@PS Audio PLEASE bring back this series, I'm dying to learn more! Darren is an excellent teacher and I'd love to learn more about building my own phono stage!
Excellent! 👏👏👏 It's refreshing when a company treats their audience with such respect. So many high-end audio vendors take the tack of "the customer wouldn't understand." Thank you PS Audio for reinforcing the reality that your and many other high end proprietors' value lies in being a Swiss watch maker, not merely in telling time, a skill all should possess.
Hi Darren, thanks for stepping up! We appreciate the engineering side of things. I see this is just the start of a whole new video series that can last a long time. Since these are technical subjects please don't dumb it down too much, so that we who are interested can remain interested.
Finally videos to engineer minded people are back... Paul did some while ago but is now doing more faq level videos (which are still great) but I sure missed some diagrams explained on a white board. Great stuff!
After getting my BS in computer science and engineering (sw & hw), I had the inspired idea of getting a masters in EE. First course, linear integrated circuits (op amps). Open book, open note tests. You wouldn't think, given how easy op amps are to use (they are easy, and you can do some magical things with them, buffering the easiest, inversion a close second, amplification a close third, then integration, differentiation, filters...), but it was the hardest course I ever took. Spent 40 hours/week just doing the homework for that one class. Dissuaded me from continuing on with the masters. Major props to the EEs.
Thanks for watching Michael! We have all had courses that we'll never forget. My electromagnetic waves course was very intense but he was easily the best professor I've ever had.
Great video showing how you can go shopping in DigiKey for parts and Amazon for tools and soon have an audiophile phono amp for the parts cost of a BigMac.
I called the other day. I am looking for a phono stage that can reproduce orchestral strings well. I find that a rarely, rarely, rarely, hear the lower strings with the woody boxy resonance of the G and D strings on violins, C and G strings on viola and 'celli. Haven't heard yours yet.
There was definitely something special about P.S. Audio's approach to design that in 1979'ish (in my & many's opinion) made the quietest & best sounding phono-preamp on the market for under £1000 (equivalent to £"loads" today) in their 4.5/hi-current PSU preamplifier which like the Stellar, was fully discreet in it's signal path with 15'ish trannies on each channel. (when vinyl was king & a preamp's phono-stage was the deal maker or breaker) I mostly run a fully tubed 2-chassis phono-stage with step-up trannies but i've heard enough about the Stellar now to re-focus my future upgrade possibility, into (somehow?) trying and possibly liking & buying a Stellar because fully tubed phono-stages are not the quietest, esp' on m.coils, at least in the price-band i could afford. (p.s. those older circa' 1980's P.S. Audio Phono-preamps make dirt-cheap s/h phono-stage bargains & i don't think today's stages could beat them for under a grand after recapping it's psu)
You’re headed in a great direction take this one step further to produce PS audios own line of do it yourself kit and schematics a phono stage,amplifiers, per-amps. Like Nelson Pass provides do it yourself kit with the Pass LABS or First Watt class A sound signature at DIYaudio.com PS Audio should become the guru of class D amps ,schematics and kits simplified for the do it yourself or with the PS audios sound signature but just lower wattage version so not to be in direct competition with your own product. Keep up the technical videos as a continuous series like “ Mr. Carlson’s Lab” on RU-vid. “Blue Glow Electronics” on RU-vid who Mark who teaches construction and repair of tube amplifiers. If you can pull off this caliber nation with your superior knowledge of class D amplifiers having a RU-vid channel and a present online in some of the major audio forms with the PS audio signature series for do it yourself first you’ll probably dominate the class D amplifier builds for high end do it yourself kits and remember these consumers some day by the real product when they can afford it or when friends ask them for suggestions that they usually suggest the manufactures amplifiers that they like building from do it yourself kits to friends and relatives or colleagues guaranteed free advertisement and return consumers for your excellent product line.
Your block diagram implies a passive RIAA EQ. In your next video you may want to touch on the differences between PASSIVE EQ and ACTIVE EQ done in the output driver feedback loop. The reason being there is much controversy in audiophile circles between passive and active phono EQ sound quality differences - or lack there of? Also note that an active EQ does not need to be OPAMP based either. Many legacy tube circuits also employed active feedback based EQ.
Andy Delle - Wouldn’t that be determined on how the vinyl was made? If it was made with a passive RIAA EQ, wouldn’t an active EQ be messing around with the original recording?
Well, there is a nifty thing that is in favor technically speaking for passive RIAA: at the very top end passive keeps on attenuating the highs as it should, active will teethe out at a fixed amplification. Passive is sound-wise better than active to my opinion, which I could, but won't, underpin this with arguments, because that is complicated and more subtle.
:@@Enemji RIAA EQ is RIAA EQ. Passive and active is just how it is done electronically. Both are passive filters, but an active EQ circuit uses the passive filter network within an amplifier feedback loop, like around an OPAMP. A true passive EQ is just an RLC filter network the signal goes through and only uses the amplifier stages as flat gain sections. Beyond that you could also do RIAA EQ digitally with discrete logic chips (a lot of them!), a DSP chip, or just software running realtime on a fast computer. But then I trust no vinyl enthusiast would be caught dead with a digital RIAA EQ setup :)
@@airgead5391 Yes, that's what I read as well. I'm not a vinyl user myself but it does seem that passive RIAA EQ is the most preferred. And it is a bit more expensive to do right. Perhaps that's why active EQ was more popular in lower priced gear.
Great video, hope this ends up in a finished and buildable project. You only use a capacitor on the input to reduce RF, what about using a ferrite cores on the input, maybe together with the capacitor, or are there issues with that idea?
Awesome question. Something I didn't touch on in this video is that fact that that cap also loads the MM cart. 100pF is a typical value. Changing this value (75pF and 200pF are also common) will affect the resonant frequency and damping at high frequency. The cable that you use has to be factored in as well. I've used ferrite beads on MC inputs without any issues but haven't done any listening to them specifically to see how or if they have any sonic impacts. One could theoretically use a ferrite bead on the MM as well but it would be recommended that the impedance of this filter stays relatively low up to 20k.
It has been awhile for me so be gentile if I am wrong, but isn't the opamp equation a linear scale ? 20log(30) = 29.54dB, I mean it works but it can be confusing if you picked a different gain.
Yes, voltage gain and DB gain are in fact different and should be properly calculated. But in the case above they are close enough for illustration. There are countless DB calculators online! No need for math anymore like my generation had to endure.
I am puzzled, are you using 5% resisters or more likely 1%. Your choice of 3k indicates 5% values, but adding 3.3 ohms to 100 ohms doesn't make sense (5% of 100 ohms is 5 ohms). Why would you want to make the gain so precise that a gain of 31 db is not acceptable.
He's not going that deep into details. He's just using convenient numbers for illustration. FWEIW, the precision needs to be in the filter section. Like you observed, if the overall gain is a little off, well that's what the volume control is for.
Hi Jim, I'm attempting to simplify some of the math and stick to a voltage gain of 30 for illustration as Andy has pointed out. Using a single 100 ohm 1% for R1 would be perfectly fine. Concerning the resistor tolerances, tight tolerance resistors are inexpensive today which is why I design the majority of our analog circuitry with .1% thin films. I guess you could call it habit. -Darren
Hi Darren was a pleasure to see your message on Mike F youtube Channel, Audio planet, i'm am an Electronics Engineer with a Passion For Audio , still trying to find my Dream job at middle age , my Passion for Vinyl/ Audio /CD with a electronics knowledge and hobby from mid 1980's , would love to contact you and have a Chat do you have an E-mail address ? do you on Linked in ?
I honestly can't understand how you arrived at that impression. 🤔I quite like him and his laid back presentation. Gauging the amount of detail to place in such a presentation is an art and I would say he did a excellent job of extracting essential elements to detail. I hope this is but the first of very many videos from Darren in this series.
