Have had some time to add a new input module: a MM/MC Phono preamplifier. based on Douglas Self's Elektor Preamp (2012) and his book "Electronics for vinyl".
The MC module can be added as "hat" module. The mm_mc_phono input board contains the high performance RIAA part. Also included is a 3 parallel ZTX951 input stage.
Unfortunately I cannot post the schematic. If anyone is interested, just buy the Elektor article or his book.
The RIAA stage is realized in C0G/NP0 SMT parts with tolerance 1%. Critical part values are paralleled to get exact values. Resistors are thin film SMT with a tolerance of 1%.
The MM and the MC stage each have a NE5534A at front. TL071 is used as DC-servo in the MC part. All other opamps are LM4562.
MC output level can be selected per channel at back side from this list: +20dB, +26dB, +34dB, +40dB.
MM output gain has also 4 selections per channel: +0dB, +6dB, +12dB and +20dB. The MM/RIAA stage gain at 1kHz is 30dB.
The subsonic filter is a 2 stage 3rd order butterworth filter with a -3dB point at 20Hz.
Have fun, Toni
The MC module can be added as "hat" module. The mm_mc_phono input board contains the high performance RIAA part. Also included is a 3 parallel ZTX951 input stage.
Unfortunately I cannot post the schematic. If anyone is interested, just buy the Elektor article or his book.
The RIAA stage is realized in C0G/NP0 SMT parts with tolerance 1%. Critical part values are paralleled to get exact values. Resistors are thin film SMT with a tolerance of 1%.
The MM and the MC stage each have a NE5534A at front. TL071 is used as DC-servo in the MC part. All other opamps are LM4562.
MC output level can be selected per channel at back side from this list: +20dB, +26dB, +34dB, +40dB.
MM output gain has also 4 selections per channel: +0dB, +6dB, +12dB and +20dB. The MM/RIAA stage gain at 1kHz is 30dB.
The subsonic filter is a 2 stage 3rd order butterworth filter with a -3dB point at 20Hz.
Have fun, Toni
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Hi Tony
Looks nice, iirc I have the article, let’s hear from you on your build,test, listening evaluation. Do you have both types of cartridges? Have you ever compared these types before?
PS. Next time put the ecap polarity silkscreen text “+” outside the circle instead of inside for visual inspection/checking after the component is installed
I have yet to figure out why smt Mlcc have no markings on them for identification. I remember at Motorola they forced supplies like Kemet to mark them with codes
Rick
Looks nice, iirc I have the article, let’s hear from you on your build,test, listening evaluation. Do you have both types of cartridges? Have you ever compared these types before?
PS. Next time put the ecap polarity silkscreen text “+” outside the circle instead of inside for visual inspection/checking after the component is installed
I have yet to figure out why smt Mlcc have no markings on them for identification. I remember at Motorola they forced supplies like Kemet to mark them with codes
Rick
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Dear Rick,
in 1981 I have bought a JVC L-E 5 Tangential direct drive. In the year 2022 after some hours of cleaning and repair of the pickup servo motor it is working now. So I decided to design a MM/MC input module for the SA2022 Preamplifier... In a few weeks it should hopefully work. A midprice Denon Phono with a DL103R MC cartridge is on my shopping list.
The Lytics checks can also be done with the above pictures which I do normally... Placing the Plus symbol outside is possible, but static and cannot be moved around.
The mlcc without marking is of curse sometimes a challenge. I use a Smart Tweezers ST-5 to place the parts on the pcb. So errors are minimized.
in 1981 I have bought a JVC L-E 5 Tangential direct drive. In the year 2022 after some hours of cleaning and repair of the pickup servo motor it is working now. So I decided to design a MM/MC input module for the SA2022 Preamplifier... In a few weeks it should hopefully work. A midprice Denon Phono with a DL103R MC cartridge is on my shopping list.
The Lytics checks can also be done with the above pictures which I do normally... Placing the Plus symbol outside is possible, but static and cannot be moved around.
The mlcc without marking is of curse sometimes a challenge. I use a Smart Tweezers ST-5 to place the parts on the pcb. So errors are minimized.
Hi Tony
Looks nice, good luck in test.
Interesting that you used dip-8 package, I assume it’s so that it’s easier to change/evaluate different opamps and possibly need an adapter to evaluate soic packaged devices. If you need some dip to soic adapters, I have done a pcb design that I can share or send you some. I did both a single and a dual with caps across the supplies
Rick
Looks nice, good luck in test.
Interesting that you used dip-8 package, I assume it’s so that it’s easier to change/evaluate different opamps and possibly need an adapter to evaluate soic packaged devices. If you need some dip to soic adapters, I have done a pcb design that I can share or send you some. I did both a single and a dual with caps across the supplies
Rick
I have so many DIP-8 opamp's and yes it is easier to change/evaluate different opamps. Thanks for your offer! I already have DIP8/SOIC adapters on stock including bypass caps...
SA2022 preamp has 6 input slots which you can currently configure using SE, balanced or phono MM/MC hardware modules.
Outputs are SE RCA and a XLR simultaneous available. A high end headphone amp is integrated.
3 unpopulated input slots are still free ...
I wish you could be here and listen with me to this fantastic vinyl sound - Dire Straits - On Every Street - 180g Vinyl from 2022 - The subsonic filter is doing its job so well ...
I wish you could be here and listen with me to this fantastic vinyl sound - Dire Straits - On Every Street - 180g Vinyl from 2022 - The subsonic filter is doing its job so well ...
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