Replacing Start/Stop and Speed Switches

[keiron99]

I previously posted about customising my SL1210 (which is currently clad in veneer).

Anyway, my plan now is to get the ever-so-helpful Mr Russ Collins of Layers of Beauty to create my a plinth (wooden surround into which the SL1210 drops). More than likely a dark walnut...in sort of classic Thorens style.

To add to the vintage effect, I’m going to get the top plate of the SL1210 sprayed in a vintage ivory colour. In fact, I have the code for the Garrard 301. I may even try knocking off the chamfered edges of the top plate for a more rounded look (any suggestions on how to do this would be welcome).

Well, I like the look even if you don’t!

The power switch is already removed, the pitch also removed and filled in, but the cue light stays – I find that really useful. The final piece of the jigsaw is replacing the start/stop and speed switches. I would really like to replace them with a single Thorens style knob for Off/33/45.
Alas, I have no clue how I could do this. Does anyone have any suggestions?

[6L6]

It's not going to happen - The Start/Stop switch is a separate electrical function to the 33 and 45 selector, and is separate from power. That can't happen on a switch like an old Thoren's.

You might be able to wire a similar switch for speed selection, but you'll need something for Start/Stop.

[Qwin]

The 33/45 switches are momentary and just send a short signal to the chip they do not remain in circuit like a conventional rotary switch would do.

Anything is possible if you are prepered to redesign from scratch, you could use a period style knob sprung to return to centre and have micro switches operating when turned to left and right to trigger the speed change but would it be worth the considerable effort required to make a good job of it?

As Jim points out the start stop is a different circuit but could be arranged so another switch mounted below the vintage knob could be operated when it was pressed down.

All this is possible, but I wouldn't like the job of getting it all to work with a nice action, I would look for a simpler solution Keiron.

[keiron99]

Thanks all.

I think the best solution is to just stick with the current arrangement!

[thommy]

I came here with the same question so rather than open a new thread will post my comments here as I am currently modifying my own Technics deck.

My plan is also to do away with the standard controls on my 1200 rebuild, and smooth out the top plate. I am going to short out start stop so the power control doubles as a start control. I am then going to put a push switch with 2 positions on the front of the plinth, to select 33/45.

I see from the comment above that the speed control buttons are soft, i.e. only a momentary press is required to send a burst of power to the chip which switches speeds, and this seems to have caused a little confusion because that doesn't mean that they have to be operated in such a way.

Taking a look at the stock deck right now, if I want to select 45 rpm and I press the 45 button it changes speed on press, not on release. It doesn't matter if the switch used is momentary or not and by connecting a double throw switch in place of the two momentaries, the chip is still getting what it needs to change the speed.

The result is a latching toggle switch, which defaults to 33rpm on startup, and when the button is pressed in gives 45 rpm. Press the button again to release, and it goes back to 33.

[Qwin]

Thommy, err you can't do that.

The Start/Stop and 33/45 buttons are only momentary push buttons, they send a brief signal to the control chip asking it to perform one of those functions.

When the deck is running there is no current from the start stop switch for instance, it is only a trigger.

They are not simple switches wich make and break to supply a constant current. If you perminantly supply current for these functions, by wiring them as you suggest, you will create all kinds of problems and maybe even fry the chip.

[thommy]

Hi Ken,

I don't know about it causing all kinds of problems, but you are right in that the chip might not like that signal being constant.

So what it really needs is a double throw double pole momentary pushbutton, rather than a latching one. Thanks for pointing that out, I was going to order the wrong thing!

[thommy]

http://www.ebay.co.uk/itm/DPDT-Minia...item19ef51cab9

The logic in this switch would be suitable.

[Qwin]

thommy- Yes you could use a momentary toggle with two positions for 33/45, that would work, but does it look any better than the stock set up?
That of course is up to you.

THE SWITCH YOU LINK TO IS NOT SUITABLE.

It is a basic on/off toggle with an extra momentary position, check their deccription of on/off/momentary off being the centre position.
You need a momentary/off/momentary.

As for the start stop, you will need a momentary toggle or push button switch.

I see you have a Paradise Phono - Nice!

Good luck with it.

[thommy]

thommy- Yes you could use a momentary toggle with two positions for 33/45, that would work, but does it look any better than the stock set up?
That of course is up to you.

THE SWITCH YOU LINK TO IS NOT SUITABLE.

Yep well spotted. I wouldn't put that particular one on my deck anyway!

I think this might be a job for Arduino. A nano could do it by operating 3 relays. to simulate presses of the panel buttons.

That way the deck could have a single momentary pushbutton for everything; short press = start/stop, long press = cycle between 33 & 45, with selected speed indicated via a bicolour led.

Made something similar for my preamp so that a single push button rotary encoder can control volume and channel selection.