Technics 1210 internal regulation mods

[Reid Malenfant]

I seem to remember Leo doing similar but with twin regulators, looks like you now have a dedicated unit to do the job of both Paul

Nice work

[leo]

Looks great Paul! is that the new series regs? a nice tidy fit.

[Clive]

Sure looks neat! I fully expect it'll sound at least as good as it looks.

[MartinT]

The regulators look superb, as with all of Paul's modules. I have them safely in my hands and am awaiting some detailed PCB instructions before making a start.

[leo]

Using a top quality external psu like the SR3/5 is great mod worth the effort which to my ears wasn't subtle, I thought the added separate internal regs was the icing on the cake, it was enough to not want to go back to the stock internal version. Looks like this latest version takes things even further.
I bet going from a totally stock unit to external psu plus internal regs would be quite an ear opener

[leo]

Look forward to see how you get on with these Martin

[Wakefield Turntables]

omg omg omg (cue panic attack) , I was just thinking about these latest mods, do you think these will be available before Xmas. Whats the cost?? This could be a neat xmas pressie to ones self!

[Paul Hynes]

Hi Mark,

Leo said that fitting the two PR3 regulators securely in the transformer well was a bit of a fiddle so I designed a new board called TDR21, with two PR3 regulators on board, to fit the pitch of the transformer mounting pillars. The transformer mounting screws are then recycled to mount the new board securely.

Hi Leo,

The two mini regs consist of one series reg and one shunt reg. They do add some more to the performance. I have wired the regs in with fine silver wire too.

Hi Clive,

I should have sent this to Leo for wiring. He is much neater than me. Now I have got this out of the way I can get on with the phono stage. I will let you know when it is on the way.

Hi Martin,

It’s a little late to get the info organised and sent tonight and I need to crash soon. I will make a start on it tomorrow.

Hi Andrew,

Don’t Panic. Now I have boards for these regs I can make them to order. They are not going to break the bank. I will post some price info in the trade section tomorrow when I get a break.

Regards
Paul

[MartinT]

Here are my Paul Hynes internal regulator upgrades on an already heavily modified SL-1210. This phase 1 involved simply mounting the TDR-21 (twin PR3) regulator board inside the deck, setting one reg to exactly 21V and driving the entire PCB from the one supply. My external SR5-21 became an SR5-27 by adjusting it for 27V output. I went for phase 1 to start with because I wanted to evaluate just a single internal regulator compared with phase 2 which involves a further three regulators (2 x 9.4V & 5V), several components to remove and PCB tracks to cut.

Opening up the deck and preparing to mount the TDR-21 into the transformer well at top left. Beware those die cast posts! I used a self-tapper just a little too large and broke it inside the post I then attempted to drill it out and broke the drill bit in there Several hours later and I had the situation under control. I also spent some time removing the base and replacing the expired bulb inside the pop-up post with a white LED. This was more fiddly than I expected.



Showing the TDR-21 wired in and running, generating 21V from the incoming 27V from the already adjusted SR5. Left meter showing SR5-27 output and right meter showing TDR21 motor drive (nearest reg) output. I've also set the other reg to 21V ready for phase 2. There is some settling time with all the Paul Hynes regs so the meters are showing a little drift, which I have now brought back in.



Phase 1 fully wired and tested.



That's it for now. There's not enough time to reinstall the arm and get eveything balanced up. I have a two-hour drive tomorrow morning so first impressions and phase 2 coming later in the week

[The Grand Wazoo]

I can't help thinking all that gubbins would be better off in a box away from the motor, Martin - is that do-able?