Next turntable project....

[Roscoe Primrose]

So, this is on the way:













May start it out in a plinth similar to what the Denon is currently in, may eventually make one out of soapstone or slate, time will tell

Guess I'm gonna be busy for a while

Roscoe

[randy warren]

where did you dig that one up? should be a fun project!

[Roscoe Primrose]

where did you dig that one up? should be a fun project!

Found it on epay... Buy It Now price was a bit lower than they've been typically going for, so I jumped on it. It's coming out of Europe, so it's almost definitely a 50Hz unit, but I've already got the parts to do my own crystal controlled 50Hz supply. tomp, that's what I was going to use one of those amp modules for, now I'll just use one channel of a USA400, and use the other channel for crystal controlled 60Hz for some of the other source components.

Roscoe

[tomp]

Should be a clean stable power supply depending on the signal generator. An adjustable signal generator would also give you speed control.

[Roscoe Primrose]

Should be a clean stable power supply depending on the signal generator. An adjustable signal generator would also give you speed control.

The signal generator is crystal controlled, using a 30ppm crystal. The table already has a speed adjustment, that's what the cryptically labeled +....- knob is.

It finally showed up today. Doesn't look near as bad in person as the photos made it look. Time to get to work

Roscoe

[Guy]

We should remember that most turntables rely on a neon lamp for a strobe that is driven by the line voltage, which in turn is not the most accurate 60-Hz source. Now that your oscillator is well controlled with a 30ppm crystal, it is time to consider the accuracy and tolerance of the strobe.

[Roscoe Primrose]

The motor and the strobe will be driven from the same source...

Roscoe

[Guy]

I knew you knew about this - I wanted to remind the community, too.

Roscoe is way too smart for me!

[dberning]

IN case anyone is interested in an accurate 60 Hz source, you can start with a 153.6 kHz crystal and count down. I was working on building a sine wave power source and considered various crystal frequencies that could be divided with various counters to get 60 Hz. Once an accurate 60-Hz square wave is obtained, it can be converted into a sine wave with a couple of cascaded L-C tank filters.

David

[Roscoe Primrose]

My 50Hz source will be based on this: http://www.mouser.com/Search/ProductDet ... 5-UCC3750N

You use a 32kHz crystal for 50Hz, 38.4kHz for 60hz. I bought two of them, will probably build both, run one into each channel of a QSC USA400, and run the TT of the 50Hz channel, and the digital sources off the 60Hz channel...

Roscoe