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HEF 4046 NXP source?
MUFF WIGGLER Forum Index -> Music Tech DIY  
Author HEF 4046 NXP source?
Hello folks,

i'm having some trouble to find some of the NXP HEF4046 chips for 2 Thomas Henry 4046 VCO's.

Currently i only have some TI chips and they are as described crappy in performance, except one who is at least able to track over 4 octaves...

As it seems almost all of the 4046 Through hole series are obsolete now, except TI brand...

Had a look at reichelt, mouser, farnell, etc. all seem to have only TI 4046's in stock and at ebay the same and when something else pops up, then at ridilicous prices...

Anyone knows a good and reliable source for the NXP chips? or had besides the other mentioned brands that should work too, tested it with the phillips HEF4046? as these seem the only other ones widely available at ebay for moderate prices. Well all from China and the likes, which makes it suspicious that these could be counterfeits that perhaps do not work or are just utter crap...
Noodle Twister -MAKE-Fairchild/401598620674?epid=3023758466&hash=item5d8124a402:g:PHA AAOSwfLpbmo8Z

Fairchild one's at the link above. It's pricey though.
you dont want the 74 version, its low voltage

and FYI NXP=Phillips , changed name in 2006
Oh that sounds cool... Hope the specs did remain the same, as i'm unsure if Phillips had produced them before too and which they kept when they swallowed Nexperia (speaking of standardizing and merging of product and production lines in bigger companies) ... fingers crossed that they kept the same specs and such as Nexperia... So i guess i must bite the bitter apple and try those chinese ebay chips.

@thanks noodle twister... but as above mentioned 5V version and btw. more than 8 Eruo is much out my desired price range wink
Reality Checkpoint
I have found one in my stash that I will never use, so you are more than welcome to it.
Noodle Twister
I spotted some of the Phillips chips and there are some Motorolla ones out there too.

For what it's worth I haven't had any trouble with chinese chips yet...
Thanks for the offer Reality Checkpoint, but one i think is perhaps some 9 units less than what i was looking for and depending on where you reside the postage costs would eat off all the budget... Keep it until they reach the 30$ margin then you can either offer it again or surprise a good fellow with a nice generous offer. wink

@noodle twister... Yes i never had any bad experience so far with my ebay buys, except some CA3080 of which half of them were broken and defunct...

I rarely buy chips at ebay as most of the stuff i use i buy from regular retailers stocking the most common chips i need... But you know, several people said that it can be sometimes adventurous to buy chips from asia, especially if it's not from one of the bigger retail sellers there...

I'll give them the chance to positively surprise me and might palce an order at one of these sellers. We'll see and hear what we get... wink
Nexperia are still making the soic version. Might be worth looking into those and some soic to dip adapters.
Or make PCB design and do the minimum order from oshpark.
just a quick update... ordered some 20 pieces of the HEF4046 philips brand via ebay... fingers crossed and thanks for the feedback and recommendations.
Noodle Twister
Noodle Twister wrote:
I spotted some of the Phillips chips and there are some Motorolla ones out there too.

For what it's worth I haven't had any trouble with chinese chips yet...

As of right now I have had some trouble with chinese chips.

Short version as it's slightly off topic hope you don't mind me posting this here wackelpeter.

Built a noise module. Including a LF398N chip for the sample/track and hold feature.

Sample and hold doesn't work. Just sounds like white noise which is normalled to the sample and hold in this module.

All soldering looks good. Replaces LF398N with a different chip (sample and hold IC) Bought five for two dollars Dead Banana Same problem.

Strong feeling it's the cheap IC's that are fake or faulty.

Buys one National semiconductor LF398N for about five dollars.

Module's sample and hold function works perfectly now. This is fun!

Did your phillips IC's arrive @ wackelpeter ? Hopefully all is good with them.
No didn't arrived yet.. The tayda package with knobs for pots, ordered the same day, arrived wednesday this week... sometimes it's pretty quick and sometimes you need some patience when ordering overseas...

Report back as soon as i have tested them.
So today those 4046 arrived in my PO Box... have just switched one of them in and was able to get some "decent" results, which read as far as i can trust the cheap multimeter frequency counter:
0V=50,04 Hz

There is a little discrepancy from the 0V to the 1V step, which i couldn't solve without getting the octaves above falling some percents below their ideal value which was always a bigger gap as the results were it's slightly above...
Also no matter what i did the 4V seems to always fall a little behind... (yes i measured the 4V to be exact)
the other higher octaves falls very slightly off and when i adjust them wiht HF trim i'm able to get the 1600 and 3200 very close or on point but then the 7V value drifts up too much... increasing by another 100 or 150 Hz...

Well that's just an quick observation, while not having placed the tempco instead of my KTY-resistor combination (as said i ran out of tempcos), so i guess with all the proper components assembled, this brand, which is actually phillips HEF4046BP, seems to track much better as my previous Ti 4046's.
Also i haven'T tried another one of the 20 pieces that arrived in the mail today to check differences in this brand... will do that later and meanwhile knock on wood that this wasn't just a happy accident...

Edit: corrected CD4046 to HEF4046BP that's what i got in my mailbox smile
Quick update... tried some different IC's from the bunch of Philips HEF4046BP i got recently... as expected every chip gives you different results so far... some only managed it to track 3-4 octaves and then went totally out of tune, but a few also managed it to track properly as the first one i put in... So on average it's a safe advice to buy a handful and check for the best results, as on average the hit and miss chance could be roughly 50:50 or worse... But you will find some that track well and reasonable...

For those interested i got mine here and they looked new and seem not to be some kind of rip-off, delivery was within 2 weeks or a little bit faster...

10 pieces for 4,50$US including s&h CK-LOOP-MCPWR-PHILIPS/253779389443?ssPageName=STRK%3AMEBIDX%3AIT&_trks id=p2057872.m2749.l2649
Noodle Twister
Glad they are working. It's peanut butter jelly time!

Did you get the tin can version of LM394 ?
Do you mean from this seller on ebay? No i do hand match my trannies myself, and so far they'll give me great results... Tested yesterday again the 4 ASM VCO's for which i used one of the expo Converters from either Thomas Henry'S 4046 or 555 VCO and a litlle adaption from the Buchla 258 clone and they track very well and precise.
Noodle Twister
Ah I see , that's a cool workaround.

I was looking in the build thread and noticed the AS394 there. Then wondered if you had taken that route.

So an old LM394 or two well matched NPN transistors or an AS394 can be used.
That's cool.

I have two CEM3340 and may well build a TH Maximus VCO with them. This 4046 VCO looks really interesting too though.
i just use regular 2n3096 or 2n3904 the most time (besides the usual BC-Series) and buy them always in at least bulks of 50, so it's pretty easy to find some very closely matched pairs. As said i once used Ian Fritz's Transistor but switched to the YATMA circuit posted somewhere in this subforum... You can test more at once...

i personally prefer the 55VCO a bit more... but in general i never had a TH design build i was not satisfied and that i wasn'T able to complete.
Troubleshooter wrote:

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