Will force higher value resistors that will make your film dream into cinemascope.🙂 If you start to feel it opens up but starts to lose slam, up the CCS current.
I had a battery powered preamp 10 years ago for a few years. I don't think it was as good as my simple opa627 buffer.
I have read that battery power is not necessarily low impedance and its AC performance won't be as good as a well design regulator.
When I try equipments, I always find that the higher the PSSR the better the sound. I guess that the problem with all opamps is that they are good at low frequencies but bad at higher frequencies.
My build of v1.1 with film caps should behave very well above 200Hz at least, even using the current value of 2k4 resistor and 1.1uF capacitor. So for me it is a solved problem. If the lower Idss could lift the resistor to about 5k, I would be happy to use 2 x 1.1uF with a single regulator to drive the entire circuit. If not, I will use two separate regulators to drive the high-mid and bass-sub separately.
Don't get your output cap very low though IMHO. It does not terminate as it should in rise time for driving current to the shunt mosfet. What is the main benefit you like for your films across vref? Less grain and lumpiness? And then you will compare boutique ones? Never ending story... Batteries must be bypassed with thousands of uf, still their impedance rises with frequency a lot though. They also can present weird chemical noise. In general, it gets a truckload of special high amperage batteries in parallel to compete. Not elegant at least. He had it much better than with 317-337 already with the batteries as he said, so the comment goes to ''it will better be a shunt in your lows too'', if the guys experience has anything to do with your line circuits.
You can lower the current through Vref by inserting a resistor between the gate and source of the jfet. The gate stays connected to R5. Then you can increase R7 and Rtrim, if you want that. I run in v2 about 250uA through Vref.
It does work, but the internal impedance will go up, so the root noise of the jfet too. A small thing, but I may remind.
The output cap is and will be electrolytic. I have never thought of film cap in that place. I don't even think I will bypass the electrolytic with film.
Replace your 470uF with a 1+uF film cap and hear it.
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Ikoflexer,
When you did the simulations with estonishing low impedance figures in the first couple of pages of this thread, did you include some ESR into the Vref bypass capacitor?
Regards,
Bill
When you did the simulations with estonishing low impedance figures in the first couple of pages of this thread, did you include some ESR into the Vref bypass capacitor?
Regards,
Bill
I have done all those things. That is why I am asking what you hear so to see if it correlates. I just give ''behaving'' practical and economic enough values that work more or less balanced in many systems and are easy for layout. In my personal phono I use 10uF Mundorf plain supreme.
250uA through Vref? You must be talking about the Vref in the CCS, not in the shunt.
With a resistor between g and s, the noise increase will be so little to justify any concerns, right?
In all simulations I try to pretend a somewhat careless implementation; For caps I usually do ESR = 1R and ESL = 15uH. Pretty extreme eh?
Yes, 250uA through Vref. That's what I used, but I didn't put any time in tweaking for sound; until I fix my HP amp I rely on you for that guys.
I see no reason to worry about the noise because of that resistor between g and s.
Yes, one of the things I have planned to do tonight is to use a 10uF ICW SA Clarity cap in that position. No, I am not really fond of the Clarity caps, though it is 100% better than the Solens. I got dozens of them for my passive crossover modelling, only because they are cheap for me (cheaper than Solens). They sounded reasonable until I compared them to the cheapiest Vishay blue boxes and many others and found the blue boxes are the cleanest sounding of all. That is what is used as you can see from the pictures I posted. I guess Mondorf Supreme is the best crossover cap but it is way too expensive for my liking - never used it.
You do well. I try to get a basic economic robust thing right first. Must not be whimsical. Then the good builds in resolute systems can take even top dollar stuff in places. In general I say run it high, dont put resolution over tone first, its tunable always if patient, but in several applications the mileage will vary. *That sqrt noise will be just a little, anyway the Vref resistor increase choice will swamp it.
I got some parts from having build maybe 50 different loudspeakers in my life from 12yrs old.🙂 Check many value things and makes. If at a point you are going to feel a little grain, it can be large caps with large legs picking some RF. Final choice you will feel alters when in the final grounded metal box.😉
Ikoflexer,
The Farnell parts from the U.S. have just arrived. So as soon as the 2sk170 from HongKong arrives I can spend a day to build v2.
Can I apply the same to v2? I mean adding some resistance between g and s of the Vref NJFECT, and use a film cap there.
Regards,
Bill
The Farnell parts from the U.S. have just arrived. So as soon as the 2sk170 from HongKong arrives I can spend a day to build v2.
Can I apply the same to v2? I mean adding some resistance between g and s of the Vref NJFECT, and use a film cap there.
Regards,
Bill
50 different loudspeakers? Design and build a pair of OB speakers to end them all. You may say it is all about personal preference, but I am a follower of John K, Linkwitz and Gedlee. I have heard all sorts of commercial speakers up to a quarter of a million dollars a pair, and my set up six months ago may equal or better than them. I will put in the v1 or v2 in it, with a recently acquired calibrated mic, I will retire from speaker building in the very short future.
Only a pair? 🙂 Let me think..of how many OB I have made...😉 Geddes I don't think he favors open back. He puts wavelaunch purity and pattern control foremost btw. You made your system without a calibrated mic up to now?
😀 Nice spirit. Keep it up. And let us know more of your findings with time. Its nice you like the shunts in your system.
Did simulations for a few years, then non calibrated mic, and now calibrated mic. I trained / calibrated my ears first before the mics.
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