Head-Fi.org › Forums › Summit-Fi (High-End Audio) › High-end Audio Forum › SRM-717 Re-Cap
New Posts  All Forums:Forum Nav:

SRM-717 Re-Cap - Page 3

post #31 of 38

This  is very interesting I like a challenge . I tested mine and both tested okay at 4.7M ohm, By removing the fuses you can test better in circuit. I agree the current shouldnt have affected them . But I have seen switch on surge take out resistors  Most of the resistors   I have come across especially in radio front ends go high. Those two resistors seem to be the only kind of that type[unless somebody has better eyesight  than me]  with capped ends. Studies of different types of caps on resistors were carried out in the UK in EW mag using special micro-ohm equipment and some were found to have a small increase in resistance over a period . The longer the higher the resistance especially high voltages employed .So the type of metal that is used for the caps[at each end] plays a part in the reliability of the resistor . I dont have the actual mag to hand but I have a good memory.It could be a combination of things that bring it about. I take it they are 500V types?

post #32 of 38

R60/61 are 1M resistors


R63/64 are 4.7M resistors

Edited by kevin gilmore - 8/5/13 at 8:51am
post #33 of 38

Sorry to disagree but in my 717---R60/R61 are 4.7 MEG.Maybe if I give you the serial no. of the mother board it will help=PB-101/08454-0010. If your board shows different  . Then--- 1-UK and US boards are different??[not counting different mains voltage--or 2-modifications that Stax hasnt mentioned have taken place and circuit diagrams dont specify--seen this happen elsewhere--only government  equipment seems to show all mods.There is a 727-11 diagram on this website saying its a 727-11 diagram with a switch added for local/global feedback -.Some of the components numbered dont comply to my 727-11 also no input components are shown [small value caps for filter/bandwidth limiting purposes.] Whats going on Kevin?? I might be a subjective but when it comes to science and circuit design I am an objective. and can only see what a circuit board shows me. ----May I add found R63/R64 they are at the front of my board look like carbon types but they too are yellow/violet/green=4.7M ohm.

Edited by duncan1 - 8/5/13 at 9:39am
post #34 of 38


post #35 of 38

Apart from the "pb" being in capitals ---yes Kevin. Can I also say that it-the 717 and the 727-11 were both bought from the one and only[as far as I know] authorized Stax dealer in the UK namely=Symmetry-quote-Authorized Distributor in United Kingdom-end quote.

Edited by duncan1 - 8/5/13 at 10:00am
post #36 of 38

Make it four times; it was the same resistors giving me the intermittent fault.  




Originally Posted by kevin gilmore View Post

its always the last thing you do that fixes the problem.


no reason those resistors should burn up, they are running at half power.

I think this is the third time I have seen problems with those 2 resistors.

And its always both of them.

post #37 of 38

Shipsupt-That makes sense to me --attached-one end to each HV fuse. We both live in the UK maybe the US has mods to their -717. But thats not very good technical business as applied to Stax.  Making different versions [apart from mains supply] causes confusion and would mean their standard circuit  diagrams dont apply.   

post #38 of 38

Hi guys,

I know this is an old thread but I am entering the world of Electrostatics and am looking at the 717 for my solution.....


I have always loved playing with electronics and am confident to solder, replace resistors, caps etc but I really have no idea regarding how to test and measure circuits.


My question is can the 717 be easily converted from 110 to 240V?  Would it require a new transformer? I note the caps are 400V so does that mean the circuitry would be fine with the change?


I would also like to thank you all for this thread... As I said before I love to tinker and could see myself trying to perform the mods as described in this thread in the future .......



New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: High-end Audio Forum
Head-Fi.org › Forums › Summit-Fi (High-End Audio) › High-end Audio Forum › SRM-717 Re-Cap