This is what to do (my rule of thumb
). Split the servo output resistor in two, then make a T-filter and calculate the FT of the filter for 5 to 10 times the FT of the servo. The filter must have a higher FT than the serve to prevent that it starts working like a phase-shift-oscillator. The purpose of the filter is to remove all (possible) noise from the servo output and shunt it (the noise) to ground. Also it halves the servo output resistor, and thus it lowers (possible injected) resistor noise.
Danke für die Blumen, Jacco. I think I fixed the controller issue (1,2,3,4) - courtesy of Daniel "Usul" and his project in the German Analogforum. It’s a signal generator doing 2 sinusoidal waves and an amplifier for each of them, frequency, phase etc. can be fine-tuned.
Anyways, back to Paradise - I just wanted to add some impressions on the sound in relation to my RIAA. Based on Ricardos calculation what I wanted was 70742R and 9550R. What I could do with the Rs available at my vendor is 70845R and 9529R (non magnetic 0.1% Vishay CMF55-143 from Schuro). Cs are 33360 (2x14000+5360) and 11432 (11000+432).
Overall I feel it’s a very balanced reproduction. I usually listen to music with people singing and I like how this frequency band is reproduced (in German “Präsenzbereich”). My impression is its very neutral and without any frills but not at all harsh, not even when I listen to singers singing with a lot of pressure at rather extreme volumes.
For me in my system heights blend in very well, I can’t say anything is too pronounced or too quiet. The bass is overall solid and full - if anything I tend to agree with Salas, my impression is the upper bass seems to be pronounced, however, it’s not bloated or anything.
So if I would want to change anything at all I’d reduce the bass a bit - but I do have too much bass in my system, anyways. My room is a bit small for Joachims outstanding Allegria speakers. So it’s very likely my individual issue.
I will hopefully have the chance to test the preamp in other peoples systems soon, I will also experiment with other termination resistors – right now I’m running my cartridge on the lower end of the suggested range.
Regards
Sven
I think I fixed the controller issue (1,2,3,4) - courtesy of Daniel "Usul" and his project in the German Analogforum. It’s a signal generator doing 2 sinusoidal waves and an amplifier for each of them, frequency, phase etc. can be fine-tuned.Anyways, back to Paradise - I just wanted to add some impressions on the sound in relation to my RIAA. Based on Ricardos calculation what I wanted was 70742R and 9550R. What I could do with the Rs available at my vendor is 70845R and 9529R (non magnetic 0.1% Vishay CMF55-143 from Schuro). Cs are 33360 (2x14000+5360) and 11432 (11000+432).
Overall I feel it’s a very balanced reproduction. I usually listen to music with people singing and I like how this frequency band is reproduced (in German “Präsenzbereich”). My impression is its very neutral and without any frills but not at all harsh, not even when I listen to singers singing with a lot of pressure at rather extreme volumes.
For me in my system heights blend in very well, I can’t say anything is too pronounced or too quiet. The bass is overall solid and full - if anything I tend to agree with Salas, my impression is the upper bass seems to be pronounced, however, it’s not bloated or anything.
So if I would want to change anything at all I’d reduce the bass a bit - but I do have too much bass in my system, anyways. My room is a bit small for Joachims outstanding Allegria speakers
. So it’s very likely my individual issue.I will hopefully have the chance to test the preamp in other peoples systems soon, I will also experiment with other termination resistors – right now I’m running my cartridge on the lower end of the suggested range.
Regards
Sven
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Says who, one can not get good sound out of a chipamp.
(looking forward to images of the PS and caseworks. Donnerwetter, that is a one big dust cover)
This is what to do (my rule of thumb
great idea!
Thanks
the thing is I have never seen it done before, and I can not understand why, am I wrong, or do I need to get a patent (most probably I am to late for that). Most probably it is a re-invention, but google-ing (Urban Dictionary: google-ing) for servo's does not reveal any prior art typically, servos like the paradise servo are pretty noiseless, since the amplifier sees its output noise at the inputs through the big C and can compensate to some degree, so I am not sure this will change things a lot with an OPA134.... nevertheless its a great idea, and I am retaining it on the big list for the....
PARADISE PLATINUM EXTREME
(evil laugh goes here.....)
PARADISE PLATINUM EXTREME
(evil laugh goes here.....)
Just this afternoon I said http://www.diyaudio.com/forums/soli...-self-wants-your-opinions-45.html#post3439885 wireless by internet
Hi Joachim, here is the "label":
An externally hosted image should be here but it was not working when we last tested it.
For some reason people obscure the serial number when they post such pictures - I don't know what kind of fraud could occure but I decided to take no risk.
If you are interested in the serial number let me know.Best Regards
Sven
From my graphs, the best, commercially available and cheap NJF is the J113, good choices are 2SK170, BF256A, BF245A, BF244A, J113, U309 and J309. If you want to propose others, then let me know, if applicable, I will add them to the graph
My batch of J113 just arrived. Only thing left is to finish testing bipolars and install them along with the FETs. From your image I gather we want Rgs to be around 1k?
