ChanServ changed the topic of ##yamahasynths to: Channel dedicated to questions and discussion of Yamaha FM Synthesizer internals and corresponding REing. Discussion of synthesis methods similar to the Yamaha line of chips, Sound Blasters + clones, PCM chips like RF5C68, and CD theory of operation are also on-topic. Channel logs: https://freenode.irclog.whitequark.org/~h~yamahasynths
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<cr1901_modern>
whitequark: Good thing your logger actually logs join/leave msgs. I can use that to figure out when my laptop decided to "crash".
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<m4t>
these ym3438's look uh, suspect, and i havent taken them out of the tubes yet
<m4t>
bent leads, they look retinned (too shiny), yamaha logo isnt bold
<m4t>
all the same lot number with different stamps on the back
<m4t>
nice!!!
<m4t>
indents on front seem sanded too
<Ultrasauce>
hopefully they're salvages and not straight up slugs
<m4t>
heh
<m4t>
also, lot number is 1030. 30th week of 2010? lmao
<Ultrasauce>
10th week of 2030
<m4t>
oh
<m4t>
the eproms i got yesterday were blacktopped too
<m4t>
on some i could see the ghost image of the original logo underneath the new one, without even removing any of the blacktop
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<m4t>
im going to use the refund to buy NOS some a legit US seller :P
<m4t>
they're like 10x more expensive tho
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<m4t>
is there a straightforwrd way to see if they're slugs or not with a multimeter?
<m4t>
e.g. pins shorted, resistances, etc
<m4t>
anyways i g2g back to work, ttyl
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<Ultrasauce>
put it in diode mode and check from vcc to gnd and vice versa
<mewtrino>
is this the correct place to ask about the firmware of a midi synth pad?
<mewtrino>
I can get details in five hours; sorry if I'm being a pain.
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<cr1901_modern>
mewtrino: I'm not a stickler for on-topic and MIDI/ROM dumping is discussed frequently. So sure, that's on topic.
<cr1901_modern>
err a good place to ask
<mewtrino>
ok
<mewtrino>
when using an SD card would it load faster if I converted the wav files to mp3
<ZirconiumX>
mewtrino: Yes
<ZirconiumX>
If it can read MP3
<andlabs>
I would like to know where I can get analog synth chips
<andlabs>
I kinda sorta want to try an analog simulation of FM synthesis
<andlabs>
yamaha-style FM, of course
<cr1901_modern>
Buy a few varactor diodes, capacitors and inductors :P
<cr1901_modern>
(Don't: VCOs you create from those components won't have anywhere near the b/w you require)
<mewtrino>
The real question is what's the best Yamaha synth to listen to Touhou with
<andlabs>
I will say this: there is one thing that I know no analog chip that currently exists can do it
<andlabs>
the ADDR envelope
<andlabs>
technically Yamaha FM chips have two decay rates, and "sustain" is just having the second decay rate set to 0
<Ultrasauce>
yeah theres no real reason to integrate that kind of functionality, since it can be implemented with a few components cheaply
<andlabs>
cool link, though, thanks
<andlabs>
what company is as...
<andlabs>
alfarzpp.lv apparently
<mewtrino>
This is coming from a girl who's saving up to buy a PC-98 laptop and Sumireko cosplay
<andlabs>
I need momiji cosplay
<andlabs>
also you really only have two choices: the chip in the PC-98 and the chip in whatever sound card TH06/7/8 supports that allow vgmrips.net to have vgm file sfrom it
<Ultrasauce>
(and now i have some neat polish stamps)
<mewtrino>
I have 1.7 TB of flac Touhou arranges
<andlabs>
good
<andlabs>
=P
<Ultrasauce>
also analog fm is quite difficult to tune
<andlabs>
heh
<andlabs>
I just want to see if it Can Be Done
<andlabs>
=P
<andlabs>
mewtrino: though if you know where I can get a momiji cosplay let me know
<mewtrino>
AliExpress lol
<Ultrasauce>
i try it pretty regularly on my modular and it produces all sorts of lovely timbres but tracking more than an octave for more than a minute is a losing battle
<mewtrino>
Or don't be a coward and make one yourself
<Ultrasauce>
even with well temperature compensated vco designs
<andlabs>
Ultrasauce: ah :/ oh well
<andlabs>
mewtrino: I'm not a coward, I'm just not a seamster =P
<mewtrino>
Who needs seams? Just use hotglue and Bobby pins
<mewtrino>
t. good cosplayers
<andlabs>
heh
<mewtrino>
tfw your only fem clothes are cosplay
<mewtrino>
I'm not even complaining,
<KitsuWhooa>
<andlabs> also you really only have two choices: the chip in the PC-98 and the chip in whatever sound card TH06/7/8 supports that allow vgmrips.net to have vgm file sfrom it <-- a YMF744 (or similar) on a modern computer with a compatible PCIe bridge and linux will let you play OPL2/3 VGMs :p
<KitsuWhooa>
thought I'd mention it :p
<mewtrino>
Are any of you witches?
<cr1901_modern>
KitsuWhooa: If you're going to be receiving the CM-32P, could you privmsg me an address?
<cr1901_modern>
ValleyBell: Will you be the person paying my contact?
<mewtrino>
my mom just tried to stab with me with a fork and kicked us out of the house.
* ZirconiumX
hugs KitsuWhooa
<ValleyBell>
cr1901_modern: Yes, I would do that.
<Lord_Nightmare>
mewtrino: I do know what you're talking about, I think. I can't help personally, though. What part of the country (or rather, what country) are you located in?
<mewtrino>
Nj
<Lord_Nightmare>
I'm in PA, but I can't directly help.
<mewtrino>
It's probably temporary
<mewtrino>
We've ran away before but forgot our passport and had to come back
<mewtrino>
It's okay
<Lord_Nightmare>
If your mom is throwing you out of the house, it doesn't sound okay to me.
<mewtrino>
I mean,
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<mewtrino>
oh.
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<Lord_Nightmare>
alright, now that that drama has been dealt with, any new interesting yamaha synth news
<Lord_Nightmare>
?
<cr1901_modern>
My laptop has been behaving sufficiently that I kinda want to stream vectorizing once a week
<cr1901_modern>
but Twitch wants a phone number now, and I don't want to give them one
<Lord_Nightmare>
my laptop randomly crashed itself last night
<KitsuWhooa>
cr1901_modern: sure, but I need to know when it will be getting shipped, and if by post or courier
* KitsuWhooa
hugs ZirconiumX back tightly
<KitsuWhooa>
I'll be going back to my flat for uni next week, so if it gets shipped next week, it's probably best to send it there directly
<Lord_Nightmare>
cr1901_modern: for 2fa twitch needs a phone number, but i didn't realize they require one for signup now
<cr1901_modern>
not for signup
<cr1901_modern>
for streaming
<cr1901_modern>
they now require 2fa to get your stream key
<Lord_Nightmare>
to get a stream key, i assume
<KitsuWhooa>
they what?
<KitsuWhooa>
wow
<Lord_Nightmare>
from what i'm seeing on reddit there's no way around that
<cr1901_modern>
literally 90% of the calls I get are robocalls
<KitsuWhooa>
I somehow doubt they support TOTP
<cr1901_modern>
I don't need them selling my number to others for more
<KitsuWhooa>
yes
<Lord_Nightmare>
twitch uses 'authy' for 2fa
<KitsuWhooa>
I wouldn't be surprised if this is one of the reasons they do that
<KitsuWhooa>
and not for "authentication"
<cr1901_modern>
And the fact is... I don't give out my cell number. So I _used_ to use it as a "if someone is calling me, it must actually be important"
<cr1901_modern>
"if someone is calling me and not in my contacts list*, it must actually be important"
<cr1901_modern>
now I can't do that
<Lord_Nightmare>
i handle that simply
<Lord_Nightmare>
if you're not in my contacts list, i ignore you
<Lord_Nightmare>
but if you call TWICE, i'll pick it up the second time
<cr1901_modern>
hmmm, that's an interesting idea that might work
<cr1901_modern>
Anyways, my theory is that if I stream once a week regularly, I'll start making more progress as it becomes routine.
<cr1901_modern>
>My laptop has been behaving sufficiently
<cr1901_modern>
Turns out blowing the dust out of the fan is a good idea once in a while lmao
<cr1901_modern>
Twitter actually has my cell already unfortunately. I don't remember why I did that :/.
<cr1901_modern>
KitsuWhooa: I'll get that info re: shipping for you.
<cr1901_modern>
ValleyBell: Thanks. I'll privmsg you w/ payment details when ready.
<KitsuWhooa>
cr1901_modern: alright, thanks
<ValleyBell>
okay :)
<linkmauve>
“20:54:09 mewtrino> I have 1.7 TB of flac Touhou arranges”, yay, I’m not alone. :D
<linkmauve>
I have some albums rwx doesn’t have yet, I contacted them at some point but they never got my torrent AFAIK.
<m4t>
i wish i could just find USED chips. on future purchases i will ask the seller for a picture of what they'd ship me.
<m4t>
lot numbers, etc. :/
<whitequark>
m4t: my strategy is to buy 5 and decap 1
<m4t>
yeh
<m4t>
thats what mine was
<m4t>
do the sellers desrve negative/neutral feedback?
<m4t>
cuz i dont understand how they maintain 99%+ ratings selling shit like this
<KitsuWhooa>
I'd suggest trying it anyway
<KitsuWhooa>
just because it's sanded it doesn't necessarily mean it's fake :p
<whitequark>
yes
<whitequark>
i would leave negative feedback if its fake
<whitequark>
based on die shot
<KitsuWhooa>
usually it's pretty obvious in the audio produced if it's fake, no?
<m4t>
i dont think theyre fake
<KitsuWhooa>
oh
<m4t>
continuity/resistances match up to ym2612 pinout
<KitsuWhooa>
by fake I meant clones
<m4t>
similar 5ohm resistance between 2 gnd points on all of them, similar voltage drop between Vcc/gnd and analog Vcc/gnd on all
<m4t>
o
<m4t>
clones? i mean...seems like that's a lot of effort for a very small market
<cr1901_modern>
Why would they remark it then?
<m4t>
not like ftdis or something
<m4t>
to make them "new"
<whitequark>
cr1901_modern: because they feel like they'd sell them easier
<whitequark>
if the datecode is new
<KitsuWhooa>
I know I got a relabelled 3438 and it was fine
<whitequark>
this is a pervasive problem
<whitequark>
has nothing to do with yamaha
<m4t>
yuuuge problem ;(
<m4t>
my eproms were all repainted/relabeled too :(
<cr1901_modern>
Sounds reasonable (if still bad/a problem)
<whitequark>
its so much of a problem the DoD has developed a number of approaches up to and including sticking the chip into SEM to see if the surface looks remarked
<cr1901_modern>
Someone not in this room (furrtek I believe) is interested in a die shot of the DAC. They're curious about how the exp2lin conversion is implemented. The patent gives a diagram of the pass transistor layout, but AIUI it's simplified
<whitequark>
cr1901_modern: oh i can do that easily
<whitequark>
i think i have yac512
<KitsuWhooa>
I have a dead 3012 DAC if anyone wants it
<KitsuWhooa>
:p
<cr1901_modern>
awesome, looking forward to that when you have the time :3
<whitequark>
KitsuWhooa: you can send me the 3012
<KitsuWhooa>
Sure. It'll probably be quite cheap to send
<KitsuWhooa>
< 4€ apparently
<m4t>
KitsuWhooa: wow what a coincidence, same lot # as mine! :P
<KitsuWhooa>
they're most likely legit, then :p
<cr1901_modern>
GAGD
<m4t>
no other explanation
<KitsuWhooa>
I meant legit but relabelled
<KitsuWhooa>
mine runs fine on my megadrive :p
<m4t>
heh
<cr1901_modern>
Ngl... I didn't know 3438 came in DIP
<m4t>
did yours originally have a ym2612?
<KitsuWhooa>
yes, they all do
<cr1901_modern>
I thought it was purely an IP that Sega implemented into their bus controller
<KitsuWhooa>
well, the model 1s that don't have it in an ASIC
<cr1901_modern>
for Model 2s and above
<m4t>
yeah
<m4t>
i read it's not a 1:1 swap tho. i was hoping to test them in my sega
<cr1901_modern>
and 3438 is what Yamaha advertised it
<m4t>
something about less drive current? different filters?
<KitsuWhooa>
I just soldered a socket on top of the 2612 and put the 3438 on top, with some resistors and caps to plug it in the amp
<cr1901_modern>
m4t: YM2612 has a bug in the DAC
<m4t>
yeah i read that
<KitsuWhooa>
m4t: different voltage levels
<cr1901_modern>
it's called ladder effect. And musicians relied on that bug for certain effects
<m4t>
quieter or?
<cr1901_modern>
different output impedance as well
<KitsuWhooa>
the 3438 is much much louder
<KitsuWhooa>
yes
<KitsuWhooa>
3438 is CMOS IIRC
<m4t>
but it otherwise sounds OK without modifying anything else on the sega?
<m4t>
oh nvm
<m4t>
i just read the "resistors and caps"
<cr1901_modern>
there's a mod you can do
<KitsuWhooa>
yeah, it's really easy though
<KitsuWhooa>
you still need the 2612 on the megadrive, otherwise games will break, because of some differences I can't remember off the top of my head
<KitsuWhooa>
the console reads form the 2612 but writes to both
<KitsuWhooa>
*from
<m4t>
weird
<cr1901_modern>
wait what?
<m4t>
i just socketed my ym2612
<cr1901_modern>
Also, are you using "megadrive" as generic regardless of country, as I do w/ Genesis?
<cr1901_modern>
but if you're tying the /RD line high, I'm guessing you're pretty confident that breaking reading from the chip won't break existing software :D
<KitsuWhooa>
well, the point is that one chip goes on top of the other, and reads are only done from one
<cr1901_modern>
Oh! Nevermind then... I misunderstood
<KitsuWhooa>
the issue is that there's something different related to the timer on the 3438 that breaks games, yeah :p
<KitsuWhooa>
timers?
<KitsuWhooa>
I don't remember any details, sorry
<KitsuWhooa>
feel free to correct me
<cr1901_modern>
Actually that would explain the labelling on the image you linked
<KitsuWhooa>
yeah it's not a great one
<cr1901_modern>
the 2612 is being used as a glorified timer
<KitsuWhooa>
well, it still produces sound
<KitsuWhooa>
so if for whatever reason you wanted to, you could toggle between their outputs
<KitsuWhooa>
just need to be careful with that because I somehow managed to fry the CXA1034 on mine
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<cr1901_modern>
KitsuWhooa: One thing I'd be curious in for shits and giggles: take both outputs and run them through an op amp subtractor, and then record the resulting output
<KitsuWhooa>
might take a lot of tweaking to get the levels right. If anything, it might be better to do it in software :p