Preamp preference
- Thread starter Oldskoolfan
- Start date
Hi Jim,
I've been very busy with my GPulse-Linear Preamp, ready for production. Picture attached. I also designed the final versions of the XLR Converters. Boards going out for purchase, as well as the Chassis Box design. Attached is the sheet with the Three converter boxes. Your interested in the 2nd one down on the sheet " GP-XLR to RCA". Have a look at the panels. approx. 5" wide, 2" high and 3" deep. All three designs look very similar with all mechanics the same except the PCB circuits and connector functions. Its taking time, as I am still working full time at the National Laboratory.
I've been very busy with my GPulse-Linear Preamp, ready for production. Picture attached. I also designed the final versions of the XLR Converters. Boards going out for purchase, as well as the Chassis Box design. Attached is the sheet with the Three converter boxes. Your interested in the 2nd one down on the sheet " GP-XLR to RCA". Have a look at the panels. approx. 5" wide, 2" high and 3" deep. All three designs look very similar with all mechanics the same except the PCB circuits and connector functions. Its taking time, as I am still working full time at the National Laboratory.
Gents, an update on the GPulseLinear 2000 preamp. Just waiting for a custom made toroid inductor to add to the "Rumble Filter" that is a unique design that does NOT affect the RIAA Curve at all. Not a High pass filter that commonly used and affects the sonic performance at 20Hz! Its a SHARP NOTCH filter centered at 6Hz at -25 dB that removes tone arm resonance amplification. Attenuation starts at 18 Hz at -3 dB, then is sharp past 10-15 Hz at -15dB! When engaged... the speakers totally settle down with no flapping! This IS PATENT PENDING. It really is a game changer using vinyl at super high level. Power amps waste no power flapping the speakers due to tone arm resonances and mechanical pickup. Saves speakers!! The sonic accuracy is totally maintained and accurate with thundering bass! The RIAA curve is maintained at +/- 0.35 dB at full line level output @ 10VRMS unbalanced AND at the BALANCED XLR line level outputs. I'm getting quotes for the special machine wound Inductor. The simulations and pic if the inductor below. Very close to releasing it for purchase. This last minute notch filter is worth waiting for!
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Did you check out Wyn’s “warp filter”? He’s doing this with off the shelf parts. (I hate what he named it but that’s exactly what it is)
I understand your enthusiasm but custom parts can cause problems.
As I understand it Wyn’s design is based on similar control circuits used on the cutting lathe. And it also stops woofer excursions outside the audible band. Several of the builders have “special” records that beat the woofers and now they’re playable. Some videos were posted and you can see those cones going!
I don’t have any records in that condition but I do keep it engaged all the time. I see no reason not to.
I don’t have the ability to compare your two designs technically but empirically they do the same job and his is simple and cheap.
I’m just trying to keep you out of the weeds with custom parts and their expense. We all know the joy of finding unique parts 40 years later…
I understand your enthusiasm but custom parts can cause problems.
As I understand it Wyn’s design is based on similar control circuits used on the cutting lathe. And it also stops woofer excursions outside the audible band. Several of the builders have “special” records that beat the woofers and now they’re playable. Some videos were posted and you can see those cones going!
I don’t have any records in that condition but I do keep it engaged all the time. I see no reason not to.
I don’t have the ability to compare your two designs technically but empirically they do the same job and his is simple and cheap.
I’m just trying to keep you out of the weeds with custom parts and their expense. We all know the joy of finding unique parts 40 years later…
The custom part is fine, The P-Spice simulator nailed it. I have a company willing and vey able to make it. I will obtain all the fabrication info to 2nd source it as part of the re-Engineering effort. It will be a plugin...so no extensive changes at all. I really love how it settled down everything subsonic, with no in-band phase shift. The total cost for 2 for the preamp is about $40. I can add it as an option for buyers, and it can be easily added at any time. Thanks for your interest and reply!!!