Thank you Zen Mod for the corrected sim.
It clears the doubt as to the schematic and components values are correct.
Now to check again the proto circuits to find where it's going wrong.
The capacitor values are checked with LCR meter and the 1% MFR values are matched closely.
Voltages at various nodes are also matching with the sim.
Maybe the 4n7 or 15n RIAA caps which are local box type polyester. Though the measured values are ok.
Best Regards
In it's original form, the RIAA of SL10 is supposed to be a very good sounding one (coming from Mr Pass this is not a surprise).
Anyone tried cloning it?
I see discussion on the SL10 High-Level Gain section, but not on RIAA clone.
As the recommended NPN BJTs (MPS6571, MPSA18) are unavailable, I had to opt for the BC550c.
The clone of high-level gain section sounds absolutely fantastic on it's own.
I'm using 7815/7915 based PSU with heavy filtering as in the schematics.
I'd like to see if it sounds any better with a discrete PSU like Erno Borbely's Simple Super Shunt regulator as per attached.
Shall try them once the signal circuits are finalized.
Regards.
Anyone tried cloning it?
I see discussion on the SL10 High-Level Gain section, but not on RIAA clone.
As the recommended NPN BJTs (MPS6571, MPSA18) are unavailable, I had to opt for the BC550c.
The clone of high-level gain section sounds absolutely fantastic on it's own.
I'm using 7815/7915 based PSU with heavy filtering as in the schematics.
I'd like to see if it sounds any better with a discrete PSU like Erno Borbely's Simple Super Shunt regulator as per attached.
Shall try them once the signal circuits are finalized.
Regards.
Attachments
Can you confirm the signal from the cartridge goes directly to the input of your SL10? You should be able to measure DC resistance of the cart at the cable end with a multimeter.
Some turntables these days have builtin RIAA corrector. Which model is your?
Some turntables these days have builtin RIAA corrector. Which model is your?
Hello Chip_mk,
I'm using a Technics Sl1200 Mk2 with Shure V15 TypeIII cart+Jico SAS stylie.
Regards
Try removing 4n7, 15n and 3n3 conds (various combinations) and see what happens. This may give some insight into the problem.
With 4n7 and 15n removed (maybe with 300k res bypassed) you should get linear response. Sound should be very thin, no bass. Same sound signature as if connected directly to line input (off course, line input would be much quieter).
With 4n7 and 15n removed (maybe with 300k res bypassed) you should get linear response. Sound should be very thin, no bass. Same sound signature as if connected directly to line input (off course, line input would be much quieter).
Chip_mk,
Thanks for your advice.
As per Zen Mod's updated sim of the RIAA circuit, the component values in the schematic are all right.
So finally I have to look into my proto built for mistake/oversight.
Unfortunately I have to report to my duty on the high seas, hence this experiment has to wait for few months now.
Best Regards
Thanks for your advice.
As per Zen Mod's updated sim of the RIAA circuit, the component values in the schematic are all right.
So finally I have to look into my proto built for mistake/oversight.
Unfortunately I have to report to my duty on the high seas, hence this experiment has to wait for few months now.
Best Regards
I wish you calm sea and good luck.
While SL10 with its simple design is good starting point for beginers, I suspect it's too unsophisticated for modern standards.
One can easily make a decent riaa stage with a single opamp and few resistors and capacitors. This is what you typically get with modern consumer integrated amp. Such riaa preamp is good reference to compare with when you start making more complex designs. When you get better results compared to the reference you know you're on a good track.
While SL10 with its simple design is good starting point for beginers, I suspect it's too unsophisticated for modern standards.
One can easily make a decent riaa stage with a single opamp and few resistors and capacitors. This is what you typically get with modern consumer integrated amp. Such riaa preamp is good reference to compare with when you start making more complex designs. When you get better results compared to the reference you know you're on a good track.
Chip_mk,
Thank you for your wishes.
I am, what you can call a compulsive phono diy-er.
In the past I have done various phonos including Pearl2, EAR834P clone, Salas RIAA, Hagerman Cornet, Bugle3, Muffsy etc. to name a few. (Though all of them are copy-paste works).
It's the variations of the "colour" of the sound from these different designs that attract me.
In that line this is my attempt to a BJT based phono which I have never made/heard before. With extra attraction of being a Nelson Pass design.
I know with available replacement components it will never sound same as the original, still getting it working will be fun.
Regards