Graemed, the link at Linear Audio seems dead, I believe Carl will send you the BOM if not drop box link.
Be aware than the main BOM is for one channel, check with the pcb to be sure one resistor is not missing. Some small errors on the power supply BOM about the connectors plugs for the wires if I remember.
Be aware than the main BOM is for one channel, check with the pcb to be sure one resistor is not missing. Some small errors on the power supply BOM about the connectors plugs for the wires if I remember.
Documents Needed to Build Preamplifier
If you have purchased the PCBs and for some reason do not have the document collection needed to build, simply send me a private message and I will be sure to get those out to you.
Incidentally I have 4 built and tested main PCBs that I assembled as first articles to verify the integrity of PCB orders. Those are available for purchase. Send me a private message if you are interested.
If you have purchased the PCBs and for some reason do not have the document collection needed to build, simply send me a private message and I will be sure to get those out to you.
Incidentally I have 4 built and tested main PCBs that I assembled as first articles to verify the integrity of PCB orders. Those are available for purchase. Send me a private message if you are interested.
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Doug Self Preamplifier - Legacy Look
I had a built v2 first article PCB that I wanted to put into an enclosure. I opted this time for a 'legacy look'. What do you think?
I had a built v2 first article PCB that I wanted to put into an enclosure. I opted this time for a 'legacy look'. What do you think?
I just realized looking at the PICs that I posted...
I still have work to do inside the box and left the knobs 'lose' and as result they are all pointing off in crazy directions! Oh well, you get the idea.
I still have work to do inside the box and left the knobs 'lose' and as result they are all pointing off in crazy directions! Oh well, you get the idea.
1976?
I think the design looks great. I guess you mounted the volume control off the PCB and added a meter circuit. The original Self Advanced preamp had a similar pair of meters and a pair of leds to show clipping. See https://www.google.fr/search?q=1976...ei=ZpQYWYWZLseLao6og8gE#imgrc=WwAVa9lVOz2tAM:
I think I would prefer to build your new version and donate my existing version to a son-in-law, who seems keen to try it out. Is there any matching documentation on meter circuitry, etc?
George
Hi Carl, well it looks amazingly like the Self Advanced Preamplifier of 1976 and which is still running underneath my desk!
I think the design looks great. I guess you mounted the volume control off the PCB and added a meter circuit. The original Self Advanced preamp had a similar pair of meters and a pair of leds to show clipping. See https://www.google.fr/search?q=1976...ei=ZpQYWYWZLseLao6og8gE#imgrc=WwAVa9lVOz2tAM:
I think I would prefer to build your new version and donate my existing version to a son-in-law, who seems keen to try it out. Is there any matching documentation on meter circuitry, etc?
George
George,
Those meters are Sifam AL29B Presenters. I happened to have them in my stash. I expect that I bought them some time ago for some long forgotten project. Modutec makes a similar product. Both show up regularly on EBay and can be bought thru dealers as well. They are both good products.
The VU meter driver is again something from my stash. What I have and will probably use in the finished build is a TEKRAM VU driver board off of EBay.
In my initial testing I took the audio signal from the IO board. My intent was to use the bouncing meters for entertainment rather than critical measurement.
Rod Elliott has a popular circuit on his page VU And PPM Audio Metering
I haven't written up anything special describing the circuit as it's not that complicated. However if enough people have an interest I could do that.
Those meters are Sifam AL29B Presenters. I happened to have them in my stash. I expect that I bought them some time ago for some long forgotten project. Modutec makes a similar product. Both show up regularly on EBay and can be bought thru dealers as well. They are both good products.
The VU meter driver is again something from my stash. What I have and will probably use in the finished build is a TEKRAM VU driver board off of EBay.
In my initial testing I took the audio signal from the IO board. My intent was to use the bouncing meters for entertainment rather than critical measurement.
Rod Elliott has a popular circuit on his page VU And PPM Audio Metering
I haven't written up anything special describing the circuit as it's not that complicated. However if enough people have an interest I could do that.
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VU Meters
Hi Carl,
I guess it would be ironic if I salvaged the meters and drivers from the 1976 Self preamp? But yours look nicer so I shall go that way. It is really nice to see a front panel with non-touch controls....simple, maintainable and readable.
Of course, as ever, the real challenge will be the front panel. How did you get the white scripting ...which looks very nice?
Here's a thought...for flexibility of front panels perhaps all of the pots should be mounted on a separate board, connected via flat cable to the mother board. The pots could not change relative to each other but as a group they would be easy to move around. Just a thought.
George
Hi Carl,
I guess it would be ironic if I salvaged the meters and drivers from the 1976 Self preamp? But yours look nicer so I shall go that way. It is really nice to see a front panel with non-touch controls....simple, maintainable and readable.
Of course, as ever, the real challenge will be the front panel. How did you get the white scripting ...which looks very nice?
Here's a thought...for flexibility of front panels perhaps all of the pots should be mounted on a separate board, connected via flat cable to the mother board. The pots could not change relative to each other but as a group they would be easy to move around. Just a thought.
George
Hmm ...
My wife gave me grief for posting those PICs with the 'crazy knobs'. So here are a few more but with the knobs tightened down.
Yea she's right, they do look better.
My wife gave me grief for posting those PICs with the 'crazy knobs'. So here are a few more but with the knobs tightened down.
Yea she's right, they do look better.
That's an engraved and inch filled panel from Front Panel Express. The cabinet (including the brushed anodized black face panel) is from our own DIYAudio store. I could supply the FPE project file to anyone that wants to build their own. I will also be doing a similar build that will be 1U in height and without meters. I could supply that as well.
FPE files
FPE files for good-looking front panels are gold dust. I would certainly be keen to try both versions...but particularly the one with VU meters
George
FPE files for good-looking front panels are gold dust. I would certainly be keen to try both versions...but particularly the one with VU meters
George
Vintage VU Meters
Carl,
May I be one of the enough that has interest?
Been hunting for VU meters since getting your boards. Looking at Vintage Simpson or Hoyt. Failing that, something like the LED's on the old Dynoco amps.
Still hunting salvage yards for now. Trying to avoid ebay.
Thanks,
H.
George,
Those meters are Sifam AL29B Presenters. I happened to have them in my stash. I expect that I bought them some time ago for some long forgotten project. Modutec makes a similar product. Both show up regularly on EBay and can be bought thru dealers as well. They are both good products.
The VU meter driver is again something from my stash. What I have and will probably use in the finished build is a TEKRAM VU driver board off of EBay.
In my initial testing I took the audio signal from the IO board. My intent was to use the bouncing meters for entertainment rather than critical measurement.
Rod Elliott has a popular circuit on his page VU And PPM Audio Metering
I haven't written up anything special describing the circuit as it's not that complicated. However if enough people have an interest I could do that.
Carl,
May I be one of the enough that has interest?
Been hunting for VU meters since getting your boards. Looking at Vintage Simpson or Hoyt. Failing that, something like the LED's on the old Dynoco amps.
Still hunting salvage yards for now. Trying to avoid ebay.
Thanks,
H.
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It looks marvelous. But I'm sorry to say it now looks better than her cooker, the one that I can see in the backgroud. This could end up being the most expensive pre-amp you ever made 😀
Those meters are useless in amps. You operate the amp in the -40 ... -15 db range most time. Nothing to do for the meters. Mixers and ADC need them.
Fun.....
To quote Carl "My intent was to use the bouncing meters for entertainment rather than critical measurement. ".. they might provr useful and they are pretty. Makes a change from the bland, plastic panels that we see all too often.
George
To quote Carl "My intent was to use the bouncing meters for entertainment rather than critical measurement. ".. they might provr useful and they are pretty. Makes a change from the bland, plastic panels that we see all too often.
George
Controls
Hi Carl,
while you are "volunteering" for all this work could you also tell us where you bought those knobs? They are very clear and readable. For some reason, they are reminding me of Revox! Which chassis are you using from DIYstore?
George
Hi Carl,
while you are "volunteering" for all this work could you also tell us where you bought those knobs? They are very clear and readable. For some reason, they are reminding me of Revox! Which chassis are you using from DIYstore?
George
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Those knobs are manufactured by KILO International. They have a 'Clear Matte' finish with a part number of HD-75-3-7. They are a bit pricey but of very high quality. Digikey (and others) sell them. KILO INTERNATIONAL
That chassis is a Slimline 2U https://diyaudiostore.com/collections/chassis/products/slim-line-2u?variant=12171074564