Coming mini "Black Box" Pre amp Master!

[NYMo]

3 humps

Obviously not a Bactrian !

 

[barfle]

3 humps

When I was working as an EE, I told people that I could put ten pounds pf s**t in a five pound bag, as long as the customer was willing to pay the price of double-density s**t. Looks like you have that skill as well.

 

[LetsRecapVintageHIFI]

Dear All

Just for a bit of fun and because the really clever bits of the new mini pre amp are kept in the DSP software, I have decided to share with you guys the FIRST CUT schematic that Dave the Bitch has been working on (he is on sanity leave for a week).

The front panel schematic has not been put to CAD but its just a bunch of pots and switches, the interesting stuff is in the main board circuitry. Please be tolerant that Dave always draws his schematics in a tedious, hard to read and put mentally together hierarchical style - I personally like one big connected diagram!!

Its probably full of stuff ups and general brain farts but it gives you guys a sniff that this is not just a toy!

Have fun copying it, if you can you deserve it!

 

[LetsRecapVintageHIFI]

Just add two more bits and nibble on that for awhile Chucky.

 

[Soundfield]

Hi Chucky, I've just noticed that there appears to be an LED above the 'Level' control - what is the purpose of that?

 

[chucky3042]

Hi there

Please put any comments on the preamp we are working on and de hiss, de click, mechanics HERE

 

[DuncanS]

Hi there

Please put any comments on the preamp we are working on and de hiss, de click, mechanics HERE

You could add in the stereo/surround enhancer that the others have talked about, so coupled with an SM would help the Involve mode do stereo to surround

 

[chucky3042]

I actually like the idea, but thinking about it we need access to the rotated 90 degree stuff, so probably keep it in the same box but with an extra knob.

 

[par4ken]

Back in the day when I was building projects from almost every issue of Electronics Today International, I built this click eliminator. It used a TL083 op amp (a TL082 in a 14 pin package) as a preamplifier. It then used a bucket brigade delay chip to delay the signal enough for the click detection and muting circuit to work. The signal was momentarily muted when a click was detected this done via a 4066 CMOS analogue switch.
The unit connected before the RIAA preamplifier. I added a relay to bypass the unit when not in use, as can be seen in the picture. The power supply was in a separate box, connected via a 3 pin DIN connector. While it did work it coloured the sound too much for my taste.

I then tried a different circuit that was published in either Popular or Radio Electronics. As I recall it came after the RIAA preamplifier. Instead of a bucket brigade delay it used an all pass network (like in our matrix decoders) to generate a slight delay. Sadly that was one project that I never got to work properly.

 

[chucky3042]

Back in the day when I was building projects from almost every issue of Electronics Today International, I built this click eliminator. It used a TL083 op amp (a TL082 in a 14 pin package) as a preamplifier. It then used a bucket brigade delay chip to delay the signal enough for the click detection and muting circuit to work. The signal was momentarily muted when a click was detected this done via a 4066 CMOS analogue switch.
The unit connected before the RIAA preamplifier. I added a relay to bypass the unit when not in use, as can be seen in the picture. The power supply was in a separate box, connected via a 3 pin DIN connector. While it did work it coloured the sound too much for my taste.

View attachment 111758

View attachment 111759


I then tried a different circuit that was published in either Popular or Radio Electronics. As I recall it came after the RIAA preamplifier. Instead of a bucket brigade delay it used an all pass network (like in our matrix decoders) to generate a slight delay. Sadly that was one project that I never got to work properly.

I forgot about that one. Do you remember the month/ year?

 

[par4ken]

I forgot about that one. Do you remember the month/ year?

It was in the May 1980 issue of the Canadian version, I'll look to see if I can find the Australian and UK issues as well.
Electronics Today International (Canada) May 1980

 

[chucky3042]

It was in the May 1980 issue of the Canadian version, I'll look to see if I can find the Australian and UK issues as well.
Electronics Today International (Canada) May 1980

I should have it, I will go hunting

 

[kfbkfb]

How about an L-R signal available as a line out jack (I've come to really like the Hafler/DynaQuad method of extracting a surround "channel" from stereo content).

Surprisingly (at least to me), Hafler "decoding" works well on popular music, I recently watched my Culture Club music video compilation, the video for 'Victims" sounds like it was mixed in surround sound (listening using my Hafler passive speaker matrix "decoder").


Kirk Bayne

 

[chucky3042]

How about an L-R signal available as a line out jack (I've come to really like the Hafler/DynaQuad method of extracting a surround "channel" from stereo content).

Surprisingly (at least to me), Hafler "decoding" works well on popular music, I recently watched my Culture Club music video compilation, the video for 'Victims" sounds like it was mixed in surround sound (listening using my Hafler passive speaker matrix "decoder").


Kirk Bayne

As a snot nosed kid of 15 that was my first experience of surround and was the basis of my first home "system ". I was enthralled at the hidden surround content.