INVOLVE AUDIO - Pre-amp design - we want your input!

QuadraphonicQuad

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Overture

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May 11, 2012
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193
Greetings fellow insane audio fiends! I come before you today with the news that we have started the design phase of our surround pre-amp.

On the preliminary feature wish-list we have

Moving magnet / moving coil inputs,
Tape in/out (remember that? I sure don't)
Stereo out, Involve 4ch, 5.1ch out, SQ decoding mode out
Dual woofer output
Headphone out.
Support for HDMI in / pass-through, , RCA in, Bluetooth in. (possibly optical in)
Remote control of all major features
LCD
Level adjust for all channels

What I would like from you is to throw sh*t at the wall to see what sticks. What sorts of things would you like to see in our preamp? I'm not going to say all or even any suggestions will be incorporated, we're only human after all and bound by things like time, cost, and the laws of physics (mostly) but I will say that all ideas will be taken into consideration, at a level of seriousness proportional to how outlandish it is, of course (I'm not putting in a whiskey dispenser. I've been told. Several times. Dammit)

So yes, please. Bring on the ideas.

And as an afterthought, how much would you expect to pay for the pre-amp of 75% of your dreams?

I await with baited breath (I had fish for lunch)

~David
 

vinylguy4

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713
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San Diego area
Thanks for asking.

1) Ability to apply tone controls to the analog inputs
2) the tape in/out to be 5.1. Would allow a processor like a surround master to be put in that tape loop.
3) Loudness button (or something similar).

vinylguy4
 

Yucca

Member
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Mar 12, 2014
Messages
31
Location
France
I'm waiting for this one for a loooooong time...

1) Totally analog design (would replace the SM with mainly volume control and my point 2 added, NO digital conversion added inside, at least for analog inputs)
2) ability to choose the cutoff freq for front/rear speakers
3) XLR outputs (no need for me to get moving magnet / moving coils /Tape inputs, so if we could have the choice between a "vinyl" and a balanced version it would be nice...)

Price : don't really know as it really depends of sound/build quality. I'd say $1000, more or less.
 

proufo

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On the preliminary feature wish-list we have

Moving magnet / moving coil inputs,
Tape in/out (remember that? I sure don't)

A combination of these that allows redirecting the phono signal (NASA-grade relays) to a CD-4 demodulator and bring it back to the preamp.

Stereo out, Involve 4ch, 5.1ch out, SQ decoding mode out

Level adjust for all channels

Full 24/96 internal conversion with INPUT level adjust to fully use the available bits. Also output level adjust. All internal and analog (no messing with the bits nor pots).

I won't suggest a price for it as I'm not in the market. I already have a clear notion where I'm heading equipment-wise.
 

chucky3042

2K Club - QQ Super Nova
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Thanks Proufo

You helped remind me - I would like a direct output from the phono preamplifiers so I can plug it into my SAE click noise eliminator (Thank's Ron/Rustyandi) and then back into the main pre amp. I know its obscure!

Regards

Chucky
 

proufo

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You helped remind me - I would like a direct output from the phono preamplifiers so I can plug it into my SAE click noise eliminator (Thank's Ron/Rustyandi) and then back into the main pre amp. I know its obscure!
Y'know, real hard-core macho Quaddies remove clicks after decoding/demodulating (no phase delay that could affect decoding), so you need TWO SAE units.
 

chucky3042

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Now that's just plain nuts!

Y'know, real hard-core macho Quaddies remove clicks after decoding/demodulating (no phase delay that could affect decoding), so you need TWO SAE units.
 

DuncanS

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Y'know, real hard-core macho Quaddies remove clicks after decoding/demodulating (no phase delay that could affect decoding), so you need TWO SAE units.

How about building in a stereo, and post Quad decode de-click .............. its only a bit more relatively simple DSP! :)
 

DuncanS

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You did say Wish List!

Moving magnet / moving coil inputs, Yes
Tape in/out (remember that? I sure don't) Yes, but 2 off, and as suggested by georgeshannon a 24bit/96kHz 4-channel USB out too!
Stereo out, Involve 4ch, 5.1ch out, SQ decoding mode out Yes
Dual woofer output Don't use them myself!
Headphone out. Yes, but with a pseudo 5.1 headphone mode for the multichannel inputs/Involve-SQ-QS decodes
Support for HDMI in / pass-through, , RCA in, Bluetooth in. (possibly optical in) Couldn't careless about Bluetooth, but Yes for rest, but also inc. optical I/O (handy for DAT), & HDMI out for surround/stereo

Remote control of all major features Yes
LCD Yes. Could you do bargraphs for output levels?
Level adjust for all channels Yes
 

chucky3042

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And now the reason I say you guys are nuts......

The first thing impulse noise reduction units do is to subtract the left and right channels - to produce the difference signals as it was found that phono impulses are normally out phase. Consequently with most matrix based decoder systems the clicks and pops will be more apparent in the rear channels. In my humble opinion it is better to de click the record before the Surround Master- as the click time period has no useful surround sound information in it.

So there

Chucky
 

Overture

Well-known Member
Joined
May 11, 2012
Messages
193
Thanks for asking.

It needs USB inputs.

Heya George,

Do you mean USB input as in hosting a drive with music on it? - Or just as a digital input so that the preamp becomes a DAC / Sound Card?

I'm not sure we want to have a full player-interface on this particular unit, but I'll consider the idea for sure. Also considering having a network port with corresponding phone app to allow lossless playback from a server / nas / whatever.

~David
 

vinylguy4

701 Club - QQ All-Star
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San Diego area
And now the reason I say you guys are nuts......

The first thing impulse noise reduction units do is to subtract the left and right channels - to produce the difference signals as it was found that phono impulses are normally out phase. Consequently with most matrix based decoder systems the clicks and pops will be more apparent in the rear channels. In my humble opinion it is better to de click the record before the Surround Master- as the click time period has no useful surround sound information in it.

So there

Chucky

Thanks for the advice, I'll give it a try.

vinylguy4
 

georgeshannon

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Heya George,

Do you mean USB input as in hosting a drive with music on it? - Or just as a digital input so that the preamp becomes a DAC / Sound Card?

I'm not sure we want to have a full player-interface on this particular unit, but I'll consider the idea for sure. Also considering having a network port with corresponding phone app to allow lossless playback from a server / nas / whatever.

~David

I'm not sure I know enough about it to fully answer your question, but what I find most useful is to put FLAC files on a thumb drive, and insert it into my Oppo player and play the files. That method of conveying music from my PC to my listening system is just so perfect that I always look for that capability when shopping for new equipment.
 

atrocity

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Sacramento, California
What sorts of things would you like to see in our preamp?

I just deleted a long, rambling, convoluted post after I realized all I really want is everything the SQ version of the Surround Master has plus a phono pre-amp, optical input and HDMI out.

The additional inputs would simplify my setup significantly. My one and only complaint with the current Surround Master is that I have to swap cables, boo hoo hoo.

The HDMI out would help in some sad future day when I find myself without multichannel analog inputs, which seem to be getting somewhat scarce lately.

Really, I just want a good decoder with flexible connections. Looks don't really matter to me in the slightest.

As for price...well, I'm an American! I want perfection for $1.98!
 

DuncanS

2K Club - QQ Super Nova
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And now the reason I say you guys are nuts......

The first thing impulse noise reduction units do is to subtract the left and right channels - to produce the difference signals as it was found that phono impulses are normally out phase. Consequently with most matrix based decoder systems the clicks and pops will be more apparent in the rear channels. In my humble opinion it is better to de click the record before the Surround Master- as the click time period has no useful surround sound information in it.

So there

Chucky

I'm a whole 5.1 nuts myself :ugham:
 
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