Note that this preamplifier was meant to have some type of buffering amp between it and the next stage, unless it was mounted on the system preamp chassis. The output is very high impedance, so the cable should be very short and low capacitance as possible. If I were designing this for stand alone use, I would add a 12ax7 buffer.
Thank you. It was also mentioned and recommended in the circuit description of Circuit 29-16 in the RCA Tube Manual RC-30, pp. 702-703, except for the inclusion of a buffer.
The frequency response, as shown in the video, is far from the RIAA equalization curve for playback of vinyl records! So this is anything but the ideal phono preamp!
I'm using an adjustable DC-DC high voltage boost module. You can adjust the input voltage from 8-32VDC to an output of ±45-390VDC. Maximum output current is 200 mA and idles at 15 mA. Thank you.
Incredible deep noise floor - in spite of using a switching power supply (and having no qualms in using this)! And only K2- distortion is visible. Great. Seems that a vented shielding cover to prevent hum pick-up may not be needed ...
@@buildaudioamps ok sir thank you kahinumdom paka nako sir eddie kato mo palet unta sa EG wala nadayon kay wa na kompleto ako kwarta c allan JJB nlang ang nipalet ok salamat sa pag reply sir
Thank you for a nice project. I think i'll try to build and test one soon. Best regards. :)
Thank you. It's a challenge that you'll enjoy.
Note that this preamplifier was meant to have some type of buffering amp between it and the next stage, unless it was mounted on the system preamp chassis. The output is very high impedance, so the cable should be very short and low capacitance as possible. If I were designing this for stand alone use, I would add a 12ax7 buffer.
Thank you. It was also mentioned and recommended in the circuit description of Circuit 29-16 in the RCA Tube Manual RC-30, pp. 702-703, except for the inclusion of a buffer.
Muy interesante es mono,me gustarie ver uno estereo.?????
It is in stereo. Thanks.
The frequency response, as shown in the video, is far from the RIAA equalization curve for playback of vinyl records!
So this is anything but the ideal phono preamp!
Ok, thanks.
Is this the same circuit as 25-17 in the RCA Manual? Uses 12AX7 / 7025 tubes..
Circuit 29-16 in the RCA Tube Manual RC-30, pp. 702-703
How do you get 250v from a 12v input??
I'm using an adjustable DC-DC high voltage boost module. You can adjust the input voltage from 8-32VDC to an output of ±45-390VDC. Maximum output current is 200 mA and idles at 15 mA. Thank you.
Incredible deep noise floor - in spite of using a switching power supply (and having no qualms in using this)! And only K2- distortion is visible. Great. Seems that a vented shielding cover to prevent hum pick-up may not be needed ...
Thanks.
sir finished products ani nga amply pila imo baligya
I'm sorry, Eddie. I don't sell kits for any projects posted here or on my website; everything is done DIY (including PCBs).
@@buildaudioamps ok sir thank you kahinumdom paka nako sir eddie kato mo palet unta sa EG wala nadayon kay wa na kompleto ako kwarta c allan JJB nlang ang nipalet ok salamat sa pag reply sir
@@eddieorevillo9269 Thank you
Nice implementation of a vintage project, but I CAN'T STAND THAT AWFUL SOUNDTRACK!