I used a 100K Alps connected to the audio source on the top and the wiper connected to the input of the BA2018 board. The bottom was of course grounded.
Two-gang (=stereo) logarithmic, 10kOhm - 25kOhm for nowadays gear, 50kOhm if you‘ll use old gear (tape-recorder etc.).
Install at the input (amplify the adjusted signal)…
Install at the input (amplify the adjusted signal)…
I recently received an Academy Audio MCL control board with my ISS kit. It has a momentary contact switch (LEFT SWITCH in the pic) which can be used for power up, if so desired. I am searching for some kind of rubbery button that could be installed on the front panel which would allow me to use the MCL switch, but am not having much luck. Specifically, I'd love to have something similar to what was on my Theta Casa Nova. It doesn't need to be lighted. I've searched Mouser for button caps, button hardware, etc., etc., but not seeing anything like this at all. Any guesses? Pics below of the MCL switch and the Casa Nova buttons. Thanks!
bhjazz:
This will probably be of no interest to you but I dispensed with the breakaway left end of the MCL board, replacing it with a toggle switch. If you can't find a nice quality, rubbery momentary switch, perhaps you'll consider a toggle alternative?
Regards.
This will probably be of no interest to you but I dispensed with the breakaway left end of the MCL board, replacing it with a toggle switch. If you can't find a nice quality, rubbery momentary switch, perhaps you'll consider a toggle alternative?
Regards.
Attachments
Hey there, SRMcgee! I was studying the pics of your build just last night and was thinking about implementing a toggle, but really want my front panel to have little or no silver/chrome except for labeling. It will be mostly anodized black which is why the rubberized button was what occurred to me. Maybe I'll have to search for an anodized black toggle.
Edit: I think what I'm up against is that the existing switch is flush to the board. I either need something to get through the front panel to activate it, find a taller switch or do what you did and move it somewhere else...
Edit: I think what I'm up against is that the existing switch is flush to the board. I either need something to get through the front panel to activate it, find a taller switch or do what you did and move it somewhere else...
Last edited:
Try google!
https://m.littelfuse.com/products/s...r-caps-for-push_button-switches/83280_03.aspx
https://www.we-online.com/de/components/products/PBTU_PBSU_9_8_X_18_5_CAPS
Or
Which is inspiring: you could print a mold (the button in negative, inner and outer shape) and make your own button cover out of silicone… 🤠
https://m.littelfuse.com/products/s...r-caps-for-push_button-switches/83280_03.aspx
https://www.we-online.com/de/components/products/PBTU_PBSU_9_8_X_18_5_CAPS
Or
Which is inspiring: you could print a mold (the button in negative, inner and outer shape) and make your own button cover out of silicone… 🤠
Nice! I did try Google, but didn't quite get the same results. The German PBTU looks nice.
The 3D print idea is really cool. I have avoided that world mostly because it will take time away from my DIY audio building 😱 but I do know someone who would take the project on. Cool!
There are enough ideas which have surfaced today that I can probably move on with. Many thanks to you both.
The 3D print idea is really cool. I have avoided that world mostly because it will take time away from my DIY audio building 😱 but I do know someone who would take the project on. Cool!
There are enough ideas which have surfaced today that I can probably move on with. Many thanks to you both.
If I use a headphone there is no bass , if I hold the positive pole to the ground connection there is bass ?
What's wrong ?
What's wrong ?
It might be easier to 3D print or otherwise fabricate a little top hat shaped post, with the larger end (brim) toward the switch. That post can go through your panel and with the brim is larger than the panel hole and will keep it from being able to be pulled out.
Something is wired out of phase.
Please post a series of well-lit, in-focus photos and the members here can start to activate debugging hive mind. Input and output connections and clear photos of the wiring will be important.
🙂 Yes!
And that's the exact part I was looking for in a rubberized form. The brim part is what I'm not seeing online, but am actually finding some rather cool alternatives.
Hi all,
After many hours of faultless operation, my preamp is faulty. One channel is way down on output. The sound is undistorted, but much quieter than the other channel.
This started as an intermittent fault, but now seems to be permanent, so I can't ignore it any more!
Would it be one of the output transistors? How would I go about tracing the fault?
Any help gratefully received.
After many hours of faultless operation, my preamp is faulty. One channel is way down on output. The sound is undistorted, but much quieter than the other channel.
This started as an intermittent fault, but now seems to be permanent, so I can't ignore it any more!
Would it be one of the output transistors? How would I go about tracing the fault?
Any help gratefully received.
I think first you need to isolate the problem to the BA2018 so you are sure this unit has the fault?
In my case I would put on my 1000 Hz test generator and look at the input and output using my oscilloscope to check the gain and waveform.
If the sound is undistorted it would be strange if it is a bad transistor. Then I would expect some distortion. But that is just a guess.
In my case I would put on my 1000 Hz test generator and look at the input and output using my oscilloscope to check the gain and waveform.
If the sound is undistorted it would be strange if it is a bad transistor. Then I would expect some distortion. But that is just a guess.
If you have recently played any pop music from 2023, that usually causes the devices to give up and light themselves on fire. Just kidding.
I'm guessing your BA2018 is already cased up. Still, if you could pop the lid and provide a handful of well-lit pics we can help you troubleshoot. And to throw my own hat into the ring, I always consider that there is a cold solder joint. Mostly because I often have at least one...
Pics, please, kind sir!
Went surfing and now the unit is working perfectly again. Go figure (must be some good vibes or something?!).
I'm going to start with the most obvious culprit - the volume pot (50k Alps) which feeds the line stage (thank you for pointing that one out Rick Ray). The fault is definitely before the active crossover, as the dropout affects both high and low frequency outputs.
I don't have a test generator or oscilloscope, so the pot is probably the limit of my investigative powers.
Hopefully that will sort it. If not, I will probably just build up the other board I have lying around and swap it in.
I'm actually keen to see what 2023 pop music does to it - a spontaneous fire sounds kinda fun!
Thanks for helpful advice everyone.
I'm going to start with the most obvious culprit - the volume pot (50k Alps) which feeds the line stage (thank you for pointing that one out Rick Ray). The fault is definitely before the active crossover, as the dropout affects both high and low frequency outputs.
I don't have a test generator or oscilloscope, so the pot is probably the limit of my investigative powers.
Hopefully that will sort it. If not, I will probably just build up the other board I have lying around and swap it in.
I'm actually keen to see what 2023 pop music does to it - a spontaneous fire sounds kinda fun!
Thanks for helpful advice everyone.
Good to hear. Due to your previous post (the quote below) I'd leave it on for 24 hours or more. If the problem surfaces again take a chopstick or some other non-metal item and gently poke at/tap on the solder joints. Then post some pics. We're here to help.
I recently built my second one of these wonderful line stages.
For the second one, I sourced the parts from Mouser since I was ordering for another project.
I ordered the wrong FETs. Instead of ordering the 2SK209BL, I ordered the 2SK209GR.
The BL has IDSS of 6.0-14mA
The GR has IDSS of 2.5-6.5mA.
Should I get the BL devices or am I OK with the GR?
Thanks.
For the second one, I sourced the parts from Mouser since I was ordering for another project.
I ordered the wrong FETs. Instead of ordering the 2SK209BL, I ordered the 2SK209GR.
The BL has IDSS of 6.0-14mA
The GR has IDSS of 2.5-6.5mA.
Should I get the BL devices or am I OK with the GR?
Thanks.
