Hi Pavel,
I like your Jfet design the Jfet as a input is unbeaten.
I would like to see the small signal response of the 100kHz square wave 50mV/div .
Keep on the good work.
Regards, Helmuth
I like your Jfet design the Jfet as a input is unbeaten.
I would like to see the small signal response of the 100kHz square wave 50mV/div .
Keep on the good work.
Regards, Helmuth
Hi Helmuth,
the response shown is without capacitor in the input RC filter. I do not have that option at the moment, but as soon as I build further module I can measure it before completition.
Basically, there is almost no difference between large and small signal responses, as the SR is very high.
I am attaching step (square) response at 200 nanoseconds per division, again without input cap. Load is ultimate 50 ohm - to prevent cable reflections.
the response shown is without capacitor in the input RC filter. I do not have that option at the moment, but as soon as I build further module I can measure it before completition.
Basically, there is almost no difference between large and small signal responses, as the SR is very high.
I am attaching step (square) response at 200 nanoseconds per division, again without input cap. Load is ultimate 50 ohm - to prevent cable reflections.
Attachments
Francesco, Q7 and Q10 are constant current sources for Q8 and Q9 - drivers of the diamond buffer output stage.
Regards,
Regards,
It is very probable that I will start production of several symmetrical boards recently. In case you are serious, I can make 2 pcs more. Single ended version is in stock.
It is still undecided, but less than twice the price of the single-ended board. The board surface area is twice the SE board.
I am serious, please count me in for a balanced set. also I dont know if you are offering sand as well. I was looking at the linear tech toshiba replacements. depending on price for the PCB, I will get 2, but definitely at least 1 balanced board
In case you mean matched set of JFETs, I am trying to offer them as well, in case I have them in stock.
OK, but please let's continue in the vendor's bazaar thread
http://www.diyaudio.com/forums/vendors-bazaar/166049-dispre-ii-pcbs-available-2.html#post2297523
about PCBs.
This thread is dedicated to technical questions and explanations.
http://www.diyaudio.com/forums/vendors-bazaar/166049-dispre-ii-pcbs-available-2.html#post2297523
about PCBs.
This thread is dedicated to technical questions and explanations.
Dispre 2 jfet preamp board and PS complete
Here is the assembled board of Dispre 2 Jfet and it's regulated power supply.
Measured (+/-) 14.9V from the output of the PS.
Main preamp board is awaiting the arrival of an 10K ALPS stereo pot.
It is configured for a gain of 1X. (max is 5X)
Can't wait to hear this glorious jfet diamond buffer !!
Here is the assembled board of Dispre 2 Jfet and it's regulated power supply.
Measured (+/-) 14.9V from the output of the PS.
Main preamp board is awaiting the arrival of an 10K ALPS stereo pot.
It is configured for a gain of 1X. (max is 5X)
Can't wait to hear this glorious jfet diamond buffer !!
Attachments
Dispre 2 jfet completed and playing on main system
Dear all,
The Dispre 2 jfet is all completed and playing on my main system. I have yet to drill holes in the alu case and mount the PCB's in. Power amp is a Rod Elliot P3A with Cambridge Audio Azur 550C CD player as source. Speakers are my 8'' 2 way MTM Scanspeak based DIY.
Well I am in shock. From the moment the first few notes were played, goosebumps erupted all over. The sonic image was extremely 3D and I never expected the speakers to image so well. Texture and tone was extremely lifelike and neutral. There is no grainy SS sound; what results is a smooth and organic musical presentation that seduces you to listen forever. I've had a few quiet preamps that the ear could hear nothing when placed 1cm from the cone. The Dispre 2 redefines "quiet". Notes emerge out of the darkest background and the transient attack shocks the soul. The goosebumps that broke out earlier still remain.
I do not hear bass, midrange or highs. They blend so well that you get lost in the music. For every other preamp that I have used, there is usually one aspect that stands out; like the sweet midrange from a tube pre etc. The dispre lets nothing stand out. Purest music. Straight wire with gain.
Pavel - You have created a masterpiece !!
Dear all,
The Dispre 2 jfet is all completed and playing on my main system. I have yet to drill holes in the alu case and mount the PCB's in. Power amp is a Rod Elliot P3A with Cambridge Audio Azur 550C CD player as source. Speakers are my 8'' 2 way MTM Scanspeak based DIY.
Well I am in shock. From the moment the first few notes were played, goosebumps erupted all over. The sonic image was extremely 3D and I never expected the speakers to image so well. Texture and tone was extremely lifelike and neutral. There is no grainy SS sound; what results is a smooth and organic musical presentation that seduces you to listen forever. I've had a few quiet preamps that the ear could hear nothing when placed 1cm from the cone. The Dispre 2 redefines "quiet". Notes emerge out of the darkest background and the transient attack shocks the soul. The goosebumps that broke out earlier still remain.
I do not hear bass, midrange or highs. They blend so well that you get lost in the music. For every other preamp that I have used, there is usually one aspect that stands out; like the sweet midrange from a tube pre etc. The dispre lets nothing stand out. Purest music. Straight wire with gain.
Pavel - You have created a masterpiece !!
Attachments
Hi chlorofille,
thanks for your remarks regarding sound. You have obviously done a very good job in assembly and set-up of your preamplifier, congratulations.
Best regards,
thanks for your remarks regarding sound. You have obviously done a very good job in assembly and set-up of your preamplifier, congratulations.
Best regards,