Pre-amps with Loudness - OSD Pre-1 ?

[john61ct]

Like buying a nice car just for the cigarette lighter.

Maybe I win the lottery

 

[john61ct]

candidate switchers

https://www.amazon.com/Bi-Directional-Switcher-Channel-Splitter-Selector/dp/B0B4JRDMG6

https://www.amazon.com/PROZOR-Bi-Directional-Channel-Splitter-Selector/dp/B0B2P4FC7L

 

[Mr_RGB]

I have several Yamaha R-S700 receivers that I occasionally use as preamps, since they have Pre-Out Main-In jacks. They have Variable Loudness and Remote Trigger out. They can be had used for $200-$300 on a certain resale site... I love the flexibility.

 

[melomane13]

have high hopes for the DSPi project in future.

Camilladsp have loudness, with variable reference level and bass treble level. the behavoir is the same as in RME sound interfaces. Camilladsp is at version 3, stable and powerfull and work perfect on rpi

 

[thewas]

Some Yamaha amplifiers have a variable loudness - like the A-S501 and A-S701.

It is telling for the state of the audio world that so few pre or integrated amplifiers have such a so important feature and even worse seemingly none operatable via remote control. Now this would a great niche market for small companies like Topping, Fosi etc and a guaranteed buy from me.

 

[john61ct]

The Forkbeard ones from Schiit like Eitr 2 are remote via their app.

The Chase RLC-1unit (OG analog) has an IR remote, or the codes can be learned by a universal unit.

Same with RME ADI-2 but LC is a much smaller part of its functionality.

 

[Bland_username42069]

Using a Yamaha with pre outs is probably the best bet if RME is out the equation. You get the physical tone controls, the LC, and you could probably pick up a suitable model used cheaply

 

[john61ct]

Are you basing that on your perception of Yamaha's LC being a better implementation?

Wouldn't a straight preamp deliver that? No need to buy a Yamaha receiver or integrated amp right?

 

[Schollaudio]

Found an Adcom GFP 555 (pre-amp not power) which has a simple loudness "Contour" toggle. Also balance, bass / treble knobs, mono, hi/lo filter buttons, decent phono stage, integrated HPamp...

Two different RCA analog outputs, one with capacitors in the chain and another bypass "Lab" output that is DC coupled for purists

Two separate input switchers, one for Listening, the other "recording" for external signal processing loop inputs

each offer FIVE choices of analog inputs, not counting phono

THREE external processing loops, two switched / bypassable + one marked "Signal Processor" unswitched full-time but via bridging inserts.

Unknown if the "Lab" RCA output bypasses that last full-time loop or not, presumably does disable the tone-related front controls.

Also unknown if the GFP-555's loudness contour is automatic-variable or not, will test it against say Chase RLC-1, maybe Schiit Mimir for use on the full-time loop as remote volume control.

Then maybe put an OG GEQ or Wiim Ultra / other DSP EQ on to a switched loop for room correction EQ, so can disable for headphone use

If Mimir is not used for volume control + loudness then putting it on the second switched loop could PEQ differently for headphones, and/or act as remote ad-hoc-adjustable PEQ tone controls

with more applicability than the GFP-555's, which only affect 40hz and 15khz

I think safe to say blows the Pre-1 out of the water...

yes likely need to renew capacitors

I've had an Adcom preamp for many years. The loudness is variable but with only the bass boost, treble remains flat. If the tone controls are bypassed the whole preamp is just one opamp circuit so very simple. Opamps are labeled "Adcom" but most likely a common type like 5532 etc. The phono does sound decent as does the headphone amp. Not bad to have around for $100-200, even less from craigs or marketplace.

Being a DIYer I've built loudness controls around the old radio shack low end Alps volume control with the extra tap just for loudness.

More info here

Better info here

 

[john61ct]

I could get into DIY, filter design etc if necessary, but only if necessary, would be a big time suck I think.

I've had an Adcom preamp for many years. The loudness is variable but with only the bass boost, treble remains flat.

Nice, in line with Dr Toole's advice apparently

@Floyd Toole

 

[john61ct]

I was thinking of using Schiit Vestri's DAC/amp as an LC / Volume level control at LP

However it turns out it's not as adjustable as the Forkbeard pre-amp version

which can be added to the Mimir DAC, which accepts AES, both S/PDIF types, and USB

or Eitr 2 USB DDC to AES and both S/PDIF types.

The algo curve stays constant, but with the Forkbeard one the "intensity" of its application can be dialed up and down to taste.

 

[john61ct]

Relevant Schiit

Schiit Happened: The Story of the World's Most Improbable Start-Up

That's a Texas charcuterie. Suitable for any time of day. ;) My word! I don't eat that much meat in an entire month. :astonished:

www.head-fi.org

 

[john61ct]

A note to self

if DSP is required, look again at that for Loudness Contour, coupled with ad-hoc user Volume level control at MLP.

Some say Camilla has a good implementation on RPi, and DSPi's is likely SOTA