Do you want to use a servo or a large capacitor to block the DC?
Some op amps come in a dual package, or a single package, both with 8 pins.
Do you want the audio circuit to use a single op amp for all the gain and EQ?
This app note shows some possible circuit variations, for example.
https://www.ti.com/lit/an/snoa586d/snoa586d.pdf
Some op amps come in a dual package, or a single package, both with 8 pins.
Do you want the audio circuit to use a single op amp for all the gain and EQ?
This app note shows some possible circuit variations, for example.
https://www.ti.com/lit/an/snoa586d/snoa586d.pdf
Last edited:
The circuit looks very similar, almost identical to one in the pdf that you mentioned in your post.
Didn't know that it comes from TI
https://www.ti.com/lit/an/snoa586d/snoa586d.pdf
Didn't know that it comes from TI
https://www.ti.com/lit/an/snoa586d/snoa586d.pdf
Ok, do you plan to design a pcb for the phono preamp? Use a ground plane if possible.
The dual DIP8 pinouts are standardized, so you can design the board before making a final decision on which dual op amp to use.
But you do need to choose the capacitors first before starting the pcb design, since lead spacing for those will vary a lot.
You can choose a standard lead spacing for the resistors, and metal film types rated at 1/4 W for all will be fine.
The dual DIP8 pinouts are standardized, so you can design the board before making a final decision on which dual op amp to use.
But you do need to choose the capacitors first before starting the pcb design, since lead spacing for those will vary a lot.
You can choose a standard lead spacing for the resistors, and metal film types rated at 1/4 W for all will be fine.
Keep in mind they have adaptor boards
for modern surface mount to dip8.
So much higher performance opamps can
be used.
RIAA preamp in general is looking for low noise
type opamp. Likewise high slew and bandwidth helps
since the gain will be high.
NE5534 is a classic go too low noise
typical Vn be about 4 nV√Hz
as with modern low noise OPA1612
Vn be about 1.1 nV√Hz
CMRR was respectable at 100dB
for the 5534
But modern types up to 120 dB
Distortion real world for old opamps
be about .001 to .004 %
when modern types are way way way below that
in the .000015 % range
and bandwidth will jump way up from
10 MHz to 40 MHz
Keeping in mind even with 4x more bandwidth
noise is still lower.
So surface mount to dip8 adaptive
always a option.
Otherwise you can have fun right away
with the good old TL072 jfet
for modern surface mount to dip8.
So much higher performance opamps can
be used.
RIAA preamp in general is looking for low noise
type opamp. Likewise high slew and bandwidth helps
since the gain will be high.
NE5534 is a classic go too low noise
typical Vn be about 4 nV√Hz
as with modern low noise OPA1612
Vn be about 1.1 nV√Hz
CMRR was respectable at 100dB
for the 5534
But modern types up to 120 dB
Distortion real world for old opamps
be about .001 to .004 %
when modern types are way way way below that
in the .000015 % range
and bandwidth will jump way up from
10 MHz to 40 MHz
Keeping in mind even with 4x more bandwidth
noise is still lower.
So surface mount to dip8 adaptive
always a option.
Otherwise you can have fun right away
with the good old TL072 jfet
I've found success with MC33078 at 50x gain for MM cartridge. Also ST33078. Low noise, good slew rate. Requires local PS bypass (.01 to .1 uF) and a bypass cap around the feedback capacitor to not oscillate. 22 to 33 pf. I bought mine from newark for $.38 ea. Use less power than NE5534 which was important in replacing 4558 which hisses.
Similar performance different vendor NJM2068. I have not used these, you have to buy them in US from Mouser.
TL072 is okay but slightly noisier IMHO.
Distortion levels below 0.5 % are IMHO inaudible. I prefer to minimize hiss & hum which are audible and depend on power supply, layout, coupling from other components like line cords and transformers. Or RF coupling from switcher supplies if you enjoy life on the edge.
My source of SOIC adapter boards is more than $1 each. You can import large lots of them from overseas for less each. Not worth the trouble IMHO.
Similar performance different vendor NJM2068. I have not used these, you have to buy them in US from Mouser.
TL072 is okay but slightly noisier IMHO.
Distortion levels below 0.5 % are IMHO inaudible. I prefer to minimize hiss & hum which are audible and depend on power supply, layout, coupling from other components like line cords and transformers. Or RF coupling from switcher supplies if you enjoy life on the edge.
My source of SOIC adapter boards is more than $1 each. You can import large lots of them from overseas for less each. Not worth the trouble IMHO.
Last edited:
I found this one - https://www.ebay.com/itm/333859992171
The guy has 100% positive reviews and someone has used the op amp for RIAA as well.
The guy has 100% positive reviews and someone has used the op amp for RIAA as well.
Can go either way pre soldered
or solder yourself and buy the opamp itself directly from mouser / digikey.
All works.
Some people are more comfortable using dip8
because of spacing for soldering.
Others are droping in higher performance opamps
in older equipment and need the dip8 for existing board.
For me I dont mind certain surface mount packages.
But cannot tolerate surface mount passive.
So if you design your own board.
Just make the passives normal through hole components.
And just use surface mount opamps.
Or for bread boarding or proto boarding
or full DIY boards. Then the dip8 converters are rather
handy to have.
Enjoy, wonderful opamp
or solder yourself and buy the opamp itself directly from mouser / digikey.
All works.
Some people are more comfortable using dip8
because of spacing for soldering.
Others are droping in higher performance opamps
in older equipment and need the dip8 for existing board.
For me I dont mind certain surface mount packages.
But cannot tolerate surface mount passive.
So if you design your own board.
Just make the passives normal through hole components.
And just use surface mount opamps.
Or for bread boarding or proto boarding
or full DIY boards. Then the dip8 converters are rather
handy to have.
Enjoy, wonderful opamp
Last edited: