New Stasis front end

[atcman]

Thought i may as well put this here i have a stasis 2 that is in very good cosmetic condition which let a small amount of smoke out the rear and now it is down on one channel so up for spares or repair it is a uk model and i am open to sens offers if of any interest

 

[TheFinisher]

Greetings to my DIY brethren. I journeyed to the mountain top, my quest to obtain the sacred scrips illuminating the second coming of the Stasis front end. As I raised my staff in supplication, I was blinded by lightning and the voice of the mighty ZM rang out:

isn't it already in post #1 ?

Are these boards available to buy ? I have a sick Stasis 2 with burnt boards

 

[Zen Mod]

you can take files and easily purchase them from any pcb fab

hinthint

or you can search more in thread and maybe even ask residents - where tf are ZM's gerbers?

so you can choose are you going to obtain gorgeous Pa's pcbs or ZM's cheapskate iteration

 

[poseidonsvoice]

or you can search more in thread and maybe even ask residents - where tf are ZM's gerbers?

Start Here.

Best,
Anand.

 

[BeardyWan]

Help question re thermistor (R24)... I assume this needs to be in contact with the heatsink or maybe one of the output stage transistors?
What is the typical approach - drilling a hole in the heatsink and using some sort of goop, or perhaps a spring clip of some sort?
cheers

 

[Zen Mod]

I knew once, but I forgot

it would be best to have it spring clipped to htsnk, with some goop

anyhow, what I knew and forgot - I've seen it on pics of original

 

[Mikerodrig27]

Mine has a hole that the thermister sits inside with goop. However, I think it would probably do just fine spring clipped as in my suggested.

 

[gary s]

Either method to secure the 2K thermistor to each channels heat sink will work fine. Also the thermostat shown on the schematic as "T" is drawn as a NO contact but NP has confirmed this is actually a NC type thermostat which opens at a temp around 65 degC to 75 degC and is also attached to each heat sink.

The thermistor is labelled TH and not R24 by the way.

 

[BeardyWan]

Many thanks,

 

[BeardyWan]

As an aside has anyone tried hot glue?

 

[TungstenAudio]

I have used hot glue for other applications, such as stabilizing extra capacitors. I would not recommend hot glue in direct contact with a heat sink. It may soften too much to hold a part in place.

 

[Blk Dynamite]

i didnt use hot glue per se but did use some type (cant remember what i used) of glue. i set the thermistor inside a mounting screw hole and glued it there.

and as Tungsten noted, thats the exact reason why i didnt use hot glue. i used something that stays set regardless of temp

 

[von Ah]

I’ve seen some builders put a small thermistor in a ring terminal with some heatsink compound. Somewhere in one of the big F5 threads…

 

[ItsAllInMyHead]

This is the search results from Mouser for 2k NTC ring-lug thermistors... I haven't built this particular project, and I am not sure if any of these parts are suitable, but I do know that there are lots of "ready-made" mounting solutions for thermistors.

https://www.mouser.com/c/circuit-pr...oduct type=NTC Thermistors&resistance=2 kOhms

 

[BeardyWan]

Allegedly hot glue doesn't melt until 250F, so I had assumed it would be OK for this application, however, there are more specific thermally conductive glues one could use. I was just trying to find the easy solution. I'd agree that a ring lug thermistor looks to be the better approach.

 

[gary s]

Back in the good old days, we used to embed thermistors in the heat sinks on thyristor stacks for variable speed drives for over temp protection if the large cooling fans failed. Simple - drill a hole in the HS about 10mm deep slightly larger than the thermistor body, fill the hole with heat sink compound ( known as goop around here) and push the thermistor into the hole. We used to hold it in place with a cable tie with the hole on the end which was screwed down next to the thermistor. We also used thermistors with insulated leads and we never had a problem with that method. That is how I have done it on my Stasis build and have mounted the Thermostat next to it on each channels heat sink. But the screw down type thermistors would be equally a s good.

 

[BeardyWan]

ZM's Stasis boards are (mostly) populated aside from power transistors. The smd capacitors on the OS were OK so I am cautiously wading into the sea of `there be dragons' with the suggested 2SK2145s. These 5 legged critters are significantly more tricky.
I have yet to build the power supply but are there any tests one can do prior to actually connecting it to a power supply?

 

[gary s]

The tests I do while completing a pcb before powering the board up are to check the resistance of every resistor used, I check every transistor with a Peak DCA75 and once all components are stuffed, I double check all solder connections with a magnifier and clean the board of all resin etc before applying power.
Also check that any trimpots are set to the correct position at start following the build instructions or designers notes.

 

[6L6]

^^ this is a good procedure!

That beats what I do… which is turn it on and look if any of the automatic “error indicating smoke and flames” engage.

 

[gary s]

Jim, I am surprised!