Replacement for loricraft power supply

P300s and later versions are still readily available. I've never played with one, but I think someone told me that the frequency adjustment is only a few Hz up and down from a center frequency of 60Hz, so it may not get down to 50Hz. But this is hearsay.

Steve, The solid-state Garrard/Lenco PS that Audioblazer and I had on order from Mark Kelly was to be a completely finished product, as received by the end user. In fact, he built them and recently sent me a photo of a completed unit. But at the last minute, literally, he found that the key IC in his prototype unit failed prematurely, and he is now unwilling to go forward with the product at all. Those of us who had one on order have been offered the option of a tube version, using KT88 output tubes. The latter is also far along in development and build, according to Mark.

Out of curiosity, what advantage would a tubed power supply offer over a solid state version? I was thinking this might be a viable option for my 401. It seems to cover all the bases, and it's relatively inexpensive. Has anyone an opinion?

Since this is out in public, I probably should respond.

Firstly, let it be said that I am very aware that I have not delivered what I promised.

When I went into this I had built a number of controllers using the "T" amp architecture and felt confident that I could do so again. I failed to predict the impact of Tripath going out of business: all my attempts to find a suitable solid state subsitute have failed.

I am also keenly aware that I have stretched people's patience with the time these attempts took and with my poor communication. Some of this was unavoidable due to health issues, some I brought on myself. When I finally called it quits on Friday it brought on a mixture of bitter disappointment that I had failed yet again and huge relief that I'd finally walked away.

The KT88 design has none of these issues: it is simply a marriage of the front end of the new controller with the power output stage of the first controller I designed almost 15 years ago. Both halves work well and I know I can make them play nice together. I now approach benchwork with alacrity rather than the dread and anxiety that characterised recent times.

Regarding the frequency and voltage issues: as Morgan Jones has said, the Garrard motor's winding inductance is barely adequate for 50Hz operation, yet it can become noisy at 60 Hz. Similarly, it can become noisy at higher voltages but can lose dynamics at lower voltages. Some people prefer high levels of drag loading (grease bearing, eddy brake on), some people prefer low (oil bearing, eddy brake off). All three settings interact.

My personal preference is to run at about 53 Hz with the eddy brake fully on, adjust voltage to get close to correct speed then trim the speed using the frequency adjustment. YMMV, my aim is to provide a device which allows you to find your preferred operational points and which then retains them.

I will not discuss delivery and price issues here, the mods don't like it. If you are on the list you'll get an email when my transformer guy gets back to me.

Mark, Sorry to have let the cat out of the bag, as it were. There was no intent on my part to embarrass you in any way. In fact, I admire you for not going ahead with the SS controller, if you had doubts about its long term reliability.

No problem Lew, I'm old enough and ugly enough to take responsibility for what I have (or in this case, have not) done.