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Simplistic NJFET RIAA
Simplistic NJFET RIAA
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Old 9th January 2021, 06:08 PM   #18721
6L6 is online now 6L6  United States
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Simplistic NJFET RIAA
F5 has lower gain because of different feedback resistors than F5T.
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Old 9th January 2021, 06:20 PM   #18722
Salas is online now Salas  Greece
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(100R//100R)/10R=5x (+1 non inverting config)=6x
20Log(6)=15.56dB

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Originally Posted by IDM View Post
My F5 is not the turbo version so I understand the gain to be 15.5dB.
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Old 11th January 2021, 06:33 PM   #18723
IDM is offline IDM  United Kingdom
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Hi Salas,

I took your advice and bought an Aneng AN8008. It seems somewhat better than the meter I was using before. Latest calculated gain is 60.3db. So slightly short of 62db but once again it sounds about right.

I was wondering about adding gain into the DCG3 and have asked the question on its thread.

Thanks,
Ian
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Old 11th January 2021, 07:16 PM   #18724
Salas is online now Salas  Greece
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Ian hi,

Nice with getting the DMM. It should be helpful for reliable AC mV range readings you are interested in. I just did a confirmation check. See photo. About the DCG3 higher gain option I replied in its thread.
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Old 18th January 2021, 07:31 PM   #18725
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50VA is humongous for the job.

What would be the minimum for this job: could two 20VA transformers with 32 V secondaries work in a 230 V environment? Or better one more powerful transformer with 32 + 32 V secondaries?

Thanks!
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Old 18th January 2021, 07:47 PM   #18726
Salas is online now Salas  Greece
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Typically both solutions would work. Its about CCS consumption loading, no time break, and full bridge rectification steals 40% of a transformer's AC current rating.
I have seen 30VA frame transformer becoming substantially warm under such conditions.
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Old 18th January 2021, 08:30 PM   #18727
SKA76 is offline SKA76
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Thanks Salas!

In other words better borderline humongous using one or two 50VA transformers with 32 V secondaries than letting the transformers sweat
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Old 19th January 2021, 08:24 AM   #18728
vgeorge is offline vgeorge  Greece
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One more UFSP finished.
As I had already the previous blue boards, this one is better.
More detail, less noise, more depth.
Of course these comments are not very objectives, as I used different and little bit better components, I feel that this new design is a worthwhile upgrade.
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Old 19th January 2021, 05:40 PM   #18729
Salas is online now Salas  Greece
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Quote:
Originally Posted by SKA76 View Post
Thanks Salas!

In other words better borderline humongous using one or two 50VA transformers with 32 V secondaries than letting the transformers sweat
50VA Antek which is very much used by American builders has magnetic shield that their lesser VA models don't have is another reason why usually recommending 50VA
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Old 19th January 2021, 05:44 PM   #18730
Salas is online now Salas  Greece
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Quote:
Originally Posted by vgeorge View Post
One more UFSP finished.
As I had already the previous blue boards, this one is better.
More detail, less noise, more depth.
Of course these comments are not very objectives, as I used different and little bit better components, I feel that this new design is a worthwhile upgrade.
Congratulations for your build. It looks by now well established from enough reports, including yours, that the black UFSP redesign also offers little more subjective performance beyond gain set up flexibility with DIP switches which was the main update goal.
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