Another Diff Pre build
As usual, my projects always take longer to complete than I originally expect them to. This project was no exception, and it also falls in to a category that is all too familiar to me: If I had known how good it would be, I would have done it sooner. It is pleasant to get back to clarity again!
Some details:
- The raw casework is 14-19102 from Par-Metal
- All in one input/fuse/filter modules are too physically large for this application. I had two Schaffner FN2020-3-06 available, along with an IEC connector, a DPST power switch, and some fuse holders.
- The motorized 48 step attenuator is from High Quality Audio & Industrial Attenuators and Passive Preamplifiers
- The motorized attenuator is powered from a Meanwell IRM-20-12, which very nicely snaps in to a size D battery holder (the holder is fastened to the chassis using contact cement).
There is one special trick here. There is a small circuit board that is at the side of the attenuator and in front of the main board. This is something that I commissioned from Tom. It is a signal polarity inverting circuit, that can be selected or deselected from the small switch on the front panel, and with invert selected indicated by a green LED.
I WAS GOING TO ADD THREE PHOTOS, BUT THE SIZE AND FILE SIZE OF EACH IS LARGER THAN THIS SITE ALLOWS. PHOTOS TO BE ADDED IF AND WHEN I LEARN HOW TO WORK ON JPG FILES!!
As usual, my projects always take longer to complete than I originally expect them to. This project was no exception, and it also falls in to a category that is all too familiar to me: If I had known how good it would be, I would have done it sooner. It is pleasant to get back to clarity again!
Some details:
- The raw casework is 14-19102 from Par-Metal
- All in one input/fuse/filter modules are too physically large for this application. I had two Schaffner FN2020-3-06 available, along with an IEC connector, a DPST power switch, and some fuse holders.
- The motorized 48 step attenuator is from High Quality Audio & Industrial Attenuators and Passive Preamplifiers
- The motorized attenuator is powered from a Meanwell IRM-20-12, which very nicely snaps in to a size D battery holder (the holder is fastened to the chassis using contact cement).
There is one special trick here. There is a small circuit board that is at the side of the attenuator and in front of the main board. This is something that I commissioned from Tom. It is a signal polarity inverting circuit, that can be selected or deselected from the small switch on the front panel, and with invert selected indicated by a green LED.
I WAS GOING TO ADD THREE PHOTOS, BUT THE SIZE AND FILE SIZE OF EACH IS LARGER THAN THIS SITE ALLOWS. PHOTOS TO BE ADDED IF AND WHEN I LEARN HOW TO WORK ON JPG FILES!!
I use IrfanView to crop and resize any pics I manage to import.
The range of export formats suits this Forum.
Look at these programs, those you need, Resizer and Viewer, are freeware and wonderfully easy to use :
FastStone Image Viewer, Screen Capture, Photo Resizer ...
Everybody I recommended them to have adopted them.
With Resizer, look carefully at Advanced options, you can get nice images of only a few kB in PNG format with a low but sufficient color depth. Width of 800 pixels is well fitted for publications on the net.
Shareware Capture is a marvel. You can try it for a month for free.
I also used Irfanview which is another very nice tool and has some functions not present in Faststone products. But it is not as handy to change sizes and formats.
Hi All,
Tom suggested Web Resizer - Making Photos Faster - Optimize pictures for websites and email
Here are the results. Photos are as shot, no cropping or any other manipulations other than the resizing.
Tom suggested Web Resizer - Making Photos Faster - Optimize pictures for websites and email
Here are the results. Photos are as shot, no cropping or any other manipulations other than the resizing.
Attachments
Fantastic! Thank you for posting your pictures. It looks like a nice build. I'm happy it came together nicely for you.
Tom
Tom
that driver
hi how does that driver used as a pre amp with a volume control and this pre amp compair in sound quality the smaller package would be more attractive to me as i dont need and so many inputs and i would have way more case work options
hi how does that driver used as a pre amp with a volume control and this pre amp compair in sound quality the smaller package would be more attractive to me as i dont need and so many inputs and i would have way more case work options
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A THAT Receiver + volume pot + THAT Driver powered by a clean supply would be sonically identical to the DIFF PRE.
My Power-86 with a small mains transformer would provide plenty of power. My SMPS-86 is a nice package. A bit overkill for preamp service, but it would certainly work.
Tom
My Power-86 with a small mains transformer would provide plenty of power. My SMPS-86 is a nice package. A bit overkill for preamp service, but it would certainly work.
Tom
Tom, what if you have a multi-channel setup with 3 or 4 THAT driver boards. Is there a way to control the volume on all the boards simultaneously in sync with each other?
hi tom thanks for speedy reply what if i am using a single ended source do i still need THAT receiver?
or would a better option be to use THAT receiver as well as THAT driver and mod a phono lead to a Pseudo-Differential Cable
Sure. Just take the output of the volume pot to multiple THAT Drivers.
Nope. Just take your input straight to the volume control (through a selector switch if you want multiple inputs).
Tom
My build
I used a SlimLine 1U 170mm case from ModuShop and sent the front and rear panels to Schaeffer for processing. Not cheap, but an excellent service and their Front Panel Designer application is easy to use.
I used Rivet Nuts to mount the PCBs
I included one of Tom's THAT Drivers to provide an output for a headphone amp and a board from CustomWorks to provide remote power on/off, volume control and trigger out to the power amp.
Here it is partnered with my Mod-286 dual mono power amp. I'm really pleased with how it sounds fed from a RaspTouch player with an IQAudio Pi-DAC Pro.
I used a SlimLine 1U 170mm case from ModuShop and sent the front and rear panels to Schaeffer for processing. Not cheap, but an excellent service and their Front Panel Designer application is easy to use.
I used Rivet Nuts to mount the PCBs
I included one of Tom's THAT Drivers to provide an output for a headphone amp and a board from CustomWorks to provide remote power on/off, volume control and trigger out to the power amp.
Here it is partnered with my Mod-286 dual mono power amp. I'm really pleased with how it sounds fed from a RaspTouch player with an IQAudio Pi-DAC Pro.
ukhopeful,
You got quite a lot going on there in a 1U chassis - well done! And also goes nicely with your Mod-286.
You got quite a lot going on there in a 1U chassis - well done! And also goes nicely with your Mod-286.
FYI: Those who wish to build the DIFF PRE 8x2 should act soon. I have four board sets left. They're on sale while supplies last. You can find them here: Differential Preamp 8x2 | Neurochrome :: Audio
Tom
Tom
Last board has sold. Thank you to everyone who supported this project. The DIFF PRE 8x2 is officially retired.
Tom
Tom
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