You must be joking, “delayed feedback”.
The op amp is simply too slow to get a stable closed loop.
It gets better when you solder in a VCVS. That is hard to do.
It also works with some TI GHz amplifiers, but their 1/f noise is so
excessive that it hurts even as a second stage.
Ferrite beads are not supposed to work as inductors, they are intended to create
dissipative losses. Unfortunately, what creates loss at a certain frequency, also
creates thermal noise. Pure inductors in the gate do not generate noise per se,
but they only shift the frequency of the disaster.
Glad you finally arrived to the solution I built 10 years ago, too bad you wasted time on all kind of other hopeless attempts. Your next step is to go to 64 JFETs in parallel, you’ll get at 0.15nV/rtHz like myself.
Don’t worry, I’m not asking for royalties, after all this idea was developed in the ‘60s.
My current design has no feedback through the FET stage; it has nevertheless no
thermal problems by using the positive vs. the negative TC of the 2 JFET TCs.
I won't go to 64 FETs, It is more like 2*8 or even 2*4, given the cross correlation
results of my Agilent 89441A. It averages out any noise contribution of the two
preamplifiers, keeping only what's in both channels at a time.
Averaging 1000 times is much cheaper than averaging over 1000 FETs
and much less of a load. It just takes some patience.
And regarding royalties, my implementation of the Wenzel design is (c) 2005,
which makes it predate yours by 5 years, as seen in the notice in the layout
of the right picture (top right).
And when you boast your space proof oscillator from ebay in the neighbouring
thread: one of mine is in orbit, comparing Cesium against H maser.
EOD now for me in this thread for being off-topic. Andrea, sorry for the abuse.
Gerhard
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The two oscillators are mixed up in the FIFO q1, I don't know the design but I suspect there isn't a multiplexer to select the right oscillator according to the sample rate frequency.
The Crystek and other oscillators have a disable pin to put the output in high impedance state, while the TWTMC-STS sine to square converter does not provide a disable function.
So the only chance is using and external clock switch like the TWTMC-STS-FSDO-S.
All clear now, you use a mysterious “delayed feedback”, but then there’s no feedback to define the gain. Then ferrite beads create noise, with pure inductors it is still a “disaster” in frequency, but you did it with gate stoppers (whatever those are) and use it in despite. Then a set of cheap shots and self promoting, and your message is over. Nothing, zip, nada to benefit from, you are the best though, never wrong, not even when paralleling 20 bipolar op amps, or wondering why those interfet monsters are nothing like they appear to be. What a joke.
That explains the scope signal, it is both clocks together.
So I need to get me another fifopi q3 for my second dac and use that until the fifo lite from Andrea is available (looking at the first graphs this is very promising)
Its very glaguy, no moving at package.
Is there anyone whose not moving the pack yet?
"Mar 30 2021 08:43 am
A Lavorazione presso il Centro Internazionale Scambi
Centro Scambi Internazionale Milano Gateway Poste Italiane"
Nothing for 20 days, standing at Milano...
I apologize for the issue, I have just contacted SDA customer service and they told me that the package had left Italy on March 30 to be entrusted to the Magyar Posta.
Can you please call your postal customer service?
Hi All,
I have been away for a couple of days thus a delayed feedback: I have received the package on 16 April (thanks, Andrea!), however, it is still indicated on SDA's tracking webpage to be in transit in Milan (since 10 April). So I reckon that SDA's tracking service may not be entirely updated with the latest status ... ??
Just FYI.
Cheers,
Jesper
I have been away for a couple of days thus a delayed feedback: I have received the package on 16 April (thanks, Andrea!), however, it is still indicated on SDA's tracking webpage to be in transit in Milan (since 10 April). So I reckon that SDA's tracking service may not be entirely updated with the latest status ... ??
Just FYI.
Cheers,
Jesper
I have a McFifo.
One channel is supplied with a DRIXO, the other still has an NDK.
they both live happy together, and the fifo works as expected. so i must assume that there's some form of switching/multiplexing on board.
But Ian is the man here
Hooked up the TWTMC-Drixo-F 22.5792Mhz board fed with a LSIB-HPULN PS Single Rail 5A set to 16V, into a Digital Linear Reference Level SD3.75 SD Player bypassing on board clocks, taking the I2S out (before differential chip) to miro1360’s AD1862 PS & DAC combo feeding a Lampizator Big7 valve output.
I had the previous Driscoll clock feeding the SD Player so this was the only change moving to the new board and it is a big step up. Listening to Eric Bibb, Jericho Road and the level of new insight into the recording is shocking to say the least. Never truly expected this much of an improvement.
I will give a few days to see how my results stand up to scrutiny but right now it’s an amazing listening experience. You have surpassed even my best expectations Andrea.
I had the previous Driscoll clock feeding the SD Player so this was the only change moving to the new board and it is a big step up. Listening to Eric Bibb, Jericho Road and the level of new insight into the recording is shocking to say the least. Never truly expected this much of an improvement.
I will give a few days to see how my results stand up to scrutiny but right now it’s an amazing listening experience. You have surpassed even my best expectations Andrea.
Thanks Sligolad
An SD player into a Big7 must be an amazing combo with this clock. Sounds like it was a big step up.
My package arrived in Canada today. It was quick. Would have been here 2 days ago but they needed import duty paid. The tax guys probably taxed it leaving Canada and got it again coming back.
I am just finishing my power supply and chassis. Look forward to reporting in a few days.
An SD player into a Big7 must be an amazing combo with this clock. Sounds like it was a big step up.
My package arrived in Canada today. It was quick. Would have been here 2 days ago but they needed import duty paid. The tax guys probably taxed it leaving Canada and got it again coming back.
I am just finishing my power supply and chassis. Look forward to reporting in a few days.
Thanks Sligolad
An SD player into a Big7 must be an amazing combo with this clock. Sounds like it was a big step up.
My package arrived in Canada today. It was quick. Would have been here 2 days ago but they needed import duty paid. The tax guys probably taxed it leaving Canada and got it again coming back.
I am just finishing my power supply and chassis. Look forward to reporting in a few days.
miro1360’s AD1862 PS & DAC combo was an eye opener with the original clocks but adding the new clock really surprised me.
A few of us are playing with different output stages for this DAC and i stuck in the Big7 with EML Anniversary 45 Tubes just to give us a good reference.
Hope you get half of what i got here at least
