Good quality rotary switches

[Bo Deadly]

Good info. Have any part numbers / part family references for the analogue gates ? Cheers.

Just glancing at datasheets on mouser I found the following:

MAX20336/MAX20337
super flat Ron seems to be why THD is so good
low capacitance
11 Vpp is "high voltage" IMO
see other Beyond-the-Rails™ parts

ADG6412
expensive but high voltage and good specs
capacitance looks high

ADG2412
very similar to above but slightly less good

XS3A4051, XS3A4052, .. other w/ diff configs
very cheap
voltage swing and THD not great but could be ok for certain designs

The usual concern with analog gates is that low Ron seems to go with high capacitance which puts limits on the impedance of circuits that can be used. Again, one would have to design the circuit around these parts. You can't just drop them in as if they were a relay. If you try to do that with whatever circuit, you'll loose bandwidth, pickup noise, get cross-talk, etc.

 

[Newmarket]

Just glancing at datasheets on mouser I found the following:

MAX20336/MAX20337
super flat Ron seems to be why THD is so good
low capacitance
11 Vpp is "high voltage" IMO
see other Beyond-the-Rails™ parts

ADG6412
expensive but high voltage and good specs
capacitance looks high

ADG2412
very similar to above but slightly less good

XS3A4051, XS3A4052, .. other w/ diff configs
very cheap
voltage swing and THD not great but could be ok for certain designs

The usual concern with analog gates is that low Ron seems to go with high capacitance which puts limits on the impedance of circuits that can be used. Again, one would have to design the circuit around these parts. You can't just drop them in as if they were a relay. If you try to do that with whatever circuit, you'll loose bandwidth, pickup noise, get cross-talk, etc.

Thanks.
Understood.

 

[JohnX]

Hi all

I hope that I am inserting this post into an appropriate thread.

I’m about to do the transformer removal mod on one of my Shure SM 57s - But… I would also like to create a an external balanced (single XLR in & out) box which will house:

1- The original Shure stock transformer
2- Tab AMI T58
3- Cinemag CM-1057
4- Lundahl LL1587
5- (possibly the guts of a Crimson Orange)
6- no transformer at all

Controlled by a a 6 position (5 without the Crimson) rotary switch - or if you have a better suggestion, please tell me.

My question relates to the fact that I have never seen the inside of a rotary switch before and that I don’t know exactly how I am supposed to choose the sort of switch that I would need to do this with.

Would that be 12 poles? 24 poles? or is just 4? It’s a fun idea, but I don’t know exactly what I’m looking for yet. I’m not even sure if it’s possible (or practical) to do what I am suggesting since there would be four connections needed per switch position/transformer.

Although I am curious about these modifications, I don’t wish to sacrifice 4 microphones just to A/B them when I can just remove the transformer from one and have the benefits of all of them in one box.

I would appreciate any help with determining whether this is possible and what kind of rotary switch or other switching I would need to do this

 

[ccaudle]

Would that be 12 poles? 24 poles? or is just 4?

Assuming you are switching input and output simultaneously the naming convention would be 4 poles, 6 position.

 

[JohnX]

Assuming you are switching input and output simultaneously the naming convention would be 4 poles, 6 position.

Thanks so much. I think I got myself confused in visualizing how the switch actually works. So that’s how I got up to the numbers like 24 and 12.
And yes, I would have to be switching input and output simultaneously to do this.

 

[JohnX]

Assuming you are switching input and output simultaneously the naming convention would be 4 poles, 6 position.

I’m looking at the layout of the 4 pole 6 position switch and I’m not exactly sure how I would wire this - it appears to have only a single terminal pair for each switch position.
Wouldn’t I need two pairs for each switch position?

 

[ccaudle]

I’m looking at the layout of the 4 pole 6 position switch and I’m not exactly sure how I would wire this - it appears to have only a single terminal pair for each switch position.
Wouldn’t I need two pairs for each switch position?

Each pole is something like this (with the appropriate number of positions, this shows 4 but you would use 6):


Your input pair would connect to the 0 terminals (sometimes labeled as C or common) of two poles, your output pair would connect to the 0 terminals of the other two poles, and e.g. the 1 pins would connect to the in and out wires of the shure transformer, the 2 pins would connect to the in and out wires of the Tab transformer, etc.
When you turn the knob on a 4-pole switch e.g. from position 1 to 2, all of the common pins on each pole change from connecting common-to-1 to common-to-2, so now input hot connects to Tab input hot wire, input cold on pole 2 common connects to Tab input cold wire, Tab output hot is on pole 3 pin 2, so now that connects to pole 3 common which would be wired to the output connector hot pin, etc.

 

[JohnX]

I think I get it now.
My next question was going to be what the 0 is for - so thanks for covering that.
I think my best bet is to order one and break out the bread board.
Again, thanks!

 

[exlabs]

Blore Edwards? Their switches are great, from the ones I've seen. Don't know what lead times are like though.

I ordered a PXR90: 2P11T, make-before-break, gold, PCB mountable switch from Blore Edwards. I'm very happy with it. I ordered it in August and got it in October. They are very busy, pleasant communications, just over worked it seems! I think if you place a larger order than I did and keep things more standard you might get them sooner. Which reminds me I need to place a larger order!

 

[JohnX]

Each pole is something like this (with the appropriate number of positions, this shows 4 but you would use 6):
View attachment 120193

Your input pair would connect to the 0 terminals (sometimes labeled as C or common) of two poles, your output pair would connect to the 0 terminals of the other two poles, and e.g. the 1 pins would connect to the in and out wires of the shure transformer, the 2 pins would connect to the in and out wires of the Tab transformer, etc.
When you turn the knob on a 4-pole switch e.g. from position 1 to 2, all of the common pins on each pole change from connecting common-to-1 to common-to-2, so now input hot connects to Tab input hot wire, input cold on pole 2 common connects to Tab input cold wire, Tab output hot is on pole 3 pin 2, so now that connects to pole 3 common which would be wired to the output connector hot pin, etc.

So I got started on it and I love the way it works. It’s exactly what it was meant to be. I’m still waiting for the Cinemag and Lundahl transformers to arrive but in the meanwhile, I have position 1 as transformerless, position 2 as the stock SM 57, position 3 as the TAB T 58

I had never heard the T58 before and I’m quite enamored with it.

Although I love the Transformers lunchbox, I’m not sure that I will make any more of these devices with thin tin boxes. They don’t seem to be nearly as solid as the ones of my youth - and those are incredibly expensive on eBay.

Again, thank you so much for all of your help. That switch recommendation was perfect.

 

[ilfungo]

https://www.commutatore.com/

https://www.commutatori-palazzo.it/inglese/commutatori/indice.htm