Getting about 0V74 across it. Rails at 32. That would be about 0W73 in each heatsink.
https://www.mouser.co.uk/ProductDetail/567-274-2AB/
25degC/W, 24degC ambient, heatsink should get to 18degC over ambient, so say 42degC (the meaning of life and everything!).
Tender digits indeed...
You recommended to check temperature on them and if I couldn’t keep my fingers on them, then I should increase the length of the heath sinks... We’ll figure something out...
just in case - you're having uni diodes in D1,D2 positions ?
1N4148 as I put, or 1N914, as in Papa's schm?
have you any way of measuring heatsink temp?
gun thingie or DMM with temp probe?
I'm not overly concerned, this just to check and forget
they look to me , not nitpicking about genuinity
T092 are JFets , smaller ones are ZTX
The D1 and D2 in the FE are 1N4148s.
I do have an Aliexpress temp gun. I'll fire the amp up later tonight and check temps.
Thanks for your help so far ZM 🙂
Thingie temp gun says about 52degC on the FE heatsinks at 160mA bias. That's without the lid on, not got to that part yet.
Both channels bias up, offset adjusted to about 0V on both sides.
Once I've completed the mains power distribution bits I can get the lid on.
Both channels bias up, offset adjusted to about 0V on both sides.
Once I've completed the mains power distribution bits I can get the lid on.
good enough
plenty of, once cherished, Japanese amps and receivers - had (some) semis at 65-70C
though, if that is not a problem, replace T0220 heatsinks with step higher
plenty of, once cherished, Japanese amps and receivers - had (some) semis at 65-70C
though, if that is not a problem, replace T0220 heatsinks with step higher
I’m still trying to find a good way to deal with this beast’s powering on and inrush current, so, I ended up ordering 3 types of big *** relays capable of up to 35 Amps of constant load, ignorant me couldn’t really understand all kinds and variations of SSRs and ended up ordering two that unfortunately the output resistance varies according to the Input voltage provided, I thought that as long as I provided the Input voltage in the specified range it will just switch on, but no, they both have variable output resistances... Shame because I really liked the skinny one with integrated heath sink.
Well I may end up using the mechanical industrial relay along with some big *** inrush current limiting thermistors in an arrangement suggested by Ametherm engineers.
The fun continues....
If you're going to use a power transformer with 115VAC primary, and if its VA rating is less than about 815 volt-amperes, this DIY project might be a candidate
PCB: low voltage On-Off switch drives AC mains relay \ includes soft start .. H9KPXG
It's not a kit and nobody sells bare PCBs; you have to upload the supplied Gerber PCB files to a Chinese fab, and you have to order parts yourself from Mouser or Element14 or DigiKey or Jaycar or Farnell. On the other hand you don't have to design anything yourself, and you get loads of reassurance + comfort, knowing that many dozens of other diyAudio members before you, have built it successfully.
PCB: low voltage On-Off switch drives AC mains relay \ includes soft start .. H9KPXG
It's not a kit and nobody sells bare PCBs; you have to upload the supplied Gerber PCB files to a Chinese fab, and you have to order parts yourself from Mouser or Element14 or DigiKey or Jaycar or Farnell. On the other hand you don't have to design anything yourself, and you get loads of reassurance + comfort, knowing that many dozens of other diyAudio members before you, have built it successfully.
Thanks Mark!
Yes, I'm aware of your project and I already have 10 of those PCBs in hand (can share), unfortunately I haven't yet found any replacement relays in that footprint that can handle 20+ Amps, the transformer I'm using is 2500VA.
Yes, I'm aware of your project and I already have 10 of those PCBs in hand (can share), unfortunately I haven't yet found any replacement relays in that footprint that can handle 20+ Amps, the transformer I'm using is 2500VA.
You'll need new house wiring and a new breaker installed in your circuit breaker box, 25 or 30 amperes. Unfortunately this means it cannot be an arc fault type of breaker in the US -- those are only available in 15 and 20 amps.
A little bit more progress.
Finally got it all in the box and wired up...
Just setting up the bias as I type this.
I have to tidy up a few of the wires here and there. 😱
Finally got it all in the box and wired up...
Just setting up the bias as I type this.
I have to tidy up a few of the wires here and there. 😱
is that cap multi?
if you don't have proper final cap cells, you'll get meeeeeeeeew sound
been there, done that, eons ago
no free launch, all you can get free is lunch
no replacement for displacement
etc.
plenty of appropriate sayings
if you don't have proper final cap cells, you'll get meeeeeeeeew sound
been there, done that, eons ago
no free launch, all you can get free is lunch
no replacement for displacement
etc.
plenty of appropriate sayings
It is a Cap multi... What do you mean by "proper" caps?is that cap multi?
if you don't have proper final cap cells, you'll get meeeeeeeeew sound
been there, done that, eons ago
no free launch, all you can get free is lunch
no replacement for displacement
etc.
plenty of appropriate sayings
Meeeeeeew could be music to my ears, I wonder?
I should invest in some caps like coffee cups?
PS. Biased at 165mV, heatsinks at about 47degC, offset at 0mV.