PRE1 and AMP1-B - Progressing.. Slowly..

[PartyPhreak]

I'm slowly progressing...

Just finished the input switching circuit for the preamplifier. It's made of 8 relays. 4 of them to switch the two color input LED's and 4 to switch the audio input, so the internal audio wiring can be as short as possible..

Next thing is the build-in USB DAC...

A little teaser
http://www.youtube.com/watch?v=nU6DZL61kOQ

The idea is that they will end up something like this drawing:
http://img.photobucket.com/albums/v2...k/PRE1AMP1.jpg

To be continued.....

[PartyPhreak]

A little further... Still just the Preamplifier, I've ordered a Audiotrak Prodigy Cube to fit inside the preamp for USB-Analog conversion..

http://img.photobucket.com/albums/v2...1/DSCN0246.jpg
http://img.photobucket.com/albums/v2...1/DSCN0247.jpg
http://img.photobucket.com/albums/v2...1/DSCN0248.jpg

[audiophool]

Nice setup PartyPhreak. I like your work. Please post more pics as you progress.

Not sure about the Elton John in the teaser though!

[PartyPhreak]

Audiophool --> Thanks..

Got a little further today..
http://img.photobucket.com/albums/v2...1/DSCN0252.jpg
http://img.photobucket.com/albums/v2...1/DSCN0253.jpg
http://img.photobucket.com/albums/v2...1/DSCN0254.jpg

Now the preamp is almost done, think I might finish it tomorrow and then the front plate just needs some engraving.. And the DAC should be in the mailbox today..

[audiophool]

Your multimeter tells me that you are a serious player...

[PartyPhreak]

Yeah, it's part of my job - so I'm told

Just got the USB DAC, sounds very nice, and the Preamp is almost ready for testing..

http://smg.photobucket.com/albums/v2...1/DSCN0261.jpg
http://img.photobucket.com/albums/v2...1/DSCN0262.jpg
http://img.photobucket.com/albums/v2...1/DSCN0265.jpg
http://img.photobucket.com/albums/v2...1/DSCN0266.jpg
http://img.photobucket.com/albums/v2...1/DSCN0267.jpg

[PartyPhreak]

PRE1 is finished! ( Though the knobs are temporary. The correct ones are en route from China.. [8D] Its tested and adjusted. Until now, only with a square generator and a oscilloscope. Looking forward to getting audio out of it.

http://img.photobucket.com/albums/v2...1/DSCN0269.jpg
http://img.photobucket.com/albums/v2...1/DSCN0270.jpg
http://img.photobucket.com/albums/v2...1/DSCN0271.jpg
http://img.photobucket.com/albums/v2...1/DSCN0272.jpg

Monday I'll start the AMP1..

I've cheated a litlle as I have already assembled the AMP1-B and the power supply, consisting of 2x24Volts SMPS and a bank of 11.000uF per side:

http://img.photobucket.com/albums/v2...1/DSCN0273.jpg

The last thing I'll do, is the engraving...

[audiophool]

Nice job, PartyPhreak. I like to see your extremely tidy layout and I appreciate that you have taken the time to plan it well before you started.

[PartyPhreak]

Thanks

I'm definetly satisfied with the job done..

[PartyPhreak]

BUT..!

Just hooked it up, and I'm definately not impressed by the sound..

Everything homemade seems to work great. No hum, even when volume is fully turned up, and switching between the inputs work great..

The preamplifier is a Smart-Kit SK1070. What kind of s... it's supposed to be a HiFi preamplifier but the treble is terrible, the volume is not at all linear, and when the volume is turned down, the treble almost dissapears, leaving a bad and muddy sound.

NOW what to do? What preamplifier can I build in to the box instead? Need assistance..