Paul160672 Posted November 1, 2020 Report Posted November 1, 2020 Anyone listened to the Heddphone compared to the stax? Quote
EtherealCereal Posted November 12, 2020 Report Posted November 12, 2020 Hello, I'm new here. I recently acquired a nice looking (and complete) pair of Realistic HP-100s (re-badged Stax SR-3, from what I understand), and upon cracking open the energizer I'm finding things aren't quite as nice as they would seem. When I'd first begun to listen to them, the left channel was nearly dead and the right channel was quiet. I quickly discovered the issue with that, this 3.3ohm ptc that had, at some point, swollen to the point of beginning to crack: The cracked one was registering 265 ohms. No wonder one side was nearly dead! So, I purchased some replacements from Mouser. 3.3ohm ptc, just like the schematic called for. I soldered them into place, and as I begun to ease the volume knob up, I started to smell burning. Turns out this was happening: Apologies for it being blurry, but it started to arc across points C1 and 3 on this top circuit board. Naturally, I removed the headphones the first time this happened. This is a screenshot of the video I took to recreate the issue, and there was nothing hooked to the headphone output when I took this. Quote
spritzer Posted November 12, 2020 Report Posted November 12, 2020 Shorting due to the flux becoming conductive over the years? Quote
EtherealCereal Posted November 12, 2020 Report Posted November 12, 2020 17 hours ago, spritzer said: Shorting due to the flux becoming conductive over the years? I don't know. I tried to remove as much flux as I could, I wiped that spot down and I sprayed it with electronics cleaner and it still shorts out. It's not just the left channel, either. The right channel is doing the same. In any case, I removed the resistors and cleaned the through-holes, and after I removed the resistors from the circuit the shorting ceased. EDIT: (Blow the picture up, it's large) Quote
Orb Posted November 16, 2020 Report Posted November 16, 2020 Hello all, I just picked up a functional Stax SRM-T1 that I’ll upgrade with new caps and Jim Lin’s CCS upgrade pretty soon. My preamp has balanced outputs, and I was wondering if it makes sense for me to do an XLR balanced input conversion to the SRM-T1, given that the T1 uses virtually the same PCB as the XLR-equipped SRM-T1S. I have the T1 schematic, but I’ve not been able to locate one for the T1S nor details on how the input circuit differs between these two amps. Is the sonic benefit from using a balanced input more trouble than it’s worth? Would the XLR mod be straightforward to do? I’m experienced with electronics work. Thank you very much for any suggestions! Quote
spritzer Posted November 16, 2020 Report Posted November 16, 2020 The XLR mod doesn't change anything really, if there is a sonic improvement it really depends on the source if the different outputs are handled differently. The XLR just doubles the input voltage (though that is not set in stone either). To do the mod, just remove the resistor which grounds the gate of one half of the input fet and copy what's on the other gate. Quote
Orb Posted November 16, 2020 Report Posted November 16, 2020 Understand, thank you for the quick response! The mod looks reasonable, I would just need to find a quad volume pot of the same value that fits mechanically (but preserving variable L-R balance may not be practical, not an issue in my case). Quote
spritzer Posted November 16, 2020 Report Posted November 16, 2020 It is pretty much impossible to find the split volume controls but the quad RK27 pots are out there and they are a drop in replacement. You will need a new knob for it though. Quote
Hifilutin Posted November 18, 2020 Report Posted November 18, 2020 On 11/12/2020 at 10:05 AM, EtherealCereal said: I don't know. I tried to remove as much flux as I could, I wiped that spot down and I sprayed it with electronics cleaner and it still shorts out. It's not just the left channel, either. The right channel is doing the same. In any case, I removed the resistors and cleaned the through-holes, and after I removed the resistors from the circuit the shorting ceased. EDIT: (Blow the picture up, it's large) I have a set of these that also do not work. Dug out my own adapter, Mine does not short out, but there is also no discernable difference between powered and unpowered functionality- as in the biasing circuit does not function whatsoever. I'll replace the capacitors here and get back with results. I doubt that the diodes are spent- they don't look cooked. As an aside, here are some pictures of the boards. The board that handles the raw audio signal is totally covered in old flux. I pulled the ptc resistors for testing, they seem reasonably functional. I used similar resistors here to check against, seems both work more or less the same- as they should. Whomever put this together in factory did not clean the excess... I've done a quick little job (and left a bunch of cotton fragments that i'll remove with compressed air later) and pulled off the old flux. I don't see much difference in our two boards- anyone know why his circuit would attempt to jump an air gap between the 100pf capacitor and a 5.3kohm resistor? I can't imagine that crossing open air is the lower resistance pathway. Doesn't make much sense. I included the schematic too for anyone else who is looking. Quote
Orb Posted November 19, 2020 Report Posted November 19, 2020 Studying the input circuit for the SRM-T1 (for future balanced input mod), came across what looks like a resistor in a neon bulb. What is special about this part vs. using a conventional resistor? Is this the same pair of parts that I’m pointed to in the attached input schematic? Thanks! Quote
luvdunhill Posted November 19, 2020 Report Posted November 19, 2020 I assume it’s used for over voltage protection?Here’s a good reference on the topic:https://www.tiffe.de/roehren/neon.pdf 1 Quote
dripf Posted November 22, 2020 Report Posted November 22, 2020 009 discontinued. https://stax.co.jp/2020/11/09/sr009dis/ Quote
Lord_Rexter Posted November 22, 2020 Report Posted November 22, 2020 Is STAX hinting us to get ready for new Omega 🤔 Quote
velomane Posted November 22, 2020 Report Posted November 22, 2020 Maybe the 009S will now to be their TOTL can? Quote
spritzer Posted November 23, 2020 Report Posted November 23, 2020 The 009BK was always the TOTL unit so they might just be moving to that direction. For me they were always the best 009's by a mile too 1 1 Quote
Lord_Rexter Posted November 23, 2020 Report Posted November 23, 2020 Luckily I was able to manage to grab 009BK and now out of production 009 silver for me 😊 2 Quote
Mach3 Posted November 24, 2020 Report Posted November 24, 2020 According the the Edifier youtube clip. The Stax Japanese team will release the Omega successor when they are ready. When are they ready: When they are ready When will it be release: When they are ready Edifier calls Stax japanese team, "What time frame you need for the new Omegas": We will let you know when we are ready 3 Quote
hekoman Posted November 29, 2020 Report Posted November 29, 2020 I am attempting to repair a SRA-3S and I am having trouble trying to figure out the value of two of the caps on the first card. I can read on one of them that they are rated for 50V, but all other marking have been worn off. I tried looking online for pictures of the card, but I can't find any pictures online that are high enough resolution to read the values. Any one that has one of these amps and can read the values on theirs would be greatly appreciated, Thanks! Quote
spritzer Posted November 29, 2020 Report Posted November 29, 2020 It's been too long since I've had one here to be but sure but here is the schematic: 1 Quote
Hifilutin Posted November 30, 2020 Report Posted November 30, 2020 I've always wanted a SRA-3s, but never decided to bite that bullet. I don't have any way to convert to 100v anyways. Would like to hear impressions of the sound once you get it recapped. Quote
faust3d Posted December 1, 2020 Report Posted December 1, 2020 So I run out of Stax Sigma replacement earpads. Are replacements still obtainable? Quote
Mach3 Posted December 2, 2020 Report Posted December 2, 2020 You should try contact vesper audio, they can custom make the earpad for them that uses much higher quality lamb skin, super soft and durable and memory foam. I've had a few custom design done from them for my ESP 950, thicker angled pads that offer better seal. Did the same for my 007 Mk1. Quote
Pirx Posted December 2, 2020 Report Posted December 2, 2020 On 11/29/2020 at 5:07 AM, hekoman said: I am attempting to repair a SRA-3S and I am having trouble trying to figure out the value of two of the caps on the first card. I can read on one of them that they are rated for 50V, but all other marking have been worn off. I tried looking online for pictures of the card, but I can't find any pictures online that are high enough resolution to read the values. Any one that has one of these amps and can read the values on theirs would be greatly appreciated, Thanks! I have one unit, that is not working, but I opened it and it is obvious that both caps are 220 nF/50 V and they are input caps. Quote
Mach3 Posted December 10, 2020 Report Posted December 10, 2020 What's the generally consensus revolving around which energizer sound best with which electrostatic earspeaker. Blue Hawaii for 007 DIY T2 for 009 & HE90 & HE60 Anyone got impression how the the nanotube sound with the above? Quote
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