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View Full Version : Wanted: Valve buffer, single input



montesquieu
03-03-2018, 23:09
Being beaten to the draw for one for sale here has prodded me to get on with posting this up.

I currently have an Esoteric Re-Equalizer in my tape loop that I switch in for use with early mono and 78s, that re-shapes the equalisation curve (these weren't standarised officially to RIAA till 1956, and actually didn't settle down until well into the 60s).

It works well but it's solid state (op amp based) I've been wondering whether it might benefit from a valve buffer before it comes back into the preamp.

Anyone got something going reasonably cheap?

Jazid
04-03-2018, 00:31
Sounds like the problem isn't the buffer to me.. Any op amp based equaliser with high output impedance must be designed about as well as a car with a square steering wheel... and wheels...

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montesquieu
04-03-2018, 00:50
Sounds like the problem isn't the buffer to me.. Any op amp based equaliser with high output impedance must be designed about as well as a car with a square steering wheel... and wheels...

Sent from my GT-I9195 using Tapatalk

Not really hearing a problem as such James in fact I’ve owned this for 6-7 years which must be getting on for a record for me in recent years anyway.

Nick Gorham built me a linear PSU for it and substantially upgraded the op amps a year or so in. On flat settings (labelled RIAA - no change since it either goes in series after a photo stage, or can be switched in in a tape or effects loop which is how I have it) it’s pretty transparent.

I’m just curious to play with a buffer with it that’s all. I have a new rack coming that will give me more space to clutter up.

EDIT you’ve just reminded me my Latin teacher had one of these even in the 70s we ribbed him for it

https://upload.wikimedia.org/wikipedia/commons/1/19/Austin_Allegro_Interior_with_Quartic_steering_whee l.jpg

Lawrence001
04-03-2018, 08:11
Is that an early Allegro?

Jazid
04-03-2018, 11:31
With the quartic magic wheel on display!

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montesquieu
05-03-2018, 18:10
now sorted thanks.