Need help figuring out/finding a rotary switch

[babadono]

Craig,

I am trying to help. When you say phono you are talking about a turntable that you want to be able to switch between the two different preamp inputs correct? And really i don't think it is prudent to leave two amplifiers hooked up to a pair of speakers even if one of them is off especially a tube amp that has a low impedance output transformer. I am certainly no expert on tube amps perhaps someone else will chime in about this part of your setup desires.

Thank you Eric. I knew you were trying to help, but the questions you asked made it seem like you didn't read my original post. I can see now that you were on a different and better track.

My answers are in bold green.

SWITCH A position - Tubes

1. Power off the SS preamp 120V using relay (the amp will be switched off using the 12v signal)one pole of switch will control a double throw relay that switches 120VAC power to either the tube equip. or SS pre I am considering adding an OFF position on the switch, which would require 2 relays. Or a main power switch ahead of the relay, but OK

2. Power on the tube pre and amps 120V using relay.#1 does this I was aware of this. I was including it as a step to keep my mind arranged. Gotcha

3. Switch phono RCA outputs to tubetwo poles(one for left, one for right) will switch the phono output to either the phono input of tube gear or SS gear Correct. I am not sure if I should call this 2 poles or 4. The reason? I don't know if it is better to use a chassis ground or a direct circuit to the output. If the phono is unbalanced(RCA) it will gain nothing to switch the ground.

4. Switch amp RCA outputs to tubeneed clarification here-aren't the tube pre outputs ALWAYS hooked up to the tube amp inputs? I had in my mind that it needed to be switched. Come to think of it, the preamp's and amps could remain connected if we did like you are saying in 3. Originally I was going to have the internal circuit of the phono output link to the appropriate box output (SS or tube amp input). With your commect on phono, I am realizing that the device could be much simplified.Yes

I think you are on to something that will simplify this. Why not leave the preamps and amps connected all the time? As far as disconnecting one of the amps, that could be a double pole relay between the amp and speaker. The new configuration of the switch would be as follows:

MAIN SWITCHBOX

front:

Rotary A/B/C switch labelled Tubes/OFF/Home Theater

Power indicator

back:

Main switchbox Inputs:

1. Phono right channel RCA/coax

2. Phono left channel RCA/coax

3. 12V Power

Main box Outputs:

1. Phono right RCA/coax

2. Phono left RCA/coax

3. Tube 12V out

4. SS 12V out

EXTERNAL POWER STATION BOX

front:

Power indicator

back:

Inputs:

1. 120V AC

2. fuse

3. 12V trigger input for tube (A)

4. 12V trigger input for SS (

External power station Outputs:

1. SS 120V (5A) out

2. Tube 120V (5A) out

Inside:

1. 12v relay for tube 120V

2. 12v relay for SS 120V

3. 12V light for power indicator

activity:

SWITCH A position - Tubes

1. Send 12V signal to "Main box Output" #3. This turns on power to the Tube preamp and amp.

2. Switch phono RCA outputs to tube

3. send a 12v signal to a relay to connect the tube amp to the speakers. Do they make these in 4 pole?Yes

SWITCH B position - SS (Home theater)

1. Send 12V signal to "Main box Output" #4. This turns on power to the SS preamp.

2. Switch phono RCA outputs to SS

3. send a 12v signal to a relay to connect the SS amp to the speakers.

[USNRET]

You've got me thinking... That Niles SPK-1 is the best device to use for [Activity/Switch x position/#3] in the new layout above.

A Niles AC-3 would work for powering on the tube gear, and I would have it off by default. I don't worry at all about the SS stuff staying on.

Now all I need is a single deck switch box with 3 poles and 3 positions. 2 poles for the +L and +R or the phono, and 1 pole for the 12v switch. The 3 positions would be tube/off/ss.

The output of the switchbox would need only 1 12v trigger for the Tubes only.

That simplifies things a great deal. I don't really care to be able to remote control the switching, so the global cache device would not be necessary.

That's sorta what I do. The AC-3 powers the stereo and the SPK-1 switches the amps to the speakers (speaker leads in the middle terminals and amp outputs to the outer terminals0. A simple 12vdc input to both Niles units would swap speakers and power up the 2 channel. BTW, I have spares of both if you get around to wanting to try.

You have a PM for the SPK-1. I already own an AC-3.

replied to

[mustang guy]

Here is the simplified schematic:

Edited February 18, 2014 by mustang guy

[babadono]

Craig,

If you get rid of the 2 poles that switch the phono ground (which will do nothing anyway) you can get by with a 3PDT (or 4PDT) sealed mini toggle switch with gold contacts. I'm pretty sure they make them with center off positions. Rotary switches with open to the environment contacts are just another problem waiting to cause you grief. Are you old enough to remember the old analog TVs? Or do you remember your Dad banging on the TV to get the channel selector switch to make contact?

Just my 2 cents.

Eric

[mustang guy]

Good points. Yes I remember the old TV's! Thank God for DeoxIT! I have revised the schematic to reflect the changes you outlined. Should I directly wire the ground to the coax outer which will in turn be grounding it. Should I be concerned with interference of the 12VDC gound? If so, what's best to do here?

[mustang guy]

I've ordered the parts to make my tubes/ss switch box:

C&K 3 Pole 3 Position 30 degree switch $7.98

1.25" black aluminum knob. $7.08

This box in black aluminum. 6.3" wide X 2.1" tall X 6.3" deep. (below is not to scale) $23.14

3 black and 3 red Keystone nickel plated rca connectors: $2.25 each - $13.50

Turret board for 12v trigger out. $.89

Switchcraft DC power connector for 12v in. $2.15

Switchcraft DC power connector for main power source: $2.28

Total cost $57.02 plus about $3 shipping. That makes it $60 grand total.

That's not bad considering what I started this thread with was going to cost me more than that for just the switch!

Thanks everybody. I will post pictures when I'm all done.

Edited February 17, 2014 by mustang guy

[babadono]

Craig,

I would leave the phono ground connection disconnected from the 12V (-) to begin with. All the 12 volts is doing is turning on and off an external relay(s) correct? From your schematic the 12 volts will be switched on to the same point whether you are in "tube" or "SS". Is that what you want? Be sure to put a commutating diode across the relay coil(s).

Eric

[minermark]

http://www.onlinecomponents.com/

I forgot about these guys being in my favorites, maybe they will have it.

[mustang guy]

Craig,

I would leave the phono ground connection disconnected from the 12V (-) to begin with. All the 12 volts is doing is turning on and off an external relay(s) correct? From your schematic the 12 volts will be switched on to the same point whether you are in "tube" or "SS". Is that what you want? Be sure to put a commutating diode across the relay coil(s).

Eric

hmmm, I see what you mean. Perhaps I won't be using a power indicator... Or maybe I could put two led's behind a crystal so there are two discreet circuits.

edit: I have updated my schematic to include 2 led's. I will mount them at the knob positions for the corresponding selection. perhaps I will use different colors so I can tell from a distance which is on.

Edited February 18, 2014 by mustang guy

[mustang guy]

http://www.onlinecomponents.com/

I forgot about these guys being in my favorites, maybe they will have it.

Thanks. I found everything I need at mouser.com. They have been a great seller.

[mustang guy]

I finished the switch. There is plenty of room on the face for extra features and switches. In the future, I may add some added flexibility. I also left room on the rear for more connections. the box itself is spacious enough for more wire as well. As soon as I get the SPK-1 in, I will try it out. I tested continuity, and everything is perfect.

I am wondering what would be good to use for labeling. I thought the whole box was black anodized aluminum, and I was going to use an engraver. As it turns out, the face and rear plate are ABS plastic.

Any ideas for labeling?

[babadono]

Craig,

The only thing that comes to mind is a Brother PTouch. I don't know if you have access to one. I think they are a little pricey for a couple of labels on one box. Sorry.

Eric

[bracurrie]

I finished the switch. There is plenty of room on the face for extra features and switches. In the future, I may add some added flexibility. I also left room on the rear for more connections. the box itself is spacious enough for more wire as well. As soon as I get the SPK-1 in, I will try it out. I tested continuity, and everything is perfect.

I am wondering what would be good to use for labeling. I thought the whole box was black anodized aluminum, and I was going to use an engraver. As it turns out, the face and rear plate are ABS plastic.

Any ideas for labeling?

How could I adapt this for my amp source selector connected to one pair of speakers?

Thanks

[mustang guy]

I finished the switch. There is plenty of room on the face for extra features and switches. In the future, I may add some added flexibility. I also left room on the rear for more connections. the box itself is spacious enough for more wire as well. As soon as I get the SPK-1 in, I will try it out. I tested continuity, and everything is perfect.

I am wondering what would be good to use for labeling. I thought the whole box was black anodized aluminum, and I was going to use an engraver. As it turns out, the face and rear plate are ABS plastic.

Any ideas for labeling?

How could I adapt this for my amp source selector connected to one pair of speakers?

Thanks

Amp source would require speaker level current, so you would have to use a relay. The best thing you could do is buy a Niles SPK-1, and put together a little toggle switch box with a 12VDC transformer input. When you toggle the power on, it would send 12VDC (minimum of 100mA, but 200 would be better) to the Niles which would switch the relay. When it is toggled off, the voltage disappears and the SPK-1 switches to the default position.

If you also want to trigger an amp to turn on/off, you would need a Niles AC-3.

Note: The AC-3 will only switch one of the devices.

Edited February 24, 2014 by mustang guy

[mustang guy]

Slight change of plans. I added discreet volume controls for the left and right, and I am now going to connect my tube preamp into the box with tube out and solid state out. My favorite tuner has no volume control on the face. I also installed lights so I could visibly see if it is on tube-tube (red), off (no light), or tube-solid state (green). Here are some pics:

[babadono]

Craig,

How'd you hook up them volume controls? If you have them wired directly off the phono inputs I think you're going to change the cartridge loading.

Eric

[mustang guy]

Craig,

How'd you hook up them volume controls? If you have them wired directly off the phono inputs I think you're going to change the cartridge loading.

Eric

I am not using them for phono any more. I have had a change of plans, and I'm using the box as a control for the preamp to amp connection now. The 10Kohm pots have a built in SPST 3A switch, which allows me to turn a channel off completely. It should be pretty slick.

I am in the market for a tube type phono amp. There is one that actually has a USB connection, and does the analog/digital conversion when in that mode. It's the Bellari VP-530. It gets good reviews and feedback. If I use that preamp, I won't need a switch. I will either go directly to the tube gear or to the computer via USB. I think my AVR has USB too. hmmm

In any event, I needed volume control on my tuner, and this was a way to kill that bird, and allow me to run that tuner into my AVR, so I can play tubes on all 5 LaScalas and the two THT's.

[mustang guy]

Back to the drawing board. That pot doesn't have any effect on volume. Not sure why. It is a 10K potentiometer (ratshack 271-0215), and on an ohmeter it registers correctly from 9.55KHz to 1.8Hz. I have measured directly on the switch and I have measured through the RCA ports. There is variable resistance happening. Just no volume change at all.

Any ideas?

I wonder if I need a 50K to see results.

Edited February 28, 2014 by mustang guy

[babadono]

Craig,

Add the pots to your schematic(1 picture worth many words yada yada), maybe then we can help with ideas. Do you have them wired as rheostats or potentiometers?

Eric

[mustang guy]

It is a potentiometer. Here is the link to the thing: http://www.radioshack.com/product/index.jsp?productId=2062298

The pot has two switched inputs, one for state closed and one for state open.

The pot has 3 other terminals. One is an input, and the other two increase (left terminal) or decrease (right terminal) the resistance when the knob is turned.