what diodes are the clipping diodes on ts9

[gutsofgold]

theres four or five diodes i can see on my ts9 board. two of them sit close together and seem to be in parallel (as best i can tell following the traces).

http://www.freeinfosociety.com/electronics/schemview.php?id=1088

are the two diodes under the 51p cap the clipping?

[s.r.v.]

im pretty sure they are 1n914 diodes, but ill check

[gutsofgold]

the schematic notes that ALL diodes are 1n914.

[JHS]

Newer TS made in Japan had been equipped with MA150 or MA165 diodes, older TS with 1S1588 diodes, 1N4148 in IBZ boxes produced in Taiwan/China.

The 1S1588 will give a warmer, clearer and more tubelike clipping compared to 1N914. MA150/165 are close, but not as warm sounding. My experience is that a TS-style circuit equipped with 1N4148/914 sounds much harsher and the tone is not as fat.

JHS

[Skreddy]

Where can an American buy some 1S1588's?  I don't think I'll be flying to Tokyo to browse the Akihabara electronic shops any time soon, and I'm not having much luck finding them online other than here @ $0.89.

Also, here's a thorough analysis of the reissue TS9 circuit with the goal of making it as close to an original as possible...
http://www003.upp.so-net.ne.jp/kazuhee/ets9mod3.htm

[bipedal]

Guts,

Relative newbie here, so I may stand to be corrected, but . . .

Yes, the diodes nearest the 51p cap are the TS's clipping diodes.  In the schem you provide, it's two of the same diode; some TS variants/mods use two different diodes or three diodes (two are placed in series) to give assym clipping.

As far as I know, the other diodes in the circuit are simply used as polarity protection for the buffer transistors.

Cheers,

- Jay

[Celadine]

SmallBear has the 1s1588.   

[Subzero]

You might want to try 1X 1n400x + 2X 1n400x in series, imho, you'll be VERY surprised .here I only 1n4007's, I don't think there's any differance in sound but you might want to try and get those just to be on the safe side ...

[Mark Hammer]

the schematic notes that ALL diodes are 1n914.

That is a redrawn schematic, so the diodes listed (1N914) are the more easily obtainable North American functional equivalents (i.e., silicon switching diodes of similar forward voltage).  Whether they or the 1S1588s have some peculiar characteristic that makes them tonally different is another matter and something I have no basis for commenting on.

Note that the remainder of the diodes are not part of the audio path, so any functional equivalent is fine.  All they do is make sure that only the right polarity of DC voltage is presented to the switching FETs to make them turn on or off.

I was brought a couple of the 1S1588 type from Japan (from someone's trip to the Akihibara, actually) a few years ago but have not tried them out on any of my TS builds.  I should probably do that sometime.

[Skreddy]

SmallBear has the 1s1588.   

Thanks!