Its alive!
Played around with the lay out and liked the weight balanced with the toroidal dead center. Going to clean up stuff, move wires a bit and make the other daughter cards still but she's singing!
Not much experience with snap in caps - are you guys soldering them or just pop em in and that's all? They feel secure and its nice to be able to swap easily down the road so I didn't solder.
Played around with the lay out and liked the weight balanced with the toroidal dead center. Going to clean up stuff, move wires a bit and make the other daughter cards still but she's singing!
Not much experience with snap in caps - are you guys soldering them or just pop em in and that's all? They feel secure and its nice to be able to swap easily down the road so I didn't solder.
It seems I like to live on the edge! Glad I asked, the power supply board is a very snug fit on those caps so they weren't going anywhere but I soldered them in for good tonight. Thanks for the warning everyone! All good and the DC offset is literally 0.00V after sitting for an hour. Time to get cracking on those daughter cards now . . .
What is the DC voltage at the first filter cap? They are rated for 25V, not a lot of wiggle room if your transformer secondaries are greater than 18V.
I'm running an AS-3218 transfo so its 18v. Figured that was enough margin that I didn't need to step up to 35v rated caps. Output DC is 24v.
Just a thought I had because I bought one of @xrk971's M2x Test PCB's for the daughterboards. Could a preamp be made utilizing only this part of the schematic?
I understand if you remove the Edcor you would run them at unity gain?
Maybe use a Sigma 22 at +-24V to feed the PCB and have a volume pot before.
Link to the board:
https://www.etsy.com/listing/1033151079/m2xyarra-format-breakout-test-board
I understand if you remove the Edcor you would run them at unity gain?
Maybe use a Sigma 22 at +-24V to feed the PCB and have a volume pot before.
Link to the board:
https://www.etsy.com/listing/1033151079/m2xyarra-format-breakout-test-board
Awesome. Could that 10uf capacitor be removed or is it necessary for the design?
Maybe some larger polypropylene/film caps?
Maybe some larger polypropylene/film caps?
The thing is you just want to be sure that there is no DC voltage on whatever the autoformer is feeding. So looking at the M2x schematic you definitely would need the DC blocking cap in that kind of situation. As a preamp...does whatever you plan on feeding have a DC voltage on it? Is there a coupling cap? The autoformer would give any DC voltage (and thus current) a path to ground and you don't want that saturating the transformer.
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I was thinking the same thing for dc offset.
Is this as simple as attaching a 1uf capacitor between the output and ground?
Is this as simple as attaching a 1uf capacitor between the output and ground?
You need a series cap connection to block DC. As far as the cap value to choose, you can use the high pass filter calculator in the "Conversion Calculators" section at Digikey.com to determine the -3dB Cutoff Frequency. Shooting for a value under 5Hz seems reasonable in most cases. You will need to know the input impedance of the circuit this capacitor will be looking into.
Hi - I read the first page of this thread, and it is really interesting.
Since that was written, what is the status of the hard-to-find parts? Better, worse, mixed? Guessing you would not be able to make all 5 boards, but could you make at least 2-3 with parts you can buy in 2025?
Thanks!
Since that was written, what is the status of the hard-to-find parts? Better, worse, mixed? Guessing you would not be able to make all 5 boards, but could you make at least 2-3 with parts you can buy in 2025?
Thanks!
Just finished building all 5 boards and the only substitution I had to do was use a KTC3503-Y on the Mt. View. The LED on that board was a available on digikey but not mouser so I did one of the substitution LEDs listed somewhere in this thread. Everything else readily available - ordered the 'fets through DIY audio for the Ishikawa board.
These 2 boards took the longest -
These 2 boards took the longest -
Thanks, that is encouraging! I have no problem waiting months for a part to come back in stock, but I really don't have interest in trying to buy something off eBay and who knows what you are getting.