Can I turn a Receiver into a Mono Unit

[thebes]

Not the whole thing, but just one channel.

Got a friend with a basement setup consisting of one '59 Khorn and two other non-nondescript speakers he uses for god knows what.

Upstairs he's got Fortes, but he's running them through a separate amp. A fellow Klipscher indeed.

A few months ago his 70's era ss receiver bit the dust, so I offered him an older Onkyo AV receiver a customer had given me.

Problem is, no mono switch for the Khorn, which, not surprisingly, is the way he really likes to listen to it. So I'm wondering if I wired the two sides of the "B Channel" together would I be producing a true mono signal. It would probably be dropping down from 8 to 4ohms but I hardly think that matters for his occasional listening.

So what say yee?

[Sancho Panza]

Could he use just the Center channel feed, if it has one?

Wouldn't that be Mono?

[thebes]

Great idea. Thanks Sancho. Problem is is this is at the dawn of the AV era. It's a standard stereo receiver in name only, with only a function switch for line in "video", no center or rears.

[mike stehr]

Maybe wire the Khorn in series with the left and right channel. Say positive from one side of the AV receiver to negative on the Khorn. Then go positive from the Khorn to negative to the other side of the AV receiver. Sumthin' like that...it'll raise the impedance.

Edited April 1, 2014 by mike stehr

[beeker]

This has totally been on my mind after listening to a 50's mono fisher i was told was worth $2-3k(thats what my buddy said idk tho lol). i really have no idea how the guy was running it my buddy was buying some speakers and he took us on the grand tour. Anyhow great thread. Thanks for making sense to my twisted dreams. Its really been rough. I was afraid to ask

[babadono]

Marty,

You need a little "mono summing circuit" which looks like this drawing. A few resistors and some rca connectors and you are all set.

Is this at the speaker output? Isn't the majority of the voltage therefore power going to be in the 1K resistors?

[babadono]

Ok, but if this is unbalanced equipment aren't the L minus and R minus both signal ground of the sending equipment? Now you're adding resistance in the signal ground to the next input? This will be more noisy than it needs to be. I say eliminate the resistors in the minus legs.

The circuit diagram looks like it might be for balanced equipment.

[thebes]

Pretty cool. so you basically plug your source into the mono summer when you want to use the khorn. I've got the parts (well not 1% tolerance resistors, but 1k's that are close close enough).

However, if it's for balanced equipment it's obviously a no-go. Looking forward to more info.

[babadono]

Thebes,

Using the simple resistive adder will result in an error voltage that gets amplified as well as the desired signal. It may or may not be objectionable to your friend. Go for it. Try it out.

[mustang guy]

This has totally been on my mind after listening to a 50's mono fisher i was told was worth $2-3k(thats what my buddy said idk tho lol). i really have no idea how the guy was running it my buddy was buying some speakers and he took us on the grand tour. Anyhow great thread. Thanks for making sense to my twisted dreams. Its really been rough. I was afraid to ask

I have 2 such units, and I can tell you I paid nowhere near that much. I would recommend a Fisher 90-T. They are excellently built, and deals on Ebay from time to time. There is only a single 80-T, which I actually like better, but it is overpriced.

Here is a picture of my 90-T:

Here is my 80-T. I just refinished a walnut case for it, but haven't got any pictures yet.

It costs some money to get them up to snuff, but once you do, they are both excellent tuner/preamps. I like the 80 a little better. It has a real brass frontplate, and is compact and more vintage looking. The 90 has a painted steel front plate.

[finallygotmyheresies]

I just ordered one of these for my bedroom setup which is a single khorn being run by a Marantz integrated amp. AUDIOPLEX MONIMIXER 200

http://www.ebay.com/itm/Audioplex-Technology-Mono-Mixer-200-/271387207543?pt=US_Video_Cables_Adapters&hash=item3f2ff02777

[BigStewMan]

So what say yee?

You can always get some smoke & mirrors and trick your friends into thinking it is.

Hope you find my advice helpful (you'd be the first).

[beeker]

This has totally been on my mind after listening to a 50's mono fisher i was told was worth $2-3k(thats what my buddy said idk tho lol). i really have no idea how the guy was running it my buddy was buying some speakers and he took us on the grand tour. Anyhow great thread. Thanks for making sense to my twisted dreams. Its really been rough. I was afraid to ask

I have 2 such units, and I can tell you I paid nowhere near that much. I would recommend a Fisher 90-T. They are excellently built, and deals on Ebay from time to time. There is only a single 80-T, which I actually like better, but it is overpriced.

Here is a picture of my 90-T:

Here is my 80-T. I just refinished a walnut case for it, but haven't got any pictures yet.

It costs some money to get them up to snuff, but once you do, they are both excellent tuner/preamps. I like the 80 a little better. It has a real brass frontplate, and is compact and more vintage looking. The 90 has a painted steel front plate.

Omg craig i always wanted to ask you to post a pic and there it is!. That is so, so, so nice looking! In the past couple weeks with recently hearing a new friends large collection largely updated modded polk vintage and new(with another friend i led there to buy some miny vintage polks) he also had this 1950's mono fisher speaker that was said to be worth $2-3k i was thinking about your mono setup the whole time. 2 weeks ago along with seeing your mono setup in your sig and now too see the picture sparks are just flying in my mind to get a mono system up and running. That what you have is something to behold to say the least. Im looking at turning my jealousy here(actually happy for you)and 1 day at a time, let alone years likely to get a mono system in toe for the few friends i allow into my home(still not over being robbed). Thanks for sharing! thats awasome. Mono has to serve its purpose and done correctly i feel it holds a comeback or actually a beginning in my life. Blessings

[mustang guy]

I would love to connect my Fisher 80-T to a Fisher 80-AZ then to a Klipschorn, and set it in a good corner. Maybe some day I will buy a single Khorn just for that purpose.