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Old 17th March 2017, 02:19 AM   #181
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This is what I did to eliminate some issues with commercial decks.
Sorry it does not help your situation, and I do not want to derail this thread.
Just saying
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Old 18th March 2017, 04:36 PM   #182
ferret is offline ferret  South Africa
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Hi Jim and Ralph,

Would there be a problem feeding a 3-phase set of amps and output toroids, from two seperate SG4s. As I said previosly I have two TD-124s with Papst motors, and by optimising settings on a SG4 per motor would simplify things a bit. I can layout some PCBs to do the switching (with low signal relays) between the two SG4s and do the same with high current relays, after the output toroids, to two seperate cable sockets - one to each TD-124. The control box will have a dedicated PSU (12V) feeding the SG4 and this can power the relays too. The class-D amps will have an independent PSU.

Your advice will be appreciated.

Regards, Kevin
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Last edited by ferret; 18th March 2017 at 04:38 PM. Reason: language
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Old 19th March 2017, 06:45 PM   #183
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I can't see any insurmountable issues with your idea, but I would probably add an extra switch to turn off power to the amps not connected to the toroids
as some class d amps do not like running without an output load.
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Old 19th March 2017, 06:53 PM   #184
Bigun is offline Bigun  Canada
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Originally Posted by Paperweight View Post
The grounds are fine. Rega turntables are known for their motors putting out electrical interference that gets picked up as the arm gets closer to the motor. MC cartridges and adding 20dB of extra gain to the mix make it more noticeable. I listen through headphones so I hear everything and it's distracting.

I'm working on building a copper box to fully encase the motor to see if that helps. I may get around to shielding the wires and cartridge clips to see what happens.
Copper will do nothing for magnetic fields unless used as a 'shorted turn'. You need something ferromagnetic like a thick piece of iron.
"The test of the machine is the satisfaction it gives you. There isn't any other test. If the machine produces tranquility it's right. If it disturbs you it's wrong until either the machine or your mind is changed." Robert M Pirsig.
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Old 19th March 2017, 08:41 PM   #185
ferret is offline ferret  South Africa
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Thanks Ralph. I fully intend to be able to power off each section independently, even the SG4s. What I didn't say in the original post, is that I will have a third SG4 with a 2-phase output for Premotec motors also in the box. Each of the SG4s will have its own power switch, and the Class-Ds too. The one Thorens (9" tonearm) will be moved out so that one of my belt drive TTs can be used too (I have a few that I like to use now and then.) As it is the Thorens decks both need to be restored to full working order.

I'll post some pictures as the project progresses. Still a way to go, and I'm still waiting for the amps. Starting on the SG4s though.

All the best, Kevin
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Old 21st March 2017, 12:33 AM   #186
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Any SG4 PCB batch leftover available? I am looking for one piece.
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Old 21st March 2017, 05:24 AM   #187
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I have two chips available for members outside the US; ideally you would be in Canada but that isn't a strict requirement.

Due to the two price increases by the USPS in the last few years, it's quite expensive for someone in Canada to have a chip mailed from the US, so if the above describes your situation, PM me.

I only have the one board set for my own use so you would have to source them yourself.

Appreciation is deserved to members kffern and Pyramid for their help making these available.
" ... Go back to the beginning of a technology before the priesthood was established; that was the time when people were communicating information, not proving why there needs to be Priests. This is why the old texts tend to be so good. ..."

Last edited by Johnny2Bad; 21st March 2017 at 05:27 AM.
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Old 23rd March 2017, 12:09 AM   #188
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Have two sets of boards and chips that I would like to offer.

One set available now and the second if everything works out with my build.

Sent @bsrdjan a PM but hasn't replied.
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Old 31st March 2017, 02:54 AM   #189
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Location: Virginia..GO ARMY!!

I have two SG4 boards and two EncoderTH boards. message me if anyone is interested,

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Old 31st March 2017, 05:23 AM   #190
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Finally got to the point that I could fire mine up.
This **** only happens to me by the way.
Works fine from the adjustment buttons on the SG4 board just fine, from the rotary encoder, it will adjust up, adjusting down it is not working so well.
When you try to turn it down, it will start to drop a little and then just float around at a certain point within a few 10ths of a Hz.
If you turn it up it works fine, but turning it down again will only drop it to a certain point, and it does the same thing.
Guessing the encoder is faulty.
Oh well, thats just the way things roll sometimes.
If anybody has a solid source on an encoder, would appreciate the link.

Thanks, Greg
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