Mono Hum

Does everyone know about this switch? If you haven't, and don't have any other way to play MONO LP's, I can't recommend it more highly. I have to say I was totally clueless as to what hearing a mono LP in the truest sense was like until I got this switch. I think it's simply amazing and from one of our forum brothers none the less!

I want to preface this post by saying I am NOT suggesting that there is anything wrong with this switch, because it is AWESOME. I have one in my system in Houston and one on another system in Brasil. You can see about the details of each system on the "Information" tab of my Profile Page, and there are links to images of them in my post signature. I hadn't had much time to play with the one in Houston until this past weekend. I don't know if I just never noticed before or if I had the volume down lower before and didn't notice, but this weekend whenever I switch from Stereo to Mono I get a slight hum. It's not overpowering or overly loud, but it is noticeable. It's dead quiet in Stereo. Has anyone else experienced this? What stupid thing have I done or am overlooking?

 

One of my amps doesn't have a mono switch. But I have a stereo-to-mono interconnect cable. It does introduce a little hum in the signal, but it's only audible if you place your ears very close to the woofers in a silent room with no music playing. So I don't care really. So maybe the flaw is inherent to the cable/switch shorting the signal to achieve mono ?

 

You could be right. Mine seemed to be a bit more audible than what you describe but I could have had the volume up quite a bit.

 

I could be wrong, but if memory serves me, I think some other folks may have experienced this as well. If you do a search, you might find something.

 

Thanks. I did search but the only thing I could see that seemed relevant was this. My situation is not nearly as complicated as that but there seems to ring some similarity. I'll have to investigate further.

 

I think I read something else. I don't have time now, but if I remember later today I'll try to find it.

 

Now that I think about this, I had some issues too. Where do you have the switch in your chain...before or after the phono stage? When I put mine between the TT and the phono stage I got noise (but IIRC it was perhaps more audible than what you describe - but not every system is the same). When I put it between the phono stage and the preamp...voila, silent.

 

Ah-ha, let me try that. Thanks!

 

Interesting. Have been using this one http://www.kabusa.com/msx1.htm for about a year in two different configurations.
Initially, my turntable was to a Cayin A5o-T via a NAD Phono Stage. The TT ground was connected to the NAD and I didn't have any hum.
Couple of months later, I got the Cayin CS-55A that I has actually been waiting on while I had the A50-T on loan. One of the main reasons for getting the CS-55A was its built Phono Stage.
Connected the TT via the kabusa box to the amp's Phono Stage, and suddenly got some hum:-(. Could substantially eliminate it by connecting both the TT ground AND the Switch boxes own ground cable to the amp, but when switching box to mono, the hum significantly increases again.
Luckily, the hum level only gets noticeably annoying when I put up the volume way past normal listening values, so it didn't turn out to be such a big issue;-)

 

I tried the set-up using a pair of stereo-into-mono Y-cables that is recommended hereabouts and it was really hummy, so I'm none the wiser and certainly not back to mono. Yet.
DD

 

I bought the mono switch and have used it for the last 6-9 months. First of all I got hum with the Y-cables..I moved them around to minimize the hum. Same thing with the switch, also moved it to minimize. I was however also getting a slight hum with the switch in the stereo mode. A few weeks ago I was listening to some stereo records I was very familiar with when I noticed ...something was missing..ie; a background vocal, a guitar lick, that I knew should have been there (usually could faintly hear it)...I disconnected the mono switch and viola!! the usual sounds were back!

I'll go back to the Y-Cables for mono. Anyone else notice this with the switch or know what could be going on??

 

Check to make sure your cartridge is wired correctly.

 

@xmas111 regarding your Stereo/Mono switch, I think I've seen it stated that the L/R leads can be connected from either direction. Is that true or is there an In and Out direction?

BTW, thanks again for making these!

 

Your right, the L/R leads can be connected from either direction, there is no In and Out.

Your more than welcome.

 

Did you have the switch engaged to mono? This sounds likes stereo being folded down to mono and the out of phase stuff being canceled out...

 

The downside of that switch, and the manufacturer will acknowledge this, as you're running your cartridge's signal through potentially inferior electronics. Let's put it this way, the signal coming out of a cartridge, whether it be a moving coil or a moving magnet, is quite small and delicate. You want to do as little futzing with that signal as possible. Let's say you have a 1m very good quality set of turntable cables running out of your turntable. Mine are the original VPI/Discovery cables that came with the turntable. Pretty good wires. Ordinarily I run that directly into my Art Audio Vinyl One phono preamp.

I'm in the market for a mono cartridge to replace one I sold a few years back to fund an ungraded CD player. In the meantime, I bought a Y-adapter set from Radio Shack to sum the channels to help stabilize the sound when playing mono records. If I used that $35 switch, I'd be degrading the sound from my wood body $1200 stereo Benz cartridge regardless of whether I'd be playing mono or stereo records. The way I have it right now, only while playing mono records is the sound degraded. Secondly, with that switch, you're going to have to buy a second set of cables to go from that to the phono stage. And, as usual, your chain is only as strong as its weakest link.

So you have a relatively low end setup, that switch will be fine. But the better your setup, the more you're going to want to do as I have done for the time being (until I can get that mono cartridge, as I have a second arm wand). You are either going to want to get a MUCH higher grade y-adapter (I think Cardas might make one) or get a much higher end switch. Plus you'll need the extra set of cables of equivalent quality to your phono cable. Again, keep in mind that the signal coming off the cartridge is very delicate and can be altered easily. It's why you need a phono stage to begin with.

 

I see what you're saying and it does make some sense. The manufacturer is here @xmas111 so I would love to get his take on this too. But to address your points.
1) I don't have a low end set up. My cartridge is 3x the price of that Benz. So I think you're saying that I probably WILL have a problem with the switch.
2) You're right about the extra set of cables, but I have that covered already.
3) Cable quality - all of my cables fall into the category of, "You paid what for those cables?"
4) Another thing that you said that really intrigues me now is "futzing" around (I love that word!) with the delicate signal. Right now I have the switch between the TT and phonostage. I'm dead quiet in Stereo but have a slight hum when switched to Mono. @marcb has already suggested that I move the switch to between the phonostage and preamp (which I am going to do this evening or weekend). At least that way I'm not touching the delicate signal with the switch at least until the signal has been boosted by the phonostage. Does that address your comment on this?

I think that leaves me down to only the switch itself. I really want that switch to work. I'm not trying to be argumentative with you, I'm just trying to address your points, which I thought had some validity, even though it's not what I want to hear. :-( I will say though that when the switch is on Stereo and I'm playing stereo, my system has never sounded better. So I would really like to hear from @xmas111 about this.

 

You don't want the switch between the turntable and the phono stage. You want it between the phono stage and the amp. You will alter the resistance with that delicate signal.

BTW, I DID talk with the manufacturer. I mentioned that in my post. The sound, with the switch in the way between the cartridge and the phone stage, will likely sound rolled off. Try it, instead, if you can, between the phono stage and the preamp stage. The signal is stronger at that point, certainly stronger than the relatively anemic signal that the cartridge itself generates. So that other user is correct. You should hear an improvement in the sound. And the hum issue might go away as well.

 

This is what I said 3 days ago...

 

Deja vu all over again.

 

Better than Vuja De - the feeling you've never been there before...

 

Give me a break guys, I've been out of town and not able to change anything yet. @AnalogJ, aren't you actually advocating not using the switch at all saying its a weak link?

 

And I gave you credit for it.

 

My comment wasn't directed at you. Or anyone in particular for that matter.

In fact, I assumed that because you have systems in different places there was a good chance you hadn't had a chance yet. I do a ton of work travel myself that quite often has me on the road as much as I'm home, so I get it.

 

Yes, if you want the purest signal. I can hear the difference. But there are some who would forgo a bit of sonic purity for the convenience.

I can hear the difference between going straight to the preamp and having a switch or a y-cable in the way. I'm spending the money on getting a mono cartridge for my 2nd armwand. For those who don't have that luxury, it's either a switch or a y-cable, the latter would at least allow playing stereo records without something in the way.