switching box for multiple tonearms inputs ?

Do you want something with buttons? A knob? I find that passive selectors that aren't balanced, especially when connected to turntables, tend to be kind of noisy.

Maybe you'll have better luck.

RE: switching box for multiple tonearms inputs ?, posted on February 3, 2016 at 08:47:04
cjspu Audiophile Posts: 99 Joined: January 18, 2016	with knob maybe.

RE: switching box for multiple tonearms inputs ?, posted on February 3, 2016 at 08:58:04

Poinzy

I suspect you'll have fewer issues with a knob. You can get cheap, multiple-input RCA boxes all over the place. Knobs, metal cases. But they're cheap for a reason.

Maybe someone else can point you towards something that works for him. I gave up on RCA selector boxes a while ago. The only selector box I use now is a TRS unit.

At any rate, here's a source of cheap-o selector boxes. I can't say I endorse any of them, but you might find something you like:
http://www.mcmelectronics.com

Niles, posted on February 3, 2016 at 09:09:41

Cuernavaca
Audiophile

Posts: 878
Location: NW
Joined: December 23, 2011

I don't know where you can find one with 2 outputs, you might have to go DIY. I use a Niles SV-5 passive preamp, a Headroom passive preamp and one from MCM Electronics, you will have to upgrade wiring, though. All are dead quiet. I don't use the volume control.

If you want one with 2 outputs prebuilt, try one of the online preamp builders like Vacuum Tube Audio, or Don Sachs, perhaps. Be prepared to pay a fair amount. Do a search on Ebay for passive preamplifier, there are a few builders who may do it for you.

Thomas
"I've never owned a firearm, but I do have an attack parrot!"

http://www.mcmelectronics.com/product/50-6180

KAB RSX-1, posted on February 3, 2016 at 09:11:23
blade Audiophile Posts: 173 Joined: October 24, 2000	https://www.kabusa.com/rsx1.htm

RE: Niles, posted on February 3, 2016 at 09:13:05

cjspu
Audiophile

Posts: 99
Joined: January 18, 2016

Thanks !

I was thinking something like this one with low level option for tonearms but with five inputs;

http://www.decware.com/newsite/ZSB.html

RE: KAB RSX-1, posted on February 3, 2016 at 09:15:44
Poinzy	I don't know about other people, but I've already done as well as that for a lot less than $300. Thanks, though.

RE: Niles, posted on February 3, 2016 at 09:18:27
Cuernavaca Audiophile Posts: 878 Location: NW Joined: December 23, 2011	That's a nice one, I may have to look into one. The truth is, the cheaper selector switch boxes are pretty crappy. It takes some work to get them noise free. Thomas "I've never owned a firearm, but I do have an attack parrot!"

RE: Niles, posted on February 3, 2016 at 09:28:08
cjspu Audiophile Posts: 99 Joined: January 18, 2016	Also found this one with 4 inputs and cheaper; https://www.don-audio.com/Classi-Phoenix-Stereo-Switch-Box-High-End-Rotary-Source-Selector

RE: switching box for multiple tonearms inputs ?, posted on February 3, 2016 at 09:30:46
Jim E Audiophile Posts: 552 Joined: April 25, 2000	This is an extremely bad idea. With such tiny voltages and currents, I can't imagine any switch that would not cause a substantial loss in sound quality. I'm not just talking about the contacts, but the added stray capacitance in the switch itself. A better idea would be to use two phono stages that feed two different inputs on your preamp. Enjoy! Jim

RE: Niles, posted on February 3, 2016 at 09:31:40
cjspu Audiophile Posts: 99 Joined: January 18, 2016	it seems that for tonearm inputs you also need to have low level output levels; Application: Line level simply means sources like CD players, DACs, tape machines, output from a phono stage, TV's, Computers, Ipods, DVD players and so on. Low level is for tonearms only and should not be mixed with line level devices due to the extreme difference in output levels between the two.

Why I own a Acoustat RP2A preamplifier, posted on February 3, 2016 at 14:57:27
BigguyinATL Manufacturer Posts: 3475 Joined: April 10, 2002	2 MM and one MC phono input... Only use one now. for a while I used all three (TD125mkII with Rabco SL8E and Grace 704 arms on a custom built in the cabinet wall plinth + Technics SL10. When LP was king I could pick my playback poison! "The hardest thing of all is to find a black cat in a dark room, especially if there is no cat" - Confucius

RE: If you are interested in maintaining SQ ..., posted on February 3, 2016 at 17:20:50
andyr Manufacturer Posts: 12550 Location: Melbourne Joined: September 2, 2000	Don't do it! At least I wouldn't - as at such low signal levels, the switch will degrade the signal (ie. it's not just a matter of voltage loss). Andy

RE: switching box for multiple tonearms inputs ?, posted on February 3, 2016 at 20:18:47
zigggy Audiophile Posts: 159 Location: Montreal, Quebec Joined: October 25, 2000	A Fidelity Research FRT-4

RE: switching box for multiple tonearms inputs ?, posted on February 4, 2016 at 06:12:38

Analog Bob
Manufacturer

Posts: 197
Location: Albuquerque, New Mexico
Joined: September 7, 2007

I have tried to build one and to date have been unsuccessful. I even tried silver contact switches with solid silver wire. I have been able to build them hum-free, but the sound difference from straight connections is noticably better. I recommend that you just switch the connectors when using another tonearm or perhaps use a DSA phono stage that has multiple phono inputs. I am not associated at all with DSA.

RE: switching box for multiple tonearms inputs ?, posted on February 4, 2016 at 07:00:24

cjspu
Audiophile

Posts: 99
Joined: January 18, 2016

Thanks everyone for the precious help.

I'm now convinced that the switch box is not such a good idea specially in the case of multiple tone arms.

I'll keep on changing manually the connectors. It's not so difficult because I have a ortofon spu verto and only have to change the connections from the multiple tone arms to the step up. The connection between the step up and the phono doesn't need to change.

DSA Phono2, posted on February 4, 2016 at 07:11:40
Lew Audiophile Posts: 10911 Location: Bethesda, Maryland Joined: December 11, 2000	That's an amazing product. Three entirely discrete phono stages, each with adjustable gain and load, and each with both XLR and RCA inputs (into balanced phono circuits). If only it weren't solid state, but if it weren't solid state it would be prohibitively large. Have you heard it, and if so what did you think of it? I had to put it out of my mind, mostly due to its cost.

RE: switching box for multiple tonearms inputs ?, posted on February 4, 2016 at 09:00:16
Crazy Dave Audiophile Posts: 14371 Location: East Coast Joined: October 4, 2001	Have you tried using shielded cabe for the internal wiring? Dave

RE: switching box for multiple tonearms inputs ?, posted on February 4, 2016 at 09:32:37
Analog Bob Manufacturer Posts: 197 Location: Albuquerque, New Mexico Joined: September 7, 2007	Yes i have tried using Shielded cables internal. But the problem is not the RF or IF interference, it is the degradation of the small signal going through a switch. The best way to switch it is after it is amplified a bit. So, if you used separate phono preamps for each input and switched it afterwards, it would work great.

RE: switching box for multiple tonearms inputs ?, posted on February 4, 2016 at 09:42:51

Poinzy

I have a dual-turntable setup. I finally caved and got a small mixing board for dedicated turntable use. The connections are post-preamp for both decks. Bye-bye noise.

I'm not saying you should go with that solution. I'm just telling you what I did.

RE: switching box for multiple tonearms inputs ?, posted on February 4, 2016 at 11:15:54

Crazy Dave
Audiophile

Posts: 14371
Location: East Coast
Joined: October 4, 2001

Interesting. My Fidelity Research FRT-3 has a Pass-30ohm-10ohm switch. I never had a problem with noise. I wonder how they did it!

Dave

RE: DSA Phono2, posted on February 4, 2016 at 12:31:12

Dave Garretson
Audiophile

Posts: 2448
Joined: June 14, 2005

I heard it at RMAF 2015 with a three-armed VPI and Joseph Audio floorstanders. I saw it with the top off(an impressive build with densely packed mil-spec looking PCBs), and spoke with the designer, a nice fellow. The room sounded very good, but down a notch from the best at that show. IIRC DSA sells direct or in partnership with a single reseller and offers an in-home trial period. He claimed that they have had just one returned. Not bad considering the finickiness of audiophiles buying at this price level. On the other hand, maybe they have sold just one unit... something that often occurs to me when looking at rare and high priced beasts at shows.

RE: DSA Phono2, posted on February 5, 2016 at 06:54:25

Lew
Audiophile

Posts: 10911
Location: Bethesda, Maryland
Joined: December 11, 2000

I know one guy who owns one, out in Colorado. He absolutely loves it. Bought it in favor of a high end tube phono stage that he previously owned. He is the one who connected me with Doug Hurlburt (sp?), the designer, and Doug subsequently came to my house where we listened to each of his two products; the Phono1 is a simpler (and less expensive) design where the box holds only one stereo phono stage, not 3 as in the Phono2. Doug was then living in Northern VA, so he did not have to travel very far to my house. I think he's re-located since.

I am sure that at least the early units were built with cost no object. And Doug is clearly a smart guy who has spent his life in electronics, knows what he is doing.

Vinyl Asylum

switching box for multiple tonearms inputs ?

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