Amplifier knobs...where to "set" on the clock?


Here is a question that has idled in my head for years...

I have a 1983 M-70 Yamaha separate amplifier...paired with a C-70 pre. On the front of the M-70 are two sets of knobs for output...for the A and B speakers. I have never been sure on where to place the output line...as if on a clock.  A  "tech" friend told me that the knobs should be at straight-up "noon"...(not wide-open at 5:00)  He saying the reason: "Let the preamp do all of the work". Then, I asked the tech who serviced the M-70 and C-70 years later and he told me the knobs should be "wide open" at 5:00. no reason, except that is where they should be set.

Hmmm.

What do the fine people here at Audiogon say to those two opposing opinions?

What a hobby!

Thank you in advance.

vinylspin
vinylspin
With the volume set at noon, where is the volume set on the pre when listening at loudest levels.
McIntosh advised me to leave my former SS MC2250 (measured accurately at 305 wpc by them) set at MAX (seems a heck of a lot doesn't it), and then send/pass less from the preamp. SS amp was dead quiet at any volume setting.

Volume (less gain) needed by the preamp, either prior SS preamp, and importantly current Tube preamp, it's tubes need to produce less gain.

Things change when using tube amps. You need to find a/the combo of amp volume and pre-amp volume working together that is noise free.

Then, boost either the preamp volume, or, if integrated amp, boost it's volume, (or both within known noise free parameters) This affects equipment location (height of physical knob rotation or location of remote sensor).

Currently, my tube preamp at 11 am; tube amp at 12 oc. Then, for different cartridge outputs, and/or more volume, I can change either devices volume.

In my particular case, I go from preamp to a Chase RLC-1 remote line controller, then to amp. My volume is a combo of the Chase's default volume/preamps volume/amp volume, which allows me source/volume/balance from listening chair, thus different cartridge outputs, do not effect my paired preamp/amp noise free volume pairing.

Remote balance helps refine individual tracks that benefit a surprising amount from a slight balance tweak. Adjusting from the listening spot remotely makes it easy,
set amp gain at max unless you can’t, such as when you cannot achieve appropriate balance, or your pre is way too hot. Here is the basic technology you need to know to understand why:

The amplifier circuit’s gain (Vout / Vin) is always exactly the same, often around 23 dB of voltage gain. The volume knobs are just resistors in front of that. Often inexpensive and prone to degrading over time. By setting the volume to maximum you minimize the amount of those resistors in the circuit.

Best,
E
+1 erik,
These are resistors in the circuit, all the way up or remove them.
Many japanese power amps of the period had this extra feature, in fact you could connect a source like tape, radio, without having a preamp.

G