LS60 12AU7 Balanced Pre-Amplifier

[bstojkovic]

I’m collecting parts and designing how to structure organize thing inside the box. Does anyone have experience with this schematic in general? What I can’t find and figure out rate of volume control potentiometer. Is it 50k or not?
Preamplifier is based on schematic in attach.

 

[Ketje]

There is no volume control, the potmeter is there to adjust the current in the ECC82.
Mona

 

[bstojkovic]

There is no volume control, the potmeter is there to adjust the current in the ECC82.
Mona

Ok, thanks for replay, I know, it is not on this schematic but you need one on the output, I am asking about that one.
I am thinking about TKD 2CP-601S 50K, I am not sure 50k is the right one.

 

[PRR]

Volume pot normally goes in front, and 100k is a fine value.

If you "must" put it after this amplifier, then replace R14 10k with a 10k pot.

 

[N101N]

I would use 50k and one half of that circuit.

 

[Ketje]

For a volume control you need a quad potmeter for stereo.
Or only a tandem like this (also took out the coupling capacitors, no need with DC-coupling)
Mona

 

[bstojkovic]

Volume pot normally goes in front, and 100k is a fine value.

If you "must" put it after this amplifier, then replace R14 10k with a 10k pot.

Yes, you right volume pot on input, sure , my mistake 🙂, I ment that.

 

[Zung]

I looked into something similar but in a single-ended topology; I ended up choosing the E80CC for the gain stage for their much better linearity. NOS E80CC from Tungsram are still available at less than exorbitant cost.