some of us both measure and calculate ;-) My 36w PL5 calculates to 93db¹ @ 3.75m with 86db/V²/m speakers. Add in a couple of db crest factor, and I'm outta gas @ 95db peak. Confirmed with scope and RTA. To reach 105db, I'd need 323w for unclipped peaks. 150wpc SS only gets me to ~100db peak because SS clips less gracefully. A 9 watter requires a listening distance of about 1.9m or 92db/V/m loudspeakers. ¹ = room effects ignored ² = 2.83V |
This is also confirmed by graph you presented from Stereophile.The graph shown by Stereophile is correct, and it shows **less than 6dB rise between 500 and 2KHz**. Again, the gradients of the graph are 5dB increments, and at 500Hz is only about 2.5dB down from where it is at 1KHz. And a similar amount up at 2KHz. With regards to the rise above 2Khz; at 20Khz its about a 15db rise; but the disk cutter is not limited to 20KHz so the pre-emphasis goes all the way up until reaching the cutter amp’s bandwidth limit. To prevent phase shift, the playback should have bandwidth with attendant EQ to at least the same frequency and most of them do (and most LOMC cartridges have the bandwidth as well). However, constant amplitude transducers like the strain gauge and ceramic cartridges aren’t properly equalized as you point out unless some additional EQ is applied. This isn’t a problem for most people though (because strain gauge cartridges are so rare that statistically they don’t exist, having so many zeros as significant digits that any numbers to the right of the decimal point that aren’t zeros are probably a figment of someone’s imagination; my respects to Douglas Adams) so really isn’t much of a concern, except for the new strain gauge cartridge guy that thinks he’s going to make a million bucks on his new entry into the market. If he doesn’t have that equalizer sorted out, he likely won’t be selling his cartridge for very long. Panasonic seemed to be the only one that really had this sorted to any degree and even they bailed on it. |
- 845 posts total