Hugo Posted October 17, 2019 Report Share Posted October 17, 2019 (edited) Two new amps have just been announced: https://stax.co.jp/products/srm-700t/ https://stax.co.jp/products/srm-700s/ Edited October 17, 2019 by Hugo 1 Quote Link to comment Share on other sites More sharing options...
Jonny Posted October 17, 2019 Report Share Posted October 17, 2019 For people, who prefer englishhttps://stax-international.com/products/srm-700t/https://stax-international.com/products/srm-700s/ Quote Link to comment Share on other sites More sharing options...
spritzer Posted October 17, 2019 Report Share Posted October 17, 2019 These amps just make me sad... Same basic stuff as the 006t and 727 but at a much higher price. Resistor plate loads at 300kYen? Seriously? Quote Link to comment Share on other sites More sharing options...
joehpj Posted October 17, 2019 Report Share Posted October 17, 2019 They claimed the 700s has JFET VAS stage. Any opinion? Quote Link to comment Share on other sites More sharing options...
spritzer Posted October 17, 2019 Report Share Posted October 17, 2019 Clearly a jfet input but I didn't see the see any mention of a jfet VAS stage. If this is the same as all the pervious Stax amps (which I'm pretty sure it is), then that would be a 700V jfet...which doesn't exist. Quote Link to comment Share on other sites More sharing options...
Hugo Posted October 17, 2019 Author Report Share Posted October 17, 2019 (edited) 21 hours ago, Jonny said: For people, who prefer englishhttps://stax-international.com/products/srm-700t/https://stax-international.com/products/srm-700s/ Thanks. I didn’t realize they had the info in English. Edited October 18, 2019 by Hugo Quote Link to comment Share on other sites More sharing options...
joehpj Posted October 17, 2019 Report Share Posted October 17, 2019 (edited) On the 700s page. ●New semiconductor driver with J-FET in the amplification stage All semiconductor driver unit that has adopted custom-made low-noise dual FET at the first stage, and for the first time in STAX driver unit history J-FET has been employed at the second stage. After so many years, Stax finally ran out of the long obsoleted Toshiba JFET. The 700t is more like a change that has to be done eventually. But still for some unknown reasons, they still refused to employ CCS in their tube amps. And the second of the 700s stage is quite interesting for me. It's so sad that it hasn't been a lot of innovations since the old Stax gone broke, so minor changes now become news. Edited October 17, 2019 by joehpj Quote Link to comment Share on other sites More sharing options...
chinsettawong Posted October 17, 2019 Report Share Posted October 17, 2019 Could it possibly be this kind of JFet? 1 Quote Link to comment Share on other sites More sharing options...
spritzer Posted October 17, 2019 Report Share Posted October 17, 2019 Could be. It is clearly a SMD part but most of these are also available in those packages but one wonders why... I doubt Stax are using any of these new fangled "non Japanese" parts as they just switched to On Semi out of necessity but yeah... who knows. Quote Link to comment Share on other sites More sharing options...
Pars Posted October 17, 2019 Report Share Posted October 17, 2019 3 hours ago, joehpj said: After so many years, Stax finally ran out of the long obsoleted discontinued Toshiba JFET. Fixed that for you. They sure as hell aren't obsolete... Quote Link to comment Share on other sites More sharing options...
spritzer Posted October 17, 2019 Report Share Posted October 17, 2019 I found these on the official Stax sale site so a bit more info: So...this is a 007t with inferior tubes (they can handle less power than the 6CG7) and the same 47k plate load. Not sure whey they fuse the B+ on each triode but that's clearly what's going on. Now for the SS: Not enough detail to see the VAS but this is clearly a take on the T8000 and 717 so resistor loaded VAS. You can spot the power resistors behind the VAS heatsink. Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted October 19, 2019 Report Share Posted October 19, 2019 so the 700s power supply voltages are exactly the same as the 717 and 727 from the transformer yellow,green,yellow go to full wave bridge rectified and regulated to +/-15 blue black blue (the filament supplies on the 700t) rectified and added to Vh- to make the - boost supply white red and brown orange are the 2 high voltage windings full wave rectified into CRC making +/-350 output boards identical to the t8000 each board has 3 x 2sc6127 and 1 resistor vas boards have 4 x 2sc6127 (2 x Darlington pair) and 4 x 150k/2W current source (on main board) vas is driven from dual low voltage n-channel jfet. (red heat shrink) (previously dual npn transistors) front end identical to 717/727 with dual n-channel jfet so about 99% identical to srm717 with non-obsolete parts and change of vas stage driver from bipolar to jfet on the D50 the front end jfet is known to be sourced by linear systems. So likely the k170 are also sourced by linear systems. so the 700T absolutely identical in every way to the srm-007t (and srm-t1 etc) with 2 x 6sn7 replacing 4 x 6cg7 plenty of room for replacement constant current sources to replace the mills load resistors both are priced the same, between $2895 and $2995 5 2 Quote Link to comment Share on other sites More sharing options...
garageboy Posted March 29, 2021 Report Share Posted March 29, 2021 So the srm500t (using 6cg7) has potential to supply more power than the twice the price srm700t? Quote Link to comment Share on other sites More sharing options...
spritzer Posted March 30, 2021 Report Share Posted March 30, 2021 No, not at all. The 500t is more similar to the 600ltd amp with presumably a bit lower rail voltages but still the same circuit as the T1. I have a 700t here and it is terrible in stock form, just awful. Utterly lifeless but adding a CCS really transforms the thing into something decent. 2 Quote Link to comment Share on other sites More sharing options...
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