Doug Self Elektor phono preamp: SA1085 substitute?

I am thinking of building the phono preamp from Doug Self's Elektor preamp circuit. I intend to buy the PCB which Elektor sells, use the components in the official parts list (may replace NE5532 with LM4562, maybe even not do that) and make my own power supply and case.

But his MC pre-preamp seems to use SA1085 which are not available any more. Any idea whether they are still being manufactured, and if not, then what can I use as substitutes? I need pin-compatible substitutes, since I want to use the same PCB.

Many thanks in advance.
 
I tried looking in digikey; they don't have it. I tried findchips.com, and I was pointed to RS Components; none of the other resellers have it. On RS Components, I found this (screenshot attached). It's not that the transistor is not in stock -- it is a discontinued product.
 

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OK :)

Well in many ways its just a generic PNP used in numerous commercial applications, however as Doug will no doubt have chosen it for some preferred characteristics such as noise etc (I'm assuming its in the front end) then perhaps he may be the best to ask on a replacement. Even something as run of the mill as the 2N5401 is probably OK.

Why not ask here and link to this thread,
http://www.diyaudio.com/forums/solid-state/209004-new-doug-self-pre-amp-design.html
 
(I'm assuming its in the front end)
Yes, the extreme small-signal stage at the input of the MC pre-preamp

... then perhaps he may be the best to ask on a replacement
I was so hoping he would comment, but he's not said anything.

Actually I discovered an earlier thread, more than a year old now, which had been started with exactly the same requirement as mine, and I'm getting some suggestions there. But Doug Self is silent. :(
 
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The Elektor article states that 2SA1085 is Mr. Self's second choice; he actually prefers the 2SB737 but these are out of production and difficult to source. The Signal Transfer Company happens to sell the 2SB737, see their "Price List" web page.

Both are TO92 with ECB pinout.
 
ZTX 851 is best choice. Extremely low noise, like the Rohm 737. In current production and freely available.
I’d recommend the ZTX 851 - rb’ of about 1.5 ohms and so very low noise.
Despite the age of this post it would be a good idea to set the record straight.
The ZTX851 is an NPN. The ZTX951 PNP would be the best replacement for the PNP 2SB737.
Note that the 2SB737 is BCE; the ZTX951 CBE pinout.
 
I did some comparisons of various ZTX and the 2SB737 and I think many will find the ZTX951 will be a suitable if not better replacement for the 2SB737. The ZTX951 typically has lower gain but the rbb is significantly lower than the '737. As I mentioned earlier the pinout is CBE not BCE but that's easily-solved.

I have both the 2SB737 and ZTX951 in my store. The 2SB737 are "S" grade and have known lineage back to John Roberts and his Popular Electronics preamp but for whatever reason the Hfe measures in the lower range. One of my customers compared noise of the lower Hfe channel to devices measuring in the S range in the other channel and they were identical. As can be seen the 2SB737 I have are indeed quiet. Curiously I have another small batch of 2SB737 given to me in the early 1980s by Al Burdick founder of Benchmark Media. Al's 2SB737, also labeled "S" measure in the same Hfe range as the ones vended to me by John Roberts. In the early days ROhm may have cheated on their Hfe binning.

The overall comparison is here: https://proaudiodesignforum.com/forum/php/viewtopic.php?t=1208

This is the ZTX951 compared to the 2SB737: https://proaudiodesignforum.com/forum/php/viewtopic.php?p=14804#p14804

The PNP ZTX789 is also a good contender for 2SB737 replacement. I have another thread comparing NPNs.

ZTX_Transistor_Comparison_ZTX951_2SB737_ZTX789A.jpg
 
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