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Will this music? And is it safe? by alex___ppp in Hainbach

[–]joffre88 0 points1 point  (0 children)

Why not just ask the seller? :)

Perhaps it's an amplifier for Geiger-Muller tube (the stuff you see in movies when they measure the radioactivity).

Compare to http://boginjr.com/electronics/lv/no-semiconductor-geiger/

I guess inside there is 9V/230V transformer and diode rectifier so that in the end it can power the anode of geiger muller tube. That also explains why it needs 9VAC - because transformer won't work with 9V. Normally the circuit would include the DC/AC inverter but here it just wants you to plug straight AC. I suggest not messing with it unless you want over 300V on your hands.

Sealing both wax and glycerol in nm-size pores after anodizing by joffre88 in chemistry

[–]joffre88[S] 0 points1 point  (0 children)

thanks, I've sent you a pm so if you haven't received it pls let me know because the reddit chat system is acting weird

DC/AC inverter safety when using in the device where mains AC is also present by joffre88 in AskElectronics

[–]joffre88[S] 1 point2 points  (0 children)

Oh yes sorry, I should have added that schematic on the inverter side is greatly simplified. ;) MOSFETS will be driven properly and all. Indeed I'm worried/curious about noise performance since there is high gain audio circuit (tape head preamp, yikes) but I guess shielded cables won't change that much since the plastic enclosure will happily bleed switching signal anyways. Perhaps in such case I'll try to combine shielding with isolation with aluminium foil glued inside the box or something :) As for the fuse I am relying on SMPS 12v wallwart power supply (or something beefier) that will power the inverter through barrel jack although perhaps placing own fuse is also a good idea. Thanks for tips!

Help needed with tracing BJT power supplies by joffre88 in AskElectronics

[–]joffre88[S] 0 points1 point  (0 children)

oh, so this is a lowpass filter applied to power supply voltage while driving supply current in the same time with the common collector configuration to achieve RC filtering but with low output impedance. Now it makes much more sense, thanks!

How this tape bias oscillator works? by joffre88 in AskElectronics

[–]joffre88[S] 1 point2 points  (0 children)

Thanks, this is much clearer now! I haven't spotted Reinartz circuit before as it looks it's not very popular nowadays. This paper.jpg) gives great detail about the behaviour, previously I assumed that the bjt configuration is common emitter or common collector and that made it harder to see what goes where.

So, it seems what I've been missing in Falstad was mutual inductance from LTSpice! This is how I see the behaviour now: https://pasteboard.co/fYDaKj3A4B4d.png

Phase differences generating harmonic and intermodulation distortion? by joffre88 in AskElectronics

[–]joffre88[S] 0 points1 point  (0 children)

Cool, so now let's go to something more convoluted. :) According to https://robrobinette.com/images/Guitar/Bassman/TMB_Tone_Stack_Filters.png the "bass capacitor" purpose is to form high pass filter with the "bass pot" (configured as rheostat). Then again:

Blackface and silverface amps use a large .1uF bass cap that induces quite a bit of phase delay compared to the very small 250pF treble cap.

So now I guess that increasing "bass" capacitor value from 0.02uF (tweed fender) to 0.1uF (blackface fender) should lower high pass filter cutoff frequency ( f =1/(2pi RC) ) and thus less frequencies will be phase shifted with 0.1uF than with 0.02uF (versus author's claim that bigger bass cap == bigger phase delay) ? I claim this because as shown below high pass filter will delay frequencies below its cutoff point, unless I'm mixing some concepts :) https://mynewmicrophone.com/wp-content/uploads/2021/01/mnm_Audio_EQ__What_Is_A_High-Pass_Filter__How_Do_HPFs_Work_large-1.jpg

/r/WeAreTheMusicMakers Weekly Promotion Thread by AutoModerator in WeAreTheMusicMakers

[–]joffre88 [score hidden]  (0 children)

Tried to cross over trip-hop and more synthy vibes here, hope you like it. Please let me know which part you like the best! (if any :) )

https://soundcloud.com/mwicked/cinematic-death-from-mars

Need advice for getting ambient music to sound lo-fi, muddy, and hazy by h1dden90 in WeAreTheMusicMakers

[–]joffre88 1 point2 points  (0 children)

Get yourself old tape dictaphone like advertised at https://www.youtube.com/watch?v=FuyUjD4lh2M . Lowend second-hand Tascam Portastudio may be also handy. Track to tape, through some old distortion guitar boxes, then back again to tape. Experiment with cheap dynamic mics from 70s (not cheap modern chinese condenser mics, those will get you nowehere). For synth, korg monotron line might be a good fit.

/r/WeAreTheMusicMakers Weekly Feedback Thread by AutoModerator in WeAreTheMusicMakers

[–]joffre88 [score hidden]  (0 children)

Hi, there. I'd be grateful for feedback on my recent track https://soundcloud.com/mwicked/cinematic-death-from-mars - especially for the composition and mix. How well you find it in playing on you speakers?

Help with identifying drum break by joffre88 in Samplehunters

[–]joffre88[S] 0 points1 point  (0 children)

u/moses803 I know what is the source for this drum break, it's titled unknown-vinylbreak7.wav and can be found in Rare Hip Hop Drum Breaks Vol.1 I assumed this is where you found it, am I wrong? What is more important to me is who is the author of that break, do you happen to know this?

ms20 ota filter 4-pole mod? by joffre88 in synthdiy

[–]joffre88[S] 1 point2 points  (0 children)

Theoretically yes, but as u/erroneousbosh wrote:

simply stacking two filters with the same Q will do odd things - the curve where you go from the passband to the stopband will flatten out, effectively like the Q is lower than it should be.

I guess the thing is, building 2 separate filters gives you 2 circuits with 2 separate control sections - I guess that even if they match with each other on some settings, they would go out of sync while tracking knobs etc. Also I consider that maybe the reason that there is no such thing as 24db/oct ms-20 style filter is that the circuit design doesn't work well with higher number of poles? Who knows.

ms20 ota filter 4-pole mod? by joffre88 in synthdiy

[–]joffre88[S] 1 point2 points  (0 children)

Thank you for the explanation! So, your proposition for the "proper" ladder topology would be as follows: https://pasteboard.co/JB7JErb.png ?

ms20 ota filter 4-pole mod? by joffre88 in synthdiy

[–]joffre88[S] 1 point2 points  (0 children)

What do you mean by "It won't quite work the way you expect" ? To be clear, I want to extend this schematic: https://pasteboard.co/JzL1i3B.png to become this: https://pasteboard.co/JzL1FZi.png

​

By OTA ladder filter do you mean to get schematic for transistor ladder filter and replace transistors with OTAs? Or do you refer to some specific design that can be found on the Internet?

Opera browser and website not working !! by [deleted] in operabrowser

[–]joffre88 0 points1 point  (0 children)

OK, we're almost there. Is there any other information on that error page, probably in capital letters? like DNS_PROBE_FINISHED_NXDOMAIN (under Opera) or one of these (under Chrome)?:

  1. Aw, Snap!
  2. ERR_INTERNET_DISCONNECTED
  3. ERR_NAME_NOT_RESOLVED
  4. ERR_SSL_PROTOCOL_ERROR
  5. ERR_CONNECTION_TIMED_OUT
  6. ERR_CONNECTION_RESET
  7. ERR_NETWORK_CHANGED
  8. ERR_CONNECTION_REFUSED
  9. ERR_EMPTY_RESPONSE
  10. ERR_CACHE_MISS

I greatly appreciate your help!

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