2SA733 "K"

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moogah
 
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2SA733 "K"

Post by moogah »

The datasheet lists K version as having a gain from 300-600. Perhaps these could make a substitute for the ap's ?

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braw
 
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Post by braw »

It looks like the CSA733k is the one you're referencing.

http://www.chipdocs.com/pndecoder/number/733.html

adafruit
 
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Re: 2SA733 "K"

Post by adafruit »

moogah wrote:The datasheet lists K version as having a gain from 300-600. Perhaps these could make a substitute for the ap's ?
this is a pretty good idea. you should try ordering a few and see what its like!

zero01101
 
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Post by zero01101 »

holy BANNED, 600??

i wonder what that would sound like...

let us know, yeah? :D

pempelson
 
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Post by pempelson »

very good link / idea !

thanx a lot - this is definetly worth to try !!

greetings, guido

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braw
 
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Post by braw »

Here's a datasheet:

http://www.cpcares.com/pdf/2SA733K.PDF

It does look as though it's rated for 300-600 and the 2SA733p's are rated for 200-400. I just ordered some and am interested in the sound differences.

moogah
 
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Post by moogah »

Excellent. Where did you order them from? I won't have the money to buy parts with for awhile so I'd like to hear some A/B 'ing between the two.

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braw
 
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Post by braw »

I got them here:

http://www.cpcares.com/BipolarTransistor/2SA733K.html

Hopefully they have a good deal of stock. If these work well, they're gonna be gone soon.

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braw
 
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Post by braw »

So here's the deal. I have the kit and haven't started assembling it yet. I have 100 2SA733p's from Mouser, and 25 2SA733k's in transit. What I would like to do is do a 3 way side by side with "standard" gain 733p's, high gain 733p's and high gain 733k's.

To do this I think I should socket the transistors. I'm wondering if there are sockets for this or if it's possible to "dremmel" a standard SIP socket for this. I really want to do the same pattern and similar filter sweeps to document the difference.

I think it will either be possible to create a 303 clone that surpasses the original in the areas that it excelled in, or a sick duck sounding monosynth that should be put to rest.

FF
 

Post by FF »

I used sip strip cut to length, maplin does it order code dc17t, trim it down and it fits perfectly. I socketed all my IC's and all the crucial transitors to facilitate easy modding/tweaks/repairs etc.

Re the "K" binned part I thought of this also but for accuracy you would want to go for the lower range beta (325-400) else it could affect the waveshape, I have not tried it yet as I have not found a source in the UK but when I do I'll post my findings here.

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subatomic
 
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Post by subatomic »

braw wrote:I really want to do the same pattern and similar filter sweeps to document the difference.
thanks for bringing science into this. I look forward to hearing the results. Also, post your luck with the 733k's, how many you had to run through before you had a few around 340-400. Looks like they're a little pricey compared to the 733p's so I'd like to minimize my order.

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braw
 
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Post by braw »

Well what the BANNED?? I finally got my order for 2SA733k's and they are labeled 733y-105 on them and what looks like a white out mark on the back. The pin configuration seems different from the 733p's. Normally it's flat side down, left to right, E C B. These seem to only read with flat side up left to right as C B E, and the gains are all under 200.

I can't seem to find much info online as to what these are. Anyone??

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controlvoltage
 
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Post by controlvoltage »

your datasheet shows typical gain 200, max 600... if typical = average, then this just means the hFE is much less consistent then for the standard part, and an average must be a mean value for all parts, meaning hFE of <200 plenty of the time. It could just be that your sample batch is too small to find any high-gain standouts.

As for the different parts code/pinout... well that's another kettle of different-colored horses...

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braw
 
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Post by braw »

Agreed. I called the place and the guy straight up said to send them back. I asked if it was for refund or exchange, and he said refund. He said they just don't have the K's, only the Y's. I can only assume there was an attempt to hoodwink me. Both the purchase order and the bag showed K's.

Damn electronic hooligans. I did find another source that I can only hope will send me that part I actually ordered.

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braw
 
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Post by braw »

Just got a batch of genuine 733k's and tested them. Most were around 370-390 while about 15 or 20 were 400-440. None were less than 370.

Not sure what if anything this will do to the sound, but I'm excited to find out.

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