Very good matching. Now start making to get those LPs spinning in time for the December holidays.
Yes, the "Starfish" is basically a Naim pre with local regulation and SMPS (Traco) symmetrical power supply on board. Designed by Jiim of PFM.
I have both of the njfet riaa adjusted and all looks good so far. I got to build the second psu next and purchase case/s etc etc.
Hi Salas,
I got the answer from Wilson & Benesch.
It is the same as they claimed in TT manual.
0.58mV min and 1.58mV max output with 47k load resistance.
No farther data available🙁.
Now, I have my dilemma...
a. I'm not going to populate Q2 and R3.
b. R2 is calculated for (Q1 = Right -> 13.51mA/ Left -> 13.52mA) about 7.95R , but for "2-2.5mV -> 43dB" R2 is gained to 68R.
What would be your advice here?
c. R13 is ranged from 2.2K (0.8-1mV -> 56-57dB) to 5.6k (2-2.5mV -> 43dB).
What would be your advice here?
I got the answer from Wilson & Benesch.
It is the same as they claimed in TT manual.
0.58mV min and 1.58mV max output with 47k load resistance.
No farther data available🙁.
Now, I have my dilemma...
a. I'm not going to populate Q2 and R3.
b. R2 is calculated for (Q1 = Right -> 13.51mA/ Left -> 13.52mA) about 7.95R , but for "2-2.5mV -> 43dB" R2 is gained to 68R.
What would be your advice here?
c. R13 is ranged from 2.2K (0.8-1mV -> 56-57dB) to 5.6k (2-2.5mV -> 43dB).
What would be your advice here?
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I would start with 56dB setting as per guide describes it and also set Rx load ranges low starting from 100R going up step by step to 1k via the DIP switch seeking good balance and good gain without audible overload so to discover the cart's nature myself. If the result will suck we will devise values for circa 50dB gain and start loading in the kOhm ranges. Trial and error due to crap data unfortunately.
It's great watching these builds come together. Still collecting my parts for Christmas build project. 😀
Did anyone thought of using JFET 2sk170 + 2N4403 CFP pairs[or similar] in parallel for the frontend for Phono, as it can ease off the hassles of matching Jfet pairs.
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Yes I had thought of that since I had some play with various CFP tests back in the SSLV1.2R experiments, but I decided to keep this one as much as solo JFET as I could out of a conceptual whim. Having a small stash of high Yfs parts to test and match made it easier to develop too. I channeled my ROHM 2N4403s appetite in the Reflektor regs instead.😀
Rega Aria phono stage is i think doing this CFP kind of thing. Well i will try it and see if anything valuable comes in.
Amazon among other places
http://www.tawelectronics.com/tools.htm
http://www.amazon.com/TOOL-LEAD-FORMING-2WATT-RESISTORS/dp/B00B888XCK/ref=pd_cp_hi_0
P.S. 802 is for 1/8W resistors, are you sure? 801 is for 1/4W & 1/2W most commonly used ones.
I started work in a transformer manufacturer this week. Just thinking out loud given the importance of the transformer in any audio project - I'm looking to make a custom wound one for my simplistic - was thinking of a 120VA with 2*36V secondaries - shielded between primary and secondary with Mylar/copper tape to earth.
If there is some consensus I could look at some sort of group buy - can make them multi tap primary so we cover most mains voltages.
The only issue is postage costs as I'm in Australia.
If there is some consensus I could look at some sort of group buy - can make them multi tap primary so we cover most mains voltages.
The only issue is postage costs as I'm in Australia.
I would consider 2x 34VAC spec in such a case since 120VA will duck a wee bit only under this load asked here if at all. Also Aussie & UK wall power are many times hovering at 240VAC++ in the main urban hubs. I would specify at 243VAC primary plus 233VAC and 120VAC taps for a practical global correctly working custom Tx job. Static shielding is nice but see if they can add magnetic shielding too.
One question. Can I use MUR160 instead of MUR120 in the raw PSU? I have a bunch of these at hand...
Regards
Regards
Well I look to have stuffed up somewhat with this build.I connected up one channel with a bulb tester,no led's lit and voltage dropped from the original 44v to 25v.Tried again this evening to verify voltages,same thing,tried without the bulb and voltage was 35v but R1x smoked🙁 The other channel was the same but only tested with bulb tester in situ.Pcb was cleaned and checked for solder links with a magnifying glass.To quote a line from a Sweet song "I haven't a clue what to do"
Guess I've stuffed something wrong and on both boards🙄
Guess I've stuffed something wrong and on both boards🙄
Most possibly. Check LEDs orientations, correct MOSFET types, correct polarity of raw DC to regs connectors. Maybe a Bjt where there should have been a Fet, a reversed electrolytic, whatever. Do a long visual check using an empty PCB clean photo and have a schematic and dmm in continuity too. No sleep till bug kill. Good luck.