Schlaudi
New Head-Fier
Hi STAX guys,
first of all greetings from Munich, Germany. Within the last weeks i read a lot in your huge 1600+ pages STAX Threads and learned a lot about the moddings that can be done throughout the hole STAX product line. But to be honest I lost control about the information I got. That is the reason why I opened a new thread.
I own a STAX SRM-1 MK2 (early A-Serie) (my father bought it in 1983 when I was born
) and it has the very early number A5327. In the PDF you can see the wiring diagram which is for units beginning with number A5494. The unit was not in use within the last 20 years and I already replaced the electrolytic caps (Nichicon LKX and Elna Silmic II) and calibrated it. Works great with my two Lambda Pros (same age and as you all know the foam was just cracking as soon as you look at it. I removed it and use it now very carefully.
I’m working from homeoffice each day, so I started to hear music while working and I had enough time to think about some more improvements/moddings. Perhaps you can give some information about the parts because I didn’t found the answers I need in your forum. My plan is to fully update the unit so it lasts the next 37 years
First of all I made a document were you can also find some of your information a few years ago in the huge STAX thread, a part list with missing parts and also some photos of my unit.
*** DOWNLOAD PDF HERE ***
I hope that you can give me some recommendations about the missing parts. I will update the PDF and upload it again, so that SRM-1 MK2 users have a guide and part list . My desoldering gun and I are waiting for your answers…
Best regards and many thanks in advance
Andi
first of all greetings from Munich, Germany. Within the last weeks i read a lot in your huge 1600+ pages STAX Threads and learned a lot about the moddings that can be done throughout the hole STAX product line. But to be honest I lost control about the information I got. That is the reason why I opened a new thread.
I own a STAX SRM-1 MK2 (early A-Serie) (my father bought it in 1983 when I was born
) and it has the very early number A5327. In the PDF you can see the wiring diagram which is for units beginning with number A5494. The unit was not in use within the last 20 years and I already replaced the electrolytic caps (Nichicon LKX and Elna Silmic II) and calibrated it. Works great with my two Lambda Pros (same age and as you all know the foam was just cracking as soon as you look at it. I removed it and use it now very carefully.I’m working from homeoffice each day, so I started to hear music while working and I had enough time to think about some more improvements/moddings. Perhaps you can give some information about the parts because I didn’t found the answers I need in your forum. My plan is to fully update the unit so it lasts the next 37 years
First of all I made a document were you can also find some of your information a few years ago in the huge STAX thread, a part list with missing parts and also some photos of my unit.
*** DOWNLOAD PDF HERE ***
- I want to change the 4 transistors which are mounted on the heatsinks. Now it’s a B832. Can I exchange them with this type: https://www.mouser.de/ProductDetail/IXYS/IXCP10M90S?qs=AzHdteqRedke4lsM8lUo2w%3D%3D or do you have another recommendation? I tried to find the 2SC5466 transistors but they arent available anymore and I don’t want to buy them at ebay from suspicous dealers (preferring mouser)?!
- I also want to replace the smaller transistors (Type C2611, B715 and K117). Do you have a recommendation which part (mouser.com) would fit?
- Foil caps (0,01uF and 0,1uF). Should I choose MKP4, MKP10 or FKP3 series or instead the KEMET 1% series (my favorite)?
- In the next step I want to upgrade to miniXLR sockets. Do you have a wiring diagram or some fotos which I could use for my retrofit? Can’t find anything on the internet… I saw a picture of spritzers version with the switch on the back so you yan choose XLR or RCA input.
- Does it make sense to rewire with silver wiring like van den Hul (https://www.vandenhul.com/product/cs-18-halogen-free/) ?
- Calibration-Pots: I already found the versions which Spritzer is recommending.
- Should I also upgrade the Alps Pot? It is working great without any cracking when changing the volume.
- Diodes: I didn’t find any recommendations for the diodes. Which parts should I use? It looks that there are two different types. 3 parts with „RA-1“ printed on it nearby the 35V 470uF capacitor, and 4 parts with an „F“-printing nex to the 400V caps/4 foil caps.
- Capacitor soldered on Power Switch (anti-interference capacitor): Wich part should i choose (WIMA MKX2) ? Now it is a NSKG135 wich 0,033uF
- Which part is the glas bulb with the resistor in it?
- Resistor-Question which hadn’t been answer in the STAX Thread: When there is no perfect matching resistor should I use the next in the product lineup with under or over value (270K = 267K or 274K?)?
- Safety Resistors: Is it necessary to built in security resistors as it is shown here: http://blog.prof-x.de/2018/08/08/stax-vacuum-tube-driver-teil-2-technische-ueberholung/ . He is using this type: 4x CPF25K1100FKE14 and 2x CMF654M9900FHEK
I hope that you can give me some recommendations about the missing parts. I will update the PDF and upload it again, so that SRM-1 MK2 users have a guide and part list . My desoldering gun and I are waiting for your answers…
Best regards and many thanks in advance
Andi
