TA-100W follow-up "work around"

norm kerr

New Member
Hello,
I am new here, and have searched for information about how to work around the fact that the TA-100W amp modules are NLA for my beloved KA-9100.

There are several threads in which someone says, "I know a work around", and then... Nothing.

There was one thread in which the pinouts are compared between a TA-100WA, and a Sanken S-100W, showing how the wiring must be revised to connect one of them in the place of a TA, which sounds great at first. But that thread ends with, "but the S-100W has no V/I limiter, so one must be created to use it in a Kenwood...". Ok, how?

There was also a thread with a schematic posted of a Sanken S-100W, which is nice, but without a hint about the necessary tricks to fitting one to a Kenwood (other than knowing the different pinout), isn't all that much help.

There are several threads (over 5 years old) where someone says, "send me a pm, I know a workaround", but no closure. One guy who calls himself "echowars" says he knows how, but his email listed in that posting doesn't work (I just tried it today).

c'mon guys, is there a link that someone can share with me detailing the necessary steps to revive a dead KA-9100, one which, until just recently, works perfectly except for dead TA-100WA modules?

Norm
 
My personal email should NOT be posted in the open forum. If it is, I wish you would point out the specific thread so I might edit it.

The Sanken S-100W is lacking the current limiting circuitry that is built into the stock TA-100W. Strictly speaking, it is NOT necessary for operation...the circuit just pulls back on the drive to the output devices when it detects the current is too high. Without it, a shorted speaker or wire will kill the module very very quickly (and it obviously had limited effectiveness, judging from the number of dead modules I read about on the web from shorted speaker cables). Anyway, a few members have noted (correctly) that many high-end amps have no such circuitry.

At any rate, you may want to take a look at this thread. I detail the pinout of each here.

I have not done the swap, but I can describe how it should go...

Pin1 and Pin2 on the S-100W are fine on the PC board. Pin3 on the PC board gets cut, and routed to Pin4 on the Sanken chip. Pin4 on the PC board is left disconnected. Pin5 is the output and is OK. Pin6 on the PC board is cut and routed to Pin7 on the Sanken chip. Pin7 on the PC board is cut and routed to Pin9 on the Sanken chip. Pin8 and Pin9 on the PC board are left disconnected.

It appears that this would work. No promises. The hard part is finding a Sanken S-100W chip.

Another member claimed to use the Sanken SAP16 and SAP16N to replace the module. These parts were 5-lead Darlington devices with internal temp compensation and built-in thin-film emitter resistors. This would also have worked well, and is the way I would have gone, except that these parts are discontinued. Sanken has replaced these with the STD01N & STD01P (150V 10A), and the STD03N & STD03P (160V 15A). There is very little difference between these new devices and the old, EXCEPT the new devices do not have the internal thin-film emitter resistor, so the emitter resistors would have to be mounted somewhere else, which complicates the install a bit. Besides that, the bias pins of these devices simply have to be joined with a 200 ohm trimpot for bias adjustment. If I were to tackle a dead 9100, I'd try to find the STD03 devices and make it work. They are apparently current production Sanken devices, but finding a reseller in the US is not easy. Profusion in the UK can source them, but I don't know what the minimum might be.
 
sweet, thanks Echo, and not to worry, there wasn't anywhere an email address, just one l place where one was alluded to with hints that I obviously didn't get!

and those two links are the threads that I have been studying that talked about, but did not summarize as well as you did above, just now, for me, how to substitute for dead ta-100wa modules.

thank you very much,
Now all I have to do is to decide whether it is worth trying (because who knows how well the amp will perform, audio-wise, with these Sanken parts, in place of what had been originally designed to be in there), or just to give up, say a little benediction over it, and move on to a new amp.

Decisions, decisions,
Norm

PS: I like your Warren Zevon reference in your avatar ("now I'm hiding in Honouras, I am a desperate man. Send lawyers, guns and money, the sh*t has hit the fan!")
 
S-100W sanken part

Glenn:
I did this a while ago and my brother inlaw has the unit and is still performing well. The only thing is the point you bring out about the current limit. I shorted the output accidentaly while testing and fried one of those S-100W's. So extreme care with hook-up is required. So as long as you don't short out the output it works fine. Risky but it works. I have 2 spare S-100w's one brand new and the other pulled from a "working unit" . I paid $33 bucks for the new one and $10 for the used one.

John Mik
 
Yes, I found the invoice ...

WOW it was 2006, and I paid $39.99 ... They may still be there but don't know if the name is the same, I used to buy obsolete IC's from these guys too
 
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Norm, these other parts are virtually identical to the TA-100Ws (with the exception of the current-limiting) and with the mods described, the amplifier ought to perform exactly as it otherwise would.
 
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S-100w

Thanks for checking. Next dead 9100 that shows up here, I'll track down some of the STD03N's & STD03P's.

Hi Glenn:

If you do let me know the results if you would. If you really want to check out an S-100w let me know.

John Mik
 
Glenn, if you do this, aren't you going to have to deal with the current-limiting business, as well? Or would you just forgo it and roll your own S-100W out of these parts?
 
My last S-100W came from B&D. A fuse or two makes and excellent current limiter.
 
Sanken STD03

Probably keep it simple...the STD03 devices, a 200 ohm trimpot, and some .33 ohm 5W emitter resistors.


I ordered 10 pair from the UK. May look to layout a small board for the emiter resistors, adjustment pot, VI protection, and interface to the Kenwood driver board. I'll need to come up with a heat sink to mount them on to interface with the large external heat sink.

Is it worth trying to reuse the heatsink plate on the original darlington amp pack?

Looks like the devices are on ceramic substraights that are glued on to the heatsink or may be soldered on somehow as there appears to be some solder flow at the top of the heatsink above the darlington packages.

Anybody have thoughts or opinions on reusing the TA100WA heatsink base
 
Using stk100 as replacement for ta100w

Both channels of ta100w modules were blown. Replaced ta100ws with sanyo stk100 modules, and now my ka-8300 sounds great. Stk100 modules are readily available at around $10 a piece. Saken module is very difficult to find and when one is available on Ebay, seller usually wants a hefty price for it.

All traces to 10 pins were cut open.

Prior to hooking up the modules and cuts were made, volages of 10 pins were noted.

Power supply pins 2 and 6 read +51, -51v respectively.

Power amp. driver output pins 3, 7 read near 51volts.(unloaded condition).
When modules are connected, should read near 1volt.

Pin 10 of stk100 to pin 3 of pc board.
pin 1 of stk 100 to pin 7 of pc board.

pin 9 of stk 100 to pin 2 of pc board.
pin 2 of stk 100 to pin 6 of pc board.

All unmentioned pins remain disconnected.

Connect 2 .35 ohms 5w resistors in series between stk100 pins 3 and 8.

Make connection from the center of two resistors to pin 5 of pc board.

Mounting stk100 modules to heasink requires some modifications as the stk module is thicker and narrower than ta100w.

Pin spacing of stk100 is near identical to ta100w. Align skt100 module pins with ta100w module pins on the heat sink. Drill two holes using drill bit slighly smaller than screws you'll be using. You may have to run to a hardware store and pick up longer screws, but same size of the screws holding the ta100w. 3/4 inch in length worked fine for me. Insert pins into pc board and solder. Also, 2 .35 ohms resistors are inserted at this point.
 
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I'd not use the quasi-complementary STK0100 in the Kenwood. If it works for you, cool, but it's not much harder to find the STK0100II, which uses a full complementary output stage. That, and I cannot locate a full data sheet for the 0100 part. I've also not seen them for $10 anywhere.
 
Possible problem?

Can you explain what types of problems I could run into by using stk100 in Kenwood ka8300? Thanks.
 
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