You are welcome Stefan
As soon as I get started with R3 I will make the SMD plug in version but this won't be for a while as is to cold to work in my loft.
The plan is that it wont be much larger than the dip switch and have two rigid pins to solder straight on the board.
And
Tanks Simon
How is it sounding.
Better than my R2 and still giving you monalisa smile while listening to it I supose...
(told you so...😀)
As soon as I get started with R3 I will make the SMD plug in version but this won't be for a while as is to cold to work in my loft.
The plan is that it wont be much larger than the dip switch and have two rigid pins to solder straight on the board.
And
Tanks Simon
How is it sounding.
Better than my R2 and still giving you monalisa smile while listening to it I supose...
(told you so...😀)
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@analog_Sa
sorry, I've got no scope, if I had one I would have no idea how to use it.
First impressions is, I am jumping around, grabbing my favourite records, listen to them one after another, I can't find faults on the performance of the Paradise. It is inviting and is pushing all the time.
Compared to my Volpe, which I like very much, it seems that I have a slightly more depht, a little more punch in the bass, some grace when playing records, which are not first grade.
I'm just listening to a live record of Townes van Zandt, recorded in Berlin late 1990, called "Rain on a conga drum", I love this recording, it is very narrow and authentic.
Thank you all,
Christoph
sorry, I've got no scope, if I had one I would have no idea how to use it.
First impressions is, I am jumping around, grabbing my favourite records, listen to them one after another, I can't find faults on the performance of the Paradise. It is inviting and is pushing all the time.
Compared to my Volpe, which I like very much, it seems that I have a slightly more depht, a little more punch in the bass, some grace when playing records, which are not first grade.
I'm just listening to a live record of Townes van Zandt, recorded in Berlin late 1990, called "Rain on a conga drum", I love this recording, it is very narrow and authentic.
Thank you all,
Christoph
Congratulation, this again proves that the Paradise can be made to work.
Depth, punch, grace, i like that.
Depth, punch, grace, i like that.
Good news, at least from a DC point of view you are up and running...
The circuit node where the RIAA caps go is very high impedance, there should be very little capacitance there. Thats strange.....
PSU compensation caps
Hi all,
here a picture of how the compensation caps in the PSU can be applied, you need to locate the transistors under the heatsinks (the footpritns with the three connections), and solder the caps between the innermost and the middle pin. The transistors closer to the corners should get 470pF, the inner transistors 2.7nF.
On the picture you will see 3.3nF caps - before you ask , that is simply because I had them on hand 😀
Many thanks to Doppelkopf who kindly lent me his boards so I could play with them..... After the PSU fix (yes they were oscillating) they sounded nice, with the groove JG/MiiB house courve....
Hi all,
here a picture of how the compensation caps in the PSU can be applied, you need to locate the transistors under the heatsinks (the footpritns with the three connections), and solder the caps between the innermost and the middle pin. The transistors closer to the corners should get 470pF, the inner transistors 2.7nF.
On the picture you will see 3.3nF caps - before you ask , that is simply because I had them on hand 😀
Many thanks to Doppelkopf who kindly lent me his boards so I could play with them..... After the PSU fix (yes they were oscillating) they sounded nice, with the groove JG/MiiB house courve....
Attachments
sorry, forgot to take that scope shot. But the output voltage was fluctuating +/-100mV with frequencies below 1Hz, and when I blew on the input stage transistors the voltage was moving quite a bit.... On my well-run-in Paradise those fluctuations were much smaller.
Thanks. I was more curious if the scope showed any noticeable hf. Mine has a couple of mV @2MHz.
no high frequency there. I remember though that when I was measuring in our lab, there were traces of other stuff (22kHz from a fluorescent lamp, 65kHz from power supplies etc etc) visible. The lab I have at work certainly is not the most quiet place, and this amplifier requires shielding to excel ....
Here http://www.diyaudio.com/forums/analogue-source/218625-paradise-builders-118.html#post3334606 you can see some 600~700uVpp (I would guess near 200uVrms) noise embedded in sampling artifacts of the scope. IMHO this noise is all/most due to fact that the PSU is operating unshielded. This all is at the measuring limit of the scope.
Noise is random not sinusoidal. Its either something produced in the circuit or in the environment picked up by it and/or the measurement loop.
The sinusoidal signal is 5nS and is the scopes sampler triggering on the noise, you can filter this out, but then the signal is even more hidden. When you remove this sinusoidal (using imagination or Photoshop 🙂) from the shown signal part then to will be left with about 700uVpp of random noise.
The main problem here (if it where a problem) is that the scope is on/over it's practical limit, and it is the best one (scope) that I have 🙂
One other 'problem' is me 🙂 getting acquainted with the scope (more learning to do).
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My paradise is running too.
In the beginning, I get PSU oscillating, add 4.7nF and 3.3nf compensation caps to solve it; then I have offset issue, the offset was fluctuating +/-200mV.
First, I used the 500R to trimming R15 but nothing change, after I reduce R43a/R43b to 9.1K then the offset was stable in between +/-20mV (change to 3.9K could down to +/-5mV)
I can see about 800uV of noise on my scope, I only used one transformer but LCLC filtering.
Will keep it to power on for stable, will listing it this weekend.
Regards,
jj
In the beginning, I get PSU oscillating, add 4.7nF and 3.3nf compensation caps to solve it; then I have offset issue, the offset was fluctuating +/-200mV.
First, I used the 500R to trimming R15 but nothing change, after I reduce R43a/R43b to 9.1K then the offset was stable in between +/-20mV (change to 3.9K could down to +/-5mV)
I can see about 800uV of noise on my scope, I only used one transformer but LCLC filtering.
Will keep it to power on for stable, will listing it this weekend.
Regards,
jj
Cool, one more fish in the pool and thanks for the DC offset experiments. That can help other to get rid of that problem.