I have a turntable with stereo output, but would like to connect to a mono amp without losing one channel. I've heard to use two 10k resistors, one from left and one from right tie the other ends together for mono. This seems like it would reduce the signal level, is there a better way?

:I have a turntable with stereo output, but would like to connect to a mono amp without losing one channel. I've heard to use two 10k resistors, one from left and one from right tie the other ends together for mono. This seems like it would reduce the signal level, is there a better way?
:
Terry

When I use a Y connector I get very low signal to the amp, I have to turn it up over half way to get any sound. When I try to run from just the left or right by itself I only get very loud hum. The turntable works good when hooked to a stereo amp. The mono amp works very well with other sources as well, any suggestions?

::I have a turntable with stereo output, but would like to connect to a mono amp without losing one channel. I've heard to use two 10k resistors, one from left and one from right tie the other ends together for mono. This seems like it would reduce the signal level, is there a better way?
::
:
:I do this all the time. Just use a "Y" adapter, stereo to mono. The impedance involved is so high, (between 10K and 100K), that you shouldn't notice any difference. Making an impedance matching network is overkill.
:Terry
:

I take it you have a magnetic phono cartridge. You do need a pre-amp before the mono amp. Connect the channels together after the pre-amp then to the mono amp. A pre-amp can be bought for converting ceramic cartridge to magnetic. A simple small box plug and play.

Thanks Warren, and Terry. I don't know why I didn't think of using a preamp. I guess my grey matter is going south. Thanks guys.

I take it you have a magnetic phono cartridge. You do need a pre-amp before the mono amp. Connect the channels together after the pre-amp then to the mono amp. A pre-amp can be bought for converting ceramic cartridge to magnetic. A simple small box plug and play.
:

:Thanks Warren, and Terry. I don't know why I didn't think of using a preamp. I guess my grey matter is going south. Thanks guys.
:
:
:
:I take it you have a magnetic phono cartridge. You do need a pre-amp before the mono amp. Connect the channels together after the pre-amp then to the mono amp. A pre-amp can be bought for converting ceramic cartridge to magnetic. A simple small box plug and play.
::
:
Duh!
My senior moments are becoming senior days.
I think if you use the preamp, the "Y" adapter will work
t.

Try the Y connector as recommended. The usual magnetic cartridge preamp has a 47 K resistor across the input anyway.

If by chance the preamp you use is overloaded and distorts because it is receiving around twice the expected voltage of a mono cartridge, especially on "loud" passages, then the two 10 K resistors would take care of that. And if you do that, use good ones, not some old junk you have hanging around.

Shielding is extremely critical in this situation, star grounding is a must, and keep the cables as short as possible.

the other way is to use a stereo preamp and use the y connector on the output to your mono amp. The output will be at line level, and should be more controllable at that stage. By the way, if you get an old transistor RIIA preamp (very common as an upgrade item a few decades back,) check the output coupling electrolytics as well as the power supply electrolytics. Very ofter they are leaky. Cheap and easy to replace them. Otherwise you may get a dangerous "POP" if you turn on that little preamp after the tube amp is already warmed up and on line. Please don't ask me how I know.

Of course, there are many, many truely great designs for tube preamp stages out there, just about all of them in the public domain at this point. The difference, even with these tired old stuffed up ears is truly amazing, even with a mediocre amp and speakers. It's a lot like the the difference between color prints (any kind including digital) and color transparancies (a.k.a. slides.) The comparison has been made more than once (dynamic range in audio, and the gamma in photographic methods.)

Have fun!

::I have a turntable with stereo output, but would like to connect to a mono amp without losing one channel. I've heard to use two 10k resistors, one from left and one from right tie the other ends together for mono. This seems like it would reduce the signal level, is there a better way?
::
:
:I do this all the time. Just use a "Y" adapter, stereo to mono. The impedance involved is so high, (between 10K and 100K), that you shouldn't notice any difference. Making an impedance matching network is overkill.
:Terry
:

I had one of those little black box preamp in one of my many junk boxes. It's working for now, but eventually I'll dig up a tubed version I built several years ago. It's in storage but I'm afraid it's buried pretty deep by now. Thanks for all your help, I'm getting pretty good at forgetting things these days.

:Try the Y connector as recommended. The usual magnetic cartridge preamp has a 47 K resistor across the input anyway.
:
:If by chance the preamp you use is overloaded and distorts because it is receiving around twice the expected voltage of a mono cartridge, especially on "loud" passages, then the two 10 K resistors would take care of that. And if you do that, use good ones, not some old junk you have hanging around.
:
:Shielding is extremely critical in this situation, star grounding is a must, and keep the cables as short as possible.
:
:the other way is to use a stereo preamp and use the y connector on the output to your mono amp. The output will be at line level, and should be more controllable at that stage. By the way, if you get an old transistor RIIA preamp (very common as an upgrade item a few decades back,) check the output coupling electrolytics as well as the power supply electrolytics. Very ofter they are leaky. Cheap and easy to replace them. Otherwise you may get a dangerous "POP" if you turn on that little preamp after the tube amp is already warmed up and on line. Please don't ask me how I know.
:
:Of course, there are many, many truely great designs for tube preamp stages out there, just about all of them in the public domain at this point. The difference, even with these tired old stuffed up ears is truly amazing, even with a mediocre amp and speakers. It's a lot like the the difference between color prints (any kind including digital) and color transparancies (a.k.a. slides.) The comparison has been made more than once (dynamic range in audio, and the gamma in photographic methods.)
:
:Have fun!
:
:
:
:::I have a turntable with stereo output, but would like to connect to a mono amp without losing one channel. I've heard to use two 10k resistors, one from left and one from right tie the other ends together for mono. This seems like it would reduce the signal level, is there a better way?
:::
::
::I do this all the time. Just use a "Y" adapter, stereo to mono. The impedance involved is so high, (between 10K and 100K), that you shouldn't notice any difference. Making an impedance matching network is overkill.
::Terry
::
: