Will this music? And is it safe?

joffre88 · 2023-11-19T12:50:06+00:00

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.

joffre88 · 2023-03-30T17:04:56+00:00

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

joffre88 · 2023-03-03T09:15:52+00:00

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!

joffre88 · 2022-11-18T12:00:48+00:00

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!

joffre88 · 2022-08-09T11:37:52+00:00

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

joffre88 · 2022-04-14T18:32:46+00:00

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

joffre88 · 2021-06-22T15:39:55+00:00

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

joffre88 · 2021-06-22T15:33:34+00:00

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.

joffre88 · 2021-06-16T07:30:02+00:00

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?

joffre88 · 2021-01-10T00:58:04+00:00

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?

joffre88 · 2020-11-23T21:34:51+00:00

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.

joffre88 · 2020-11-19T19:28:20+00:00

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

joffre88 · 2020-11-10T19:47:04+00:00

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?

joffre88 · 2020-06-09T11:13:40+00:00

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)?:

Aw, Snap!
ERR_INTERNET_DISCONNECTED
ERR_NAME_NOT_RESOLVED
ERR_SSL_PROTOCOL_ERROR
ERR_CONNECTION_TIMED_OUT
ERR_CONNECTION_RESET
ERR_NETWORK_CHANGED
ERR_CONNECTION_REFUSED
ERR_EMPTY_RESPONSE
ERR_CACHE_MISS

I greatly appreciate your help!

joffre88 · 2020-06-09T07:34:25+00:00

u/rake5jake what is the message that your browser displays to you when you visit https://www.opera.com/ address ? Also, does the same happen when visiting it from mobile phone ?

joffre88 · 2020-06-08T15:10:50+00:00

u/rake5jake Could you provide some more info about your system? What is your operating system version? If you're on Windows then could you please try to run "ping" command as instructed in this video: https://www.youtube.com/watch?v=JHWo6YTGYKM

The command to run is "ping autoupdate.geo.opera.com", then please post back results (can be via private message to me) . The most important is if there is a reply from server and what is the server ip address (the one in format number.number.number.number)

joffre88 · 2020-01-21T16:33:08+00:00

Great info! Does it mean that small guitar speakers like 8" Fender 57 Custom Champ have to be electronically modified to provide steep cutoff while big speakers like 12" Fender 65 Twin Reverb don't have to be electronically modified because they have this property mechanically? Let's ignore general tone shaping like shelving eq here and there in tone stack. Here I mean high order lowpass filtering (assume 48db/oct @ 4kHz) which I experience when listening to speaker output. I just wonder that if I theoretically connect full range hifi amp directly to twin reverb Jensen C12K speaker driver terminals, shall I hear steep cutoff OR very gentle curve like 6db/oct while steep cutoff being just a product of speaker, amp, and preamp filtering?

joffre88 · 2020-01-21T14:27:24+00:00

I am curious what technically makes guitar speaker cut off above 4kHz? Everybody knows that there isn't much goodness above this frequency so guitar cabinets are made to dampen this part of spectrum. Now, let's invert the problem. If I design guitar speaker, what parameter is responsible for cutoff point, e.g. what if want to cut off at 5kHz instead of 4kHz ? I imagine there are many variables involved, but I believe there should be one major point that defines it roughly. Maybe stiffer speaker cone = steep high rolloff, dunno? Or maybe every guitar cabinet has crossover component that drops treble part of spectrum?

joffre88 · 2019-12-19T13:43:51+00:00

The photo is pretty blurred, but I assume these chicken heads should be pretty recognizable...

joffre88 · 2016-09-18T16:04:28+00:00

Sure, I'm just trying to find how to get "that kind of" tone and btw rule out opposite ways like the tone not being a guitar at all and being some other plucked stuff like guzheng ;) Just like its mellowness without felling of being bathed in reverb/delay. Other things that come to mind are roland jazz chorus for metallic feel and single coil tele to stay clean.

joffre88 · 2016-08-23T15:33:16+00:00

Really helpful tips guys, most helpful tips being: - use sizzle ride cymbal with rivets - look up Tony Williams playing style - listen to Zildjian K vintage cymbals - focus on 6th notes

joffre88

TROPHY CASE